Perspectives on Pests 7/4/01 6:14 PM Page 1

selected CPP/IPMSA publications,CD-ROM 1989-2001Includes of

ESETVSO ET 1996–2000 PERSPECTIVES ON PESTS PERSPECTIVES ON PESTS

This report highlights achievements from research carried out between 1996 and 2000 under the Crop Protection Programme (CPP) of the UK’s Department for International Development Achievements of research under the UK (DFID). The programme focuses on generating and promoting knowledge to improve pest, disease and weed management in cropping systems that are relevant to poor people. The CPP Department for International Development’s and its predecessor, the Integrated Pest Management Strategy Area (IPMSA), have funded over 350 research and dissemination projects since the inception of the IPMSA in 1989. Crop Protection Programme, 1996–2000

The work of the programme is guided by DFID’s Renewable Natural Resources Research Strategy, which has as its objective the generation and application of new knowledge which will benefit the livelihoods of poor people. The programme is managed on behalf of DFID by Natural Resources International Limited, a specialist research and development management company.

Perspectives on Pests presents the work and findings of CPP-funded research in sub-Saharan Africa, South Asia and South America. The report begins with an overview of how crop protection research relates to poverty alleviation, sustainable livelihoods and environmental issues. Summaries of selected research projects outline the background to each project, the key findings, and current and potential uptake of the technologies developed. A full listing of all CPP projects undertaken between 1996 and 2000 is given, as well as contact information for the main organisations participating in the research. Also provided (on CD-ROM) is a bibliography Natural Resources International Limited of publications generated by the programme since 1989.

Perspectives on Pests is intended to be of use to technical specialists and non-specialists alike, and should be of interest to researchers, research managers and policy-makers in the field of crop protection.

CROP PROTECTION PROGRAMME

This publication is an output from the DFID Crop Protection Programme for the benefit of developing countries. The views expressed are not necessarily those of DFID. DFID CROP PROTECTION PROGRAMME

Perspectives on pests

Achievements of research under the UK Department for International Development's Crop Protection Programme, 1996–2000

Edited by Anne Sweetmore, George Rothschild and Simon Eden-Green

Natural Resources International Limited

i DFID CROP PROTECTION PROGRAMME

Department for International Development The Department for International Development (DFID) is the UK government department responsible for promoting development and the reduction of poverty. The policy of the Government was set out in the White Paper on International Development published in November 1997. The central focus of the policy is a commitment to the internationally agreed target to halve the proportion of people living in extreme poverty by 2015, together with associated targets including basic healthcare provision and universal access to primary education by the same date. The renewable natural resources (RNR) research strategy funded by DFID’s Rural Livelihoods Department (RLD) has the primary purpose of generating benefits for poor people by applying new knowledge in natural resources systems. The bilateral component of the strategy is organised as eleven research programmes, the largest of which is the Crop Protection Programme (CPP). The CPP is managed by Natural Resources International Limited (NRIL).

Natural Resources International Limited NRIL specialises in managing programmes and projects in the natural resources, environmental and rural development sectors, as well as in such cross-cutting areas as institutional development. The company is owned by the University of Greenwich, the University of Edinburgh and Imperial College of Science, Technology and Medicine, University of London (incorporating Wye College), and draws on the expertise of these and other institutions, both in the UK and overseas. In addition to the Crop Protection Programme, NRIL also manages the Crop Post-Harvest, Livestock Production, Forestry and Post-Harvest Fisheries research programmes on behalf of DFID.

 Natural Resources International Limited, 2001 Short extracts of material from this publication may be reproduced in any non-advertising, non-profit-making context provided the source is acknowledged as: SWEETMORE, A., ROTHSCHILD, G. and EDEN-GREEN, S.J. (Eds) (2001) Perspectives on Pests: Achievements of Research under the UK Department for International Development's Crop Protection Programme, 1996–2000. Natural Resources International Limited, Chatham Maritime, Chatham, UK.140 pp. CD-ROM of selected CPP/IPMSA publications, 1989–2001 ISBN 0-9539274-1-5

Permission for commercial reproduction should be sought from: The Research Dissemination and Promotion Manager Natural Resources International Limited Pembroke Chatham Maritime Chatham Kent ME4 4NN UK Tel: +44 (0) 1634 883542 Fax: +44 (0) 1634 883937 E-mail: [email protected] Website: www.nrinternational.co.uk

Typeset by: Anne Sweetmore Publishing Services, Witney, Oxon, UK Printed by: Pragati Offset Private Limited (www.pragati.com) Cover design: Medway Design Team, University of Greenwich Database software programming: SADs Limited, Maidstone, Kent

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Contents

Page

Preface v Pests and poverty: the continuing need for crop protection research vii Integrating crop protection research and sustainable livelihoods xi Crop protection and the environment xiii

Africa Improved methods for the management of Striga: nitrogen, tolerance, screening and cultural practice R6921 1 Integrated control of Striga in Tanzania R6654 2 Moisture conservation through improved weed management in conservation tillage systems R6655 4 Control of water hyacinth in the Shire River, Malawi R6392 7 Improving the health of seed yams in West Africa R5735, R6691 8 Characterization of sweet potato and cassava virus diseases R6617 10 Management of cassava virus diseases in southern Tanzania R6765 13 Control of African cassava mosaic disease R6614 15 Functional diversity of Phaseolus bean mixtures in East Africa R6651 18 Development of integrated management strategies for termites in maize-based smallholder cropping systems in Uganda R6653 20 Development of strategies for maize streak virus disease R6642 21 An investigation into the biology, epidemiology and management of finger millet blast in low- input farming systems in East Africa R6733 24 Groundnut rosette disease epidemiology R6811 27 Molecular and biochemical techniques for detection and identification of Ralstonia solanacearum and other plant-pathogenic bacteria R6520 29 Investigation of banana leaf speckle in Africa R6794 31 Adaptation of novel techniques for detection of fungi causing fusarium wilt and Sigatoka leaf spots of banana and plantain R6006/7, R6692 32 Epidemiology of rice yellow mottle virus disease in rice farming systems in Tanzania R6763 35 Epidemiology and crop loss assessment of rice nematodes in West Africa R6009, R6658 38 Optimizing insecticide barriers for locust control R7065 40 Field demonstration of vertical-looking radar as a cost-effective, automatic monitor of desert locust migration R5445 42 Identification of the factors which lead to changes in desert locust populations at the beginning and end of recession periods R6822 43 Statistical analyses of desert locust movements R6809 44 Models of Quelea movements and improved control strategies R6823 45 Detection of phytoplasmas in putative insect vectors of Cape St Paul wilt disease of coconut in Ghana R6521 46 Evaluation of the significance and potential for control of mistletoe in cocoa and citrus R6656 47 Development and evaluation of a pilot field handbook on natural enemies of vegetable pests in Kenya and Zimbabwe R7266 48 IPM of vegetables in Ghana R6657 49 Pest management in horticultural crops: integrating sustainable pesticide use into biocontrol- based peri-urban production systems in Kenya R6616 50 Investigation of biorational methods for control of insect pests of vegetables in Kenya R6615 53 Development of pheromone traps for monitoring the legume podborer Maruca testulalis (M. vitrata) R6659 56 Development of coffee IPM components in Kenya R6782 59 Integrated management of the fusarium wilt/root-knot nematode complex on cotton R6761 60 Assessment of major soilborne pests of the multi-purpose agroforestry tree Sesbania sesban, and the development of IPM strategies R6736 63

Asia Development of appropriate management systems for hymenomycete disease of perennial crops R6628 66 Coconut diseases of uncertain etiology R6604 68 Development of pheromones for management of coconut pests in Sri Lanka R6929 71

Continued...

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Nematode resistance in bananas R6391 72 Identification, vector relationships, epidemiology and control of virus and bacterial diseases of banana R6579 74 Investigation of the Rhizoctonia sheath disease complex in rice R6643 77 Epidemiology and management of rice tungro virus disease R6519 80 Application of mating disruption to control yellow rice stem borer in India R6739 83 The Pakistan–UK fruit fly project R6924, R7447 86 Sustainable management of the whitefly, Bemisia tabaci, and tomato leaf curl virus (ToLCV) on tomato in India R6627 88 Use of insect viruses to control Helicoverpa R5540, R7004 91 Detection, identification and epidemiology of mycoplasma-like organisms (MLOs) associated with little leaf of sweet potato (Ipomoea batatas) R5881, R5885 94 Sustainable insect pest management in Indian cotton R6734, R6760 95 Use of pheromones in insect pest management on cotton R5272 98 A biocontrol strategy for management of the alien perennial weed Mikania micrantha in tree crop-based farming systems in India R6735 100

Other locations Pest constraints affecting tree crops in Bolivia R6820 103 Improved ecological and economic recommendations for the control of Hypothenemus hampei in coffee in Mexico R6812 104 Development of an integrated management strategy for itchgrass in maize-based cropping systems in selected areas of Latin America R6690 105 Management of herbicide-resistant weeds of rice in Bolivia, Mexico and Central America R6652, R6793 108 Improved monitoring of conventional and microbial pest management sprays R6620 110

Acronyms and abbreviations 111 Project list 1996–2000 113 Addresses of main participating institutions 120

Perspectives on Pests – Bibliography A compilation on CD-ROM of selected publications produced by the Crop Protection inside back Programme and its predecessor, the Integrated Pest Management Strategy Area, 1989–2001 cover

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Preface

In order to help define strategic priorities for generation of new knowledge, the then UK Overseas Development Adminis- tration (ODA; now Department for International Development, DFID) implemented a Renewable Natural Resources Research Strategy in 1989. Reduction in loss and damage caused by pests was a major element of this strategy, reflecting the long tradition of experience and expertise in this area established by UK development programmes since colonial times. Work on crop protection was coordinated under the Integrated Pest Management Strategy Area (IPMSA) and management was delegated to the ODA’s executive agency, the Natural Resources Institute (NRI). The IPMSA1 continued until 1995 when a major revision of the Research Strategy was published as what became popularly known as ‘The Yellow Brick’, on account of its size and the colour of its covers. This established a framework of six Production Systems, corresponding to agro-ecological zones or cropping systems, and sought to guide and link the work of 11 component natural resources research programmes covering different sectors. The IPMSA became the Crop Protection Programme (CPP) and remained under NRI management until 1996, when the Institute became part of the University of Greenwich. Shortly afterwards management was transferred to Natural Resources International Limited (NRIL). Although some of the work started under the IPMSA continued under the CPP, there was an increasing emphasis on integration of research within cropping systems, as well as a shift in geographical focus towards semi-arid cropping systems in sub-Saharan Africa and the Indian subcontinent. Important objectives for the programme are to link high- quality research more closely to clearly identified demands from those affected by pest problems, and to package and promote outputs for use by those best able to adapt and implement research solutions for the benefit of poor communities. The DFID’s White Paper on International Development in 1997 set clear targets for elimination of world poverty, and reaffirmed the role of research in improving the livelihoods of poor communities and the quality of the environment in which they live. This presented the CPP with both a challenge and a responsibility to develop accessible solutions to pest constraints affecting poor communities, and to make knowledge available to those able to adapt and implement it. In pursuit of that objective, this publication highlights many of the projects carried out under the first phase of the CPP. It begins with an assessment of the ways in which pests contribute to poverty and the importance of pest management for sustainable livelihoods. It has not been possible to report all the projects that have been funded during this period, but a full list of projects is appended, together with contact addresses of participating organizations. Accompanying this publication, in the form of a compact disk (CD-ROM), is a searchable list of technical papers and reports produced by projects funded under the CPP since its inception, together with updated references to many of those produced under the IPMSA. All projects produce Final Technical Reports, copies of which can usually be obtained on application to CPP Management. Details of recent or current projects, some of which follow up results reported in these highlights, can be found in DFID’s Natural Resources Information System (NARSIS) database at www.narsis.org or via the CPP website at www.nrinternational.co.uk. The timetable for research to achieve impact can be lengthy and unpredictable, and achievements of this programme owe much to the past efforts of others. This publication aims to disseminate knowledge that has been gained over the past 4 years, to improve awareness of the programme, and to acknowledge the efforts of those who have carried out the work or have contributed to the knowledge base on which it has been founded. I wish to thank the editor, Anne Sweetmore, for her tireless efforts to assemble this information from numerous and often lengthy project reports and for dealing with many queries and communications with project partners; Jill Lenné and Karen Wilkin for contributing to the introductory sections on poverty, livelihoods and the environment; George Rothschild for critically reviewing the technical content of the highlights; and Len Budd, Angela Milligan, Tina Rowland, Rob Fenn and Christine Wheeler for checking and editing the accompanying bibliography.

Simon Eden-Green January, 2001

1See HILLOCKS, R.J. and EDEN-GREEN, S.J. (1998) Research Highlights under the Integrated Pest Management Strategy Area 1989–95. Chatham, UK: Natural Resources Institute on behalf of Natural Resources International Ltd.

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Pests and poverty: the continuing need for crop protection research

The DFID Crop Protection Pro- of pesticides, biological control and may spend up to 80% of their gramme is committed to the integrated pest management (IPM) income on food (Lipton and development and promotion of will have an increasingly important Longhurst, 1989). Ensuring food socially and environmentally role to play in the future. entitlement is a major priority for acceptable management technolo- poverty elimination in most gies to reduce crop losses from WHO ARE THE POOR? national development policy pests1 in developing countries. frameworks. Improved pest management is an The poor are a very heterogeneous Raising productivity and overall essential part of a holistic approach group, differentiated by gender, age crop production are key to enhanc- to crop improvement, substantially and ethnicity, and they face ing food security and agricultural contributing to poverty elimination, different opportunities and con- incomes at national and household enhanced livelihood security and straints. Vast numbers of the world’s levels. These requirements should reduced environmental degrada- poor are dependent in some way or be addressed in the early stages of tion. Excellent progress has already another on agriculture, whether as a sequential process for eliminating been made in the development, producers, consumers, labourers, poverty (UNDP, 1998). Continued application and promotion of a small entrepreneurs, or all these agricultural growth is a necessity, broad range of pest management categories at once. The economic not an option, for most developing technologies which farmers have impact of improved agricultural countries (Hazell, 1999) but must already adopted and continue to technologies can benefit: be compatible with, rather than in adopt, especially in South Asia and • producers, through increased competition to, protection of the sub-Saharan Africa, home to most productivity and/or greater environment and the natural of the world’s poorest people. profitability resource base. Without the advances made by • agricultural labourers, by A central component of agricultural agricultural research over the past generating employment and growth is the ‘enabling environ- 30–40 years, including crop improving health ment’ within which technological protection technologies, the effects development takes place. This is of poverty would have been far • agricultural traders, transporters the complex of policies, markets, worse. Studies show that economic and local food processers, by culture and laws that shapes growth, particularly agricultural providing an assured supply of people’s ability to turn new growth, has contributed to a product knowledge and technologies into threefold increase in food produc- • consumers, through increased productivity and production tion over the past four decades availability and quality of food, increases; and to translate these, in (Lipton and Longhurst, 1989). and lower prices. turn, into better food security and History records no increase in food incomes. For consumers, traders production that was remotely We also need to recognize that and petty entrepreneurs, it deter- comparable in scale, speed, spread poverty is dynamic, the poor mines the overall supply of and duration. shifting in and out of different poverty levels over time. This produce, their individual access to Further support is essential to meet means that it is important to it, their ability to respond to the challenges of producing even understand the processes by which demand for sold-on or processed more food from even less land, these shifts occur and the role of foods, and so on. At national and using technologies that have agricultural research in catalysing regional levels, the enabling minimal adverse environmental change. environment can shape policies impacts and contribute to poverty that encourage economic growth elimination. Technologies such as while reducing degradation of the host-plant resistance, judicious use IMPORTANCE OF natural resource base. AGRICULTURE PESTS AND POVERTY 1. The term ‘pest’ is used throughout Agriculture is the most important this document to refer to weeds and economic activity in most develop- Globally about 50% of all food and fungal, bacterial, viral and phytoplasma ing countries. Over 60% of the cash crops are lost to pre- and post- pathogens, as well as to insect, economically active population harvest pests. Even with existing nematode and vertebrate pests that and over 50% of the rural economy protection levels, based on signifi- affect crops. The term is qualified when are involved with agriculture. cant advances in crop protection it is used to specify a particular group of Meeting basic food requirements is research during the past 40 years, pests. the first priority of the poor, who about 30% of pre-harvest crop

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yield is lost annually. Without the development of successful TARGETING RESEARCH protection, and especially in agricultural technologies. OUTPUTS TO THE POOR developing countries, these losses As producers, poor farmers may are even higher. Pests are also gain from increased yields and dynamically changing in response GEOGRAPHICAL TARGETING profits as a result of new technolo- to new environments and selection gies provided by crop protection The Crop Protection Programme pressures (sometimes imposed research. As consumers, the rural has a strong geographic focus on through the misuse of protection and urban poor may gain from the poor, with approximately 60% practices) by evolving new, often more reliably available, cheaper, and 30% of projects and pro- more damaging variants. Crop safer, higher quality food produced gramme budget targeted at sub- losses negatively affect all catego- through environmentally friendly Saharan Africa and South Asia, ries of the poor. Continued crop pest management strategies. When respectively. These regions are the protection research is essential to food prices decrease and stabilize, ‘hot spots’ of poverty and malnutri- keep pace with these changes by the poor gain proportionally more tion, with more than 70% of the extending and improving existing than the rich (Lipton and Longhurst, world’s most food insecure – more successful technologies and 1989). As landless agricultural than 800 million people (43% in developing new, more robust labourers, the poor may gain from South Asia, 24% in sub-Saharan methods to meet future challenges. increased employment opportuni- Africa; Pinstrup-Andersen et al., Pest problems add to producers’ ties as a result of increased produc- 1997) – who do not have enough risks, and divert resources from tion and more labour-intensive dietary energy and protein. In other priorities (school fees, inputs technologies (but not necessarily addition, of the estimated 160 for cash crops, etc.) if pest control higher wages). They may also gain million malnourished children inputs have to be purchased, or if from improved health due to safer globally, approximately 100 million time is diverted from other activi- management technologies, such as live in Asia and 40 million in sub- ties to pest control practices such crop varieties with pest resistance Saharan Africa. Bolivia, the only as weeding. Crop failure due to which need judicious use of (or no) other country outside these two pests may mean an individual farm pesticides. As petty agricultural regions where the Crop Protection family will starve because of the traders, transporters and local food Programme supports several direct loss of food, loss of income, processors, the poor may benefit projects, is considered to be one of inability to repay debts, lack of from an assured supply of the the poorest countries in Latin money or credit to buy inputs for product. America; the focus here is on the the next cropping season, and a fragile and erosion-prone hillsides, Since the 1970s, host-plant variety of other effects. This home to many resource-poor resistance has been increasingly initiates a downward spiral from people. successful in controlling many which it is very difficult for the important pests of staple food household to escape. If the crop PRODUCTION SYSTEM TARGETING crops, with substantial and continu- failure is widespread – not unusual ing benefits both to small-scale, The Crop Protection Programme as a result of pest outbreaks such as poor farmers and to the environ- also targets the poor by prioritising locust plagues or wind-dispersed ment. The value of natural and production systems which have a pathogens – not only will produc- enhanced biological control is high concentration of poor people ers move into abject poverty, but increasingly being realized and and/or where investment in that those groups who depend on developed as the backbone of production system will contribute producers, including agricultural many successful IPM programmes. to poverty reduction elsewhere. labourers, traders, transporters and For example, the semi-arid produc- processers, will also suffer. Pest management – whether based tion system is home to about one on genetic, cultural, biological or billion people, of whom approxi- IMPORTANCE OF CROP judicious chemical control prac- mately 350 million (44% of the tices or their integration into an PROTECTION RESEARCH global total) are poor, food inse- IPM strategy – has successfully cure, and mostly involved in Much of the increase in food increased production, increased agriculture. The largest proportion production globally during the past profitability, decreased food prices, of the Programme’s budget pres- 40 years can be attributed to improved yield stability, reduced ently supports projects developing research, including crop protection economic risks, increased employ- technologies to combat damaging research, with internal rates of ment, and improved the environ- pests of staple cereals and associ- return of 30 to 50% (Pinstrup- ment for the benefit of the poor, ated legumes and cotton, as well as Andersen et al., 1997). Agricultural especially over the past 30 to 40 migrant pests (Table 1). research has a high poverty years. DFID, through its support for elimination pay-off, and reduction crop protection research, has made Similarly, a considerable proportion of losses from pests in both food a major contribution to this of the poor live in rural forest- and cash crops is an integral part of progress (Table 1). agriculture production systems and

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Table 1. Contributions of the Crop Protection Programme to poverty elimination on priority crops in key production systems in sub-Saharan Africa and South Asia

Production Management Crop/Project* system Pests strategy Poverty elimination target

Rice in South Asia Land-Water Tungro, sheath Resistance, cultural Major food source for most of the (R6519, R6643, R6739); High blight, yellow stem control, IPM world’s poor: decreased losses; Rice in sub-Saharan potential borer, weeds, rice increased production, reduced inputs, Africa (R6763, 6658, yellow mottle virus, increased profits for producers, 6738) nematodes, blast cheaper rice for consumers, safer working environment for labourers. Maize in eastern and High Streak, Striga, ear Resistance, cultural Major food source for the poor: southern Africa (R6642, potential rots, gray spot, control, IPM decreased losses, stabilised yields, R6921, R6654, R6582, termites increased availability, increased profits R6653) for producers, cheaper maize for consumers, increased employment opportunities for labourers. Cassava in Uganda Forest- Mosaic virus Resistance, biocontrol Major food security crop: decreased (R6614) Agriculture disease losses, increased food availability, increased profits for producers, cheaper cassava for consumers. Banana in East Africa Forest- Sigatoka leaf spot, Resistance, cultural Major food for the poor: decreased (R6692, R6582, R6580, Agriculture fusarium wilt, and biocontrol, IPM losses, reduced costs of production for R6579) nematodes, producers, increased food availability viruses, weevil for consumers, increased employment opportunities. Cotton in India (R5745, Semi-arid Bollworm Resistance Major base of the rural economy and 6734, 6760, 7004) management, export crop: reduced costs and biocontrol, IPM increased profits for producers, increased employment opportunities and safer environment for all. Vegetables in sub- Peri-urban Diamond-back IPM, biocontrol, Major base of the peri-urban economy: Saharan Africa (R6146, moth, fungal biorationals, decreased losses, secure and 6799, 6615, 6616, 6629, diseases, resistance, cultural profitable livelihoods for producers, 6620, 6764, 6657) nematodes, control safer food for consumers, safer working viruses, weeds environment for labourers. Coffee in eastern and Forest- Diseases, insect IPM, biocontrol Major base of the rural economy and southern Africa (R6782, Agriculture pests export crop: decreased losses, R6807) increased production, higher quality, lower production costs, reduced health risks for producers and labourers. Groundnut in sub- Semi-arid Rosette virus Saharan Africa (R6811) disease Resistance, IPM Major food and cash crop: decreased losses, increased production, greater profitability, increased food availability for consumers, women will benefit most. *Examples only are given. depend on agriculture for their the Programme has recently developed that favour one category livelihoods. The Programme also increased spending in the peri- of poor at the expense of another. invests a large proportion of its urban production systems. budget in developing technologies FUTURE NEEDS Production systems may have for management of serious pests of different levels of poverty and banana, root and tuber crops, World population will grow different proportions of categories perennial cash crops and substantially over the next 20 years, of the poor: producers, landless agroforestry species (Table 1). and 95% of this growth will occur rural labourers, petty entrepreneurs in developing countries. The Growing urbanization in develop- and rural and urban consumers. world’s farmers will have to rapidly ing countries has made it necessary Care is taken to balance contribu- increase food production (Pinstrup- to manage serious pests of staple tion to high yields with reduced Andersen et al., 1997). Severe food foods (such as rice and maize) and inputs for poor producers and shortages, increased poverty, nutritional crops (such as vegeta- reduced food prices for poor livelihood insecurity, political and bles) to meet the needs of increas- consumers. It is inevitable that social instability, and environmen- ing numbers of urban poor. Hence sometimes technologies are tal degradation could occur in

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many developing countries early in continues, and natural resources production efficiency, and will this century unless more food is are used more wisely in the ensure environmentally friendly produced and prices are kept low. future will depend on even inputs to agriculture, all of which greater investment in agricultural contribute to the elimination of The proportion of the world’s development, including crop poverty and sustainable livelihoods population living in urban cities is protection research. for poor producers and consumers, predicted to grow from just under landless labourers and small half in 1999 to almost 60% in The Crop Protection Programme agribusinesses. 2025. Most of this increase will be focuses on what it can do best to in the developing world, and in contribute to poverty elimination: secondary rather than primary developing pest management cities. Urbanization and economic strategies that contribute to reduc- REFERENCES growth are likely to bring about ing losses; increasing and stabiliz- changes in preferences in types of ing yields; reducing pesticide use; CONWAY, G. (1997) The Doubly Green food consumed and in food safety and reducing economic risks. Such Revolution: Food for All in the 21st Cen- and quality (Wiggins et al., 2000). strategies will benefit human tury. London: Penguin. DFID-funded crop protection health, the environment, food research will track these changes to safety and water quality; increase HAZELL, P.B.K. (1999) Agricultural ensure that it targets crops upon employment; increase incomes; Growth, Poverty Alleviation and Envi- which the poor depend. and decrease food prices. Some of ronmental Sustainability: Having It All. these objectives, however, can be IFPRI 2020 Vision Briefing. Washington, The agricultural productivity achieved only through working in DC: International Food Policy Research increases needed to lift rural and collaboration with other pro- Institute. urban populations of low-income grammes within DFID and with a developing countries out of poverty multitude of external partners, LIPTON, M. and LONGHURST, R. (1989) and food insecurity without doing through well defined uptake New Seeds and Poor People. London: irreparable damage to the environ- pathways. The integration of the Unwin Hyman. ment will be possible only if the different contributions throughout appropriate government policies DFID is key to ensuring that are pursued and continued invest- PINSTRUP-ANDERSEN, P., PANDYA- research results lead to poverty LORCH, R. and ROSENGRANT, M.W. ment in agricultural research is elimin ation. supported. Enlightened policies, (1997) The World Food Situation: Recent together with the introduction and Crop protection scientists, working Developments, Emerging Issues and Long- development of pest-resistant in collaboration with breeders, Term Prospects. IFPRI 2020 Vision Food varieties, have generally resulted in agronomists and social scientists, Policy Report. Washington, DC: Interna- reduced pesticide inputs, use of have been able to bring many tional Food Policy Research Institute. safer chemicals, and improved important pests under control in farmer safety. many developing countries during UNDP (1998) Poverty Eradication: A the past 30 to 40 years. Future Policy Framework for Country Strategies. Without DFID’s support for success will depend on continued New York: United Nations Development agricultural research for develop- investment in improved pest Programme. ment, including significant support management practices and their for crop protection research, integration with crop improvement WIGGINS, S., ORUKO, O.L., PROCTOR, poverty in developing countries programmes. Strategic partnerships S. and UPTON, M. (2000) Population, would have been far worse. The with international and national Migration and Rural Diversification; The extent to which the growth of agricultural research services and Implications for the Post-Harvest Sector. poverty is slowed, food security is non-governmental organizations DFID Crop Post-harvest Programme, improved, livelihoods are made will contribute synergistically to Issues Paper No 1. London: Department more sustainable, economic growth increasing yields and improving for International Development.

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Integrating crop protection research and sustainable livelihoods

With a new goal of improving the landscapes reduces pressure IMPROVED ACCESS TO livelihoods of poor people through on natural resources elsewhere, as EDUCATION, INFORMA- sustainably enhanced production for example in the promotion of and productivity of renewable leguminous agroforestry trees for TION, TECHNOLOGIES natural resources, there is a need which the Crop Protection AND TRAINING, BETTER to shift from how crop protection Programme provides support in NUTRITION AND affects pests and crops, to how eastern Africa (R6736). it affects people. Although the HEALTH emphasis remains on producers, A MORE SUPPORTIVE there is now a more explicit A wide range of stakeholders appreciation not only of farmers, AND COHESIVE SOCIAL benefit from improved knowledge but also of others such as consum- ENVIRONMENT about crop protection targeted at ers and labourers. The following the poor. A range of projects within examples illustrate the contribution Farmer-based crop protection the Crop Protection Programme of crop protection research to research, information acquisition have developed diagnostic tools sustainable livelihoods. and management strategies may all that allow researchers, extension benefit from group rather than workers and others to identify important diseases of rice (e.g. BETTER MANAGEMENT individual action. For example, the formation of farmer research groups R6643 and R6519) and vegetables OF NATURAL RESOURCES to control sorghum fungal patho- (R6657 and R7266), and many gens in Kenya (R6581); area-wide stakeholders have participated in One of the challenges in crop group action to implement chemi- targeted workshops. To gain the protection research is to sustain cal control systems, as in fruit and best advantage from integrated natural resources whilst managing vegetable pest control in Pakistan pest management, farmers need losses due to pests, thereby (R6924), and access to reliable to know about the biology of the increasing productivity. This is sources of planting material with crop, the pests and their natural particularly important in areas of resistance to virus diseases of enemies. This means building on higher crop intensity where there cassava in Uganda (R6614) and farmers’ existing knowledge and tends to be greater potential for Tanzania (R6765) and maize in enhancing their capacity to pest damage. Projects within the Uganda (R6642). Some crop observe and experiment, encour- Crop Protection Programme are protection interventions may not aged by a farmer-field school contributing to sustaining natural be feasible without collaboration approach, and/or having pest resources in such areas as: between farmers, and research may experts available to give advice • reducing pesticide use to be needed to assess the feasibility to farmers. control insect pests and vectors for adoption of a technology over a Reduction in crop losses in general of tomato viruses (R6627) and large area, as with group action for can contribute to improved cotton pests (R6734 and R6760) use of pheromones to control rice nutrition for the poor, directly, e.g. in India; yellow stem borers in India through research on finger millet (R6739). • tackling insect pests on vegeta- blast in Kenya (R6733), or indi- bles in Kenya (R6615) and rectly, through increased food Zimbabwe (R6620); SECURE ACCESS TO availability and lower prices for FINANCIAL RESOURCES poor consumers. The effects of • reducing the risks of spread by pesticides on the health of labour- contaminated seed of persistent Areas where crop protection ers, farm families and possibly also soilborne diseases of cotton and strategies can affect financial consumers are a major issue, tomato in Tanzania (R6761 and capital include increased income especially in crops such as vegeta- R6627); through improved crop yield or bles where high levels of pesticides • understanding and enhancing quality, as with management of are commonly used. Project R7071 natural enemies of rice pests in African cassava mosaic disease works with a community based Bangladesh (R7296), minimiz- (R6614); and increased net income NGO in north-east India to reduce ing effects on non-target through reduction in the costs of the quantity and/or toxicity of organisms which may include crop protection methods, for chemicals, and a cross-cutting other food sources for the poor. example for cotton in India project is exploring with small- (R6734), yams in Ghana (R6691), scale manufacturers constraints on Enhanced productivity in agricultural and many other projects. production and adoption of

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environmentally benign microbial POLICY AND INSTITU- is helping the Programme to assess pesticides in India (R7299). Other TIONAL ENVIRONMENT the impact of new crop protection health problems addressed by the technologies and their potential programme include control of the The policy and institutional benefits for the poor, and to identify allergenic weed Parthenium environment is a major determi- areas that need to be strengthened hysterophorus in India (R6695), nant of the type, effectiveness to encourage the uptake of sustain- and toxins from fungal pathogens and impact of research. The Crop able pest management practices. causing ear-rots of maize in Africa Protection Programme will (R6582). increasingly invest in identifying Lack of uptake of crop protection technologies by poor farmers is The effects of crop protection and, where appropriate, support- usually due not to the quality of the practices on labour may be more ing suitable institutional partners technology, but to the lack of a complex. For example, projects (public or private), with a much pathway or mechanism for uptake aiming to reduce the labour and clearer focus on target crops and and promotion. The Programme drudgery of weeding have poten- countries. Research activities will places great emphasis on building tially significant effects on the time be attuned with the priorities and robust uptake pathways in all and effort spent by disadvantaged policies of target countries, groups: it is often the children where these reflect the needs of newly commissioned projects, by (instead of attending school) or poorer communities. Policy and including at the planning stage women (prevented from doing more institutional environments are activities for ongoing interactions productive jobs) who are involved. rarely static, and where opportu- between collaborators. In some But weeding can also be a valuable nities arise the Crop Protection cases long-standing collaborative source of rural income, and the shift Programme will seek to influence research relationships are being to less labour-intensive methods has the policy and institutional further enhanced; in other cases potential consequences for the environment, as has already efforts have been made to bring distribution of rural income. happened in India, through new partners into the fold, includ- interaction with national IPM ing NGOs and the private sector. BETTER ACCESS TO policies under the National Linkages to functional regional INFRASTRUCTURE Agricultural Technology Pro- research networks in sub-Saharan gramme. Africa (ASARECA, Association for Both researchers and farmers are Strengthening Agricultural Research affected by physical capital. For SUSTAINABLE LIVELI- in Eastern and Central Africa; example, pest forecasting and HOODS FRAMEWORK SACCAR, Southern African Centre surveillance systems require for Co-operation in Agricultural sufficient infrastructure – roads, The Sustainable Livelihoods Research; CORAF/WECARD, West radio, computers etc. – to monitor Approach has been adopted by and Central African Council for and analyse pest movements DFID as a way of analysing poverty Agricultural Research and Develop- (relevant to migrant pest projects issues and formulating more ment) and South Asia (APAARI, such as R6762, R6788, R6822 and effective development strategies to Asia-Pacific Association of Agricul- R6823). Good roads and radio alleviate poverty. This analysis of tural Research Institutions) are services are necessary for the how pest management strategies being sought. The programme is extension services to serve farmers can work for particular groups of increasingly acting as a broker and in more remote areas. Access to people is being followed by the a catalyst to promote the uptake of water can affect planting times and Crop Protection Programme. The crop protection research outputs by weed control methods. Sustainable Livelihoods framework poor farmers.

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Crop protection and the environment

The mission of the Crop Protection to levels where they do not cause and varietal resistant lines. Programme is to develop, through economic injury to the crop. These Projects such as R6583 (banana research, improved, environmen- methods are essential components nematode resistance) and tally acceptable crop protection of an integrated pest management R6738 (rice blast and scald strategies which are appropriate for (IPM) approach. Some examples resistance) are investigating the small-scale farmers in developing are: variability of these pathogens in countries. Priorities are set and order to provide information for • The assessment of biocontrol approaches selected that respond development of improved agents to control pests, e.g. to demands from farmers and resistant lines. smut and rust species are being consumers, or from those interme- used to control the weeds • Interactions between pests and diate users who will adapt or apply itchgrass (R6690) and natural enemies have to be improved technologies on their Parthenium weed (R6695), understood by researchers in behalf. respectively; the pathogens order to assess the potential of Agricultural systems in developing Pasteuria penetrans and the use of such predators and countries have evolved as a Verticillium chlamydosporium parasitoids for effective pest delicate balance between crop and are used for control of root-knot control. For example, the pest communities and traditional nematodes (R6611). effectiveness of parasitoids in controlling whitefly was low-input farming systems, and are • The development and use of assessed in project R6627. often particularly fragile and viral and fungal biopesticides, Project R7296 is researching vulnerable to change. Through e.g. a viral insecticide to control species interactions in farmers’ partnership with intermediary diamond-back moth in Kenya rice fields in Bangladesh. organizations, the Crop Protection (R6615); research into the use Programme aims to develop and of the fungal entomopathogen • Pest management controls need promote appropriate IPM strategies Metarhizium sp. to control to be robust enough and stable that reduce pest damage, through termites in maize (R6653). enough to meet farmers’ careful integration of available pest requirements. Poor farmers may • Development and testing of control options that are sustainable not be able to afford to adopt resistant crop varieties such as and best suited to local needs. They biological controls if their tomato varieties resistant to leaf involve rationalizing (and usually effectiveness is highly variable curl virus (R6627), or rice reducing) the use of agrochemicals, when applied in their own varieties resistant to tungro and maximizing the impact of fields. Projects such as R6615 disease (R6519). biological and cultural components are working on refining biologi- to provide environmentally sound • Pheromones to disrupt mating, cal controls to provide pest control that is less dependent e.g. for diamond-back moth in increased efficacy under field on external inputs and more Kenya (R6615). conditions. Project R7299 is accessible to the poor. The impor- • Assessment of cultural methods researching issues of production tance of IPM was highlighted in and uptake of biopesticides in Agenda 21, the action plan of the such as planting density and timing of legume cover crops order to meet the needs of United Nations Conference on farmers. Environment and Development in for weed suppression (R6690); Rio de Janeiro in 1992, and has development of simple, non- • Environmentally sustainable since been the basis of numerous chemical seed treatments to pest management often requires national and international propos- reduce sorghum head smut in more precise application of als and initiatives. Kenya (R6581). controls and increased under- standing of pests and natural The successful development of Developing more environmentally enemies by farmers themselves environmentally sustainable acceptable and sustainable than is required for pesticide controls that are appropriate for approaches to crop protection is a application. Projects such as poor farmers has a number of fundamental component of the R7266, based in Kenya and requirements. Crop Protection Programme. Many Zimbabwe, have developed projects are developing biological • Firstly, there is a need for field handbooks and posters to and cultural methods of pest researchers to understand the enhance farmers’ knowledge of management aimed at minimizing biology and diversity of pest pests and natural enemies, so damage to non-target organisms species in order to develop that they are better able to take whilst decreasing pest populations controls such as biopesticides up IPM methods. Some pest

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management strategies require environment and, directly and effectively and safely, in addition to group action by farmers in indirectly, on human health. integrating these with biological order to work most effectively: Selective use can also reduce the controls. In India, project R7071 is for example, in project R6739 likelihood of insect resistance working with local NGOs to which has developed building up quickly. For example, reduce the level of pesticide use on pheromones for control of over half the pesticides in India are dry-season vegetables. yellow stemborers in rice, the used on cotton, so that projects potential for effective group such as R6734, on insecticide In recent years, the use of herbi- action by farmers is one of the management strategies in cotton, cides has been increasing rapidly research issues. which have reduced insecticide use across many farming systems; by up to 70%, have had an impact however the effects of herbicide The use of pesticides remains a and raised local awareness about residues in the environment are not significant component of plant the misuse of pesticides. Vegetables well understood. Project R7347 is protection for many farmers. are another crop where pesticide investigating the effects of herbi- Minimizing pesticide use by better use is often high. Project R6620 in cide residues on non-target organ- selection and application can have Kenya is researching improved isms in irrigated rice systems in a major impact both on the ways of using pesticides more south Asia.

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Improved methods for the management of Striga: nitrogen, tolerance, screening and cultural practice

R6921 Striga species are root parasitic weeds that infect staple crops (maize, sorghum, millet and M. C. Press, A. L. Gurney, A. Taylor, upland rice) throughout some 40% of the cereal-producing land of sub-Saharan Africa. J.D. Scholes, They are responsible for significant reductions in yield, sometimes even resulting in total Department of Animal and Plant crop failure. Smallholder farmers suffer most from the parasitic weed, and there is an Sciences, University of Sheffield, UK urgent need to identify practical control methods. This project has made progress in un- A.M. Mbwaga derstanding the mechanisms through which Striga affects its host, and has begun to iden- Agricultural Research and Training tify sources of tolerance and/or resistance to Striga in small-grain cereal crops that can be Centre, Tanzanian Agricultural Research used by plant breeders. Methods have been developed to allow in vitro studies of the Organization (TARO), Ilonga, Tanzania parasite’s life cycle that can be used in rapid screening to detect early infection in the April 1997–March 2000 field. Progress has also been made in understanding how nitrogen fertilizer and the timing of its application influence the response of cereals to infection by Striga. ISSUES Striga species are weeds that known. In sorghum, pearl millet • Early application of nitrogen parasitize the roots of cereals, and maize there are as yet no lessens the impact of Striga infecting major staple crops (maize, reliably resistant varieties. It is more effectively than later sorghum, millet and upland rice) critical to identify firstly how Striga application, but there are throughout ~40% of the cereal- reduces host yield, and secondly important genotype x environ- producing land of sub-Saharan how management practices can ment interactions that can Africa. The two most important best mitigate the effects of the modulate its efficacy. weed species are S. hermonthica weed. • The project has provided and S. asiatica. Yield losses of education and training to local 30–50% are common under heavy ACHIEVEMENTS scientists and extension workers infestations, and infection some- Work was carried out through a in Tanzania and Kenya, in times results in total crop failure. combination of laboratory studies collaboration with colleagues It is not uncommon for farmers to and on-station and on-farm field from target institutions. Basic abandon severely infested land or studies, principally in Tanzania but scientific information on Striga– to adopt a different cropping with some activities in western cereal interactions has been pattern in an attempt to overcome Kenya. provided to researchers in both the problem. It has been estimated developed and developing that grain production in Africa is • Cultivars have been identified worlds to facilitate the develop- threatened by Striga on 44 Mha that perform well in the ment of new control strategies. (3.2% of the world’s arable land) presence of Striga, e.g. the which represents an economic loss maize cultivar Staha. FUTURE from infection of US$3–7 billion. • Useful traits and characteristics The findings from this study, Striga is therefore a serious eco- in cereals have been studied together with those from a previous nomic problem, and is arguably the that will allow breeders to project in Tanzania (R6654; see most important biotic factor develop potentially useful page 2), form the basis of an constraining the production of cultivars. Reducing the number ongoing collaborative programme major cereal subsistence crops in of Striga plants that the host (R7564) that aims to complete semi-arid tropical Africa. The weed supports does not exert a major screening and farmer evaluation of is a particularly critical problem for impact on grain enhancement, resistant cultivars; to incorporate resource-poor households in the since competition for resources these into integrated management densely populated drier areas of between host and parasite is not strategies with a particular empha- West, East, central and southern the primary mechanism sis on matching resistant cultivars Africa, as it is commonly associated responsible for yield depres- with soil fertility levels; to multiply with low soil fertility and continu- sion. Delaying attachment of selected sorghum lines for ous cropping. the parasite to the host’s root registration and release to system is one of the most useful Despite major efforts to identify farmers; and to identify sources traits for alleviating the effects sources of resistance to Striga of resistance in maize. The latter of the parasite. species, completely resistant cereal will also be addressed in col- cultivars have not been identified, • Novel sources of resistance in laboration with colleagues at the although cultivars of cowpea wild relatives of maize are International Maize and Wheat resistant to S. gesnerioides are now being investigated, which may Improvement Center (CIMMYT), be used in the medium term to building on achievements from Publications: see Bibliography on CD. alleviate the impact of Striga. this programme.

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Integrated control of Striga in Tanzania

R6654 Striga is one of the most important weeds in East African smallholder cereal production, affecting 40% of the cereal-producing areas of sub-Saharan Africa. Serious infestations C.R. Riches, R.I. Lamboll can cause total crop loss. This project has worked with farmers to select from the most Natural Resources Institute (NRI), resistant sorghum lines currently available, and a start has been made to assess the pro- University of Greenwich, UK ductivity of these lines when used in combination with other Striga control measures, by A.M. Mbwaga conducting trials in four villages of two zones in Tanzania. Preliminary work has also Agricultural Research and Training been carried out on identifying sources of resistance in finger millet and rice. Striga resist- Centre, Tanzanian Agricultural Research ance in sorghum was shown to be less pronounced at sites with low fertility, but it can be Organization (TARO), Ilonga, Tanzania enhanced by applications of manure or by intercropping. Efforts to introduce farmer par- ticipatory methods new to some of the study areas, and to extend knowledge of Striga, an and staff of: ‘invisible’ source of crop problems, have resulted in knowledgeable farming communities Hombolo Research Station, Dodoma, who will provide a resource for further investigations. Tanzania; Ukiriguru Agricultural Research and Training Centre, Mwanza, Tanzania; ISSUES management of Striga in Tanzania Uyole Agricultural Research and Training through farmer participatory Parasitic weeds in the genus Striga Centre, Mbeya, Tanzania; Dodoma research. Potentially resistant are widespread constraints to the District Extension Office, Dodoma, sorghum lines were obtained for production of staple cereal crops Tanzania screening, and investigations were in semi-arid areas of eastern and carried out on the problems of April 1996–September 1999 southern Africa, including finger Striga in finger millet and upland millet, sorghum and upland rice. rice. This work collaborated with They have been estimated to infest project R6921 which has investi- some 40% of the cereal-producing gated the effect of nitrogen on areas of sub-Saharan Africa; parasitism of maize by Striga, and S. hermonthica alone may now has undertaken detailed laboratory infest over 10 million hectares. studies to describe mechanisms of Semi-arid areas of Tanzania lie in tolerance to Striga in the sorghum a zone where the three most lines tested in the field. The aims significant Striga species infesting of the project were to develop and cereals (S. asiatica, S. forbesii and evaluate practices for the control S. hermonthica) all occur. Reports of Striga species in cereal-based of 5–30% loss of potential yield, cropping systems in Tanzania, with crop failure at heavily infested integrating techniques appropriate sites, are common for various parts to smallholder farmers. of Africa. Other consequences of Striga infestation include farm ACHIEVEMENTS abandonment, now difficult in the face of a shortage of productive A series of on-station and on-farm arable land, or a change of crop- trials were undertaken to investi- ping pattern to less favoured, albeit gate components of an integrated resistant crop species. system of Striga management for sorghum, finger millet and rice in A number of sorghum breeding Tanzania. This work was supported lines have been produced else- by glasshouse studies conducted where in Africa, and specifically in the UK. Sorghum lines were by the International Crops Research selected on the basis of low SELECTED PUBLICATIONS Institute for the Semi-Arid Tropics susceptibility and farmer prefer- (ICRISAT), in an attempt to intro- ence in on-farm trials in the Lake MBWAGA, A.M., LAMBOLL, R. and duce parasite resistance into lines Zone (S. hermonthica infested) and RICHES, C.R. (1998) The Striga Problem adapted to Tanzanian conditions. Central Zone (S. asiatica infested). in Dodoma Region and the Lake Zone of However, due to limited local Farmers showed particular interest Tanzania: Analysis of the Problem and funding these had not been in the early maturing line P9405, Research Priorities. Chatham, Kent: screened, and findings from obtained from Purdue University, Natural Resources Institute. on-station trials had not been USA, which also performed well RICHES, C.R., (Ed.) (2000) Striga Distri- followed up on-farm within at a site infested by S. forbesii. bution and Management in Tanzania. Pro- affected farming communities. This was also tested in combination ceedings of a Stakeholder Workshop, Sep- This project aimed to support with the application of animal tember 1999, Dar es Salaam. Chatham, national programme efforts to manure or a legume intercrop. Kent: Natural Resources Institute. develop integrated methods for the Efforts are now needed to multiply

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Involving farming commu- nities in the assessment of Striga management options has required the introduction of new methodologies in some of the areas of Tanzania where the project has been working. Although the use of farmer research groups is well established in the Lake Zone, these are not well known in other areas, including Dodoma. It therefore took some time for research and extension staff to fully embrace this way of Left, Striga asiatica; right, S. hermonthica working. By the end of selected lines for wider testing improved yields. The parasitic the project the group approach prior to registration. weed Rhamphicarpa fistulosa was had become well established in identified as a constraint to lowland the study villages, and these will Studies of farmers’ perceptions of rice production in Kyela. provide ideal locations for further the Striga problem indicated that studies. they have little understanding The project has demonstrated that of the life cycle or biology of the Striga resistance in sorghum is less FUTURE parasite – this is a considerable pronounced at sites with low As the project developed there was constraint to the process of farmer fertility, but it can be enhanced by increasing interest in Tanzania in evaluation of control options. applications of manure or by addressing the Striga problem. With Posters were produced to inform intercropping. No resistance has the establishment of Zonal Research both extension workers and farmers been found among the finger millet Programmes, Striga has now been about key aspects of Striga biology lines made available to the project identified as a priority issue via and control. for screening. Partially resistant zonal internal programme reviews Oryza glaberrima and O. sativa S. hermonthica is a problem on in Eastern, Central, Lake, Southern rice lines from West Africa were finger millet in the Mara Region Highlands and Southern Zones. tested but were not favoured by of Tanzania. Pot screening of local Expertise on Striga research remains farmers, and did not show high landrace lines did not reveal any concentrated at Ilonga, the Eastern levels of resistance. resistance. Laboratory and green- Zone research centre. As other house systems for screening this During two seasons, unusual zones have begun to develop their crop were demonstrated as conditions of drought in some areas programmes, it was requested at suitable. combined with excessive rainfall in the stakeholder workshop that S. asiatica is associated with others meant that few crops went follow-on work should help back- declining soil fertility and falling through to yield. A critical assess- stop efforts to develop and promote yields of upland rice in Kyela ment of the economic value of the Striga management recommenda- District, southern Tanzania. Work management practices investigated tions at the zonal level. In Kyela, was undertaken with farmer groups was compromised by the difficult the District Council has allocated formed by district extension staff to weather conditions and associated funds so that district and village evaluate rice cultivars and prac- pest infestations. It therefore proved extension staff can continue to tices for improving soil fertility. difficult to take crops to yield in work with Striga researchers from Lines which had shown partial on-farm trials. In the villages of outside the district until 2002. resistance to other Striga species in Dodoma Rural and Urban Districts Research is continuing with inputs West Africa (R5228) were suscepti- food became particularly short from NRI, Sheffield University and ble. Farmers indicated a clear during early 1999, and a number of the national programme, with an preference for tall, vigorous rice participating farmers were forced to emphasis on farmer cultivar selec- lines with aromatic grains, and leave their farms in search of work tion, matching sorghum cultivars to have requested the opportunity to and food. Farmers at some sites differing soil fertility conditions, and evaluate a number of lines on were unable to leave their plots the development and testing of larger plots. Application of urea until the crop matured, and ‘learning tools’ which will facilitate at 25–50 kg N per ha reduced the removed and consumed sorghum the promotion of Striga management parasite density in rice and heads as they ripened. options to farmers (R7564).

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Moisture conservation through improved weed management in conservation tillage systems

R6655 Weeding accounts for up to 60% of the labour used in maize production in Zimbabwe. Because of poor returns from cropping (particularly in semi-arid regions), and an acute C.R. Riches shortage of draught animal power and labour in many households, conservation tillage/ Natural Resources Institute (NRI), weed control systems need to be based on low-cost, labour-saving technologies. This University of Greenwich, UK project follows up previous on-station research into low-cost weed management, using a S.J. Twomlow, J. Ellis-Jones participatory technology development approach. A range of crop establishment and weed- Silsoe Research Institute, Bedford, UK ing practices have been developed with and assessed by farmers, and information to support further promotion of their use has been made available to extension agencies. T. Gatsi, S. Mabasa, L. Jasi Agronomy Institute, Harare, Zimbabwe A good understanding has been developed of the extent to which combinations of practices can be used by, and be of benefit to, households in different resource categories. I. Chatizwa Agritex–Institute of Agricultural Engineering, Harare, Zimbabwe ISSUES evaluate the recommended technologies for themselves. April 1996–September 1999 Approximately 90% of the small- holder farmers in Zimbabwe are Using knowledge of farmer located in semi-arid areas which resource categories, the aim was are marginal for the production to use participatory research SELECTED PUBLICATIONS of most annual crops due to techniques to develop a better unreliable rainfall. As in much understanding of farmers’ percep- CHATIZWA, I., TWOMLOW, S. and of sub-Saharan Africa at the tions of weeds and weed control, RICHES, C. (1999) Weeding and drudg- smallholder level, excessive weed and to provide extension staff with ery! Is it inevitable? 17th Biennial Con- growth is a major constraint to the guidelines for the wider testing and ference of East and Southern Africa. Weed adoption of conservation farming promotion of a range of crop Science Society, Harare, September practices and increased crop establishment and weeding 1999, University of Zimbabwe. production. options. In Zimbabwe this SIMS, B.G. and TWOMLOW, S.J. (1999) contributes to the Participatory Previous research in Zimbabwe Extension Approach adopted by Small-farm soil and water management: (R5236) demonstrated how weed Agritex (the national Agricultural participatory R&D experiences from Latin management influences the Extension Service) and NGOs, America and sub-Saharan Africa. 5th In- availability of soil moisture, and by providing farmers with ternational Meeting on Soils With Medi- examined weeding regimes in information on which they can terranean Type of Climate, July 1999, terms of crop water-use efficiency base the selection of weed Barcelona, Spain. and grain yield. In addition to site management practices relevant effects, the level of weed infesta- TWOMLOW S. and BRUNEAU, P. (2000) to their circumstances. The influence of tillage on semi-arid soil tion a farmer has to deal with is a reflection of cultivation history, water regimes in Zimbabwe. Geoderma ACHIEVEMENTS 95: 33–51. and varies with changes in primary tillage, planting and in-crop Trials were planned and imple- TWOMLOW, S. and DHLIWAYO, H. cultivation practices. These are all mented with farmers in Masvingo (1999) Semi-arid maize yield responses linked to and influence soil Province, in collaboration with to conservation tillage and weeding. moisture availability to the crop. Natural Resources System Pro- Brighton Crop Protection Conference – Tillage, crop establishment, and gramme project R4840, on three Weeds, 391–396. weeding must therefore be consid- soil types: the sandy toplands and ered as an integrated system; little TWOMLOW, S.J., RICHES, C.R., valley bottom wetlands of the benefit is to be derived from O’NEILL, D.H., BROOKES, P. and ELLIS- hydromorphic vlei margin, and studying components in isolation. JONES, J. (1999) Sustainable dryland seasonally inundated vlei. Tech- smallholder farming in sub-Saharan Results from on-station trials nologies were initially tested in Africa. Journal of the Arid Zone 38: showed that combining weeding replicated researcher-managed 93–135. with a plough or a cultivator with trials, then assessed by farmers VAN DER MEER, F.B., TWOMLOW, S., planting using a ripper tine to themselves using paired plots. BRUNEAU, P. and REID, I. (1999) Weed create planting furrows could Three farmer groups were identified management in semi-arid agriculture: provide a low-input draught tillage/ according to access to application of a soil moisture competi- weeding system. This project resources such as labour and tion model. Brighton Crop Protection sought to take the work to the next draught animal power, and Conference – Weeds, 385–390. stage, in which farmers could involvement in the market.

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a ripper at planting, for example, Table 1. Farmer preferences for crop establishment allows timely crop establishment and weeding in Zimuto based on pairwise ranking and will be of benefit to more than Soil type Stage Method Score 60% of households who own draught power. The ways in which Topland Crop establishment Hand hoe 1 weed management needs to be Rip 3 modified when a ripper is used, Open furrow 3 Third furrow 0 compared to traditional methods First weeding Hand hoe 0 of ploughing and planting, have Cultivator 2 been evaluated and information is Plough 1 now available, based upon farmer Second weeding Hand hoe 2 assessment criteria, on which to Cultivator 1 Plough 0 base promotion of the technology to farmers. For resource-poor Vlei Crop establishment Hand hoe 1 households who may be unable to Rip 0 gain access to a ripper or cultivator, Open furrow 2 the project has demonstrated that Third furrow 3 First weeding Hand hoe 2 weeding can be undertaken with Cultivator 0 the existing mouldboard plough Plough 0 and the advantages and disadvan- Second weeding Hand hoe 2 tages of this practice have been Cultivator 0 described. These outputs can be Plough 0 used by extension services to better 0 = considered unsuitable target promotion of improved weed 1 = only used because resources for other methods not available control, within an overall package 2 = suitable method (crop establishment) and best method (weed control) of tillage/crop establishment/weed 3 = best method (crop establishment) control methods, to farmers with Methods in bold preferred differing access to resources. Weed problems and farmers’ accumulates. Farmers appreciate During the final season, on-farm current weeding practices were the need for practices that enhance assessments were all farmer- described in both areas. Major soil moisture conservation on the managed. Following exposure problems with sedges and perennial topland in dry years and enhance of farmers to the practices tested grass weeds were identified at vlei drainage in the wetland fields in during the previous two years at margin and vlei sites. Timely wet years. Better-resourced farmers field days, volunteers carried out planting on residual moisture own cultivators. Female-headed assessments using paired plots on ahead of the onset of the rainy households tend to weed with their own fields. These compared season is essential in these a hoe; women lack the skills and their existing methods, usually third ecologies to allow weeding to be experience to undertake weeding furrow planting and hand weeding completed before surface water with draught animals. The use of or ox-cultivation, with an improved

Planting furrows created with a ripper tine in a weedy fallow. Insets: top, a ripper tine; below, ripper tine attachments made by a local blacksmith

5 DFID CROP PROTECTION PROGRAMME

Group meeting discussing the strengths and weaknesses of different crop establishment and weeding technologies

method. The preferred options for ate to each category of household, FUTURE crop establishment and weeding, and provides guidance to exten- Transfer of the project outputs as indicated by farmer groups in sion workers on the information to farmers is proceeding through pairwise ranking completed during farmers need when assessing a number of channels. Establish- the season, are shown in Table 1. which practice to use. ment and weeding practices Perceptions of weeding methods During the project, farmers developed and tested by the project strongly reflect the unusually heavy became particularly interested have been incorporated into the rainfall experienced, and the in adopting a ripper tine. Bolted on-farm programmes of an consequent inability of farmers to onto the existing plough, this International Fund for Agricultural weed with animals in the vlei and Development (IFAD)-funded much of the topland and vlei margin. allows for rapid, timely planting and has a low draught require- project for Midlands and Project staff assisted farmers with ment. Agritex staff collaborating Matebeleland, and the DFID- a simple record-keeping scheme. with the project undertook funded CARE Small Dams Project The records were maintained in workshops for rural blacksmiths in Masvingo Province. the form of participatory budgets, in the area to provide instruction Outputs from this work have also with group discussion and on making the ripper assembly led to the implementation of further a formal survey undertaken to and on implement maintenance DFID-funded work in Zimbabwe. establish farmers’ perceptions in general. A project is now being funded by of each technology option. the Livestock Production Programme In addition, during the course An economic analysis was (R7352) to examine the problems of the project a detailed quantita- undertaken to establish costs involved with the use of draught tive assessment was undertaken and benefits, and likely value animal implements identified by to households with differing of water uptake by weeds, and this project, involving field work levels of resources. the relative effects of mechanical to examine the impact on crop All this information has been used weeding and frequency on weed productivity of implement avail- to develop the leaflet An Extension transpiration, the infiltration ability, maintenance, and farmers’ Guide on Participatory Assessment process, and the soil water knowledge of correct implement of Crop Establishment and Weed- regimes that develop. The settings. New work has also started ing Methods. Given the variations information collected was used to investigate opportunities for in soil and climatic conditions to further refine the soil-water improving production in the vleis faced by farmers, as well as the balance component of the through the use of sustainable differences in access to key predictive model PARCHED- tillage/weed management practices resources, it is difficult to provide THIRST. The model can now be (R7473). Both projects are using the firm ‘blanket’ recommendations. used to examine the effects participatory technology develop- Rather, the project has clarified the of different weeding practices on ment approach evolved by this range of options that are appropri- maize yield in semi-arid areas. project.

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Control of water hyacinth in the Shire River, Malawi

R6392 Water hyacinth is the world’s worst aquatic weed. It causes considerable disruption to G. Hill communities, particularly to fishermen and housewives. It blocks access to water, disrupts CABI Bioscience, Ascot, UK fishing efforts, harbours harmful aquatic disease vectors and snakes, disrupts water trans- port and hydro-electric power generation, and damages wetland biodiversity and fish abun- G. Phiri, R. Day dance. The weed has been controlled in several tropical countries by the introduction of CABI Bioscience, Nairobi, Kenya specific biological control agents. This project has introduced several self-sustaining bio- S. Mapila logical control agents into the Shire River, Malawi, and evaluated the socio-economic Malawi Fisheries Department, Lilongwe, impact of the weed on local communities and its effects on wetland biodiversity. Commu- Malawi nity education and participation was a major feature of this work. M. Hill Plant Protection Research Institute (PPRI), and were reared in large numbers support for the invasion of indig- Pretoria, South Africa (over 100 000) for release through- enous aquatic plants which are out the length of the river. Both then able to colonize the area August 1995–March 1999 species were established and well much more effectively. ISSUES distributed by the end of the Meetings and open days were held project. Two other insect species, with fisheries extension officers and Water hyacinth (Eichhornia a mirid bug, Eccritotarsus catarinensis, local community groups, at which crassipes) is an aquatic weed with and a moth, Niphograpta albiguttalis, they were informed of the objec- enormous growth potential. Relative were also introduced but had not tives of the project, the dangers growth rates may be between 2 and been confirmed as having estab- associated with the weed, and the 20% plants per day. Even a 2.5% lished by the end of the project. principles of controlling it using relative growth rate would lead to A fifth species, the mite Orthogalumna introduced insects and mites. Local a doubling of water hyacinth in less terebrantis, was already present on communities assisted with releas- than 1 month. water hyacinth in the Lower Shire ing and redistributing biological A 1993 socio-economic study of at the start of the project, and was control agents. Extension messages the fisheries sector in Malawi successfully redistributed through- were conveyed to local communi- described the weed as one of the out the Shire river. ties through posters and radio greatest constraints on the fisheries The full effects of the agents jingles in local languages. of the Lower Shire valley. Water established will not be seen for As well as establishing procedures hyacinth competes with indigenous 2 years, once their populations which will lead to the permanent water plants, leading to a reduction have built up sufficiently for suppression of water hyacinth, the in the diversity of plant and animal maximal impact on the weed. The project has put in place mecha- life. A preliminary study of the biocontrol agents appeared to be nisms for monitoring the impact effects of water hyacinth on biodi- growing and increasing more quickly of the weed and biocontrol agents versity in Lake Victoria showed that in the Lower Shire than in the from a socio-economic perspective, fish species diversity and abundance, Upper Shire, probably due to more and the effects on biodiversity and as well as biodiversity of other favourable climatic and nutrient wetland plant communities. species, were at significant risk from conditions lower down the river. Suppression of the weed through water hyacinth. Water weed The project carried out a socio- biological control, which is likely infestations also harbour vectors of to be in the order of 75–90% by diseases (including schistosomiasis, economic survey (participatory rural appraisal) to identify the weight, should lead to substantial malaria and encephalitis), and benefits for local communities. disrupt water transport and hydro- problems that local communities electric power generation. associate with the weed. The survey confirmed that water hyacinth is FUTURE Classical biological control, which a major problem for communities in is self-renewing and self-sustaining, Biological control of water hya- the Shire River, and has established cinth takes several years. Since the is the preferred means of control- a baseline against which future ling water hyacinth. start of the project, the weed has surveys can be judged. been found in several rivers north ACHIEVEMENTS Permanent sampling plots were set of the River Shire, and also in Lake up to evaluate the impact of water Malawi. These areas are being Four biological control agents were hyacinth on the succession and addressed as part of a World Bank- introduced during the course of the biodiversity of aquatic species. The funded project, and CABI Bio- project. Two of these, the weevil data showed that water hyacinth science and PPRI are supporting species Neochetina eichhorniae has a profound effect on ecological the Fisheries Department to and N. bruchi, established readily succession in wetland habitats. continue the biological control Publications: see Bibliography on CD. Stable mats of the weed provide programme.

7 DFID CROP PROTECTION PROGRAMME

Improving the health of seed yams in West Africa

R5735, R6691 White yams (Dioscorea rotundata) and yellow yams (D. rotundata-cayenensis) originated L. Kenyon in West Africa, and have been a staple food there probably ever since man first inhabited Natural Resources Institute (NRI), the area. They are thought to be one of the first crops tended by man in the region. It is University of Greenwich likely that cultivation practices have changed little over the centuries, and yams remain a relatively difficult and labour-intensive crop to grow. Generally it is necessary to plant A.O. Nwankiti University of Agriculture, Makurdi, large tuber pieces in order to obtain reasonable yields, and clean planting material has Nigeria been difficult if not impossible to obtain. The main objective of this project was to adapt, develop and test a menu of phytosanitary treatments/practices applied to minisett or seed R. Asiedu tubers, in order to provide an effective package of measures for control of major yam pests International Institute of Tropical and diseases. This project built on previous work using well tried techniques (including Agriculture (IITA), Ibadan, Nigeria fungicidal seed dressings, hot-water treatments and tuber selection) to improve the health November 1992–March 1996 of seed yams produced from minisetts. A simple preplanting treatment with fungicide July 1996–March 1999 (one of the benzimidazoles or conazoles) was the most effective of the methods tested, and has the potential to make the minisett technique for rapid production of seed yams much more reliable, and hence to sustainably increase the productivity of yam cultivation in West Africa.

ISSUES establish facilities and train staff in Nigeria in methods of tuber crop The cultivation of yams in disease research. Links were West Africa remains a difficult, established with previous research risky and labour-intensive practice at the Federal University of for most farmers. Traditionally, Agriculture, Makurdi/University relatively large pieces of tuber are of Reading (R5675; R5738, see used as planting material, making Research Highlights 1989–95) on for a very low multiplication rate. aspects of the epidemiology of yam This reliance on vegetative planting anthracnose disease. In the second material also means that carry-over year of the project a link was of pests, viruses and diseases from established with the International one crop to the next is a major Institute of Tropical Agriculture problem, and reliably disease-free (IITA) and field trials were con- planting material is difficult and ducted at the high-rainfall field expensive to produce. The minisett station at Onné near Port Harcourt. technique has been promoted as a possible means of increasing the multiplication rate by including a ACHIEVEMENTS crop produced from small (~25 g) Field trials to compare the efficacy tuber pieces (minisetts) in the of a range of fungicide treatments production cycle. The seed yams of yam minisetts were established produced from minisetts in the first at several locations in Nigeria. The season are planted to produce ware results collected from these trials yams in the second season. At the indicate that the mortality rate for commencement of this work minisetts can be significantly SELECTED PUBLICATIONS (R5735) in 1992/93, the minisett reduced by a preplanting applica- technique had not been taken up KENYON, L., NWANKITI, A.O., EKEFAN, tion of a systemic fungicide such by many growers in West Africa E. and PETERS, J.C. (1998) Chemical and as one of the benzimidazoles because the unpredictably poor hot-water treatments to improve the sur- (benomyl, thiabendazole, germination and survival of the vival of yam minisetts. Tropical Agricul- carbendazim) or conazoles minisetts made it unreliable, and ture 75: 150–151. (imazalil). Water yams (Dioscorea it was seen to be more time- alata) were generally more amena- consuming and difficult to manage. KENYON, L. and FOWLER, M. (2000) ble to the minisett technique than Study of factors affecting the uptake and The aim of this project was to test white yams (D. rotundata). For adoption of outputs of crop protection and adapt a menu of phytosanitary white yams, even with the best research on yams in Ghana. NRI Report treatments/practices to improve the fungicide treatment mortality was No. 2522. Chatham, UK: Natural germination and survival of yam still often as high as 50%. Neem Resources Institute. minisetts, and in doing so, to help leaf powder, the only ‘natural’ and

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minisetts treated for even the Table 1. Average number of yam minisetts per plot surviving to shortest time failed to sprout and produce a mature plant with various fungicidal seed treatments, rotted in the ground. The water yam with or without insecticide variety UM680 was much more tolerant of these treatments, White yam Water yam although none of the treatments With Without With Without conferred a significant improve- carbosulfan carbosulfan carbosulfan carbosulfan ment in sprouting, establishment or ultimate health compared with the Benomyl 14.6 ** 12.6 ** 22.66 ** 19.66 * control, untreated minisetts. Thiabendazole 5.3 13.6 ** 20.00 17.33 Imazalil 10.6 ** 6.0 20.00 18.00 The project has shown that a Tolclofos-methyl- 5.6 2.0 20.66 * 19.00 simple preplanting treatment with Pencycuron 1.0 4.3 14.00 17.33 Iprodione 13.0 ** 5.6 20.00 21.33 * fungicide is an effective method of Sulphur 7.0 * 7.6 * 15.00 15.33 making the minisett technique for Neem 5.6 2.6 18.66 11.66 the rapid production of seed yams Control 1.3 1.0 14.00 13.33 more reliable, providing a viable LSD = 5.61 LSD = 6.27 (0.05) (0.05) alternative to the traditional LSD = 7.51 LSD = 8.39 (0.01) (0.01) method of planting large pieces of * = significantly better than control at 5% level, ** = significantly better than control at 1% level. yam to ensure survival. Small demonstration trial plots to show locally produced treatment tested, growth regulators at different the effect of the best preplanting gave very variable results in these concentrations showed that the fungicide treatments were set up at trials. cultivar used (D’anacha) is several locations in Nigeria. extremely sensitive to gibberellic None of the preplanting fungicide acid, with the lowest concentration A further project (R6691) was treatments had a significant carry- used (immersion in 2.5 mg/l centred in Ghana to investigate the over effect on the storability over for 1 h) causing 100% inhibition of identity and role of tuber-borne the dry season of yam tubers germination. None of the hormones diseases of yam. The project produced from the treated tested significantly improved the demonstrated that there was a minisetts. At Makurdi, storage rate of sprouting or survival of the significant yield advantage to using losses were primarily due to rotting minisetts. yam-planting material collected initiated by rodent attack, while at from sites where apparent disease Onné storage losses were primarily Hot-water treatment of yam incidence was low. Yam mosaic due to desiccation, or rotting of minisetts prior to planting had very potyvirus was the most commonly tubers predisposed by harvest variable results. The white yam detected virus of white yam in damage or insect attack. variety D’anacha was very sensitive Ghana, and most transmission from to hot water, and almost all Pre-planting treatment of mini-setts one crop to the next appeared to be with an insecticide such as vertically via the tubers. Tubers carbosulfan or aldrin, or incor- collected from areas with poration of an insecticide such visually high disease incidence as carbofuran or diazinon into (crops that appear unhealthy) the planting hole, appeared to also did not store well over the have no significant effect on the dry season. All this reconfirmed survival or ultimate yield from the importance of tuber-borne the minisetts of either water or infection and the need to white yam at the sites used. produce or select and use clean, healthy planting material. In a separate experiment at Makurdi in 1993 it was found FUTURE that coating minisetts with paraffin wax before planting Recently, much of what has (in an attempt to reduce their been learnt through the various desiccation) resulted in most of projects about the uptake and the minisetts rotting. The fungus adoption of crop protection Aspergillus niger was usually research outputs has been visible underneath the wax collated for a short programme coating of the rotted yams when development study (R7504). This they were exhumed. should help in guiding the development of future work on Treatment of minisetts of white Assessing the yield and quality of seed yams from yam crop protection. yam with a range of different a minisett trial in Nigeria

9 DFID CROP PROTECTION PROGRAMME

Characterization of sweet potato and cassava virus diseases

R6617 This project covered two whitefly-transmitted viruses of root crops, sweet potato virus disease and cassava brown streak. The whitefly-borne component of a sweet potato virus R. W. Gibson, S. E. Seal disease causing increasing losses in East Africa was identified for the first time as a distinct Natural Resources Institute (NRI), strain of sweet potato chlorotic stunt closterovirus (SPCSV). Characteristic symptoms of University of Greenwich, UK the two main diseases caused by SPCSV in sweet potato were described, and an ELISA- N. Fenby based method for detecting the virus has been developed and proven in Africa. Polyclonal Namulonge Agricultural and Animal antiserum has been developed using bacterially expressed coat protein. Differences in Production Research Institute (NAARI), the incidence of the virus disease in Uganda and Tanzania have been mapped in districts National Agricultural Research Organisa- around the perimeter of Lake Victoria: areas where chlorotic stunt was rare tended to have tion (NARO), Uganda few whiteflies throughout the year, or a very disease-resistant cultivar predominated. The causal agent of cassava brown streak disease was found to be a single virus (CBSV), a W. Monger, G. D. Foster member of the Potyviridae family. CBSV is most closely related to the whitefly-transmitted University of Bristol, UK virus sweet potato mild mottle virus; these two viruses now form the only two sequenced April 1996–March 1999 members of a genus called the Ipomoviruses. The first reliable test for this disease, a PCR detection method, has been developed. Three distinct isolates of CBSV have been found in Tanzania and one in Mozambique: this diversity explains the different symptoms re- ported here and previously with experimental host plants. Preliminary work was carried out towards developing a reliable polyclonal antiserum for field identification. Given the importance of sweet potato and cassava to rural livelihoods, and the major yield losses incurred annually in these crops in many areas of East Africa, the project will contribute substantially to increasing crop yields in the region as superior resistant varieties are developed.

SWEET POTATO Affected plants commonly produce less than half the yield of ISSUES symptomless ones. SPVD is considered to be the most damag- African sweet potato production is ing disease of the crop in the concentrated in East Africa, region, with average incidences of especially in the countries around 30% and greater being found, and the perimeter of Lake Victoria. many crops have much higher Sweet potato is an important crop levels of disease. throughout much of East Africa, The presence of a whitefly-borne grown particularly by women SELECTED PUBLICATIONS component of SPVD was con- around the homestead for daily firmed by a previous project food and to sell for family needs. It (R5878). Resistant varieties are is also grown extensively in some GIBSON, R.W., MPEMBE, I., ALICAI, T., being actively sought by national areas as a cash crop, sold particu- CAREY, E.E., MWANGA, R.O.M., SEAL, sweet potato programmes in Africa, larly to the urban poor as a staple S.E. and VETTEN, H.J. (1998) Symptoms, particularly the Ugandan National food. Sweet potato is valued for its aetiology and serological analysis of Potato Programme (UNPP), and by ability to yield in poor soils and to sweet potato virus disease in Uganda. the International Potato Center provide food quickly following the Plant Pathology, 47: 95-102. (CIP), as resistance is considered to onset of rains. In East Africa an be the most effective means of epidemic of African cassava mosaic GIBSON, R.W., KAITISHA, G.C., and controlling the disease. This virus has caused widespread required a suitable means of RANDRIANAIVOARIVONY, J.M. (1998) destruction of the cassava crop, and Identification of the East African strain of accurately diagnosing the compo- sweet potato production has risen nent viruses. A further aim of the sweet potato chlorotic stunt virus as a dramatically in compensation. major component of sweet potato virus project was to examine the disease in southern Africa. Plant Disease, Sweet potato virus disease (SPVD) variability of the virus within East 82: 1063. is the name used commonly in Africa by a range of serological and Africa to describe a range of severe molecular methods, so as to assess KARYEIJA, R.F., GIBSON, R.W. and symptoms on sweet potato gener- the likely durability of resistance. ally attributed to virus infection. VALKONEN, J.P.T. (1998) Resistance to ACHIEVEMENTS sweetpotato virus disease (SPVD) in wild Symptoms vary with plant genotype East African Ipomoea spp. Annals of but typically include stunted plants The whitefly-borne component of Applied Biology, 133: 39-44. with small, distorted leaves. SPVD has been identified as

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a. b.

Figure 1. a. Numbers of adult whiteflies, and b. incidence of SPVD during 1996 and 1997 in farmers’ fields around Kanoni (K), Namulonge (N) and Busia (B)

SPCSV, both by showing its general strain of SPCSV throughout eastern control where they can be grown. association with the disease, and and perhaps all of southern Africa. The significance of whitefly by inducing SPVD through control- This strain is distinct from, and numbers in the epidemiology of led virus inoculations. An ELISA- appears to be more severe than, a SPVD in different areas of Uganda based method of detection has strain found in West Africa. Small has been investigated (Fig. 1). been developed and tested. This serological and nucleotide se- Results show that resistant varieties method has been taught locally to quence differences have been can protect nearby crops of Ugandan and Kenyan national found within this East African susceptible varieties by limiting the programme staff and to Makerere strain. This finding provides local inoculum levels of SPVD, and University students, and through scientific support to UNPP’s role of local phytosanitation may also international meetings, to other providing superior sweet potato assist control. genotypes and seed stocks to all East African sweet potato FUTURE programmes. The small differences To fully exploit these results, SPVD- found within the East resistant sweet potato varieties will African strain of be tested (R7492) in areas where SPCSV support SPVD remains a serious problem, UNPP’s policy of to confirm that resistance is using broad, quantita- maintained, and that the available tive sources of SPVD-resistant varieties are broadly resistance rather adapted to yield well in those than more specific areas. On-farm trials have revealed single gene sources that, whilst resistance is generally maintained, the yield of NAARI Comparison of SPVD-affected sweet potato (left), (although the latter is largely because varieties is not always superior to showing the severe stunting effect, compared with local landraces. an unaffected plant (right). no single gene sources of resistance The second phase of the Inter- workers from the region. CIP has are available). This should lead to Centers Initiative on Whiteflies been closely involved with all the varieties with durable resistance. and Whitefly-borne Viruses project’s work, and has provided a Preliminary results have shown that begins in 2000. The component key route for disseminating the sweet potato varieties may have on sweet potatoes in Africa will detection method. The method is limited adaptability, and so may not again be managed by CIP and currently being used at NAARI, for be useful in some regions; and that will have three main compo- example, by the senior sweet the areas where most of the UNPP nents: the dissemination of potato breeder, contributing to an superior resistant varieties are information on the importance, understanding of the inheritance currently being disseminated are identification and control of and mechanism of resistance in largely areas where SPVD is SPVD; evaluation and distribu- sweet potato to SPVD. relatively unimportant. However, tion of superior, SPVD-resistant The variability of SPCSV has been the results of this work do provide sweet potato varieties; and the investigated. There appears to be a clear evidence that SPVD-resistant evaluation of local phytosanitation single serologically identifiable varieties can provide effective practices.

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CASSAVA FUTURE ISSUES To use this test effectively, more Cassava is a major food testing on cassava staple in sub-Saharan in East Africa is Africa. It is a drought- required. There is hardy crop, and can a need to obtain survive and produce a samples of infected yield where cereal crops cassava from fail. As much as 85% of across East Africa. the cassava root dry Further research on weight is starch, making isolate differences it the highest yielding is required to calorie source per ensure the test will hectare of all the staple work for all crops. Cassava is a isolates, and staple food for 500 cassava varieties million people, and 11 need to be tested out of the 12 countries against all isolates where consumption per Necrosis in CBSV-infected cassava which makes the tubers inedible. of the virus if these capita exceeds 100 kg varieties are going each year are in Africa. Potyviridae). Previous work had to be promoted under the suggested that the cause was two Cassava brown streak disease assumption that they are resistant. viruses, a carlavirus of 650–690 (CBSD), so called because of the nm, and a potyvirus accounting for This work has found a number of brown lesions that sometimes the presence of pinwheel inclusion isolates of the virus from just a appear on the young green stem of bodies. Through sequencing, small area of the affected region. affected plants, causes damage to polymerase chain reaction (PCR), These isolates differ from one the edible roots. Cassava is propa- partial purification and Western another by as much as 10% at the gated through cuttings and as such analysis, this work has shown that DNA level across their coat is particularly prone to virus the carlavirus-length virus previ- proteins. Cassava brown streak problems because infection tends ously isolated is the Ipomovirus disease has been found over a large to build up in selected clones. sequenced here. The Ipomovirus region of East Africa, and the extent Natural spread of CBSD occurs, also accounts for the presence of to which this virus may differ in and the vector is believed to be pinwheel inclusion bodies. The sequence could be enormous. a whitefly. Diagnosis of CBSD is differences observed in symptoms If this is the case, the PCR test may difficult because immature leaves of the disease, especially on prove ineffective for other regions of infected cassava are secondary host plants, can be with uncharacterized isolates of the symptomless, and symptoms vary accounted for by isolates of this virus. Further work is needed to greatly with the variety of cassava Ipomovirus. No evidence for a explore the diversity of this virus and environmental conditions (see second virus was found. throughout its range. R6765, p. 13). A sensitive detection method was required both to A reliable and repeatable RT-PCR Traditional breeding methods have support breeding programmes for test has been developed as a result given rise to cassava varieties that cassava, and to detect the spread of of sequencing part of the virus are believed to be more resistant the disease in previously unaffected genome. This test has been used to to pests and diseases than other regions of Africa. detect the virus even in the young varieties. However, this work with leaves of cassava that are not yet CBSV isolates raises a question CBSD was first reported in the showing symptoms of the virus. The about so-called resistant varie- 1930s, but despite the disease extreme symptom differences with ties. In this work, different being assumed to be a virus, its these isolates are thought to be the isolates of the virus gave rise aetiology has remained obscure. main reason a second virus was to different severities of infection, The main aim of this work was mistakenly linked with this disease which has implications for to identify the virus/es that cause in the past. The potential uses of selective breeding – particular CBSD, using molecular tools. this test are to identify further cassava varieties may be selected isolates of the virus, to screen for for resistant qualities which are ACHIEVEMENTS the virus in plant breeding pro- not, in fact, reliable, as the variety grammes, and to provide quaran- may have only been challenged This project has identified the virus tine measures by which unaffected with a ‘weaker’ isolate of the virus. that causes cassava brown steak areas and countries can remain Further work is needed to clarify disease as an Ipomovirus (family: free of the disease. these issues.

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Management of cassava virus diseases in southern Tanzania

R6765 Cassava is the staple crop for large areas of southern and coastal Tanzania and also in northern Mozambique. Although it has poor storability once harvested, cassava can be R.J. Hillocks kept in the ground and harvested as required, and it therefore has a major role as a food Natural Resources Institute, University security crop even in areas where there are alternative staples. Virus diseases are a major of Greenwich, UK constraint to cassava production in Tanzania. In this region cassava is affected mainly by M. Raya two virus diseases, cassava mosaic disease and cassava brown streak disease. This project Agricultural Research and Training set out to develop management strategies for cassava virus diseases. Socio-economic and Centre, Tanzanian Agricultural Research biological surveys were carried out to assess the importance of the diseases and identify Organization (TARO), Naliendele, appropriate control measures. A‘tolerant’ cultivar, Nachinyaya, identified by the project Mtwara, Tanzania has now largely replaced CBSD-susceptible cultivars in some areas. Systems have been K. Mtunda developed for the production of virus-free stocks of cassava for producing virus-free plant- Sugarcane Research Institute, TARO, ing material. Management recommendations include the use of more tolerant varieties Kibaha, Tanzania and of virus-free planting material, and phytosanitary measures such as roguing. T. Russell World Vision International/Department ISSUES necrosis increases with the length for International Development (DFID) of time the crop is in the ground. Project, Quelimane, Mozambique Vegetatively propagated crops such as cassava are prone to virus The aim of this project was to September 1996–August 1999 infections. At least 17 different develop management strategies for viruses of cassava have been cassava virus diseases in Tanzania described, of which eight are in order to minimize cassava losses known to occur in Africa. The main due to the disease, and increase research focus in Africa has been food security. on the viruses causing cassava mosaic disease (CMD) and cassava ACHIEVEMENTS brown streak disease (CBSD). Surveys conducted by a previous Activities consisted of on-station project (R5880; see Research and on-farm field trials; biological Highlights 1989–95) showed that and socio-economic surveys; the both viruses were present in organization of farmer research Tanzania. Subsequent surveys found groups in five villages; and basic SELECTED PUBLICATIONS that CBSD was the more important research to identify the means of disease in coastal Tanzania, but any transmission and spread of CBSV. management strategy would have HILLOCKS, R.J. (1997) Cassava virus dis- CBSD was found to cause reduc- to take account of the virus disease eases and their control with special refer- tions in root yield of up to 68%, complex as a whole. ence to southern Tanzania. IPM Reviews with a further 7–20% loss in 2: 125–138. The contribution made by cassava quality. The quality loss is due to HILLOCKS, R.J., RAYA, M. and THRESH, to sustainable livelihoods in the those roots which are unmarket- J.M. (1999) Distribution and symptom coastal region of eastern Africa able or the necrotic tissue which expression of cassava brown streak dis- is twofold: firstly it is the main farmers’ families have to cut from ease in southern Tanzania. African Jour- subsistence crop, and secondly the roots before they can be dried nal of Root and Tuber Crops 3: 127–134. it provides a source of income for storage. through the sale of fresh cassava Disease surveys were extended to THRESH, J.M. and MBWANA, M.W.(1998) root and stem cuttings for planting the East African coast from the Cassava mosaic and cassava brown streak material. CBSD affects livelihoods Kenya border through Tanzania to virus diseases in Zanzibar. Roots 5: 6–9. directly by causing root damage the Zambesi river in Mozambique. which both decreases yield and MTUNDA, K., MAHUNGU, N.M., CBSD was recorded for the first makes fresh roots unmarketable. THRESH, J.M., KILIMA, M.S. and KIOZYA, time in Mozambique, where it was Decreased incidence of CBSD H.C. (1999) Cassava planting material present at very high incidences. would allow smallholders to sanitation for the control of cassava brown A number of local Tanzanian increase the amount sold for cash streak disease. In: Akoroda, M.O. and Teri, cultivars have been identified as or decrease the area of cassava J.M. (eds) Food security and crop diversi- having some resistance to CBSD. fication in SADC countries: the role of grown, which could then be used cassava and sweet potato. Proceedings of for other more valuable crops such Surveys in southern Tanzania have the SARRNET Scientific Workshop, as maize or groundnut. CBSD has shown that CBSD is rarely found Lusaka, Zambia, 16–20 August 1998, pp its main impact on food security above 1000 m, and is present at 300–304. because the severity of root low incidences above 600 m.

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Between 300 and 600 m it is Table 1. Constraints to cassava production as perceived by present at moderate incidences, farmers in the Southern and Coastal Zones of Tanzania and high incidences are found mostly below 300 m. It is not Southern Zone Coastal Zone possible to draw strict divisions (respondents = 247) (respondents = 50) between these zones based on altitude, and occasionally high Number of Number of farmers farmers incidences may be found at identifying identifying altitudes above 300 m, depending Constraint constraint Constraint constraint on the planting material. Little spread of the disease appears to CBSD 89 Theft 19 (36%) occur at higher altitudes. This has Soft rot 56 Vermin 38 influenced the design of disease CMD 47 Mealybug 12 management systems. At low Mealybug 16 Shortage of 30 altitude, where incidence is high planting material and spread is rapid, phyto-sanita- Insect pests 10 Diseases 18 tion must be used with resistant (36%) Vermin 7 Lack of knowledge 1 (or tolerant) cultivars. At mid- of disease control altitude, where disease incidence Juma (pupal stage 12 Lack of capital 1 is moderate and there is less of mealybug) spread, virus-free planting material Rodents 4 Weed control 3 would be helpful provided farmers Labour shortage 3 Poor soils 2 continue to select their planting Too much rain 2 Poor variety 3 material from symptomless mother Low yield 1 plants. At high altitude, where little Low manpower 1 spread occurs, selection of planting material and roguing should of the planting material in the and one in the high-altitude areas. provide sufficient control. World Vision cassava improvement Farmer research groups have been Socio-economic surveys revealed programme in Mozambique was set up in each of these as a prelimi- that farmers in the Southern Zone later found to be infected with nary to further adaptive research on of Tanzania were highly aware of CBSD. A stock of three local CBSD management. cultivars was produced by the end ‘root rot’ as a problem, and it was Awareness of the disease has been of the project, ready for further mentioned as the primary produc- raised and information provided on multiplication and distribution. tion constraint by more farmers symptom recognition. The screen- (36%) than any other factor. The design of disease management ing methodology developed has been The disease was also present at systems is assisted by some adopted by the National Pro- very high incidences in Zambesia knowledge of the epidemiology gramme in Tanzania, the Southern Province of Mozambique where and means of transmission of the African Roots and Tubers Research there is almost complete reliance virus. Some understanding of the Network (SARRNET) in eastern and on cassava for food security. epidemiology was gained, but it southern Africa, and the DFID/ was not possible to transmit the Screening techniques have been World Vision cassava improvement virus with potential whitefly vectors developed to assess the reaction programme in Mozambique. in transmission tests, and there is of cultivars to CBSD, based on still no certainty as to the vector. FUTURE evaluation of both above-ground The most likely candidates remain and root symptoms. Cultivars have Although the tolerant cultivar the whiteflies (Bemisia tabaci and been identified with resistance or Nachinyaya has been adopted B. afer). Trials conducted in ‘tolerance’ to CBSD. The ‘tolerant’ spontaneously by farmers, unfortu- Tanzania have shown conclusively cultivar Nachinyaya identified by nately this does not represent a that CBSV spreads from a line the project has now largely long-term solution because, source from plant to plant within replaced the CBSD-susceptible although tolerant of root necrosis, a field, and that the main period cultivars in Mtwara. There is strong it is still susceptible to infection by of spread coincides with the peak demand for planting material CBSV, and further work is required periods of whitefly infestation. of Nachinyaya. in this area. A number of local However, it remains a priority varieties with resistance to CBSD Systems have been developed at to identify the vector. have been identified in Tanzania Naliendele and Kibaha research Five villages have been identified and Mozambique. A new project stations for the production of virus- for further work on disease man- (R7565) began in January 2000 to free stocks of cassava for producing agement. Two of these are in the promote control measures and to virus-free planting material. This is low-altitude areas of high disease multiply and distribute resistant vital for cassava; for example much incidence, two in the mid-altitude cultivars to farmers.

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Control of African cassava mosaic disease

R6614 Cassava is an important crop to small-scale subsistence farmers in Africa, and is relied upon as a food reserve when other crops fail. The recent epidemic in Uganda of a severe R.J. Cooter form of cassava mosaic disease (CMD), caused by a virus and spread by a whitefly vector, Natural Resources Institute (NRI), has meant that some local varieties of the crop have failed completely, with a major effect University of Greenwich, UK on food security. This project studied farmers’ use of cassava varieties and their responses W. Otim-Nape to the epidemic in order to develop socially acceptable control strategies. Investigations Namulonge Agricultural and Animal were carried out on the strains of virus causing the epidemic, the whitefly (Bemisia tabaci) Production Research Institute (NAARI), responsible for disease spread, and their interactions. Resistant varieties were studied, National Agricultural Research and a model of the epidemic’s progress formulated to assist in forward planning. Organisation (NARO), Uganda In Uganda, farmers’ participation in on-farm trials and variety multiplication and their January 1996–December 1998 access to extension information and training were found to promote earlier adoption and greater use of cassava varieties resistant to CMD. This epidemic involves a different strain of the virus, known as the Uganda variant. The resistance identified to this disease is partial: plants will develop inconspicuous symptoms and can still provide clean planting material, a phenomenon known as ‘reversion’. This is important for preventing build-up of infection, particularly as reproduction of the whitefly vector is significantly higher on severely infected varieties. Planting material has been diffused from participating farmers to others through local social networks, with the support of community-based multiplica- tion initiatives. Improved yields from resistant varieties have helped towards eliminating the problem of food shortages, and interest has been expressed by farmers in technologies SELECTED PUBLICATIONS for cassava processing and ultilization. The findings obtained in Uganda are highly rel- evant to other countries in the region experiencing the onset of the CMD epidemic.

BYABAKAMA, B.A., ADIPALA, E, OGENGA-LATIGO, M.W., TUSIIME, G. and OTIM-NAPE, G.W. (1997) The ISSUES north-west Tanzania. The epidemic resistance of improved cassava varieties was associated with increased Cassava is a major crop for subsist- to cassava mosaic disease in Uganda. abundance of the whitefly vector ence farmers, particularly women, African Journal of Plant Protection 7: (Bemisia tabaci), and more severe for domestic use and as a food 45–57. CMD. reserve in times of drought. In many GIBSON, R.W. and OTIM-NAPE, G.W. areas sales of fresh and dried The project was established to help (1997) Factors determining recovery cassava are an important source of farmers to combat the disease and reversion in mosaic disease in cash income for poorer households. through the use of resistant varie- African cassava mosaic virus resistant ties and phytosanitation, and to Cassava mosaic disease (CMD) is cassava. Annals of Applied Biology 131: obtain a better understanding of the most damaging insect-borne 259–271. the processes driving and sustain- disease of African crops, and in ing the epidemic. HOLT, J., JEGER, M.J., THRESH, J.M. Africa is arguably the main disease and OTIM-NAPE, G.W. (1997) A model of cassava. Estimates of average ACHIEVEMENTS of plant virus disease dynamics yield loss of cassava in Africa due incorporating vector population to CMD range from 15 to 50%. FARMERS’ CONTROL STRATEGIES processes applied to African cassava Unlike the usual situation in much mosaic virus disease in Uganda. Journal of Africa, where CMD is endemic Farmers’ strategies under different of Applied Ecology 34: 793–806. and fairly stable, a major epidemic degrees of infection pressure were of a severe form of the disease has monitored in Mubende and LEGG, J.P. et al. (1999) Emergence, been expanding southwards across Mukono districts in Uganda at spread and strategies for controlling the much of Uganda since the early regular intervals along a fixed pandemic of cassava mosaic virus 1990s. By 1995 two-thirds of the transect, perpendicular to the path disease in east and central Africa. Crop country had been affected, and of the epidemic. Farmers’ main Protection 18: 627–637. famine and associated deaths were adaptations to CMD infection were OTIM-NAPE, G.W., THRESH, J.M. and being widely reported in local a switch from local to resistant SHAW, M.W. (1997) The effects of newspapers and to a Government varieties, and increasing the area African cassava mosaic virus on yield Commission of Enquiry. A similar planted to other crops, losing both and compensation in mixed stands of catastrophe has now occurred in biodiversity and a valuable source healthy and infected cassava. Annals of western Kenya, where cassava was of nutrition in cassava. The price of Applied Biology 130: 503–521. locally the main staple food, and in cassava increased at and immedi-

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ately behind the epidemic front. CMD is not a problem and post- whiteflies recorded on a variety epidemic farmers will return to and the incidence of CMD; partial The acceptability and subsequent using them. Resistant varieties resistance to infestation by adoption of improved cassava include the introduced TMS 30572 whiteflies and to infection with varieties by farmers was influenced (released in Uganda as Migyera) CMD are separate and unrelated both by cassava variety attributes and the Ugandan selection SS4. attributes. The virus is incompletely and by the farmers’ socio-eco- These varieties, especially Migyera, systemic in the most resistant nomic status (family size, age, off- are being multiplied in quantity for varieties, which generally develop farm activities, education, access to release to and by farmers. Interme- inconspicuous symptoms and may credit). Clear targeting of farmer diate varieties include the Interna- ultimately recover. Such plants can categories is necessary; their tional Institute of Tropical Agricul- be a source of virus-free material participation in on-farm trials and ture (IITA) introductions TMS 30337 when cuttings are collected for multiplication promotes earlier (released in Uganda as Nase 2), propagation. This ‘reversion’ adoption and intensity of use, as TMS 60142 (Nase 1) and TMS phenomenon is an important does their access to planting 4(2)1425. An important feature of feature of resistant varieties, material, information, training and these varieties is that they grow restricting the progressive build-up extension recommendations. and yield satisfactorily despite of infection that would otherwise high CMD incidence. occur with successive cycles of AHEAD OF THE EPIDEMIC FRONT Resistance to CMD is of the propagation. A study with farmers’ groups in two quantitative, rate-reducing type that Some varieties (such as the local areas of Iganga district, in the pre- is sometimes referred to as ‘partial’ Ugandan variety Ebwanateraka) epidemic area, explored what level resistance. There was no obvious have been so badly affected by the of intervention could best prepare relationship between the number of epidemic that they have been farmers for the disease. Five ‘intervention’ groups were given resistant material, training and extension support; five ‘non- intervention’ groups were given resistant material without addi- tional training or extension input. Progress of the disease epidemic was more rapid than anticipated, reaching some sites within 6 months. Knowledge and under- standing of CMD and the adoption of improved management practices were higher among the intervention group, and both sets of groups did better than neighbouring individual non-participants who had limited access to improved varieties.

RESISTANT VARIETIES Many local and introduced varieties have been evaluated by the Cassava Programme in a series of formal experiments and on-farm trials in different agro-ecologies and in pre-epidemic, epidemic, and post-epidemic areas. The main findings are described below. Figure 1. Progress of the cassava mosaic disease (CMD) epidemic front through Uganda. Areas along the eastern border with Kenya were affected in 1994 and There are great differences between the epidemic was first reported in Kenya in 1995. During the project the varieties in their susceptibility and epidemic continued to move southwards across Uganda and around the response to infection by CMD. northern shore of Lake Victoria into western Kenya and northwest Tanzania Susceptible varieties include Ali as predicted. In Uganda the epidemic reached the research station at Matumba (Tanzania), Bao and Namulonge in 1995, Kampala in 1996, and the northern shore of the lake Ebwanateraka (Uganda). Bao and at various times between 1996 and 1998. The epidemic has crossed the Ebwanateraka are popular and Tanzanian border on the northwest side of Lake Victoria, and in 1998 severe highly productive varieties where damage was reported in the Bukoba area

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largely abandoned. EPIDEMIOLOGICAL Others partially withstood MODELLING infection and they have A mathematical model of become increasingly the processes driving the important, especially in CMD epidemic has been areas where officially developed which allows released varieties have not the importance of different been readily available. epidemiological factors to The fact that CMD still be assessed. By judging affects the growth and how management interven- yield of resistant varieties tions will affect these means that there is little parameters, their likely obvious incentive to adopt impact on CMD incidence phytosanitation measures A susceptible cassava variety amongst CMV-resistant plants can be predicted. involving the selection of ‘clean’ virus-free planting material phytosanitation is strengthened by PROJECT WORKSHOP and the removal (roguing) of any this evidence that whiteflies build The workshop Cassava mosaic diseased plants that occur. But up preferentially on virus-infected disease management in small- there would undoubtedly be plants, which could be a source of holder cropping systems was substantial yield gains from resistance-breaking virus strains. held in Jinja, Uganda between adopting this approach. Bemisia tabaci collected from areas 7 and 9 December 1998. Sixty- VECTOR ENTOMOLOGY ahead of the epidemic can transmit two delegates attended from UgV. At the epidemic front UgV Uganda, Rwanda, Kenya, Tanza- As the project started, reports of appears to out-compete and nia and South Africa, represent- a new form of the virus were displace normal African cassava ing researchers, extensionists, confirmed; this epidemic form has mosaic virus (ACMV), as most national and international become known as the Uganda diseased plants contained UgV programmes, NGOs and farmers. variant, UgV. The possibility that a alone or mixed with ACMV; very The workshop was well received; new biotype of the vector, B. tabaci, few plants at the front contained workshop proceedings, recom- might be associated with the ACMV alone. mendations and a video are epidemic also needed clarification. being produced. Key results were as follows. TRANSECT STUDY Bemisia tabaci collected from FUTURE epidemic and pre-epidemic areas Cassava plants in the transect plots A new project (R7505) will carry were maintained as separate were monitored for such variables out further adaptive research on the cultures at NRI. RAPD DNA as disease incidence and severity, sustainable use of resistant varieties ‘fingerprinting’ revealed consider- and numbers of whitefly nymphs and maintenance of varietal able variation between them, but and adults, in order to track the diversity. The main focus will be there was no evidence for distin- passage of the epidemic in terms of participatory research on farm- guishable epidemic or pre-epi- vector populations, virus and ers’ varietal choices and the demic groups. Reciprocal crossing symptom expression. options for utilization, processing experiments between epidemic and The study confirmed unequivocally and marketing; a study of rever- pre-epidemic colonies showed that that unusually high B. tabaci sion that considers the full range there is no mating barrier between populations occurred at the CMD of varieties and takes into these populations. epidemic front, and that both the account the possible interactions Host-specific strains of B. tabaci front and the high populations of between the different factors from Uganda and India were whitefly moved southwards to involved; quantitative information crossed. Indian cassava B. tabaci occupy previously unaffected on disease incidence and severity did not mate successfully with regions. The spread of the CMD and on yield losses; and the either Indian cotton or Ugandan epidemic is due to the immigra- probable interactions between cassava B. tabaci. The fecundity tion of B. tabaci carrying UgV UgV, the whitefly B. tabaci, and the and survival of B. tabaci reared on into previously unaffected areas. widely grown UgV-susceptible healthy plants of susceptible These individuals infect new cassava varieties. Research aimed (Ebwanateraka) and UgV-resistant plants which results in a boost to at incorporating B. tabaci resist- (SS4) cassava varieties were similar. the fecundity of the whitefly ance into the current CMD- The fecundity of B. tabaci reared when they feed on them. The resistant cassava varieties, for on UgV-infected Ebwanateraka progeny of these individuals then instance, could have the potential cassava was significantly increased: migrate into new areas of suscep- to prevent the genesis of future the argument for adopting tible cassava and the cycle recurs. CMD epidemics.

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Functional diversity of Phaseolus bean mixtures in East Africa

R6651 Common bean (Phaseolus vulgaris) is the most important legume grown in East Africa, providing up to 40% of protein for many in the region. Pests and diseases are a major D. M. Teverson constraint to production, and subsistence farmers commonly grow mixtures of landraces Natural Resources Institute (NRI), with a wide diversity of seed colours, patterns, shapes and sizes, which provides some University of Greenwich, UK protection. Earlier work focused on the complex epidemiology of diseases within these J.D. Taylor, B. Everett mixtures, and began to identify the resistant components. This project has continued to Horticulture Research Institute (HRI) characterize resistance to major bean diseases of components of traditional bean mixtures, Wellesbourne, Warwickshire, UK and has contributed to improved strategies for the management of bean diseases, and to the maintenance of genetic diversity in traditional bean farming in East Africa. C.S. Mushi, F. Ngulu Selian Agricultural Research Institute, Arusha, Tanzania ISSUES between diversity, disease resist- ance and yield stability in tradi- Within-crop diversity, that is, April 1996–March 1998 tional bean mixtures. This project planting a mixture of varieties continued the aim of understanding of a crop, is often used as a means the genetic diversity of bean of stabilizing yields in variable mixtures in terms of disease resist- environments where adequate ance, and providing a rational basis inputs cannot be guaranteed and for their manipulation. It sought to harvest uniformity is not a problem. characterize disease resistance in In East Africa, particularly southern two major pathogens (three others Tanzania, subsistence farmers tend having previously been studied), and to grow their beans as a mixture of to quantify the contribution landraces rather than as pure of mixtures to disease control under varieties. field conditions. In southern Tanzania bean mixtures provide a sustainable source of ACHIEVEMENTS protein, vital in resource-poor SELECTED PUBLICATIONS households where meat is a rare Three representative mixtures had luxury. Farmers select the compo- been selected for intensive study on BRIAND, L., BROWN, A.E., LENNÉ, J.M. nents of their bean mixtures on the the basis of the diversity present and TEVERSON, D.M. (1998) Random basis of a range of factors, includ- (seed size, shape and colour), amplified polymorphic DNA variation ing yield, disease resistance, comprising 300 subcomponents. within and among bean landrace mixtures growth habit, maturity, cooking Single seeds of each subcomponent (Phaseolus vulgaris L.) from Tanzania. time and taste. Beans have a range were multiplied to produce geneti- Euphytica 102: 371–377. of seed coat colours, some of cally uniform stocks for disease which are favoured more than evaluation. Isolates of key patho- SMITHSON, J.B. and LENNÉ, J.M. (1996) others, and generally large beans gens were collected and tested, Varietal mixtures: a viable strategy for are preferred to the small grain so that representative, fully patho- sustainable productivity in subsistence types. Several diseases have been genic isolates from appropriate agriculture? Annals of Applied Biology identified which, along with soil geographical areas could be used 128: 127–158. fertility, are considered major for disease screening. constraints to bean production. TAYLOR, J.D., TEVERSON, D.M. and The previous projects had screened There exists considerable natural DAVIS, J.H.C. (1996) Sources of resistance for disease reaction against nine resistance to the different diseases to Pseudomonas syringae pv. phaseolicola races of halo blight (Pseudomonas within the diversity of the mixture races in Phaseolus vulgaris. Plant Pathol- syringae pv. phaseolicola); four components. However, it would be ogy 45: 479–485. isolates of anthracnose just as impractical to try to breed (Colletotrichum lindemuthianum); resistance to all diseases into one TEVERSON, D.M., TAYLOR, J.D., and several strains of bean com- type of bean as it would to produce MUSHI, C.S., BISANDA, S.Z. & LENNÉ, mon mosaic virus. The present one type of bean to satisfy all J.M. (1998) Biodiversity for disease resist- project concentrated on angular culinary requirements. ance and potential for in-situ conserva- leaf spot (Phaeoisariopsis griseola) tion of Phaseolus vulgaris landrace mix- Previous research projects (R5530, and common bacterial blight tures in the southern highlands of Tanza- R5532; see IPM Research High- (Xanthomonas campestris pv. nia. Seventh International Congress of lights 1989–95) have been analys- phaseoli). The resistance screening Plant Pathology, Edinburgh, Abstracts Vol. ing three farmers’ bean mixtures in has produced a volume of informa- 1: 4.1.3F. order to unravel the relationship tion that can be used to improve

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farmers’ mixtures by modifying halo blight, and four strains of Further work on bean mixtures in resistance gene frequencies anthracnose. Such resistance to the southern highlands of Tanzania according to the anticipated halo blight is very rare, particularly has centred around biodiversity disease problems. in combination with resistance to aspects. A recently completed In an additional experiment, anthracnose. Studies showed that project funded by the Environmen- selected resistant mixture compo- resistance to halo blight is controlled tal Research Programme of DFID nents were compared with exam- by a single recessive gene, and that (R6670; Dynamic conservation, ples of the world classes of beans to anthracnose is controlled by enhancement and utilization of to find out how they compared a different, dominant gene. agrobiodiversity in situ: Phaseolus with the worldwide vulgaris beans in the gene pool in terms of southern highlands resistance gene of Tanzania) frequency. Forty-one conducted socio- bean accessions were economic studies in screened against 16 the form of inter- different isolates of five views with farmers important pathogens who grow bean sourced worldwide. mixtures, in order to find out what influ- Field trials at three ences farmers in contrasting sites in their decisions to Tanzania were con- select different bean ducted in both the 1996 and 1997 types. seasons, but the format On the basis of the and aims of the trials findings of both the were very different. ‘Functional diversity’ A variety trial format and ‘In situ’ projects, was used in 1996 to Components of bean mixtures grown by farmers in southern Tanzania a new 3-year project compare the perform- has recently begun ance of selected mixture compo- As well as identifying sources of (R7569; Participatory promotion of nents with standard sources of resistance, discussions with farmers disease-resistant and farmer- resistance and local commercial allowed those beans which are acceptable Phaseolus beans in the cultivars. In 1997 competition/ preferred by consumers for factors southern highlands of Tanzania). compensation/density trials were other than disease resistance to be This project combines the results conducted, both at the three identified, so that the two attributes and expertise of both scientists and Tanzanian sites (with disease can be matched. farmers, working together in inoculation) and in the UK under a participatory manner, to take disease-free conditions. Data forward the disease-resistant analysis showed that there is no FUTURE varieties that have been previously competition between plants at the identified. Emphasis will be placed traditional spacing of 0.5 m, and The target institution for this on varietal promotion in the maximum yield at this spacing research is the Tanzanian National resource-poor environment of the could be achieved by one or two Programme, and the beneficiaries southern highlands of Tanzania, plants per planting hole. Increasing are the smallholder farmers of in the context of a clear under- the plant density to 0.375 m Tanzania who grow bean mixtures. standing of local seed uptake spacing gave a reduced yield per However, the results will be pathways. planting hole, but yield per square valuable globally to bean breeders, metre was increased, especially in who will be able to use the climbing beans. A combination of characterized sources of resistance, It is important that the resistant climbing and bush types produced especially the multi-disease bean lines should be multiplied the highest yields. resistance shown by ‘small and made available, along with The completed disease screening masusu’, in breeding programmes. appropriate information, for provided a wealth of data from The Tanzanian National Pro- selection and exploitation by both which resistant mixture compo- gramme is already using some of bean breeders and farmers. These nents can be selected. Of special the disease mixture components in materials need to be available significance were the sub-compo- their breeding programme, but locally, in adequate quantities, as nents 5084/2 and 5084/5 of the further input and resources are good quality seed (several bean variety ‘small masusu’, which were necessary to take the promotion diseases are seed-transmitted), and resistant to all nine known races of further. at an affordable price.

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Development of integrated management strategies for termites in maize-based smallholder cropping systems in Uganda

R6653 Current termite control tactics for annual crops in sub-Saharan Africa are are too expensive for resource-poor farmers. This project investigated a range of cultural, biological and crop A. Russell-Smith Natural Resources Institute, University resistance strategies for the control of pest termites in maize-based smallholder cropping of Greenwich, UK systems in Uganda. The choice of strategies resulted from biological and socio-economic surveys of resource-poor farmers in Uganda. The project has identified effective low-cost B. Sekamatte biological control agents for pest termites and quantified their effectiveness in farmers’ Namulonge Agricultural and Animal fields; identified cultural practices (intercropping) that contribute to reduction in termite Production Research Institute (NAARI), National Agricultural Research damage to maize; and identified local landraces of maize that show some tolerance to Organisation (NARO), Uganda damage by pest termites. April 1997–March 2000 tolerance to termite attack into new ensured that the results of the work ISSUES maize hybrids in future. are now widely known in the region and elsewhere in Africa. This has Termites can cause severe losses to Studies of on-farm crop loss due to led to proposed collaboration with maize and associated legumes in pest termites indicate losses in crop the USAID-funded Investment in Uganda and throughout East and yield of between 15 and 30% of Developing Export Agriculture southern Africa. In Malawi, that in a protected crop, equivalent (IDEA) project and ICIPE in the smallholder farmers estimate crop to 0.2 to 0.5 t/ha. Losses from development of a mycoinsecticide losses to maize alone as up to 700 hybrid and open-pollinated, based on M. anisoplae for the kg/ha. This project aimed to limit improved varieties were signifi- control of pest termites. losses by developing appropriate cantly higher than losses from a and sustainable integrated pest local landrace, but the hybrid Baits to attract ants into maize management strategies for termites, varieties gave the highest mean fields as a means of reducing in collaboration with smallholder yields overall. Such findings have termite damage were tested in both farmers. clear implications for the adoption on-station and on-farm trials. of new hybrid maize cultivars by Fish bones buried beneath mulch ACHIEVEMENTS poor farmers. significantly reduced termite damage to maize, and gave A survey of 150 farmers in the Trials demonstrated that inter- yields 50% greater than in an project area provided insights into cropping maize with legumes can untreated control, a yield gain farmers’ knowledge of pest termites. reduce damage caused by termites, of almost 900 kg/ha. As fish is Termites were categorized by but that the most consistent yield widely available in southern a significant majority of farmers as gains can be obtained from Uganda, this could form the basis serious pests, despite being used intercropping maize with sorghum of an effective, low-cost method as human food. Indigenous crop at low densities. Since such of termite control for poor protection methods and natural combinations are already used by farmers in the region. farmers, this approach could form enemies were surveyed. In particu- part of a strategy for increasing lar, a negative correlation between A number of different botanical maize yields. the abundance of ants’ nests in insecticides were tested against maize fields and the damage to termites. Although all reduced Screening of maize cultivars for maize caused by termites was termite damage to maize, none was susceptibility to termite attack has demonstrated. The importance of as effective as Metarhizium. shown that while local landraces ants as control agents was con- appear to be less susceptible to firmed by farmers, who have an FUTURE attack by termite pests than modern extensive knowledge of this group. The information obtained on the hybrid cultivars, the latter still susceptibility of different maize produce higher yields than local A strain of the fungus Metarhizium anisopliae, provided by the cultivars to termite attack is now landraces in on-farm experiments. being applied through breeding International Centre for Insect However, as there is some evidence strategies within the maize pro- Physiology and Ecology (ICIPE), that the lodging of hybrid maize by gramme of NARO. Further work is was shown to be effective in termites contributes to their relative proposed on cultural control unpopularity amongst poor farmers controlling termites when applied (mulching and intercropping), and in the project area, consideration to soil after planting in maize fields, on attracting ants into maize fields should be given to incorporating giving yield gains of 50% over an as a means of natural termite control. untreated control. genetic characteristics which confer A video has been produced on the Feedback and dissemination of work of the project for training Publications: see Bibliography on CD. results to farmers and scientists has purposes within NARO.

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Development of management strategies for maize streak virus disease

R6642 Maize streak virus disease (MSVD) occurs throughout sub-Saharan Africa, and can cause damaging yield losses. Earlier work has focused on the epidemiology of the disease and R. J. Cooter its leafhopper vectors; this second phase of the maize streak virus project concentrated on Natural Resources Institute (NRI), University of Greenwich, UK the development of management strategies for MSVD based on cultural control practices that are acceptable to farmers. These were developed through an understanding of the D. Kyetere behaviour of the leafhopper (Cicadulina) vectors and their role in MSVD spread within Namulonge Agricultural and Animal maize plots and between maize plantings. Results demonstrate that various farming prac- Production Research Institute (NAARI), tices can affect the incidence of MSVD, and this can be explained by knowledge of vector National Agricultural Research Organisation (NARO), Uganda behaviour. The project has confirmed that farmers can successfully select and produce their own maize seed. Farmers are keen to understand, and have proved able to benefit January 1996–March 1999 from knowledge on how to select and maintain open-pollinated varieties with preferred characteristics from season to season. The Ugandan Cereals Programme has benefited from the observations and experiments made during the course of the project, and has incorporated some of the techniques into its breeding programmes.

ISSUES acceptable and profitable for the maize farmers in the region. This Maize streak virus disease (MSVD) second phase of the project sought is a serious constraint to maize to develop these aspects of research production throughout sub-Saharan and to integrate them with the use Africa. Yield losses in trials in East of MSV-tolerant varieties, as they Africa have varied between 33 and become available through the 55% under natural infection Uganda Maize Programme, into an conditions. In northern Nigeria, at integrated management strategy for the end of the growing season in the disease. epidemic years, 75-100% of maize plants can be infected. Studies on ACHIEVEMENTS the epidemiology of MSVD have been limited to Zimbabwe, Surveys within villages clearly Mauritius, Nigeria and Zaire, but indicated how little farmers and these areas represent only some of other stakeholders knew about the agro-ecological zones in which MSVD. The surveys also showed the virus can be epidemic. This that the lack of a reliable seed SELECTED PUBLICATIONS work aimed to study the disease in supply was a major problem. The the mid-altitude agro-ecological project found that, due to cross- GIBSON, R.W. and PAGE, W.W. (1997) zone, typified by maize production pollination by local susceptible The determination of when maize plants systems in Uganda. The first phase landraces and farmers’ seed were infected with maize streak virus from (R5246) focused on determining selection strategies, MSVD resist- the position of the lowest diseased leaf. the role of the leafhopper vectors in ance was probably being selected African Crop Science Journal 5: 189–198. the epidemiology of the disease. out from the only available resistant Data on the leafhoppers were open-pollinated variety in Uganda, RILEY, J.R., DOWNHAM, M.C.A. and incorporated into a geographic Longe1. COOTER, R.J. (1997) Comparison of the information system (developed performance of Cicadulina leafhoppers On-farm monitoring showed that through project R5360) to investi- on flight mills with that to be expected the later maize was planted, the gate the relationship between virus in free flight. Entomologia Experimentalis higher the incidence of MSVD, and incidence, topography and meteor- et Applicata 83: 317–322. that this appeared to explain why ology in Uganda. Further research there was an indication that SMITH, M.C., PAGE, W.W., HOLT, J. and on MSVD was carried out under women’s fields had a higher KYTERE, D. (2000) Maize streak virus dis- project R5237 on the identification incidence of MSVD than men’s ease: spatial dynamics of epidemic de- and characterization of economi- fields, since the women tended to velopment within fields. International cally important strains of maize plant later in the season. The on- Journal of Pest Management 46: 55–66. streak geminivirus. farm monitoring also showed that PAGE, W.W., SMITH, M.C., HOLT, J. and Preliminary trials were previously the incidence of MSVD was nearly KYTERE, D. (1999) Intercrops, Cicadulina undertaken on developing appro- three times higher in the shade of spp. and maize streak virus disease. An- priate intercropping systems that trees. Subsequent on-station nals of Applied Biology 135: 385–393. minimize disease spread, yet are experiments showed that the

21 DFID CROP PROTECTION PROGRAMME

Joint preparation of training manual for farmers by researchers and collaborating farmers at Namulonge

majority of the principal MSVD carrying MSV in the field, and that intercropped maize were too vector species, Cicadulina mbila, they also had a much higher variable to produce any clear were found in the shade, and the proportion of active transmitters recommendation, but might merit majority of the second most than C. storeyi. This confirms that further examination. important vector, C. storeyi, were C. mbila is the most important Taking into account the complexity found outside the shade, effectively vector of MSVD in Uganda. of farmers’ situations in the study separating the two species by their Experiments have shown that, areas, the project has improved behaviour. above a certain density, there was farmers’ knowledge of MSVD so Results from analysing the numbers a significant attraction of wild male that they can make informed C. mbila to cages containing of vectors and disease incidence decisions about managing the leafhoppers of the same species. within monitoring plots suggest that disease. This has been through the In addition, the different sexes of progress of MSVD is determined by involvement of local extension Cicadulina locate each other by conditions in the crop at an early staff, on-farm training, and the using vibrations transmitted production of information leaflets. stage in the epidemic. Thus plots through the material on which they that are characterized by a high are sitting, and the acoustic It has been shown that various initial rate of increase were those properties of the plants may be an farming practices can affect the in which final incidence was also important factor in the insects’ incidence of MSVD and this can high. In addition, diseased stands selection of plants on which to be explained by the knowledge of were found to be highly clumped, settle. This may account for the vector behaviour. The most but new foci were generated vector’s preference for plants of important are summarized below. throughout the season. These a certain height, which had been findings are thought to be related to Intercropping. It was thought that shown previously, and which the mating behaviour of the vector, if the spaces betwen the maize would have a considerable effect where the more mobile males plants were filled with a dense, low on the distribution of MSVD within locate the relatively sedentary crop then male activity would be fields. females. In addition, females are hampered and the spread of MSVD thought to prefer maize plants of Intercropping maize with beans or reduced. Results showed clearly a favoured height, the distribution millet results in a reduction in male that the activity of male vectors was of which changes over the season. Cicadulina activity within the considerably reduced, but reduc- intercropped host, but the catches tion in streak occurred only when Transmission studies showed that of females are not reduced. the densities of the intercrops were there was a large increase over time Reductions in MSVD incidence and particularly high, and to the in the proportions of C. mbila competition effects on yield in detriment of the maize yield.

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Time of planting. Maize fields where the vectors have a chance FUTURE planted later will have far more of selecting plants on which to plants infected with MSVD because settle. The unreliability of available leafhopper numbers have already maize seed was a major con- Growing MSVD-resistant varieties. built up. In addition, because the straint to farmers producing good Although MSVD-resistant varieties leafhoppers appear to prefer maize yields from their maize crop. can be infected, they show a good at a height of 25–40 cm, a maize Through collaboration with tolerance to the disease, with very field planted later than others in an village groups, extension officers little leaf area lost to streaking. area will be at the preferred height, and NGOs, it has been possible Thus little or no crop loss due to increasing the chances of heavy to train farmers as village trainers MSVD occurs. One problem that infection. in their villages. The project was found on-farm was a farmer- began exploring the idea of Gap filling. Replanting where seeds perceived ‘breakdown’ in resist- empowering farmers to produce have not germinated will also ance to MSVD in the Ugandan their own seed through selection increase the amount of MSVD open-pollinated variety Longe1. and controlled pollination. The because of the leafhoppers’ On-farm, Longe1 is being grown farmers have been very preference for the younger enthusiastic about taking up plants in the field, and because this technique, and a follow- the numbers of leafhoppers up of this work has been carrying the virus will be high by agreed. the time these new plants reach the preferred height. This does The on-farm studies, particularly not necessarily mean that gap those related to seed selection filling should be discouraged, as by farmers, have reached a point many of the plants may still where they could become fully produce a cob of some sort, participatory. Suggested activi- which is better than none at all ties are the provision of appro- from empty stands. priate training and information on seed production to farmers’ Roguing. Removing diseased groups in Namukubembe and plants does not really help, Bugodi villages; monitoring of because there are many leaf- seed production activities in hoppers with virus continuing to Namukubembe, Bugodi and spread MSVD, and plants that selected sites; and evaluating the are pulled out might have grown process and the output from on to produce a small cob. both the farmer’s and research- Spacing. Other workers have er’s perspective. If evaluation shown that the closer the indicates the approach is spacing, the higher the inci- appropriate, activities should be dence of streak. It is therefore scaled up to other villages important to understand the through the FOSEM (Food relationship of plant density, Security and Marketing for disease incidence, and agro- Maize plant infected with MSV showing systemic Smallholder Farmers) network in nomic characteristics with yield. chlorotic streaking Uganda. Shade. It is strongly recom- amongst other, ‘local’, open- The project has encouraged links mended that maize is not grown in pollinated varieties of maize and is between researchers, the shade, as a greater proportion therefore being cross-polli- extensionists and NGOs operat- of plants are likely to become nated. Investigations suggest that ing in the project areas, and has infected, and at an earlier stage in farmers may be selecting out established good rapport and growth. MSVD resistance by selecting collaboration with groups of Vector resistance. There are large seeds for replanting: farmers in key maize-growing indications from experimental and because Longe1 seeds are smaller areas which will continue, for on-farm work that Cicadulina show than those of many local varie- example with the termite project varying preferences for different ties, selection of large seeds from (R6653) and a short project to varieties of maize. It is suggested cross-pollinated plants selects for continue the on-farm seed that when maize breeders select the local variety and not Longe1. selection study (R7429). This will for MSVD resistance, they should This was addressed by showing form a good basis from which to challenge plants with infected farmers how to isolate their continue developing pest vectors confined in pots, and Longe1 to avoid the risk of cross- management and cropping should not use a release method pollination. strategies.

23 DFID CROP PROTECTION PROGRAMME

An investigation into the biology, epidemiology and management of finger millet blast in low-input farming systems in East Africa

R6733 Finger millet is an important staple food in western Kenya, and a valuable source of nutrients. It is considered the domain of women, who also use it as a cash crop, generally N.J. Hayden, M.A. Conroy, J. Holt, managing the resulting income for the benefit of their household. Farmers cited labour A.M. Julian and the cost of land preparation as factors limiting the cultivated area of this crop. High Natural Resources Institute (NRI), yield and early maturity are considered favourable variety characteristics, whereas dis- University of Greenwich, UK ease susceptibility is an important negative attribute. Farmers recognize blast (caused by F. Makini Pyricularia grisea) as a major disease which they correctly associate with high humidity Kenya Agricultural Research Institute and variety susceptibility. Progress towards sustainable control of blast on finger millet (KARI), Regional Research Centre, Kisii, has been achieved through identification of cultural and field hygiene measures to reduce Kenya disease carry-over; documentation of the agronomic and socio-economic context into which control strategies will be placed; farmer participatory evaluation of the released September 1996–March 1999 resistant millet varieties P224 and Gulu E; and development of a laboratory-based bioassay to screen finger millet varieties for resistance and blast isolates for pathogenicity.

ISSUES seedling to grain formation. Under suitable conditions (humid, wet Finger millet is an important food and cloudy weather), initial brown crop within traditional low-input, specks on the leaves of seedlings cereal-based farming systems in develop into spindle-shaped Africa. It is of particular importance lesions, then change colour, and an in upland areas of eastern Africa olive-grey overgrowth of the fungus where it commands a high price can be seen over the central in the market place, fetching three portions of the spots. Severe to five times the price of other infection may lead to death cereals. This crop has particular in seedlings, whereas the disease relevance for food security as it is tends to be less severe during the more drought-tolerant than maize, vegetative stages of the crop. and less susceptible to bird damage Much greater damage is caused than sorghum. In addition it can be during the heading stage when stored for prolonged periods, and grey-brown lesions are produced so may be the only cereal food on the peduncle or ‘neck’ of the source available at certain times cereal. The tissue within these of the year. Finger millet provides lesions turns black as it rots and, a valuable source of minerals and in severe cases, the neck may snap nutrients, and is recommended for resulting in complete loss of the pregnant or nursing mothers and ear of grain. infants. It is also a traditional crop and occupies a central role in Although blast was first recorded ceremonies and other community in 1933, there has been limited activities. research on the biology and sources of P. grisea on finger millet. Although a range of fungal and Seeds, crop debris and weed hosts bacterial diseases have been have been implicated as potential reported on finger millet, the most disease sources. Preliminary work important disease is blast, caused to assess variation was undertaken by the fungus Pyricularia grisea. on a limited number of isolates of The pathogen is highly destructive P. grisea from finger millet (R5349) and economically important, and there appeared to be consider- causing in excess of 50% able variation. The existence of this reductions in yield, particularly in potential variability within the blast wet years. Losses of up to 90% population means that evaluation SELECTED PUBLICATIONS have been recorded in field studies of control measures, for example in Uganda, 64% in Kenya, and the use of resistant cultivars or MAKINI, F.W.M. (1999) Epidemiology near total losses in India. and control of finger millet blast using fungicides, should be conducted in farmer participatory methods. PhD Blast may affect finger millet at all those areas where the work is to be thesis, University of Greenwich, UK. stages of development from promoted and adapted.

24 AFRICA

The purpose of this project was to cultivar Enaikuru third. However, a potential source of finger millet contribute to improvement of traders and extension officers blast. yields of finger millet in low-input ranked Gulu E as first overall, Experiments were undertaken to farming systems in East Africa with P224 best for traditional determine the survival of P. grisea by providing information on the foods (ugali and ugi). Thus the on crop debris. These studies biology and disease sources released varieties showed a high showed that the fungus can survive of finger millet blast. The investiga- degree of consumer acceptability. on crop debris in the soil for up to tion was based on constraints The yields of released varieties 5 months (see Figure 1), although and potential control strategies P224 and Gulu E were similar to there is considerable reduction in identified by farmers themselves, those of Enaikuru during on-farm inoculum potential 2 months after and included consideration of the evaluation under low disease incorporation. Therefore although social and cultural significance pressure, although in the long rains ploughing to a depth of 15 cm and of the crop, and evaluation of yields were higher for the tradi- a rotation period of >5 months released finger millet varieties. tional cultivar than for either of the would appear necessary for This information can be used by two released varieties. Gulu E complete control of debris-borne breeders such as the International demonstrated most resistance to inoculum, there is considerable Crops Research Institute for the blast. The observed yields were benefit from ploughing and a Semi-Arid Tropics (ICRISAT) and the national crop improvement pro- grammes to assist in selecting resistant varieties, and towards the development of an integrated control strategy. Blasted finger millet heads in the field ACHIEVEMENTS Twenty-two varieties of finger millet were found to be grown on the farms surveyed. This range reflects the numerous end uses of this crop, as well as farmers’ recogni- tion that different varieties perform better in different seasons. Farmers often grew more than one variety (either in separate plots or not correlated to disease as variety mixtures), but one, scores in these experiments. Enaikuru, predominated. Yield losses were related to time of onset of the disease: The need for blast-resistant varieties when crops were inoculated was identified by farmers them- with the blast pathogen, selves. As a consequence, the maximum losses occurred in suitability of the released varieties finger millet inoculated 90 P224 (blast-tolerant) and Gulu E days after sowing. (moderately resistant) was investi- gated on-farm by participating During interviews with farmers, and by a wider audience farmers it was found that through community workshops and finger millet crop debris, rotation period of just 2 months farmer days. A range of domestic including diseased heads, is between successive finger millet and culinary attributes for the usually incorporated into the crops. released varieties and farmers’ soil at the end of the season. existing varieties were evaluated. The blast fungus, P. grisea, was Twenty-one accessions of finger Overall, women ranked Enaikuru isolated from this material, and millet seed were screened for first, then Gulu E and P224. it was found that these isolates P. grisea, which was found to In contrast, men ranked Gulu E could infect healthy finger millet, contaminate about 10% of the first, then P224, with the traditional indicating that crop debris is total seed tested, indicating that

25 DFID CROP PROTECTION PROGRAMME

FUTURE

The work reported here has provided valuable information on the basic biology and ecology of the blast pathogen, and preliminary data on epidemiological factors such as inoculum survival and cultivar performance. The farmer participatory approach employed has highlighted the importance and value of this crop to the culture and livelihoods of smallholder farmers. In keeping with the agronomic and Figure 1. Survival of blast inoculum on crop debris on soil surface and buried socio-economic context, further at 15 cm work in Kenya is required to:

contaminated seed could poten- cation. The information conveyed • determine disease versus yield- tially be a source of inoculum. via these routes will empower loss relationships, taking into smallholder farmers to reduce account compensatory growth; Data on finger millet blast potential losses due to finger collected during a final survey of • further evaluate the potential millet blast through modification role of resistant varieties by 200 farms confirmed the correla- of cultural practices, particularly tion between incidence and screening farmers’ varieties and rotation and field hygiene and other existing germplasm using severity of the disease. The growing of improved varieties. the laboratory bioassay devel- highest average disease inci- The enhancement of production oped by this project; dence and severity were 48 and should improve food security at 42%, respectively. Thus the the family level and, if sufficient • undertake farmer participatory disease resistance of evaluation of selected Gulu E and tolerance of germplasm, along with P224, along with their sampling and molecu- social acceptability, lar characterization of will be potentially P. grisea populations at valuable for small- those sites. holder millet growers, Finger millet has also particularly if used in been identified as a key conjunction with crop in the Teso cultural measures Agricultural System in (including field hy- Uganda, and the giene) to limit or delay following activities are the onset of disease. suggested:

Project activities • evaluation of involved groups of seedborne incidence farmers (participating and transmission of and non-participating); blast; finger millet traders • investigation of (mostly women whose management of blast livelihoods depend on Farmer hand-harvesting finger millet through the use of the income from this seed treatments; crop); and agricultural production is achieved, generate • identification and evaluation extension officers. In addition to increased household income of blast-resistant finger millet the benefits to be gained through through the sale of grain to cultivars in the context of dissemination of information by traders, resulting in availability variable pathogen populatons; agricultural extension officers of grain to those who may be to farmers, there will also be otherwise unable to grow the • socio-economic studies on farmer–farmer and trader– crop, for example due to land farmers’ perceptions of the consumer pathways of communi- shortages. disease and agronomic factors.

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Groundnut rosette disease epidemiology

R6811 Groundnut cultivation has a direct bearing on the nutritional and economic status of smallholder farmers in sub-Saharan Africa because it is an important source of protein F. M. Kimmins, Natural Resources Institute (NRI), and oil, and also provides cash income, contributing significantly to food security and University of Greenwich, UK poverty elimination. Rosette disease, caused by the groundnut rosette virus complex, is the most destructive virus disease of groundnut in the region. The International Crops R.A. Naidu, P.J. van der Merwe, Research Institute for the Semi-Arid Tropics has estimated that rosette disease causes greater E. Minja, P. Subrahmanyam yield loss to farmers in the region than any other virus disease affecting groundnut. International Crops Research Institute Although chemical control and cultural practices are known to reduce risk of rosette, they for the Semi-Arid Tropics (ICRISAT), Lilongwe, Malawi are seldom adopted by smallholder farmers because of labour and capital constraints. Improved high-yielding lines with resistance to the disease and/or the vector may be the December 1996–March 1999 best low-input rosette disease management strategies. This project focused on under- standing the interaction between the transmission of the three causal agents of rosette disease by the aphid vector in a range of virus- and vector-resistant genotypes, particularly short-duration lines which are less susceptible to drought and which can contribute to food security for smallholder farmers.

ISSUES genotypes and germplasm lines which have been analysed to date, Groundnut rosette disease is resistance has been found to the endemic to sub-Saharan Africa and groundnut rosette virus component its offshore islands. Economists at of the virus complex. SELECTED PUBLICATIONS the International Crops Research Institute for the Semi-Arid Tropics Earlier work at the Scottish Crop NAIDU, R.A., BOTTENBURG, H., (ICRISAT) have estimated that the Research Institute, UK and ICRISAT SUBRAHMANYAM, P., KIMMINS, F.M., value of the potential yield gain (R5235) has shown that rosette THRESH, J.M. and ROBINSON, D.J. (1998) through rosette disease manage- disease is complex and involves Epidemiology of groundnut rosette virus ment is US$121 million per year. three agents: groundnut rosette disease; review of current status and re- The 1996 Working Group on assistor luteovirus (GRAV), ground- search needs. Annals of Applied Biology Groundnut Virus Diseases in Africa nut rosette umbravirus (GRV), and 132: 525–548. confirmed that rosette disease a satellite RNA (sat RNA) of GRV. The three agents are intricately NAIDU, R.A., KIMMINS, F.M., DEOM, continues to be a severe constraint dependent on each other and all C.M., SUBRAHMANYAM, P., CHIYEM- to groundnut production in sub- play a crucial role in the biology BEKEZA, A.J. and VAN DER MERWE, P.J.A. Saharan Africa, and recommended and perpetuation of the disease. (1999) Groundnut rosette: a virus disease that host-plant resistance should be Variants of sat RNA cause different affecting the sustainability of groundnut improved because it is regarded by forms of the disease, whereas production in sub-Saharan Africa. Plant many national programmes and GRAV or GRV alone cause asymp- Disease 83: 700–709. NGOs as potentially the most effective disease management tool tomatic infections. GRAV acts as a NAIDU, R.A., ROBINSON, D.J. and for smallholder farming systems. helper virus in aphid transmission KIMMINS, F.M. (1998) Detection of the The Southern African Development in that GRV RNA, which does not causal agents of groundnut rosette dis- Community (SADC)/ICRISAT code for a coat protein, and sat ease complex in plants and aphid vec- Groundnut Project places major RNA are packaged in the coat tors. Journal of Virological Methods 76: emphasis on the development of protein of GRAV to form virus 9–18. rosette-resistant lines, particularly particles that are aphid-transmissi- ble. The sat RNA depends upon NAIDU, R.A., KIMMINS, F.M., HOLT, J., short-duration varieties which are GRV for replication, and GRV ROBINSON, D.J., DEOM, C.M. and frequently preferred by farmers but depends upon sat RNA for aphid SUBRAHMANYAM, P. (1999) Spatio- which have not hitherto been transmission. temporal separation of groundnut rosette available. virus disease agents. Phytopathology 89: The Groundnut Project’s breeding The aim of this work was to 934–941. and screening programme has improve understanding of ground- MINJA, E., VAN DER MERWE, P.J.A., resulted in the identification of nut rosette disease epidemiology, KIMMINS, F.A. and SUBRAHMANYAM, P. several high-yielding, agronomi- in order to contribute to the (2000) Screening groundnut breeding cally acceptable short-, medium-, development of appropriate lines for resistance to aphids, Aphis and long-duration lines with good integrated management strategies craccivora Koch. International Arachis levels of resistance to chlorotic based on host-plant resistance to Newsletter 19: 21–23. rosette. In all rosette-resistant the virus and/or vector.

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ACHIEVEMENTS Table 1 Fecundity of Aphis craccivora on four Aphis craccivora is the principal groundnut genotypes with agronomically acceptable aphid vector of rosette disease characteristics. agents. The source of virus-carrying aphids that initiate rosette disease Age Total is not known, and the factors (days Mean offspring in associated with the development after days to first 5 days’ of disease epidemics are poorly Cultivar sowing) reproduction SE n reproduction SE n understood. In this project, JL24 7–22 6.00 0.09 23 49.20 1.41 22 which interacted directly with 11–26 6.27 0.12 22 34.43 1.42 21 the ICRISAT initiative to under- 28–43 6.62 0.16 21 37.80 0.98 20 stand the epidemiology of the CG7 7–22 6.47 0.10 21 44.43 1.60 21 11–26 6.22 0.11 23 35.86 1.87 21 disease, detailed studies of the 28–43 6.45 0.18 20 36.33 1.98 21 transmission characteristics of the ICG 90704 7–22 5.91 0.09 22 43.36 1.93 22 three causal agents by the aphid 11–26 6.24 0.10 21 35.45 1.34 21 vector have improved under- 28–43 6.42 0.18 19 28.42 2.50 19 standing of rosette disease ICG 12991 7–22 6.47 0.14 19 25.20 1.87 10 spread. 11–26 7.67 0.17 9 14.70 1.35 6 28–43 8.55 0.16 11 15.00 0.00 2 Specific outputs include: • the development of a new • the identification of vector This has important implications for method to detect the three resistance in the short-duration the release of ‘resistant’ groundnut agents of the rosette disease line ICG 12991(Table 1) genotypes such as ICG 90704 – in complex in plants and aphid the event of high rosette disease • an assessment of yield loss due vectors by reverse transcription- pressure, as in an epidemic, there to the aphid-transmissible polymerase chain reaction will still be significant yield loss on GRAV in a range of groundnut (RT-PCR) this genotype because it is suscepti- genotypes. ble to GRAV. Only low numbers of • an improved understanding of The preliminary results of yield-loss plants of genotype ICG 12991 were the transmission efficiency of experiments indicate that ground- infected with GRAV, apparently the three causal agents of nut yield is reduced by between 25 because it could not be inoculated rosette disease by the aphid and 60% due to rosette disease, into the plants by the aphids. In the vector on a range of groundnut depending on the cultivar. The absence of any genotypes with genotypes, including rosette- lowest yield loss (23%) was GRAV resistance, further work on resistant and vector-resistant recorded on ICG 90704, which is the nature of resistance in ICG lines, under field and laboratory resistant to both GRV and sat RNA. 12991 and its inheritance is conditions needed because it is proposed to develop durable resistance by combining vector resistance with GRV resistance.

FUTURE

Left, a farmer from The outputs of this project are Soroti town, Uganda, being used by breeders at ICRISAT showing her groundnut to develop improved groundnut crop destroyed by genotypes with a range of resist- rosette disease (~80% ance mechanisms to either the incidence). Below, causal agents of rosette disease chlorotic rosette and/or the vector. A second phase symptoms involving a farmer participatory project using the promising rosette disease and vector resistance is being developed with ICRISAT in Uganda at the Serere Agricultural and Animal Production Research Institute based at Soroti (R7445).

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Molecular and biochemical techniques for detection and identification of Ralstonia solanacearum and other plant-pathogenic bacteria

R6520 Bacterial wilt is one of the major constraints on the production of a wide range of tropical and subtropical crops, including Solanum potato, banana and plantain, groundnut, to- R. Black, S.E. Seal, M. Brown mato, eggplant and pepper. The disease is particularly difficult to control because it is Natural Resources Institute (NRI), soilborne and has such a wide host range. The use of resistant varieties is therefore an University of Greenwich, UK important component of control, but existing resistant varieties are often poorly adapted to Zakia Abubakar local conditions, are often tolerant rather than truly resistant, and may carry latent infec- Plant Protection Division, Ministry of tions. Improved techniques are needed for detection of this and other bacterial pathogens Agriculture, Livestock and Natural locally, to contribute to the development of better resistant varieties. Various diagnostic Resources, Zanzibar, Tanzania techniques have been developed in previous projects, including low-cost kit-based meth- ods adapted for the particular conditions faced by tropical pathology laboratories; meta- R. Nono-Womdim bolic profiling; various molecular techniques including probes and the polymerase chain Asian Vegetable Research and Develop- reaction; and enzyme-linked immunosorbent assays. In addition to field testing and further ment Center (AVRDC) – Africa Regional refining these methods under local conditions, valuable data have been gained on the Program, Arusha, Tanzania importance of a range of bacterial diseases in cropping systems. Most significantly the I. Swai approach of ‘targeted seed pathology’ has indicated the contribution that germplasm-borne Horti-Tengeru, Arusha, Tanzania inoculum of the bacterial pathogens studied makes to the spread and development of plant diseases in the field. October 1995–September 1998

ISSUES bolic profiling; various molecular techniques including probes and Bacterial diseases such as bacterial the polymerase chain reaction wilt are very serious in the subtrop- (PCR); and enzyme-linked SELECTED PUBLICATIONS ics and tropics, but most plant immunosorbent assays (ELISA). pathologists in these regions have In this project the techniques were BLACK, R. and ELPHINSTONE, J. (1998) had little exposure to bacteriology, applied in Malawi and Tanzania, Developing appropriate detection meth- compared to mycology or even both to study the bacterial diseases ods for developing countries. In: Bacterial virology. One reason for the and their spread in the field, and to Wilt Disease (Prior, Allen and Elphinstone, comparative neglect of bacteriol- evaluate the different techniques eds). Berlin: Springer, pp. 123–127. ogy in developing countries is the in developing country laboratories. lack of techniques for identification The project focused on other BLACK, R., HOLT, J. and SWEETMORE, and detection of plant pathogenic diseases of vegetables in addition A. (1996) BACTID: Bacteriological Iden- bacteria that are appropriate for the to bacterial wilt: vegetable cash tification System for Resource-poor Plant prevailing conditions, particularly cropping has intensified in Pathology Laboratories. Chatham, UK: the lack of financial resources for response to growing urban markets Natural Resources Institute. purchasing and storing the many in Tanzania and Kenya, but their different reagents and media SEAL, S. (1997) Cost analysis and detec- bacterial diseases have not been required in classical bacteriology. tion of bacteria and phytoplasmas in plant studied in any detail. The research The application of modern tech- tissue cultures by PCR. In: Pathogen and in Tanzania centred on PhD studies nologies, such as serological and Microbial Contamination Management of the principal collaborator. The molecular techniques, is also in Micropropagation (Cassells, ed.). work in Malawi had to be curtailed problematic because of frequent Dordrecht, Netherlands: Kluwer, pp. 123– due to the transfer of the chief power cuts and other deficiencies 130. collaborator to other duties. in the infrastructure. SEAL, S.E. and ROBINSON-SMITH, A. Various techniques for the diagno- (1999) Bacterial Wilt: Laboratory Detec- ACHIEVEMENTS sis of bacterial wilt and the detec- tion of Ralstonia (Pseudomonas) tion of the causal pathogen Participatory appraisal of farmers’ solanacearum. NRI Technical Manual. Ralstonia solanacearum have been knowledge and perceptions Chatham, UK: Natural Resources Institute. developed, refined and field tested established that seedborne and SEAL, S., TAGHAVI, M., FEGAN, N., in previous projects (R5313, tuberborne bacterial pathogens are HAYWARD, A.C. and FEGAN, M. (1999) R5535, R5922, R5447; see IPM among the important disease Determination of Ralstonia (Pseudomonas) Research Highlights, 1989–95). causing agents that affect vegetable solanacearum rDNA subgroup by PCR These included the ‘BACTID’ crops in Tanzania. Certain cultiva- tests. Plant Pathology 48: 115–120. bacterial identification kit; meta- tion practices actually promote the

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spread and development of the target pathogens. Most importantly, poor seed and potato seed tuber quality, including contamination with bacterial pathogens, should be addressed; this will require a combination of screening and quality control by Tanzanian suppliers to produce disease-free material and controls on imported seed. Unless the quality of vegeta- ble seeds from commercial compa- nies conforms to farmers’ require- ments, farmers will continue to produce and depend more on their a. b. own germplasm in order to satisfy their needs. Therefore it is worth- BACTID biovar kit used to determine the biovars of isolates of while to support farmers’ efforts by R. solanacearum from tomato and potato: a. biovar 2 (potato ensuring that reasonable quality isolate); b. biovar 3 (tomato isolate). A yellow colour indicates germplasm is being used to sustain the metabolism of one of the differential substrates of the vegetable production. biovar test. Biovar 2 only metabolizes disaccharides (right- Among the project’s major outputs hand side of each set), biovar 3 metabolizes disaccharides and were: sugar alcohols (left-hand side of each set)

• the adaptation of a suite of diagnostic technologies for Before this project started various specialists. Consequently, wilting plant-pathogenic bacteria, assumptions were made about the was often attributed erroneously including the production of causes of wilting in vegetables on to the wrong cause without manuals on BACTID and PCR/ the basis of symptoms observed in further investigative work. It is ELISA (right); the field and, in general, little was now confirmed that the bacteria known about bacterial diseases in R. solanacearum and Clavibacter • evaluation of the various Tanzania, even by plant protection michiganensis subsp. techniques in relation to the michiganensis are both signifi- purpose of the diagnosis and cant causes of wilting in solana- prevailing conditions such as ceous crops, while the commonly infrastructure and supply of observed necrosis of pith associ- electricity and water; ated with wilting in tomato is not due to Pseudomonas corrugata as • data on the distribution and previously thought. incidence of target pathogens, several pathogens being FUTURE confirmed for the first time; The BACTID bacterial identifica- • data on the contribution of tion system is being improved infection of germplasm within and expanded under a project cropping systems; originally funded by the Higher Education Funding Council for • sources of variation in the England. New BACTID software bacteria R. solanacearum and is being produced that will Xanthomonas campestris pv. include an improved version of campestris (black rot) identified the core identification system that will be important for (expert system); an encyclopae- disease control strategies; dia of media, tests and reagents used in the BACTID kit, taking • culture collection of reference advantage of practical experience isolates established; gained from the project; and a learning module incorporating • strategies for control identified – animated graphics of the tests internal quarantine, seed taking place in the BACTID quality, cultivation practices. tubes.

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Investigation of banana leaf speckle in Africa

R6794 Leaf speckle disease of banana, a relatively little-studied disease, is causing significant J.C. David damage in highland agroecosystems in Uganda. This project carried out an initial investi- CABI Bioscience, Egham, UK gation into the variability and pathogenicity of the causal agent of the disease in Uganda, Kenya and Cameroon. Detailed examination of the material collected supports the recent W.K. Tushemereirwe transfer of the main pathogen from Cladosporium to Periconiella. It also reveals a more Kawanda Agricultural Research Institute, Kampala, Uganda intricate picture of the banana leaf speckle complex than has been appreciated previously. Molecular studies suggest that variation exists across the geographic range of the G. Siboe fungus, which will be important in identifying and developing resistant varieties of University of Nairobi, Kenya banana. F. Gauhl International Institute of Tropical fungus. The isolates obtained were of P. sapientumicola, and could Agriculture (IITA), Cameroon used for molecular studies of also be used for assessing the genetic variability and to develop pathogenicity of Periconiella musae January–June 1997 pathogenicity tests. and Ramichloridium musae, the other two leaf speckle fungi found ISSUES Preliminary results indicate that banana leaf speckle is more com- on banana. Recent studies in Uganda have plex than previously thought. Firstly, A brief study of molecular markers shown that cladosporium leaf the actual identity of the causal of genetic variability indicates that speckle of banana is as damaging organism has been questioned. variability does exist in populations a disease as black Sigatoka in Detailed examination by scanning of P. sapientumicola, but this needs highland agroecosystems of East electron microscope of isolates to be investigated further. The Africa. It is a major cause of leaf fall collected in East Africa confirmed potential connection between gen- which, together with a number of that Cladosporium musae does not etic variability and pathogenicity other factors, results in a significant belong in Cladosporium but appears needs to be explored in relation to decline in yield. Although predomi- to be better placed in the genus environment and geography. nantly affecting highland bananas, Periconiella, and has been renamed it is also known to be a sporadic The findings of this project suggest P. sapientumicola. The fungus is of that the banana leaf speckle complex problem in lowland areas else- considerable scientific interest as it where in Africa. A key concern was has different fungal components has two quite different spore- according to host cultivar, region whether the pathogen found in East producing forms, something not Africa is the same as that found in and climatic conditions. The previously observed in either Cameroon collections made at the West Africa. Knowledge about the Cladosporium or Periconiella. genetic variability of the pathogen end of the dry season comprised Secondly, P. sapientumicola was mainly R. musae and two undescri- has been virtually non-existent, and revealed to be genetically variable is needed to formulate a disease bed species of Cladosporium: not only in East Africa, but also P. sapientumicola was not management programme utilizing across the banana-growing regions resistant varieties. apparent. The Ugandan and of the tropics. Kenyan samples, collected from This study arose out of existing A firm conclusion from this prelimi- regions where rainfall is more links with the Kawanda Agricultural nary work is that symptoms of evenly distributed, were pre- Research Institute, particularly with banana leaf speckle are not dominantly P. sapientumicola, an ongoing project (R6692) to sufficient for accurate diagnosis. and R. musae was not found. develop techniques to detect the It is essential that the fungus These observations are the fungi causing fusarium wilt and causing the disease is examined in product of one set of samples, Sigatoka leaf spots of banana. The detail to confirm its identity. This is and this possible pattern needs aim of this work was to develop critical as fungi in this complex to be tested further. a method for pathogenicity testing appear to have developed a of the fungus causing leaf speckle strikingly similar appearance. FUTURE disease, in order to confirm the Meaningful studies of resistance to The results confirmed the main identity of the pathogen on high- banana leaf speckle can be con- causal agent of the disease. The land bananas as a basis for future ducted only if the correct fungal breeding programme can now testing for host resistance. species is isolated and used for target the pathogen when im- inoculation. ACHIEVEMENTS proving the resistance of high- The project also developed a land bananas to diseases. Surveys were conducted in Uganda repeatable method for infecting A study to identify sources of and Kenya, and samples were highland bananas with the fungus. resistance for incorporation in collected from these two countries This method can now be used to highland bananas has already plus Cameroon for isolation of the study the variation in pathogenicity begun at Kawanda.

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Adaptation of novel techniques for detection of fungi causing fusarium wilt and Sigatoka leaf spots of banana and plantain

R6006CB/R6007CB/R6692 Bananas and plantains are a key staple food in many parts of the world, and are of vital importance to many subsistence and tenant farmers, and ultimately to the rural economy M.A. Rutherford as a whole. Recent reports from East Africa have indicated that productivity has been CABI Bioscience, Egham, UK declining. A number of pests and diseases, including black and yellow Sigatoka and Panama A. Johanson disease (fusarium wilt), have been identified as major factors in this decline. Cultural prac- Natural Resources Institute (NRI), tices and the use of plant resistance are considered to be the two main components of any University of Greenwich, UK future disease management strategy, but their use has been limited by a lack of information A. Kangire on pathogen variability that exists in East Africa. Molecular biological and biochemical Uganda National Banana Research techniques for identifying and diagnosing the fungi (Mycosphaerella spp. and Fusarium Programme (UNBRP), Kampala, Uganda oxysporum f.sp. cubense) which cause these diseases, have been developed under previ- ous projects to monitor and characterize the pathogens in East Africa. This work has adapted J.N. Kung’u and established these techniques in Uganda and Kenya through the installation of labora- Kenya Agricultural Research Institute tory facilities and training of local scientists in their application, and through the develop- (KARI), National Agricultural Research ment of research programmes employing the techniques to provide information on the Laboratories (NARL), Nairobi, Kenya geographic distribution, host range, variability and severity of the pathogen. The informa- R.B. Mabagala tion obtained will be of benefit in developing improved disease control measures, initially Faculty of Agriculture, Sokoine through more accurate disease diagnosis, and ultimately by assisting in the selection of University of Agriculture, Morogoro, resistant cultivars and the development of ecologically based control strategies. Tanzania January 1994–January 1998 ISSUES pathogens from leaf symptoms alone. The difficulties in accurately Banana is the most important staple diagnosing these diseases have food crop in the Lake Victoria Basin contributed to a lack of basic area of East Africa, particularly in biological and epidemiological Uganda where it occupies approxi- information, and have been a SELECTED PUBLICATIONS mately 40% of utilized arable land. major constraint to the develop- However, the productivity of ment of sustainable control JOHANSON, A. (1996) Detection of banana plantations in the area is strategies, including the develop- Sigatoka leaf spot pathogens of banana decreasing. National programme ment and use of host-plant resist- by the polymerase chain reaction (PCR): surveys in Uganda and Kenya have ance, where knowledge of the draft protocols. Manual for workshop at identified the fungal diseases black nature of the pathogen being KARI, Nairobi, Kenya, September 1996. and yellow Sigatoka leaf spots assessed is essential for success. Chatham, UK: Natural Resources Institute. (Mycosphaerella spp.), and Panama Previous research projects com- disease (Fusarium oxysporum f.sp. pleted at CABI Bioscience and NRI KANGIRE, A., RUTHERFORD, M.A. and cubense) as causing severe losses have resulted in the development GOLD, C. (2000) Distribution of fusarium to smallholder crops of banana and of rapid and accurate biochemical wilt and populations of Fusarium plantain. The diseases are also of and molecular techniques for oxysporum f.sp. cubense on bananas in major concern in Tanzania. characterizing and differentiating Uganda. In Proceedings of an Interna- pathogenic forms of both diseases. tional Seminar and Workshop on Banana Fusarium oxysporum causes major The major aim of this project was Fusarium Wilt Disease (Kuala Lumpur, yield losses on a wide range of to adapt these existing techniques Malaysia, October 1999). economically important crops, for use in developing countries, including banana. Host- and KUNG’U, J.N., RUTHERFORD, M.A. and and to integrate the technologies cultivar-specific pathogenic groups JEFFRIES, P. (2001) Distribution of into the research programmes of exist within the species, including a fusarium wilt of banana and its impact national agricultural research number of pathogenic races of on smallholder farmers in Kenya. services in Uganda and Kenya. F.o cubense that are of major InfoMusa (in press). economic importance on banana LODWIG, E.M., BRIDGE, P.D., RUTHER- worldwide. The fungal species ACHIEVEMENTS FORD, M.A., KUNG’U, J. and JEFFRIES, P. involved in the Sigatoka diseases, (1999) Molecular differences distinguish M. fijiensis (black leaf streak) and FUSARIUM WILT clonal lineages within Kenyan popula- M. musicola (yellow Sigatoka), also tions of Fusarium oxysporum f.sp. appear very similar, and consider- Laboratory-based techniques for cubense. Journal of Applied Microbiol- able difficulty has been experi- diagnosing fusarium wilt of banana ogy 86: 71–77. enced in identifying the individual and for characterizing F. oxysporum

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has partly been achieved through a stakeholder workshop held in Nairobi in March 1997.

SIGATOKA The previously developed PCR diagnostic test for Mycosphaerella spp. was adapted for use under local conditions, and a protocol developed. PCR equipment was set up in Nairobi, Kenya and Kampala, Uganda, and staff were trained in its use, resulting in further revisions to the draft protocol manual. Disease surveys were carried out in Uganda and Kenya. A preliminary Smallholder banana farm in Mukono, Uganda map of disease distribution in were adapted for use by scientists techniques for determining the Uganda was produced, which in East Africa. A local capability for genetic diversity of F. o. cubense revealed that the spread of black characterizing and identifying the within East Africa and how it relates Sigatoka within Uganda has not pathogen was created in Uganda to other characters, including been as rapid as anticipated. The and Kenya through establishment pathogenicity. disease was detected only at sites of appropriate laboratory facilities where mean annual minimum Results of the research have been and training of local counterparts in temperatures exceeded 13.8 C, disseminated to stakeholders, their use. As a result, a range of in which corresponded with sites including NARS, extension services vitro characterization techniques, below 1350 m above sea level. The and farmers, in the form of up-to- including analyses of secondary incidence of black Sigatoka was date reports, disease distribution metabolite production, extracellu- always 100% where the disease maps and advisory bulletins. lar isoenzyme production and occurred. In contrast, yellow vegetative compatibility testing, are Plans have been developed, in Sigatoka was present at all the now being used routinely in collaboration with counterpart survey sites, but always with a very laboratories in these countries as scientists in Uganda, Kenya and low incidence. The cultivar Kayinja part of national banana research Tanzania, for adoption and incor- supported more M. musicola than programmes. poration of techniques for diagnos- any other cultivar, and appears to ing fusarium wilts and characteriz- be a good reference cultivar for This work, coupled with compre- ing F. oxysporum within integrated monitoring the disease in areas hensive surveys and disease pest management programmes, in where incidence of yellow Sigatoka assessment trials undertaken, has particular those involving screening is low. In Kenya, at present black provided extensive information on for resistant banana cultivars. This Sigatoka is confined to the Coast the incidence, severity and distribu- tion of particular forms of the fusarium wilt pathogen in Uganda, Kenya and Tanzania. Fusarium wilt was found in all of the key banana growing regions in the three countries with a number of widely grown and economically important cultivars (Gros Michel, Bluggoe, Ney Poovan, Pisang Awak) being affected. Disease incidence was higher than 80% in some instances. Reports have been produced on the feasibility and relative value of different pathogen characterization techniques in the East African context. These include preliminary information on the relative benefits, ease of application and potential Examination of bananas exhibiting symptoms of fusarium wilt during survey in for future use of DNA molecular Mbeya, Tanzania

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development/modernization of farming practices. In addition, the survey work in particular has led to important recommendations concerning issues such as the restriction of germplasm within the countries, and regarding the type of varieties that should be planted in certain areas and produced within national tissue culture programmes. FUTURE The depth of information acquired on the distribution and incidence of fusarium wilt and Sigatoka leaf Sigatoka leaf spot symptoms on banana leaf, Mbeya, Tanzania spots in East Africa, the existence of Province, and has not spread from techniques as tools for rapid differing pathotypes and the its introduction here into the rest of identification of host-specific susceptibility of cultivars, will the country. Neither has the disease strains of the fungus has, and will depend on the extent to which the spread into Western Kenya from continue to, provide important established technologies are Uganda, where it is present around information on the distribution and utilized in local research pro- Lake Victoria. incidence of differing pathotypes grammes. In order to maximize within these two countries. An outputs, and ultimately the poten- The reason for the absence of black ability to generate this information tial impact of the technologies, Sigatoka in the other important locally will reduce the reliance of research efforts should be ex- banana growing areas has been East African scientists on the panded to take account of possible assumed to be because it has not expertise of overseas institutions, pathogen variability across all been introduced, rather than and will be of major benefit in the banana production areas. However because it would not survive and development and promotion of this will, for the most part, depend flourish. The present findings have integrated pest management on prioritization of, and allocation implications for transport of strategies appropriate to East of funding for, relevant activities by germplasm throughout the country. African smallholder farming NARS. In Uganda and Kenya the The rise in importance and popular- systems, in particular those con- diagnostic techniques developed in ity of the Cavendish banana types in cerned with the development and the UK will continue to be utilized many areas is also worth consider- use of resistant banana cultivars. through close links forged with ing, as these are highly susceptible Ultimately, reductions in yield national banana research pro- to black Sigatoka, and disease on losses resulting from these diseases grammes, and in particular through these types could be severe if it will lead to an increase in farm ongoing PhD research programmes spreads into the Western and income, subsequent improvements initiated in 1995. Central Provinces. Although yellow in family welfare and gradual Sigatoka is present in most areas Knowledge gained to date and in the country, it does not at this through future utilization of the stage appear to be an economic newly adopted technologies and problem except perhaps in supporting research must be Central Province in the commer- collated and disseminated in cial production areas near an approprate form to potential Maragua. beneficiaries. These include NARS, plant disease clinics, Through the establishment of plant breeders, extension services appropriate laboratory facilities and farmers. Funding has already for utilizing previously devel- been obtained from CPP to oped identification techniques, initiate this process in Uganda local capability has been created under a new IPM project in Uganda and Kenya for (R7567). Where not already studying pathogenic variability available, efforts should be made of F. oxysporum and to establish pathways to permit Mycosphaerella strains infecting rapid and frequent dissemination banana and plantain in these Typical symptoms of fusarium wilt on newly of such outputs in order to countries. The use of these planted banana suckers, Murang'a, Kenya maximize uptake and impact.

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Epidemiology of rice yellow mottle virus disease in rice farming systems in Tanzania

R6763 Rice is becoming an increasingly important food crop in Africa, including Tanzania where it is a staple food for 60% of the population and is particularly important in urban areas. F. M. Kimmins, D. Overfield Rice yellow mottle virus (RYMV) has become a severe constraint to rice production through- Natural Resources Institute (NRI), out sub-Saharan Africa, but little is known of the epidemiology of the disease in East University of Greenwich, UK Africa. This project has obtained information on farming practices and farmers’ percep- F. Ali tions of RYMV in four main rice-growing regions of Tanzania; described the incidence Kizambani Research Station, Zanzibar, and variability of the virus; carried out a preliminary investigation of transmission by Tanzania beetles, leaf contact and seed husks; and assessed yield losses from farmer-preferred rice varieties and improved RYMV-tolerant lines, working towards appropriate integrated crop J. Mbilipa management strategies to reduce the risk of the disease. Agricultural Research and Training Centre, Tanzanian Agricultural Research the continent, an understanding Organization (TARO), Kilombero, ISSUES of the epidemiology of this disease Tanzania Rice is the second cereal after is essential in developing appropri- December 1996–July 1999 maize in terms of production and ate control measures to protect rice preference in Tanzania, and per crops of smallholder farmers capita consumption of rice has in Tanzania. increased from 15 kg/year in the 1970s to the current 35 kg/year. ACHIEVEMENTS 74% of the rice is grown under rainfed lowland systems. Following Information on farming practices increasing reports of rice yellow was collected using participatory mottle virus (RYMV) outbreaks rural appraisal, through observa- in major rice-growing regions of tions, interviews and ranking. Tanzania in 1995, a preliminary Farmers provided information on survey (1995–97) reported that the types of crops grown in the RYMV disease was present in all area, the importance of rice in the major rice-growing areas of the relation to other crops, farming country. First identified in Kenya, practices, and constraints to rice it has been found in many other production. The most important countries throughout sub-Saharan constraints to rice production in Africa including Niger, Côte d’Ivoire the bunded systems of Mwanza/ and Madagascar. In general it is Shinyanga are water shortage and believed that changes in farming pests and diseases in general, practices such as continuous whereas in shallow flooded areas cultivation, introduction of irriga- of Morogoro and Kyela, pests and tion schemes, and use of improved diseases were the first priority (see varieties have aggravated the Table 1). incidence and severity of the The distribution of RYMV in four disease. major rice-growing regions of This project aimed to link Tanza- Tanzania has been mapped, and nian scientists with initiatives of the farmers’ perceptions of this disease West Africa Rice Development in their farming systems have been Association (WARDA), and Euro- obtained. RYMV was confirmed in pean projects on the development all the cropping systems surveyed, of RYMV-resistant lines at John but is more prevalent in the Innes Centre, UK (Plant Sciences shallow flooded system, where Research Programme project it can cause crop failure. In Kyela R6355) and Laboratorie de it has become a political problem, SELECTED PUBLICATIONS Phytovirologie des Régions and District Agricultural Officers in Chaude, France. Little work has this region are being pressurized by ALI, F.H. (2000) Rice yellow mottle dis- been carried out on the epidemiol- farmers and politicians to provide ease in Tanzania; its distribution and char- ogy or impact of the disease in East effective management options. acterisation. PhD thesis, University of Africa. Given the inevitable Overall the disease is of economic Greenwich, UK. intensification of rice cultivation on significance to farmers in three of

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the four regions studied: Morogoro, Pemba and Kyela. Location-specific factors are likely to be extremely important in the epidemiology of this disease in Tanzania; during the survey in Mwanza, RYMV-infected plants appeared in the same three sites between 1997 and 1999, and in Morogoro and Kyela farmers claimed that the disease appeared in their fields every year. An Echinochloa species was identified as a weed host of RYMV at one site in Mwanza, and it is possible that other alternative hosts are present. The virus is known to be transmit- ted by Chrysomelid beetles. Beetle vectors (Chaetocnema and Trichispa spp.) were found in or at the edge of the rice fields around Mwanza, but many did not transmit RYMV; the low beetle populations found in the rice fields could explain the relatively low incidence and patchy distribution of the disease. No beetles were found in the large RYMV-infected plots in Morogoro. There is currently Figure 1. The major rice-growing areas (shaded) in Tanzania inadequate information on the populations of beetle vectors in the Morogoro and Kyela locations. Experiments suggested that leaf and root contact and seed are unlikely to be the major means of transmis- Table 1. Pests and disease constraints to rice production sion of the virus. mentioned by farmers in different regions Gel-diffusion and ELISA tests were carried out to determine differences Percentage of farmers among the samples of one region. The results suggest that there are at Mwanza/ Ifakara/ Shinyanga Morogoro Kyela Pemba least two distinct RYMV strains that Disease/insect (n=55) (n=109)* (n=22) (n=107) can be identified in Tanzania; the ‘Mwanza’ strain, and the Insects ‘Morogoro’ strain which is similar Stem borers 21.8 – – 76.6 serologically to strains from Pemba, Leaf hoppers 10.9 – – – Moshi and Mbeya. Using tech- Long–horned grasshopper – – 10.9 – niques developed by the project, Armyworm – 41.3 – 68.2 Trichispa sp. – – – 100.0 different strains of the virus have Diopsis sp. – – – 23.4 been made available for resistance breeding work. Diseases Yellowing1 14.5 – – – Experiments to collect data on the Sheath rot 2 7.3 – – – field spread of RYMV were unfortu- Leaf spot diseases 1.8 22.0 – – nately disrupted by drought in RYMV 3 8.2 100.0 50.0 100.0 years 1 and 3, and by theft of field cages in year 2. However, despite 1 Symptom description by farmers. the lack of information on field 2Based on field observations. spread in the rainfed system, the 3Based on field observations and symptom description – samples removed from farmers’ fields and confirmed by serological tests. project has provided the first

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detailed description of the virus disease in Tanzania.

FUTURE Information on Tanzanian farming systems will be of use to WARDA and the Tanzanian national pro- gramme as they collaborate through the International Network for Genetic Evaluation of Rice (INGER- Africa). The second phase of this project will be developed in collaboration with WARDA. The data on varieties, constraints etc. gathered during the surveys will assist national agricultural research services in selecting suitable materials for specific locations. Information on the variability of RYMV in Tanzania has been passed to the the Plant Sciences Research Programme project on RYMV and Kyela used in screening trials of transgenic RYMV-tolerant materials. RYMV-tolerant lines from WARDA have been field tested against the ‘Mwanza’ strain of RYMV, and at least one may have acceptable characteristics in terms of yield for farmers in these regions, but may Figure 2. Sites surveyed for the presence of rice yellow mottle virus (RYMV) lack the aromatic characteristics disease 1997–99 of the locally grown varieties.

Future work should undertake farmer participatory trials with RYMV-tolerant materials developed by WARDA, who have 20 lines available for testing. The mechanism of RYMV transmis- sion is still poorly understood, and the principal means of spread within and between fields is still unresolved. It has been proposed that vector specificity for the beetle-transmitted sobemoviruses appears to be controlled by the interaction of the virus particles with the host plant following beetle feeding and delivery of the virus to the plant through regurgi- tation. The major transmission route for RYMV must be estab- lished to facilitate the development of cultural management.

Farmer from Kyela discussing causes of RYMV disease in his rice crop

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Epidemiology and crop loss assessment of rice nematodes in West Africa

R6009, R6658 Escalating demand for rice in West Africa is being met by imports rather than by increased production. The West Africa Rice Development Association (WARDA) is working to en- R. A. Plowright able the region to become less reliant on imported rice. This project aimed to add to International Institute of Parasitology limited existing knowledge on rice nematode pests in the region. The research has clari- (now CABI Bioscience), UK fied nematode pest distribution, both throughout West Africa, and on a more local scale. D. L. Coyne The contribution of individual nematode species to crop damage has been addressed, but Natural Resources Institute (NRI), the complex nature of interrelationships between nematode species and their environ- University of Greenwich, UK ment has been challenging. As rice cropping practices change to meet the increased demand for rice and production systems become more intensive, nematode problems will M. Dingkuhn become increasingly serious. This is already taking place in the savannah, but is also West Africa Rice Development apparent in the forest zone. The project has identified very good sources of resistance to Association (WARDA), Côte d’Ivoire some important nematode pests which will enable the development and extension of September 1994–March 1996 practical and appropriate nematode management. These outputs are being adopted by April 1996–February 1998 WARDA as part of their selection process for improved rice lines.

ISSUES sound management strategies. This work aimed to provide the basic Rice is a major food staple in West background knowledge, examining SELECTED PUBLICATIONS Africa. Rice consumption in the the pest status of nematodes in region is rising at the rate of 45% upland, hydromorphic and lowland COYNE, D.L., PLOWRIGHT, R.A. and a year, but currently this escalating swamp rice-growing environments FOFANA, I. (1996) Preliminary investi- demand is met by imports rather of West Africa; examining the gations of plant parasitic nematodes than by increased production. influence of shortening fallow on associated with rice in Guinea, Benin and Imported, subsidized rice competes emergent pest species; and making Togo. Afro-Asian Journal of Nematology with local production and at the a preliminary assessment of likely 6: 70–73. same time fuels demand, producing nematode management options. an acute need to increase rice COYNE, D.L., THIO, B., and FOFANA, production in the region. Tradi- ACHIEVEMENTS B. (1996) Reaction of nine rice cultivars tional upland rice-farming systems to cyst nematodes and weeds. In: 1995 in West Africa are built around Rice fields in West Africa are very WARDA Annual Report. Bouaké, Côte forms of shifting cultivation in a variable in terms of water availabil- d’Ivoire: West Africa Rice Development mixed farming system. Population ity, which results in nematode Association, pp. 70–71. and production pressures have led communities of unusually diverse to a decrease in the fallow periods composition, species normally DE LEY, P. and COYNE, D.L. (1997) between crops, and to more separated by stable ecological Actinca irmae sp. n., a new species of intensive cropping. The West Africa adaptation to lowland or upland Actinolaimidae (Nematoda: Dorylai- Rice Development Association rice occurring together. Nematode mida) from Ivory Coast. Russian Journal (WARDA) is working to enable this species have preferred environ- of Nematology 5: 45–54. intensification to proceed in a mental distributions, dictated by sustainable way. water conditions, although some COYNE, D.L., NDONGIDILA, A., In the context of shortening fallow species are less specific than OYEDIRAN, I., HEINRICHS, E.A. and and more intensive cropping, plant others. Research results indicated PLOWRIGHT, R.A. (1998) Pratylenchus parasitic nematodes are likely to be the wide distribution of potential zeae in upland rice as influenced by the an important production constraint. rice nematode pests within the ratio of intercropped maize. International However, there is very little region. The rice nematodes Rice Research Newsletter 23: 27–28. information available on nema- surveyed in the forest zone in todes in West African rice-based the Ashanti region of Ghana are COYNE, D.L., PLOWRIGHT, R.A., THIO, smallholder cropping systems, and fairly typical of West African B. and HUNT, D. (1998) Plant parasitic WARDA has insufficient resources hydromorphic environments nematode diversity and prevalence in tra- to rectify this. Understanding of the (Table 1). In northern Ghana, ditional upland rice in Ivory Coast: pre- nematode communities and an undescribed species of liminary observations on the effects of population dynamics within the Ditylenchus of unknown impor- cropping intensification. Fundamental diverse rice-growing environments tance was highly prevalent on and Applied Entomology 21: 723–732. is needed to assist in developing rice. Nematode communities tend

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larly H. sacchari which is not Table 1. Prevalence of plant parasitic suppressed by improved crop nematodes in rice in the forest zone of rotations. Ashanti Region, Ghana Resistance to both H. sacchari and Nematode species Prevalence* M. incognita has been identified through screening trials, but not Coslenchus franklinae 76 for P. zeae or H. oryzae. Weed Helicotylenchus dihystera 47 infestation reduces H. sacchari Meloidogyne sp. 26 Pratylenchus zeae 26 population densities in upland Tylenchorhynchus annulatus 24 fields, and H. oryzae in lowland Heterodera sp. 12 fields. Pratylenchus zeae popula- Pratylenchus brachyurus 12 tion densities on rice are higher Xiphinema bergeri 12 under mixed cropping conditions Helicotylenchus cf. mucronatus 9 with maize. Mineral fertilizer inputs Longidorus laevicapitatus 6 Sakia 6 affected nematode distribution, Aphelenchoides 3 but inconsistent results indicate that Axodorylaimellus 3 many more variables need to be Basiria 3 accounted for in further research. Chronogaster sp. 3 Dorylaimellus 3 A range of other avenues of Filenchus 3 nematode management have been Hemicriconemoides cf. affinis 3 researched, such as improved crop Longidorus pisi 3 rotations, which will prove impor- Rotylenchulus reniformis 3 tant elements of fully integrated *Percentage of farms with particular nematode spp. pest management technologies in rice cropping systems. This project has also highlighted important to be complex, comprising a wide over 50% reduction in nematode issues concerning the interaction diversity of species. As a conse- diversity in upland fields. In the of nematodes and other constraints quence, and due to the varied and savannah zone nematode preva- in rice production. In many cases often contiguous conditions lence increased markedly with nematodes have been overlooked, present in rice-growing situations, intensification of rice production, despite their importance, for assessment of yield losses caused particularly of P. zeae. example in determining the by nematodes is complicated. outcome of competition between In mixed populations, H. sacchari rice and weeds. Also, drought stress In field trials and on-farm studies, replaces the widespread upland is recognized as an important high populations of root lesion rice pest Meloidogyne incognita constraint to upland rice produc- nematode, Pratylenchus zeae, were (root-knot nematode), and becomes tion, but is far less severe in the consistently associated with low dominant. The nematode is more absence of particular nematodes. grain yield in upland rice. More- prevalent in rainfed lowland/ over, high nematode populations hydromorphic conditions where The project also served to build a in farmers’ upland rice fields at rice production is more intensive. nematology capacity in West Africa harvest were associated with low It is less pathogenic under such through in-service training grain size. Heterodera sacchari was conditions, but is nevertheless of technical and regional NARS found to be highly pathogenic on damaging. Heterodera sacchari staff, and specifically through an susceptible rice cultivars under appears less prevalent than intensive one-week training upland/hydromorphic conditions. M. incognita in the region, but the workshop. It severely suppressed crop devel- slow hatching of juveniles over opment, and in field trials caused several weeks means that its FUTURE complete crop losses in some prevalence was underestimated cases. Losses were greatest in using standard extraction tech- The research results will aid combination with drought stress. niques. It appears to have a low WARDA in assessing the impact incidence in the first few years of of current cropping practices on In lowland rice, Heterodera oryzae rice following secondary forest, nematode pests, and the implica- populations at harvest were after which population levels tions of this for future production. negatively associated with yield. increase rapidly. With intensifica- Information on nematode-resistant In the forest zone, current fallow tion of rice production, improved cultivars will be used by WARDA periods appear sufficient to prevent weed management and widespread in their selection procedure for nematode build-up, but pest use of improved cultivars, it is improved cultivars. species quickly predominate within likely that nematodes will be a single rice crop, accompanied by increasingly problematic, particu-

39 DFID CROP PROTECTION PROGRAMME

Optimizing insecticide barriers for locust control

R7065 Locust outbreaks have affected farmers on all continents since agriculture began, and often necessitate treating thousands of hectares with insecticidal sprays. Usually when J. Cooper treating locust hoppers the whole area is sprayed, but an alternative is to treat only narrow Natural Resources Institute (NRI), strips of vegetation. These strips or barriers are then encountered by gregarious hoppers as University of Greenwich, UK they roam around in search of food, and they consume a lethal dose of insecticide within January 1998–March 2000 the barrier. Although the barrier technique is not new, research support was required to analyse barrier spacing for different species of locusts, to identify suitable insecticides, and to determine effects on non-target species. The project’s findings will allow hopper- infested areas, which can be extremely extensive, to be managed in a way which is effective, practical and potentially less damaging than either full coverage spraying or reliance on organochlorine insecticides. The sensitive non-target species which are at risk from locust control operations have been identified, and field assessments linked to a literature review on behaviour indicate that the combination of insect growth regulators with the barrier technique is relatively benign for the environment: insect growth regula- tors are innately less toxic than alternative pesticides, and the barriers are applied to only a fraction of the affected area.

ISSUES ‘treated’, and although it is inap- propriate for winged adults, the When environmental conditions technique can successfully control are favourable, locust numbers many species of locusts and increase, sometimes producing grasshoppers at the gregarious devastating results. Historically this stage, which is induced by high has required extensive control population density. In this stage operations using insecticides which hopper behaviour and appearance are usually applied as total cover- change markedly, and they become age treatments, often over very much more of a threat to crops and large areas. Even in recession years grazing areas. Elegantly, it is this some species of locusts and changed behaviour which enables grasshoppers congregate in groups the barrier technique to work, and threaten crops and grazing because hoppers roam around areas, so routine control operations together in their search for grazing, using insecticides are necessary. and encounter the sprayed barriers. Many operational constraints to The efficacy of insecticide barriers safe and efficient locust control relies on the movement and exist. There are often deficiencies feeding behaviour of these gregari- in the information, equipment and ous groups or bands of hoppers so trained personnel needed to survey that they encounter the treated and control locusts by covering the strips and consume a lethal dose of whole area with sprays. The barrier insecticide. technique involves spraying narrow There has been uncertainty strips of vegetation, termed concerning the best spatial arrange- barriers, with insecticide, rather ment of insecticide barriers to than treating the whole area. As the achieve an effective compromise barrier spraying technique is used between high control efficacy, low as an alternative to full coverage or control cost and low environmental blanket spraying, the reduction in impact. The objective is to use the the area treated provides logistical maximum barrier separation and advantages. Compared with the the minimum barrier width that tactic of finding and spraying all provides effective control. SELECTED PUBLICATIONS hopper bands individually, which is almost impossible in practice, the In this project four important locust HOLT, J. and COOPER, J.F. (2001) A barrier method is easier because it species were considered: desert model to compare the suitability of lo- removes the need for high-intensity locust (Schistocerca gregaria), cust hopper targets for control by insecti- surveys. By laying down barriers African migratory locust (Locusta cide barriers. Crop Protection (in press). the whole area is effectively migratoria migratoriodes), brown

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optimum distance moved conditions in order to recommend by a target hopper was which might be appropriate for approximately 160 m field use. All three insect growth per day. The analysis regulators tested appeared to be suggests that species with sufficiently photostable to be intermediate rates of suitable for barrier use, whereas the displacement form the results were less clear for fipronil, best targets for barrier which rapidly degraded into two treatment. main components in the presence of strong light. Choice of insecticide is critical because barriers In order to assess the non-target must remain active for effects of barriers, behavioural several weeks. Dieldrin information on a range of key non- was previously the barrier target invertebrates was gathered, insecticide of choice and an environmental monitoring because of its persistence, exercise in Madagascar evaluated Figure 1. Effect of distance moved and feeding but environmental accu- the impact of two of the pesticides behaviour on the proportion of hoppers mulation, which was having on non-target organisms during surviving barrier treatment an effect on non-target emergency locust control opera- locust (Locusta pardalina) and red species such as birds, caused the tions during 1998. The most locust (Nomadacris septem-fasciata), organochlorine insecticides to be significant result was the negative although these are not the only withdrawn. Now more modern impact of fipronil on termite species for which barriers are replacement insecticides are populations, which appears to be appropriate. Data on the four required for barrier use which have very severe. Apart from this marked species were gathered from impact on termites, when the locust archives held at applied in barriers, fipronil NRI, and information on the generally affects fewer non- behaviour of other locust target invertebrates than species is not sufficiently triflumuron, and has rela- complete to incorporate into tively minor adverse effects. the model. Immature spiders, non-target grasshoppers and flies were ACHIEVEMENTS the other terrestrial inverte- brates that showed indica- A mathematical model of the tions of adverse, short-term barrier technique was impacts. Work on triflumuron developed which encom- confirms evidence of some passes the behaviour of minor adverse impacts of different locust species, Figure 2. Swarming hoppers in Madagascar barrier-sprayed insect growth in order to rationalize the regulators on the relative optimal barrier width and spacing suitable characteristics such as abundance of spiders, grasshoppers, for different species and growth relative stability and acceptably crickets and caterpillars, with stages. The model demonstrates low mammalian toxicity. In this termites also being affected in the that when the probability of work the insect growth regulators short term. The model, and other feeding within a barrier is taken teflubenzuron, triflumuron and results obtained by the project, have into account, there is an optimum diflubenzuron were compared with produced a greater understanding rate of hopper movement which is fipronil, an insecticide with a more of barriers, and will allow more a compromise between maximiz- conventional mode of action. rational decisions on insecticide ing the probability of a hopper Sunlight is an important factor in choice. encountering the barrier during the degradation of insecticides and period when the barrier remains rapidly renders them inactive. FUTURE biologically active, and the Simulated solar degradation was probability that a hopper will used as a measure of the robustness Deployment of barriers for different engage in feeding activity whilst of the molecules and relative field species of locust hoppers will lead inside the barrier. The optimum persistence. Survival under power- to environmental benefits over full movement rate of the target was ful artificial light was used as a coverage spraying. The agencies sensitive to the pattern of feeding means of comparing their suitabil- concerned with locust control will activity, and a range of feeding ity as barrier insecticides. The four be working to validate the hypoth- patterns were explored. With candidate barrier insecticides were eses developed in this project by a barrier width of 50 m, the compared under simulated field carrying out field trials.

41 DFID CROP PROTECTION PROGRAMME

Field demonstration of vertical-looking radar as a cost-effective, automatic monitor of desert locust migration

R5445 If conditions are favourable for breeding, solitary desert locusts can show enormous popu- lation growth over successive generations, leading to swarming and the major destruction J.R. Riley of crops and livelihoods. To help in detecting early signs of population increase, a novel Natural Resources Institute (NRI), vertical-looking radar for monitoring the migratory flight of insects at high altitude was University of Greenwich, UK previously developed by NRI. This project involved a series of field trials in Mauritania, December 1992–March 1996 followed by an all-weather trial in the UK, which confirmed the system’s capacity to ac- quire and store large amounts of data on insect migration. The method is inexpensive to run, and is well suited to monitoring desert locusts. Improvements in locust forecasting will enable targeting of control measures, and the control of swarms before they reach devastating proportions.

ISSUES work resulted in the development describe the speed and direction of of a novel form of vertical-looking locust migration. The trials also Once non-swarming, solitary desert radar (VLR). The aims of the present revealed that the prototype equip- locusts begin to breed there may be project were to evaluate prototype ment needed re-engineering to make an enormous increase in numbers VLRs in overseas field trials, and to it suitable for long-term use by non- over successive generations, demonstrate the system’s capacity specialists. Thus in a 1-year accompanied by a change into the to make long-term, automated extension to the original project, a swarming, gregarious phase. measurements of insect migration new VLR antenna system suitable Monitoring these population in general. for long-term running was designed upsurges would enable early and built in the UK. The very prediction of swarms and targeted ACHIEVEMENTS satisfactory technical performance application of control, and thus the of this VLR has demonstrated that alleviation of huge crop damage Two radars were deployed: one automatic, routine monitoring of and consequent poverty. However, VLR, and one scanning entomologi- insect aerial migration is now a desert locust solitaries migrate at cal radar of conventional design, to feasible and economic proposition. night, and at altitudes of several provide a control. Locust The trial has yielded valuable hundred metres, so it has not been populations, and those of other information about the range of possible to monitor their move- large insect species (which could conditions over which the current ments effectively. The only method be confused with locusts by the configuration of the VLR can of observing the migration of radar), were monitored by ground operate satisfactorily. The data set solitary locusts has been with radar, surveys and light-trapping. on insect movement incidentally but the use of conventional The 1993 field trials in Mauritania constitutes the first systematic scanning entomological radars is revealed errors in the processing record of insect migration at high very time-consuming and highly routines which had not been altitude over the UK. specialized, and it is not practical revealed by previous trials with to use these systems routinely. simulated data, so processing FUTURE In the late 1980s work was carried algorithms were rewritten for the There is great potential for the out at NRI to design an inexpen- 1994 trials and were then found to application of this practical and sive, automatic radar suitable for produce size distributions consist- inexpensive technique in monitor- monitoring insect migration. This ent with those estimated from the ing programmes for locusts and scanning radar. The processing other insect migrants. Although algorithms were also modified to SELECTED PUBLICATIONS there has not yet been any long- make them more robust when term VLR deployment in Africa, SMITH, A.D., RILEY, J.R. and GREGORY, challenged by atypical signals, and two remotely operated VLRs are R.D. (1993) A method for routine to improve error handling. now operational in Australia, monitoring of the aerial migration of Overall, the field trials confirmed deployed against the Australian insects by using a vertical-looking radar. the validity of the VLR concept. The plague locust, and two are also in Philosophical Transactions of the Royal results indicated that reliable continuous, routine use in the UK, Society of London B, 340: 393–404. differentiation between locusts and monitoring the abundance and SMITH, A.D. and RILEY, J.R. (1996) other flying insects was achieved, movement of insects over southern Signal processing in a novel radar for and that although the prototype England. In this second pro- monitoring insect migration. Comput- VLR flight trajectory data did not gramme the emphasis is on ers and Electronics in Agriculture 15: exactly match that derived from the environmental issues rather than on 267–278. scanning radar, it was adequate to pest control.

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Identification of the factors which lead to changes in desert locust populations at the beginning and end of recession periods

Smallholders in marginal, semi-arid areas are most vulnerable to desert locust attacks as R6822 they have fewer options for mitigating the impact of damage to staple crops, other than J. Rosenberg abandoning the land and moving to urban areas. Since locust outbreaks are often associ- Natural Resources Institute (NRI), ated with major climatic fluctuations such as the occurrence of droughts, they pose University of Greenwich, UK a significant additional threat to food security in rural areas that are already vulnerable. This project has compiled and analysed basic data needed to improve the locust-forecast- December 1996–November 1999 ing capacity of the Emergency Centre for Locust Operations in Rome; assessed the proc- esses leading to changes in desert locust populations; and laid the groundwork for using this improved knowledge to develop a decision-making tool to assist forecasters.

ISSUES stretches over 16 million km2 from ECLO’s forecasting capacity by Mauritania to north-west India. determining the processes leading Plagues of the desert locust, to changes in desert locust The current control strategy Schistocerca gregaria, intermit- populations, and using this knowl- tently affect over 65 countries in assumes that any locust population edge to develop a decision-making Africa, the Middle East and south- gathering in groups could lead to tool to assist forecasters. Desert west Asia. This pest poses a particu- an upsurge and subsequently locust plagues begin and end lar control problem since, unlike a plague. Successful control relatively quickly, and the key to most species of locust, it has no depends on the adequate flow of successfully sustaining survey and permanent outbreak area but lives information on weather, locusts and control capability in affected in relatively scattered populations vegetation between national and countries is the ability to efficiently in a generally arid environment regional organizations and the increase and reduce survey and known as the recession area, which FAO’s Emergency Centre for Locust control capacity as plagues start Operations (ECLO) in Rome. The and finish, through timely opera- Publications: see Bibliography on CD. aim of the project was to enhance tional forecasts. ACHIEVEMENTS Breeding season j The project has completed an (j = 1–4) analysis of changes in the distribu- tion and numbers of desert locusts, particularly on a seasonal/annual Input locust data distribution, basis. Key indicators of the relation- size, density and age ships between environmental factors and locust population changes at the beginning and end of recession periods have been Calculate population development periods analysed, and will be incorporated from Reuss Development Model in a decision-making tool for assisting ECLO forecasters. FUTURE Calculate 10-day running Extract rainfall data from composite NDVIs for seasonal locust bulletins, climate The methodologies developed for breeding area monthly bulletins deriving improved forecasts need to be tested operationally over at least 2 years to assess their appropriate- Calculate threshold Compare NDVI and values for breeding risk rainfall values with ness in real-time forecasting. A previous season for long- follow-on project to produce a term forecast of locust validated decision-making tool population should incorporate historical Breeding/migration options developments analogues of spatial and temporal patterns of rainfall and vegetation for Migration different locust breeding seasons End of breeding season? developed by this project (Figure 1), YES to be used in conjunction with NO Figure 1. Flow chart of activities for monthly information on locust population assessment of locust breeding conditions distribution, density and maturity, (NDVI = normalized difference vegetation index) and synoptic weather data.

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Statistical analyses of desert locust movements

R6809 The extensive damage to crops that can be caused by locust plagues is well known. This project investigated the relationship between desert locust swarms and the weather sys- P. Burt Natural Resources Institute (NRI) , tems that influence them. More detailed knowledge of these interactions is essential for University of Greenwich, UK more accurate forecasting and control. Through a detailed examination of the large-scale weather conditions in the Mediterranean Basin, North Africa and the Middle East for a January 1997–May 1998 14-year period between 1958 and 1989, and of the behaviour of the desert locust popula- tion at the same time, relationships between locust movements and weather systems were investigated, and data extracted and incorporated into a geographical information system.

ISSUES The aim of this project was to • from winter to spring breeding develop statistical analyses areas in the Middle East Plagues of desert locust (Schistocerca of locust movements in synoptic • from spring breeding areas in the gregaria) start when rains occur weather situations (in particular Middle East to summer breeding close together in both time and Mediterranean cyclones and desert sites in India and Pakistan (in space, prolonging breeding and depressions) in order to improve association with movement on allowing populations to build up. forecasting of movements in these Persian Gulf cyclones). At times of plagues, locusts can systems and to promote improved spread to over 65 countries in survey and control strategies in A data capture, management and Africa, the Middle East and South- locust-affected countries. dissemination system (SWARMS: West Asia, causing devastation Schistocerca Warning Management to crops relied upon by large- and ACHIEVEMENTS System), based on a geographical small-scale farmers alike. information system, has been Locust movements for 14 years Because locust breeding areas developed by NRI and the Univer- between 1958 and 1989 were generally have scanty and erratic sity of Edinburgh under UNDP examined and plotted. Weather rainfall, a considerable degree of funding, and was installed at FAO data were also examined. coincidence is required between in 1996. This system permits adult locusts and rains in order to Six principal tracks of cyclones improved analysis and forecasting maintain populations. Downwind from west to east within the of locust events. The weather and migration takes locusts towards Mediterranean Basin have been locust data generated during the areas of horizontal wind conver- identified, as has a general trend for current project are suitable for gence and rainfall. Breeding areas disturbances to move eastward inclusion in SWARMS, as well as are connected by seasonal migra- across North Africa. There are, in national systems such as tion circuits, although the detail however, some variations on these RAMSES (Reconnaissance and of the circuits differs from year to routes, with some northward Management System of the Envi- year as they are dependent on movement both out of North Africa ronment of Schistocerca), making sources of emigrants and locust and across the Mediterranean them available to a wide audience trajectories in the windfields Basin, depending on season, of regional and country locust during migration flights. topography and weather condi- information officers. tions. No direct relationship Seasonal movements are influ- between cyclone frequency and the FUTURE enced by the effects of large-scale movements of desert locusts has (synoptic) weather systems and also This data analysis has increased been found, but such movements by local winds, both of which can our knowledge of the complex that do occur affect swarming move populations to areas unsuit- relationship between desert populations; there is no evidence of able for breeding and survival, as locusts and the weather systems any relationship between cyclone well as to new breeding areas – that influence their movements, movement and non-swarming synoptic and local windfields are and has added to the data populations. The movements of thus important in ending upsurges available for locust forecasting. swarming populations lead to three and plagues, as well as maintaining In the long term, the analysis of important desert locust them. More detailed knowledge such data will lead to the devel- displacements: of such interactions is essential to opment of a forecasting rule enable the development of more • from summer breeding areas in which can be used to improve accurate forecasting and control West Africa to winter breeding control measures against this systems. areas in North-West Africa devastating pest.

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Models of Quelea movements and improved control strategies

R6823 The Red-billed Quelea bird is a major pest of small-grain cereal crops throughout semi- R.A. Cheke arid areas of Africa, attacking millet seed heads, mature sorghum seeds and other crops. Natural Resources Institute (NRI), Annual losses in Africa have been estimated as US$45 million. This project has achieved a University of Greenwich, UK better understanding of the factors governing Quelea migrations in southern Africa and a P.J. Jones framework with which to predict their movements, allowing control interventions to be Institute of Cell, Animal and Population planned in good time and more efficiently. Steps have also been taken to develop tech- Biology (Ashworth Laboratories), niques to minimize the environmental damage that such control engenders by research on University of Edinburgh, UK a detoxification mechanism, which shows much promise. P.J. Mundy Ornithological Research Unit, Depart- The aim was to develop a forecast- led to the appearance of important ment of National Parks and Wildlife ing method for Quelea in southern colonies in Namibia. Immediate Management, Bulawayo, Zimbabwe Africa, to be used to improve the advice on appropriate measures P. Barnard management strategies of national was made available by e-mail, Directorate of Environmental Affairs, pest control authorities. followed by on-site visits by project Ministry of Environment and Tourism, personnel. Windhoek, Namibia ACHIEVEMENTS A Quelea database compiled by E. van der Walt Methods of typing Quelea birds the project has been distributed to Quelea Research Unit, Plant Protection using microsatellite DNA have national agricultural organizations, Research Institute (PPRI), Pretoria, been developed in conjunction and provides information on South Africa with known plumage polymor- Quelea breeding sites (some of M. Mphathi phisms, which will assist which are traditional). These data, Department of Crop Production and in establishing migratory routes of coupled with a prototype computer Forestry, Ministry of Agriculture, different subpopulations in south- Gaborone, Botswana model driven by remote-sensed ern Africa, and the extent to which data on rainfall and vegetation October 1996–March 1999 these populations might remain conditions, will permit forecasting geographically discrete. ISSUES of zones where Quelea are The two subspecies involved in expected to occur. The Red-billed Quelea bird Quelea southern Africa are Q. q. lathamii In addition, a promising method for quelea, sometimes described as the and Q. q. spoliator, but the taxo- cleaning up sites contaminated by ‘feathered locust’, is a major pest of nomic validity of the latter is fenthion, the pesticide used against small-grain cereal crops throughout in doubt. Q. q. lathamii breeds Quelea birds, has been identified semi-arid areas of Africa. US$45 in Angola, Botswana, Malawi, using the fungus Phanerochaete million worth of grain loss was Mozambique, Namibia, South chrysosporium, which has been attributed to Quelea damage Africa and Zimbabwe. The sub- shown to break down fenthion in in Kenya and Tanzania in 1989. species Q. q. spoliator, thought by the laboratory. Quelea birds regularly migrate some to have a separate migration Combined with more efficient long-distance from one area or system from Q. q. lathamii and thus control technologies, forecasts country to another. The routes and to need a separate control strategy, incorporating relevant climatic and timing of movements of the cannot be considered a valid taxon ecological data should lead to different subspecies of Q. quelea on the basis of morphological substantial benefits in terms of in southern Africa, and the influ- research conducted during this increased crop yields, reductions in ence of environmental variables, project. Thus control plans and pesticide usage and improved are not fully understood. Quelea forecasting do not need to assume control strategies. migrations are determined by the existence of two separate weather patterns and vegetation as migration routes within the south- FUTURE the birds feed on grass seeds which ern African system. germinate following rain. The Follow-up research to promote the number of times they can breed These results have improved the ability of the Problem Bird Control findings of the project should depends on the prevailing condi- include testing and refining of tions, with good rains tending to Unit of Zimbabwe, and similar organizations in southern Africa, to forecasts based on model outputs permit more breeding attempts. in relation to real-time events in It is the young birds from successful respond to Quelea attacks on crops by enhancing their understanding southern Africa, and the develop- colonies at the periods when millet ment of the prototype model into a or sorghum is about to be harvested of Quelea ecology. In just one example, project personnel and form for general dissemination. If that are responsible for most these tests prove successful then damage to subsistence agriculture. target country collaborators noted extensive Quelea breeding in the model could be adapted for use Publications: see Bibliography on CD. Botswana and Zimbabwe which in other African countries.

45 DFID CROP PROTECTION PROGRAMME

Detection of phytoplasmas in putative insect vectors of Cape St Paul wilt disease of coconut in Ghana

R6521 Diseases caused by phytoplasmas are causing considerable economic damage to coconut production in the Caribbean and Mexico, East and West Africa, and possibly in parts of L. Kenyon South and South-East Asia. Identification of the vector(s) of the disease in specific areas is Natural Resources Institute (NRI), important , and may allow the development of protocols for screening of germplasm for University of Greenwich, UK resistance. However, conventional transmission tests are difficult to do for coconut and P. Jones have so far been unsuccessful in Africa. This project focused on the detection of the Cape Institute for Arable Crops Research St Paul wilt disease phytoplasma in insect vectors and infected coconut palms; the im- (IACR), Rothamsted, UK provement of procedures in the Molecular Biology Laboratory in the Department of Crop Science, University of Ghana; and the establishment of links with the Coconut Sector S.K. Offei Rehabilitation Project under the French Development Agency and the Government of University of Ghana, Accra, Ghana Ghana. Methods developed to detect the phytoplasma using a nested PCR protocol suc- January 1996–March 1999 cessfully amplified disease-specific products from both symptomatic and asymptomatic palms. This is the first time that a non-destructive sampling method has been successfully used in Africa to diagnose the coconut disease phytoplasmas. ISSUES Coconut is of unique value to of Cape St Paul wilt in the different actions needed to perform PCR. coastal smallholder communities as regions so as to monitor and Both techniques were transferred to a source of food, shelter and rural control infectivity in vector the laboratory in Ghana where they income, and the localized impact populations and to develop a immediately improved the results. of phytoplasma diseases has been controlled resistance screening These improved techniques have devastating, particularly in Ghana. technique (infection can only take enabled the detection of phyto- Cape St Paul wilt was first observed place by the vector route). This is plasma in all parts of infected in the Volta Region in 1932, where difficult to achieve by con- palms, the highest concentration by the 1950s it had destroyed the ventional tra nsmission tests. The being in meristem and young frond coconut industry. It was first objective was to develop and apply tissues. Preliminary studies suggest detected in the Western Region in specific, sensitive techniques to that there could be more than one the 1960s, and now affects 40% of detect phytoplasmas in putative phytoplasma strain present in the remaining 40 000 ha of palms insect vectors, using the polymer- coconut palms in Ghana. Nested in the western coastal belt. ase chain reaction (PCR) to amplify PCR has shown that Myndus spp. the DNA of this phytoplasma. Research in southern Florida has leafhoppers can carry a phyto- defined the main features of lethal ACHIEVEMENTS plasma in Ghana, but further work yellowing disease in the New is needed to establish its identity, World, and identified a This project built on work begun then the role of the insect as a planthopper vector, Myndus under R6160, and made two major vector will have to be examined. improvements to the testing crudus, in that region. A highly Contact with the coconut rehabili- resistant variety, the Malayan dwarf regimes. The first was to adopt a non-destructive method for tation project funded by Agence variety, was identified and provided Française de développement has the basis for what has often been sampling palms without having to cut them down. It involved the been established. The diagnostic regarded as a model coconut facilities established in Ghana, if rehabilitation programme. How- drilling of an 8-mm hole about 100 mm into the trunk of the palm, maintained, will be invaluable to ever, although the diseases in Africa collecting the wood shavings the project in screening potentially show many symptomatological produced and placing them in resistant/tolerant germplasm, and similarities to lethal yellowing, solution from which DNA was then monitoring for disease in seedling differences in varietal susceptibility extracted in the laboratory. The nurseries and new coconut and epidemiology suggest that second improvement was the plantings. different phytoplasmas have introduction of a nested PCR using evolved in each region. Also, early commercially available dried-down FUTURE experimental plantings of Malayan PCR reagents. These are stable at A further project is being formu- dwarf and other varieties in Ghana room temperature and have a long lated with the goal of reducing and Tanzania did not perform as shelf life, reducing the need for losses due to phytoplasma diseases well as expected. freezer storage of the DNA of coconut in Ghana and Tanzania An important part of these studies polymerase leading to fewer through the standardization of has been to identify insect vectors accidental losses due to power molecular diagnostic techniques cuts. They also reduce pipetting and their use to monitor coconut Publications: see Bibliography on CD. errors by cutting the number of rehabilitation programmes.

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Evaluation of the significance and potential for control of mistle- toe in cocoa and citrus

R6656 This project has determined the extent and significance of mistletoe infestations of citrus and cocoa. Demand for improved methods of mistletoe control was identified among C.R. Riches, D. Overfield cocoa farmers in Ghana. The study confirmed the macro- and micro-economic impor- Natural Resources Institute (NRI), tance of cocoa and its fundamental role in rural livelihood systems in the cocoa-growing University of Greenwich, UK belt of Ghana. It also showed that mistletoes are a very significant and high-ranking con- June 1996–March 1998 straint on the productivity of cocoa. There is institutional support in Ghana for work aimed at investigating the local manufacture and promotion of an inexpensive pruning tool. There does not appear to be the need for further work in commercial citrus, and no significant problem was identified which affects smallholder citrus growers.

ISSUES Latin America and the Caribbean. security, probably the only The general practice is to pull the vehicle which many households Mistletoes, woody shoot parasites parasite by hand from the citrus can use to access loans. Farmers in the plant families Loranthaceae canopy twice a year, which is said see the maintenance of the farms, and Viscaceae, cause stunting, to cost in the region of 25 US cents albeit at a very low level yield loss and, in severe cases, per tree, representing a significant of productivity, as an essential death of cocoa, citrus and many input for large estates. duty so that the trees can be other tree-fruit and forest species passed on to future generations. throughout the humid tropics. Little In cocoa, relatively few problems up-to-date information was are reported from South America, Farmers report that mistletoe previously available on the current where the crop is native. In the infestation has increased during status of mistletoes as pests. The humid forest zone of West Africa, the past 20 years, largely due to aim of this project was to assess the however, cocoa is parasitized by the lack of availability of service- extent of parasitic mistletoe a number of mistletoe species, 70% able pruners (last sold in 1991). infestations of citrus and cocoa of infestations being by Tapinanthus Mistletoe removal with a cutlass, crops, and to report on the feasibil- bangwensis. Mistletoe infestation while using a ladder or climbing ity of developing appropriate occurs in all types of cocoa farm, the infested tree, is the only control measures. but is most prevalent in poorly alternative to using a pruner but maintained cocoa with little or no is perceived to be a dangerous, ACHIEVEMENTS shade. unpleasant task. In consequence The infestation of cocoa by labour hired for this purpose A full literature review of the Tapinanthus and other mistletoe attracts a significant premium. distribution of mistletoes on cocoa species in West Africa is the most A widespread demand for and citrus in Latin America, Asia widespread and economically pruners was identified. and Africa was carried out, along significant pest mistletoe problem with consultations with local identified by this review. This study FUTURE researchers. therefore focused on the current In Central America, Mexico and the situation on smallholder cocoa Future research should focus on Caribbean, commercial citrus farms in Ghana, where cocoa is by developing an appropriate design estates undertake regular pruning to far the most important source of for a locally manufactured long- control Struthanthus, cash income for households. Since handled pruner. The institutional Phoradendron, Phthirusa and other the 1960s productivity has been arrangements for funding pro- species. Mistletoe infestation declining, with Ghanaian produc- curement and maintenance of citrus is an important factor tion now accounting for 10% of pruners at the village level in orchard management in parts of of world cocoa output. This decline should be the focus of future is attributable to a number work which could be imple- of factors including the ageing mented by local appropriate SELECTED PUBLICATIONS cocoa tree stock; ageing landown- technology consultants with ers and associated land tenure experience in small-scale agricul- OVERFIELD, D., RICHES, C., ASAMOAH. issues; lack of control of key pests tural engineering. In order to kick- M., SARKODIE, O. and BAAH, F. (1997) and diseases; the high cost of start the supply of locally produced A farming systems analysis of the mistle- inputs; poor producer prices and pruners, a pilot project should be toe problem in Ghana. Cocoa Growers the resulting poor returns. Cocoa established to stimulate their Bulletin 51: 42–50. plots are an important form of manufacture.

47 DFID CROP PROTECTION PROGRAMME

Development and evaluation of a pilot field handbook on natural enemies of vegetable pests in Kenya and Zimbabwe

R7266 Surveys of farmers in Zimbabwe and Kenya found that, despite moderate or high aware- R.H.J. Verkerk, D.J. Wright ness of the existence of natural enemies, the majority were unable to distinguish between Imperial College of Science, natural enemies and pests on their crops. Most admitted to spraying crops regularly, in part Technology and Medicine, UK to help eliminate arthropods that were not recognized as natural enemies. This project S. Simons developed training materials to encourage farmers to identify natural enemies and to modify CABI African Regional Centre, Nairobi, their control practices accordingly. A draft field guide was produced for use by extension Kenya workers and trainers, and multilingual (Swahili, Shona and English) posters and flip-cards G. Kibata for use by farmers and trainers were developed. Workshops were conducted in both coun- Kenya Agricultural Research Institute (KARI)/National Agricultural Research tries to evaluate the materials produced by the project, and farmers’ recognition abilities Laboratories (NARL), Kenya were seen to increase dramatically following exposure to the training materials. S. Sithole Plant Protection Research Institute imported/established) natural field guide. The flip-cards comprise (PPRI)/Department of Research and enemies, and it is likely that sets of 36 photographs of key Specialist Services (DRSS), Zimbabwe conservation of these will be more natural enemies, each with a blank H. Dobson relevant to smallholder farmers card to allow farmers to include Natural Resources Institute (NRI), than the introduction of exotics. their own notes. This suite of three University of Greenwich, UK complementary materials is thought S. Page ACHIEVEMENTS to be the first of its kind worldwide African Farmers’ Organic Research and This short project operated in close for use in pest management or Training (AfFOResT), Harare, Zimbabwe collaboration with DFID-funded natural enemy training programmes. October 1998–March 1999 projects in Zimbabwe and Kenya, Feedback from the workshops has ISSUES and built on improvements in been incorporated into the final understanding of the current and drafts, and the training materials There are numerous programmes in potential role of natural enemies have already been exposed to sub-Saharan Africa that aim to help in vegetable production systems. farmers working with Crop Protection farmers improve pest management An important aspect of the initial Programme projects in Zimbabwe and sustainability of production, field surveys was the photographic (R6764) and Kenya (R6616). Local while reducing unnecessary recording of natural enemies on scientists from counterpart institu- pesticide inputs and minimizing the farmers’ fields. Generally, photo- tions all indicated that they had human health and environmental graphs of natural enemies are much learned a great deal about natural problems associated with pesti- less readily available than those of enemies during the course of the cides. Organizations working in the pests – pest species have received project and this information will, in region have identified the need to more emphasis in educational due course, filter through to farmers. improve smallholder farmers’ and training materials and, as knowledge of natural enemies and natural enemies tend to be FUTURE their use in pest management, and smaller and more mobile, they Large-scale production of the point to a lack of suitable training are more difficult to photograph. training materials, with possible materials for smallholder farmers. The field-based photographs (mainly linguistic) adaptation for This project represents the first were an indispensable medium neighbouring eastern and southern effort to compile a field guide and used in the training materials to African countries, will assist associated materials to be used help farmers recognize specific substantially in developing specifically within ‘Training of groups of natural enemies. sustainable pest management Trainers’ and ‘Farmer Field School’ systems for smallholder farmers programmes on biological and IPM. The primary outputs were the training materials, produced as and improving compatibility Most published work in this field drafts for distribution during and between biological and chemical relates to the introduction of exotic after the workshops for evaluation pest management systems. natural enemies, an approach and comment. These are being Strategically planned dissemina- favoured by many large-scale published under a current project tion, preferably coupled with commercial farmers. The surveys which is also sponsoring further farmer participatory research and conducted here reveal a range workshops in Zimbabwe. The main training on the integration of of indigenous (as well as previously publication is a pilot field guide on chemical and biological pest management in smallholder SELECTED PUBLICATIONS natural enemies for use by trainers and smallholder vegetable farmers systems, will be critically impor- VERKERK, R.H.J. et al. (1999) Important (see Selected publications). tant to help translate progress in Natural Enemies of Vegetable Pests in In addition, multilingual posters natural enemy recognition into Kenya and Zimbabwe: Recognition and and flip-cards were produced to improvements in biological Conservation. London: Imperial College. complement the English language control, IPM and sustainability.

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IPM of vegetables in Ghana

R6657 Over-intensive agricultural production, particularly of vegetable crops, has led to increased B.R. Critchley pest and disease problems. Farmers tend to respond by over-using chemical pesticides. Natural Resources Institute (NRI), Work with farmers in the Brong Ahafo region of Ghana highlighted their need for accessi- University of Greenwich, UK ble information, particularly on problems that are not easily visible such as plant diseases S.R. Gowen and nematodes. A pest identification manual for use by extension workers has been com- University of Reading, UK piled with this in mind, published and distributed. Two potential biocontrol agents for the specific problem of root-knot nematodes were evaluated, and practical methods of pro- J.C. Norman duction and application developed. Initial results suggest that both organisms (the bacte- Council for Scientific and Industrial rium Pasteuria penetrans and the fungus Verticillium chlamydosporium) could be useful Research (CSIR), Accra, Ghana components of an integrated system for vegetable pest management in Ghana, particularly B. Hemeng, R. Addae in cabbage. Kwame Nkrumah University of Science and Technology, Kumasi, Ghana April 1996–March 1999 of pests in two of the five major evaluated against these nematodes vegetable crops grown in the were a bacterium, Pasteuria ISSUES region: tomato and eggplant. penetrans, and a fungus, Farmers identified 15 groups they Verticillium chlamydosporium, In peri-urban farming situations land perceived as pests. These included combined with either poultry has a high value for alternative uses, grasshoppers, caterpillars, ants, manure or mulch. A series of pot such as housing, and there is con- termites, millipedes, beetles (found experiments showed that pepper stant pressure on farmers to increase on leaves), maggots, aphids, and cabbage supported the greatest productivity. In the Brong Ahafo crickets, butterflies, spiders, bees, amounts of the fungus region of Ghana this has encouraged mice, frogs and nematodes. By far V. chlamydosporium in their farmers to cultivate their land the most commonly mentioned rhizosphere, and led to the highest continuously and to use high levels were caterpillars and grasshoppers. infection rates in Meloidogyne of chemical pesticides. As a result However, despite their effects on eggs. Both the fungal and bacterial a single crop such as tomato may be yield, only one farmer mentioned biological control agents were grown almost continuously on the nematodes as a problem. The more effective when used in same land for 15 or more years. This majority of farmers were not aware conjunction with organic mulches intensity of production has led to the of insect life stages or of the process and amendments such as Panicum development of intractable and of metamorphosis, although a few maximum mulch and poultry costly pest and disease problems did have some knowledge. Plant manure amendments. including whitefly, nematodes and diseases were far less easily recog- Work was also conducted on virus diseases. nized by farmers, symptoms often culture media for producing being attributed to natural processes The project’s aims were to improve V. chlamydosporium: the best such as ‘hotness of the sun’ or methods for the control of weeds, media were based on milled maize ‘dampness in the soil’; some felt that insect pests, diseases and nematodes mixed with sand. Field trials showed leaf spots were caused by insects. in market gardening and commer- that P. penetrans will establish in Weeds were generally well recog- cial horticulture, and to develop and nematode-infested soil without the nized by farmers, who were mainly promote environmentally friendly need for further applications; concerned about grassy weeds. pest management packages. V. chlamydosporium did decline A pocket pest manual has been and re-application of this fungus ACHIEVEMENTS published, containing simple will be necessary, but as it is easy to Socio-economic studies concen- descriptions and clear illustrations culture this is not a major drawback. trated on farmers’ perceptions of pests and/or damage for use by extension officers who advise the FUTURE SELECTED PUBLICATIONS mostly illiterate vegetable producers in peri-urban communities. Free The latter phase of this project CRITCHLEY, B.R. (1997) Pests of Vegeta- copies have been distributed to formed links with studies by CABI bles. Their Identification and Control in government extension services, Bioscience on composting urban Ghana. Chatham, UK: Natural Resources universities, relevant NGOs and waste (R6941), with the objectives Institute, University of Greenwich. other national agricultural research of increasing vegetable production institutions in Ghana. and controlling pests and pathogens YVON, J. (1997) Farmers’ Perceptions: in peri-urban agriculture. Pests and their Management for Tomato Root-knot nematodes (Meloidogyne and Garden Egg Production. Kumasi, spp.) cause severe galling and root The results obtained here are now Ghana: Bureau of Integrated Rural damage on many food crops. being taken forward in Kenya Development (BIRD), internal report. Biological control organisms under projects R7403 and R7449.

49 DFID CROP PROTECTION PROGRAMME

Pest management in horticultural crops: integrating sustainable pesticide use into biocontrol-based peri-urban production systems in Kenya

R6616 Smallholder, peri-urban vegetable farmers in Kenya rely heavily on the use of chemical pesticides to control pests and diseases. This has led to increasing concern about pesticide J. Cooper residues in produce, operator exposure, and the development of resistance and envi- Natural Resources Institute (NRI), ronmental damage, especially to beneficial natural enemies. The cost of pesticides University of Greenwich, UK absorbs a significant proportion of farmers’ income, but currently they have few G. Oduor alternatives. This project has identified the key vegetable pests and diseases and their CABI-Africa Regional Centre, Nairobi, potential natural enemies, assessed which natural enemies could be useful in integrated Kenya pest management systems, investigated how pesticide use could be improved, and rec- ommended alternative pest management strategies. G. Kibata Kenya Agricultural Research Institute (KARI)/National Agricultural Research Laboratories (NARL), Nairobi, Kenya ISSUES The aims of the project were to Ministry of Agriculture, Livestock develop and promote improved Development and Marketing, Nairobi, Smallholder vegetable production methods for the control of pests Kenya provides an important source of and diseases affecting the quality employment, income generation and production levels of vegetables April 1996–March 1999 and poverty alleviation for more in peri-urban areas in Kenya, and than 200,000 households in rural specifically to improve pest areas around Nairobi. Peri-urban management methods used by production systems are character- smallholder vegetable growers in ized by intensive land use, and the vicinity of Nairobi, who supply typically produce high-value crops the urban population with fresh such as vegetables. A dependable produce. supply of safe and affordable vegetables is an important require- This project followed on from ment for the general health of the initial work in Kenya under R6146 urban population, especially low- (see Research Highlights 1989–95), income households, as fresh and benefited from data on vegetables provide vitamins and environmental effects of pesticides energy to supplement the staple and methods for ecological hazard maize diet. assessment compiled under projects R5368 and R6764. The major constraints in peri-urban SELECTED PUBLICATIONS production systems are pests and diseases, and to control these ACHIEVEMENTS MWANIKI, S., KIBATA, G., PETE, S., smallholder farmers still rely KAMAU, J., DOBSON, H. and COOPER, J. A participatory rural appraisal was heavily on pesticides. This can be (1998) Pest management in peri-urban undertaken to gather information hazardous to the health of both vegetable systems in Kenya: Spray on pest management practices and suppliers (through contamination application rates and distribution in the identify potential farmer collabora- while applying pesticides) and crop. In: Proceedings of the Second tors. From this appraisal it emerged consumers (through pesticide Biennial Conference on KARI/DFID that four main crops (kale, cabbage, residues in produce). Over-use of NARP II Crop Protection Programme, tomato and spinach) accounted for pesticides is also damaging to the 16–17 September 1998. pp. 1–11. over 95% of peri-urban vegetable environment, leading to pesticide production, and these crops ODUOR, G., ONGARO, J., PETE, S., resistance among insect pests and became the major focus of subse- KARANJA, P., COOPER, J., MWANIKI, diseases, and reducing the numbers quent research activities. S., KIBATA, G. and SIMONS, S. (1998) of beneficial natural enemies. By Pests of horticultural crops on small- developing an integrated pest PEST AND DISEASE SURVEYS scale peri-urban farms in Nyathuna, management strategy for vegetable Kiambu: Influence of pesticide regimes production which reduces reliance A series of season-long, on-farm on pests and natural enemies. In: on pesticides, the volume and surveys of the four crops grown in Proceedings of the Second Biennial quality of vegetable production will two contrasting agro-ecological Conference on KARI/DFID NARP II be increased in a sustainable way zones and under different manage- Crop Protection Programme, 16–17 in order to meet the requirements ment practices, i.e. organic and September 1998. pp.18–29. of an expanding urban population. high pesticide use (intensive),

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Table 1. Summary of importance of pests, natural enemies dose rate. Although manufacturers and diseases indicate on the pesticide label how much spray should be applied to Factor Cabbage Kale Spinach Tomato crops, the way the information is Most Diamond-back Diamond-back Aphids Leaf miner expressed varies from product to abundant moth moth Trichoplusia Thrips product and it is easy for farmers to pests Aphids Aphids Leaf miner Aphids be confused about how much to Trichoplusia Whitefly use, even when they measure Most Diamond-back Diamond-back Trichoplusia Bollworm carefully. Ambiguous or incomplete damaging moth moth Leafminer Leafminer pests Aphids Aphids Aphids Thrips label information resulted in under- Trishoplusia Trichoplusia dosing or over-dosing (up to six Most Syrphids Syrphids Spiders Ants times the volume rate required). abundant Spiders Spiders Ants Spiders Both are undesirable – the former natural Ants Ants Coccinellids Coccinellids risks crop failure and leaves enemies Most Black rot Black rot Cercospora Early blight surviving pests to breed, which damaging Ring spot Downy mildew Virus Late blight encourages development of diseases Downy mildew Virus Virus pesticide resistance; on the other hand, too much pesticide is identified the major pest and Following the results from the uneconomic and leads to excessive disease problems and areas of pest baseline survey, where unexpect- residues on harvested crops. management which required edly low numbers of natural On most farms, spray distribution improvement (Table 1). The enemies were observed, a more was poor (<5% coverage), highly diversity and severity of pests was detailed comparison was made in variable and gave minimal cover- substantially higher in the lower, which the effects of conventional age on the lower surface of leaves warmer locations, whereas in pesticide regimes were studied and where many pests and pathogens higher, cooler places diseases were compared with a control (organic) are found. A modified spray lance the greater problem. Extensive in the same agro-ecological zone (the V lance), which releases spray surveys of natural enemies, for their effect on natural enemy upwards from within the crop particularly of the major brassica abundance. Farmers who grew rather than downwards from above, pests (diamond-back moth and their vegetables organically had all was developed. Whereas the aphids), revealed a rich diversity of undergone training with the Kenya conventional lance achieved <50% arthropod natural enemies, both Institute of Organic Farming (KIOF), reduction in pests and natural predators and parasitoids (a para- and were selected in collaboration enemies, with the modified lance sitoid is a parasite that actually kills with KIOF. The four most com- there was almost complete control. its host). But at both locations monly grown crops were moni- However, it also had a negative natural enemy numbers were far tored for pest, disease and natural impact on natural enemy lower than expected, probably due enemy populations on 20 farms (10 populations. Further work is now to the long history of pesticide use. high-pesticide and 10 organic) just required to test the lance on more Natural enemies were found to be prior to harvesting (spatial experi- benign or target-specific formula- more abundant on organic farms, ment); and on three farms (high- tions such as Plutella xylostella although this could not be corre- pesticide, intermediate pesticide granulosis virus (PxGV) which lated with the severity of damage and organic) at weekly intervals infects diamond-back moth, and to caused by pests and diseases; pests throughout an entire cropping determine whether, with improved often caused damage in the season (temporal experiment). application efficiency, it would be presence of natural enemies. Figure 1 shows the effect of pesti- possible to reduce dose rates. cide regime on natural enemies However, from the taxonomic (spinach differed from the other Operator exposure was assessed identifications it emerged that a vegetables in receiving few qualitatively using a fluorescent number of the natural enemies pesticide treatments). tracer technique. A significant identified were, in fact, hyper- quantity of pesticide was found on parasitoids (hyperparasitoids attack PESTICIDE USE the protective suits used in the other parasites within a host trials, which indicates that farmers— organism). Further studies are Pesticide use by farmers was who often wear little or no protec- needed to understand these studied in terms of the choice of tive clothing – are being heavily complex interactions in order to active ingredient, quality of exposed to the pesticides they are quantify the impact of natural application and its effectiveness. It using. enemies on pest management. The was clear that the majority of potential benefits of using natural vegetable crops were receiving an CONTROL METHODS enemies in conjunction with more incorrect pesticide dose. Only 22% benign pesticides also need to be of the applications observed were The influence of pesticide regime explored. within 25% of the recommended (conventional and non-conven-

51 DFID CROP PROTECTION PROGRAMME

tional) was studied in a series of quantities of individual ingredients. the farms. These experiments need large, multifactorial experiments None of the non-conventional to be repeated before definite conducted either on-station or on- pesticides was particularly effective conclusions can be drawn. farm in contrasting agro-ecological against the aphid Brevicoryne, Plant virus diseases were found in zones over consecutive growing which is the second most important samples taken from almost all seasons. Non-conventional pest of brassicas. brassicas and peppers collected pesticides included a botanical For root-knot nematodes on tomato from farms. It is likely that yields concoction developed by KIOF, seedlings in the nursery, the are being significantly reduced. The PxGV, Bacillus thuringiensis (Bt), treatments applied had a limited extent of this viral infection and the neem, Mexican marigold, burnt effect on nematode populations, source of the infection (whether trash, chillies, hot water and milk. with only fresh marigold and hot largely seedborne or spread by On brassicas, both PxGV and Bt water showing a relatively small insect vectors) remains to be were promising against diamond- reduction in nematode populations. determined. back moth with only slight or zero The standard conventional pesti- impact on natural enemies, but Active farmer participation has cide, Furadan (carbofuran), was none of the non-conventional been a key feature of this project, found to be ineffective. Biological pesticides was particularly effective from the initial stakeholders’ control using Kenyan isolates of the against aphids. The standard meeting through to the pest risk nematode pathogens Verticillium conventional pesticide Karate assessment and conducting of and/or Pasteuria may be the answer. (lambda-cyhalothrin) gave poor collaborative on-farm experiments, Having been proven in the labora- control of diamond-back moth, and several farmer participatory tory, these organisms now need to which is attributed to insecticide workshops and in-field demonstra- be assessed on-farm. resistance, but gave good control of tions. The farmers themselves have played a significant role in direct- ing the research. FUTURE The complexity of the cropping system and the two types of production constraints (insects and diseases) require a longer-term approach than for a specific pest– crop interaction. The first phase of the peri-urban vegetable IPM project has laid a good foundation for developing a ‘basket of pest management Figure 1. Percentage of natural enemies in insect populations found on four options’ for the production of crops under three different pesticides input regimes peri-urban vegetables. It is now necessary to develop practical aphids; however, it also had a Control of tomato blight (early and and appropriate IPM strategies negative impact on natural enemies. late), the major constraint to tomato which will be adopted by The biopesticides Bt and, to a lesser production, was investigated in a smallholder peri-urban farmers. extent, PxGV were promising series of experiments on the Other areas include work with against diamond-back moth, with epidemiology of blight, the extent benign pesticides, and an only a slight (or no) negative impact of tolerance or resistance in exploration of the potential role on natural enemies. As expected, different varieties, and a compari- of clean and improved planting the specific virus PxGV had no son of conventional and non- materials. effect on anything but diamond- conventional control methods. Late back moth. It was particularly blight was found to be the domi- Existing routes for uptake include disappointing to observe the poor nant of the two diseases and farmer field schools in the peri- performance of the KIOF ‘concoc- frequently masked the symptoms of urban area, and collaboration with tion’, a botanical formulation early blight. None of the tomato NGOs (including KIOF) and with which is widely used by organic, varieties currently available in more traditional extension services peri-urban vegetable farmers, Kenya showed a consistent toler- (Ministry of Agriculture and KARI). although it would be useful to ance or resistance to blight, and In the second phase of this project compare the farmer-prepared KIOF there was no clear difference (R7403), farmer-friendly publica- mixture used in these experiments between the control treatments, tions will be produced and dis- with others – the recipe promoted although the application of milk seminated through a series of by KIOF does not specify the did suppress the disease on one of farmer participatory meetings.

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Investigation of biorational methods for control of insect pests of vegetables in Kenya

R6615 The diamondback moth (Plutella xylostella) is one of the most serious pests of cruciferous crops worldwide. In recent years it has become increasingly difficult to control by conven- A. Cherry, D. Grzywacz tional means because of the widespread development of resistance to chemical insecti- Natural Resources Institute (NRI), cides (including the newer pyrethroid insecticides), to insect growth regulators, and even University of Greenwich, UK to the bacterial biocontrol agent Bacillus thuringiensis (Bt). There is a need to develop new J. Pell control technologies that could be used as an alternative to Bt, or as part of an integrated Institute for Arable Crops Research (IACR), pest management system to prevent Bt resistance building up to uncontrollable levels. This Rothamsted, UK project, based in Kenya, has developed and refined methods for the management of veg- etable insect pests based on new biorational alternatives to chemical insecticides. Re- D. Moore search focused on a number of promising approaches, including the use of other microbial CABI Bioscience, Ascot, UK pathogenic agents such as insect viruses; mating disruption with synthetic pheromones; G. Kibata and the use of fungal pathogens. Kenya Agricultural Research Institute (KARI)/National Agricultural Research ISSUES was therefore to develop improved Laboratories (NARL), Nairobi, Kenya methods for the management of Kale and cabbage are typically the Kenyan vegetable insect pests April 1996–March 1999 most important vegetable crops based on new biorational alterna- grown by smallholders in Kenya, tives to chemical insecticides. with pests rated as the most important constraints to production. ACHIEVEMENTS Diamondback moth has been identified by a number of agencies VIRAL CONTROL OF as the key pest on crucifers and DIAMONDBACK MOTH brassicas throughout East and Southern Africa. A granulosis virus (PxGV) of diamondback moth was first Damage by diamondback moth in recorded in Japan in 1970. Kenyan vegetable production was Although since then PxGV has significantly reduced in the 1970s been extensively studied, little as smallholders’ use of organo- progress has been made towards chlorine insecticides spread. This its application for diamondback SELECTED PUBLICATIONS situation was maintained through moth control. the 1980s with the introduction of LUKE, B.M., BATEMAN, R.P., synthetic pyrethroids. However, by Previous work in Asia had identi- GRZYWACZ, D., PARNELL, M., the mid 1990s control was faltering fied non-Kenyan strains of insect THOMPSON, E.C. and MOORE, D. (1998) due to the decreased effectiveness viruses as potential control agents. Preliminary studies on the development of chemical control. Trials of However, there were difficulties in of a co-formulation of Beauveria bassiana standard insecticide (R6616; see obtaining clearance to work on and a granulosis virus. In: VII International page 50) have confirmed the high exotic viruses in Kenya, so this Colloquium on Invertebrate Pathology level of resistance to chemical work focused on the study of native and Microbial Control, Sapporo, Japan, insecticides in Kenyan diamondback moth viruses. New August 1998. diamondback moth. African strains of PxGV have been VEGA, F., KLEIN, M., DOWD, P., LACEY, discovered that are highly infec- Failure of chemical control in L., PELL J.K. and JACKSON, D.M. (2001) tious to diamond-back moth, and several countries in the late 1980s Dissemination of beneficial microbial have been shown in field trials to led to the widespread adoption of agents. In: Lacey, L. and Kaya, H.K. (eds) be more effective than insecticides the microbial pesticide Bacillus Field Techniques in Invertebrate Pathol- at controlling damage (see Figure 1). thuringiensis (Bt) in the early 1990s, ogy. London/San Diego: Academic Press. Field trial results with the new and for several years Bt-based strains were better than those PARNELL, M.A., ODUOR, G., KIBATA, integrated pest management (IPM) reported previously using Asian G., ONG’ARO, J. and GRZYWACZ, D. systems were successful. However, virus strains. (1999) The strain variation in granulovirus experience in the USA, Central of the diamondback moth (DBM), Plutella America, Hawaii and Malaysia has MATING DISRUPTION WITH SEX xylostella, isolated from wild insects in shown that diamondback moth PHEROMONES Kenya. In: Abstracts of the 33rd Annual rapidly develops resistance to Bt Meeting of the Society for Invertebrate when it is used repeatedly and Mating disruption with Pathology, No. 63. extensively. The aim of this project pheromones has been developed

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typical of small- that male moths attracted to the scale vegetable pheromone in the trap would enter producers in and be inoculated with a lethal Kenya. dose of the fungus. The moths would then leave the trap and PHEROMONE disperse to the crop, carrying the TRAPS TO inoculum to susceptible larvae and SPREAD thus spreading the fungal infec- ZOOPHTHORA tion. Moths succumbing to RADICANS infection would also be a source of inoculum in the crop. The The fungus advantages of this system over the Zoophthora conventional spraying of radicans com- mycoinsecticides are that: monly infects diamondback • only small quantities of fungus moth in the field and pheromone are required and is therefore of • the trap can be designed to interest as a protect the fungus from harmful biological control Figure 1. Effect of virus treatments on damage to kale effects of UV radiation and to agent. However, (OB = occlusion bodies) provide a suitably moist applications of environment to promote the for a number of economically Z. radicans direct to field crops activity of the fungus important lepidopterous pests (see against a number of pest targets, pp. 56, 71, 95). By permeating the including diamondback moth, have • only male diamondback moths air with a synthetic blend of female provided variable levels of control are attracted by the pheromone, pheromone components, male because of the need to apply the so the fungus specifically targets moths are prevented from following fungus to saturation point for this pest with minimal effects on odour trails of pheromone released germination and infection to take other organisms and the by females, resulting in a reduced place. Also, it is necessary for environment. level of mating and a significant microbial insecticides to be stored A prototype pathogen-dispensing reduction in the larval population for long periods, and stabilizing pheromone trap has been field of the next generation. This project fungal spores in a viable form poses tested in Malaysia (Figure 2). The has identified a combination of a significant technical problem. preliminary field work in Malaysia pheromone blend and dispenser At IACR-Rothamsted a novel was restricted to small-scale trials formulation that shows promise as system involving specially designed with the single pathogen a component of diamondback pheromone traps for the spread of Z. radicans; the current project moth control. The formulation Z. radicans by diamondback moth provided an opportunity to consists of poly vinyl chloride adults was developed to overcome conduct larger trials, to integrate (PVC) dispensers (originally these problems. The strategy was other fungal pathogens into the developed by NRI and now manufactured commercially by Agrisense-BCS), produced in a ‘string’ form for easy manual application to the crop. Field trials in Kenya have demonstrated that this can be used for successful mating disruption. In trials the formulation was more effective than chemical insecticides in controlling diamondback moth, reducing yield losses by 50% compared to control plots. Although there have been a few reports of the successful use of diamondback moth pheromone for control over large areas (>5 ha) in the USA and South-East Asia, Figure 2. PVC trap for importantly, this is the first time the dispensing pheromone technology has been demonstrated and insect fungal to be effective in small plots (0.1 ha) pathogens in the field

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Damage caused by Plutella xylostella on cabbage in Kenya; inset, adult diamondback moth.

system, and to determine the identification and distribution The results obtained, while focused suitability of this strategy for studies. on Kenya, have potential world- integration into diamondback wide significance, as the same pest moth management strategies for The results established that it is complex is a major constraint to subsistence farmers. possible to co-formulate viruses brassica production throughout the and fungi and retain their viability. tropics. These technologies could Following on from the work with a The development of dual-action have applications in a wide range Malaysian isolate, this study carried biological pesticides using PxGV of peri-urban vegetable production out field work in Kenya with a and fungus for control of centres throughout Africa and local isolate of Z. radicans. Cage diamondback moth and other South Asia. Given the simplicity trials confirmed that using these important species in the brassica of the technologies developed, autodissemination traps 10% of pest complex is therefore feasible. and the possibility of one appli- diamondback moth males could be cation where previously several infected with a fungal pathogen, The project has successfully had been necessary, there is a showing that the technique is developed and tested several new strong likelihood of adoption, feasible. Further research suggested approaches to the control of a key resulting in increased food produc- that the efficiency of the system pest of vegetable production in tion and quality, and reductions in could be improved further if a Kenya. Two technologies, insect the costly and risky use of chemical second insect pathogenic fungus, virus and pheromone mating pesticides. Beauveria bassiana, was used in disruption, have been successfully the pathogen dispensers alongside field tested in Kenya. The two other Z. radicans. technologies, autodissemination and FUTURE co-formulation, have been shown to The next stage of the project COMBINED FORMULATION OF be technically feasible, although VIRAL AND FUNGAL INSECT further research is needed before (R7449) will involve the develop- PATHOGENS they can be evaluated in the field. ment of these promising technolo- gies to the point where they can be A combined formulation of viral Currently used chemical insecti- evaluated on farm and, if appropri- and fungal insect pathogens will cides do not control diamondback ate, transferred and promoted to offer benefits by creating a cocktail moth effectively, and these new farmers. As evaluation, uptake and of specific agents to provide a biorational technologies can promotion become increasingly practical means of managing a pest produce very significant increases important Kenyan-based partners complex. A multiple mode of in yield (up to 100%) through should become more diversified. action will be advantageous for reduced losses. The impact on peri- It will be important to involve resistance management and may urban farmers of the introduction of potential commercial producers of show synergistic effects. In this new methods of control is likely to the new technologies. Market study, methods for producing a be both positive and significant in studies should be carried out in co-formulation of a granulosis virus scale. Reduced crop losses would Kenya to determine the likely and B. bassiana were investigated, directly improve the cash income commercial market for the tech- including aspects of storage, of these farmers and improve both nologies developed so that com- formulation and application, and the quality and quantity of the mercial involvement in their scanning electron microscopy for urban food supply. production can be facilitated.

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Development of pheromone traps for monitoring the legume podborer Maruca testulalis (M. vitrata)

R6659 The legume podborer, Maruca testulalis, is a major, pan-tropical pest of legume crops. In a previous project a major and two putative minor components of the female sex pheromone M. C. A. Downham, D. R. Hall, A. Cherry, D. I. Farman of M. testulalis were identified. The project described here aimed to complete identifica- Natural Resources Institute (NRI), tion of the pheromone, optimize traps baited with the synthetic pheromone, and investi- University of Greenwich, UK gate their use to study the ecology of the pest. Pheromone traps will assist researchers in developing integrated pest management strategies to control the podborer by providing A. Regupathy information concerning its behaviour and activity in the field. Traps will also provide Tamil Nadu Agricultural University farmers with a simpler alternative to pest scouting so that they can better time the appli- (TNAU), Coimbatore, India L. Jackai cation of control measures, reducing both the cost inputs and the environmental and International Institute of Tropical resistance problems experienced with less specific pesticide application. Agriculture (IITA), Ibadan, Nigeria M. Tamò International Institute of Tropical ISSUES effects. However, it has proved Agriculture (IITA), Cotonou, Benin difficult to transfer this to cultivated The legume podborer, Maruca N.S. Talekar varieties. No screening of resist- Asian Vegetable Research and Develop- testulalis (now called Maruca ance to M. testulalis in beans has ment Center (AVRDC), Taiwan vitrata), is a pest of legumes yet been reported, but there are throughout the tropics – it is a considerable differences in L.D. Galanihe major pest of cowpea in Africa and susceptibility among pigeonpea Food Crops Research and Development Asia, and is of sporadic importance Institute (FCRDI), Sri Lanka varieties. in South America, causing yield 1 April 1996–31 March 1999 losses of 20–80%. It is a particu- There is a lack of information on larly serious pest of early-maturing the behaviour and activity of adult varieties of pigeonpea, and M. testulalis in the field, particu- development of these varieties is larly in relation to possible migra- leading to an increase in the area tion patterns and off-season of pigeonpea grown in India and occurrence. This has hindered the other countries in South-East Asia. development of integrated pest It is also an important post- management strategies. There is flowering pest affecting beans in a need for ecological studies to Africa and Asia, and an occasional enable the successful implementa- pest of soyabean. tion of strategies involving manipu- lation of cowpea planting dates The larvae are highly mobile, and use of short-season varieties or feeding continuously on flowers companion crops to reduce and newly formed pods and M. testulalis damage. To achieve causing severe damage throughout this, pheromone-baited traps for the reproductive cycle of the crop. M. testulalis could provide simpler The use of insecticides to control alternatives to pest scouting by insect pests in cowpea does result farmers, to help them time the in several-fold increases in yield application of control measures and crop value; however, studies more effectively and reduce the with Nigerian farmers show that number of sprays necessary. Such only a minority apply insecticides an approach has been developed due to their high cost and lack of as part of an IPM package availability. Where insecticides are against Spodoptera litura on used, webs protect M. testulalis groundnuts in India, and larvae, so careful and timely pheromone traps are being used application is required. by farmers to monitor for cotton pests in India, Pakistan and Some cowpea varieties have been Egypt, and for pests of rice shown to possess modest levels of in India. host resistance, based on plant architecture, but wild species of In a previous project (R5292), Vigna (cowpea) show much greater methods for rearing M. testulalis Publications: see Bibliography on CD. resistance through antibiosis were developed in the UK,

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Left: a white, plastic jerry-can is being adapted for on-farm use – it attracts most moths and is practical and robust. Right: moths caught inside the trap as was a convenient wind-tunnel Institute of Tropical Agriculture Cotonou, Benin, lures containing bioassay in which male moths (IITA), Nigeria and the IITA Plant the synthetic three-component responded well to both live virgin Health Management Division at blend produced significantly more female moths and extracts of Cotonou, Benin; the Asian Vegeta- moth captures than with one-or female pheromone glands. These ble Research and Development two-component blends, live studies showed the behaviour of Center (AVRDC), Taiwan; and the females or unbaited controls. this species is unusual in many Food Crops Research and Develop- The proportion of the two minor respects, particularly in terms of ment Institute (FCRDI) of the components, relative to the major delayed sexual maturity and Department of Agriculture in component, was not critical over mating. The major active compo- Sri Lanka have all expressed the range tested. Polythene vials nent in extracts of pheromone interest in the project and carried containing 0.1 mg of pheromone glands from virgin female out testing of experimental lures. attracted more males than other M. testulalis was identified as combinations of dose or dis- The project described here aimed (E,E)-10,12-hexadecadienal penser, but differences were not to develop and promote im- (EE10,12-16:Ald). The correspond- statistically significant. A locally proved methods for control of ing alcohol, (E,E)-10,12-hexadeca- constructed water trap was pod-boring caterpillars on food dienol (EE10,12-16:OH), was also shown to be as effective as a legumes by completing identifi- shown to be present, but these commercial funnel trap and cation of the pheromone of the compounds, singly or in combina- superior to a commercial sticky, legume podborer, optimizing tion, were only weakly attractive to delta-trap design. Evidence traps baited with the synthetic male M. testulalis moths in labora- indicated that lures suffered no pheromone, and investigating the tory bioassays. Thirty-two synthetic loss of attractiveness over a use of these to study the ecology blends were tested in traps: no period of up to 4 weeks under of this pest. M. testulalis males were caught, field conditions. An unexpected but night observations showed that finding was that females comprised approaches to lures by male ACHIEVEMENTS 20–50% of total catches with M. testulalis moths were increased synthetic lures, although almost by the presence of (E)-10-hexa- SYNTHETIC LURE DEVELOPED none were attracted to live females decenal (E10-16:Ald) and EE10, In laboratory wind-tunnel studies or unbaited controls. 12-16:OH. In the UK, male responses were OPTIMIZED TRAPPING SYSTEM optimal when both putative minor The work was originally requested components were present in small Experiments were carried out to by scientists at the International proportions relative to the major relate catches of M. testulalis moths Crops Research Institute for the component; a significant effect of in pheromone trap catches to those Semi-Arid Tropics (ICRISAT), India. lure dose was also demonstrated. in a light trap situated away from Subsequently, scientists at Tamil cowpea fields at the IITA station, Nadu Agricultural University In trapping experiments in cowpea and to larval infestations in cowpea (TNAU), India; the International fields at the IITA station near fields. The temporal patterns of

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catches in the light trap and in ECOLOGY AND BEHAVIOUR control by smallholder cowpea pheromone traps within fields were farmers. Specifically, it will attempt different, but there was better The data obtained show that the to develop trap-catch thresholds to correspondence between catches ecology and behaviour of allow optimal timing of conven- in the light trap and in pheromone M. testulalis in relation to phero- tional insecticide applications, or of traps placed outside fields, and mone trap catches are unusual, and novel botanical or microbial these preceded the appearance without further studies interpreta- control agents, manipulation of of eggs and larvae in nearby fields tion is uncertain. It is likely that planting dates or resistant varieties. by a few days. Thus pheromone infestations in cowpea crops at the The project will also aim to provide traps placed outside fields could be IITA station arose principally a better understanding of the used to predict larval infestations. through immigration of moths into population dynamics, ecology and Catches in pheromone traps in the the vicinity around the start of a behaviour of M. testulalis, based on fields appeared to be of moths cropping season. Immigrants were long-term monitoring through which originated from larval only well detected by the light trap networks of pheromone traps infestations within those fields, and and perimeter pheromone traps within crops, alternative host areas these were not detected in the light (in the second season). Immigrating and elsewhere; information gained trap. Catches in the light trap were moths gave rise to larval infesta- will aid the further development of greater than in individual tions some days later, and only sustainable control methods. pheromone traps, but, within each after this did pheromone traps type of trap catches of one sex within fields catch moths which IITA, through the Swiss Develop- accurately reflected the presence were presumably either the ment Corporation-funded PEDUNE of the other. progeny of the original immigrants, (Protection ecologiquement or, possibly, late immigrants. These durable du niébé) project in West Thus from a practical trapping moths emerging from field infesta- Africa, has already collected standpoint the development of an tions were detected well by the baseline socio-economic data to effective synthetic lure is consid- within-field pheromone traps, but facilitate future impact assessment ered complete, at least for West not by the distant light trap. The of IPM technologies. PEDUNE was Africa: it consists of a polythene most important conclusion is that instituted to promote the transfer vial containing 0.1 mg of the pheromone traps placed outside and implementation of research on three-component blend, in cowpea fields can be used to cowpeas to smallholder farmers a 100:5:5 ratio. For the first time predict larval infestations beginning through the farmer field school a synthetic pheromone blend has a few days later. approach. It consists of collaborat- ing research, extension and NGO been identified that is more Within fields, moths were trapped organizations in nine West African attractive to male M. testulalis than in generally low numbers, intermit- countries. This needs to continue, virgin female moths under field tently or for short periods, particu- and the follow-on project will conditions. larly in the second season. This conduct surveys to determine may go some way to explaining the farmers’ attitudes to traps and their However, the lack of effect of absence of catches in Sri Lanka potential for use in the develop- varying the relative amounts of and Kenya, in that traps may not ment of new IPM strategies against minor blend components, and the have been used over periods M. testulalis. It will also evaluate attraction of female moths to coinciding with the presence the impact of the technologies synthetic lures, were both unusual of adult moths in fields. The use developed. A further long-term and unexpected findings in the of what is now known to be an objective is the development of a context of previous research on inferior trap design may also have formal predicative model for female-produced sex contributed to these results. pheromones. It is unlikely that outbreaks of M. testulalis. other pheromone components FUTURE Outside West Africa, links devel- remain to be identified, although oped under the previous project there may be scope for further The project has produced effective with the FCRDI, Sri Lanka, TNAU, optimization of the ratio of the pheromone lures and working traps India and the Japan Society for the three components, and other for the first time. A follow-on Promotion of Science’s Nairobi aspects of the species’ reproduc- project (R7441) based in Ghana Research Station will be main- tive behaviour remain to be and Benin, in collaboration with tained informally. Experimental understood. Regardless of IITA-Benin and with cowpea as the results will be exchanged in explanation, catches of females commodity base, will complete respect of M. testulalis pheromone may actually improve the predic- optimization of the design and trapping; if results are promising tive power of traps, since catches operation of pheromone traps for more formal collaboration may be of both sexes should more M. testulalis and integrate their use attempted, for example in Sri Lanka accurately reflect population with other novel IPM technologies with pigeonpea as the commodity events. to provide improved methods for base.

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Development of coffee IPM components in Kenya

R6782 Coffee is an important source of income for an estimated 300 000 smallholder farmers in Kenya, who produce over 60% of the export crop. Recommended pest control measures G. Oduor CABI Africa Regional Centre, Nairobi, for coffee rely heavily on the use of pesticides, which are costly to the farmer (fungicides Kenya can account for over 30% of total production costs), and potentially harmful to the envi- D. Masaba ronment and natural enemies. This project has begun to identify safe biological and cul- Coffee Research Foundation (CRF), tural control methods, together with host plant resistance, which could be incorporated Ruiru, Kenya into an integrated pest management strategy for smallholder, coffee-based cropping sys- tems in Kenya, thus reducing reliance on inorganic pesticides. October 1996–December 1999

ISSUES economic survey of about 200 (Telenomus seychellensis) of smallholder coffee farmers, were antestia bug were reared success- Coffee, a major source of income conducted at the start of the project fully in vivo in the laboratory and for smallholder farmers in Kenya, is and revealed that pests and diseases initial field releases made at CRF susceptible to a wide range of pests were perceived by farmers to be in order to establish correct and diseases which are responsible major constraints to coffee produc- procedures for rearing and field for significant yield losses, as well tion. The survey identified measures release. Additional field releases as affecting the cup quality. Coffee taken by farmers in order to try and and detailed follow up studies are berry disease (Colletotrichum reduce losses. Subsequently, a year- now required to quantify the kahawae) alone can cause up to long biological survey of farms in impact of these parasitoids on the 30% yield loss, whilst infestations different agroecological zones population of antestia bugs. Other by antestia bugs (Antestiopsis spp.) confirmed that pests and diseases natural enemies which were reared and coffee berry borer (especially coffee berry disease, and are being maintained at the (Hypothenemus hampei) directly coffee leaf rust and antestia bugs) laboratories at CRF include preda- affect the bean and liquor qualities were economically important, and tors of the giant looper, Ascotis of coffee. also established the distribution selenaria (e.g. Rhinocoris sp. and Recommended pest control of pests, diseases and their natural Macrorhaphis acuta), and predators measures currently rely heavily on enemies in central Kenya. and parasitoids of green scale, the use of inorganic pesticides – it On-farm experiments on the effects Coccus viridis (e.g. Chilocorus spp. has been estimated that fungicides of farmers’ practices (intercropping and Metaphycus spp.). account for 30% of the total cost with banana; pesticide use; use of Field trials were conducted on of production. Increasing reliance improved coffee varieties) revealed farmers’ fields, thus transferring on broad-spectrum chemical that they generally had little or no new technologies directly to the pesticides has led to concerns effect on the incidence of pests, contact farmers. Recommended about health and environmental diseases or natural enemies, with IPM components were also risks, detrimental effects on natural the exception of fungicides for passed on through farmer enemies of pests, pesticide resist- control of coffee leaf rust. However, participatory meetings and farmer ance, and cost, particularly for the coffee variety Ruiru 11, bred by field schools established under smallholder farmers. Despite such the Coffee Research Foundation a separately funded FAO project. concerns, inorganic pesticides (CRF), was found to be highly The research liaison section of CRF continue to be the control method resistant to coffee berry disease, also served as an important preferred by smallholder coffee coffee leaf rust and also possibly adoption pathway. farmers themselves. root-knot nematode. Currently, the main drawback with this variety is FUTURE Using a combination of natural the limited availability of seeds/ enemies, cultural practices and Under the guidance of the Associa- seedlings. CRF is addressing this resistant varieties, and by raising tion for Strengthening Agricultural shortage through a separately awareness of such strategies, the Research in Eastern and Central funded coffee variety multiplication aim of this project was to reduce Africa (ASARECA), in the light of project. the current reliance on inorganic these results a proposal for a pesticides in coffee production. Sixty potential biocontrol agents Regional Coffee IPM project was (pathogens, parasitoids and preda- revised and expanded into a ACHIEVEMENTS tors) of key insect pests and diseases regional Coffee Research Network of coffee were collected, identified (CORNET), to include all aspects of Participatory rural appraisals, and characterized. Some of the coffee production, processing and together with an extensive socio- more promising natural enemies marketing. The proposal was were subsequently evaluated in the endorsed by ASARECA in 1999 Publications: see Bibliography on CD. laboratory and field. Egg parasitoids and is currently under review.

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Integrated management of the fusarium wilt/root-knot nematode complex on cotton

R6761 Fusarium wilt has long been the major disease of cotton in Tanzania, and phytosanitary measures and the use of resistant varieties have been practised with some success for R. Hillocks Natural Resources Institute, University many years. However, the impact of root-knot nematode which increases plants’ suscep- of Greenwich, UK tibility to the disease, in addition to changes in the cotton sector leading to less regula- tion, have led to the disease increasing and threatening the hitherto unaffected southern T. Kibani zone of Tanzania’s cotton-growing area. This project conducted surveys and analysed Agricultural Research and Training existing survey data in order to update the current status of fusarium wilt in Tanzania and Centre, Tanzanian Agricultural Research Uganda, and also surveyed farmers to obtain an idea of their perceptions of the disease. Organization (TARO), Ukiriguru, Tanzania Farmers’ difficulty in recognizing the Fusarium fungus as the cause of cotton wilt means that control measures should realistically be taken at the national level. There are two P. Takan main aspects to the management of fusarium wilt: to prevent its spread on planting seed Serere Agricultural and Animal by organizing a certified seed multiplication system; and to reduce losses experi- Research Institute (SAARI), Soroti, enced by farmers whose land is already infested. In Tanzania the wilt-resistant variety Uganda UK 77 performs well in the absence of root-knot nematode; where the nematode is also September 1996–March 2000 present, improved resistance to root-knot nematode is required.

ISSUES Both UK77 and UK91 have good levels of resistance to fusarium Cotton is one of Tanzania’s major wilt and although some infection export commodities and, together still occurs, it is much less than with coffee, is foremost amongst would occur with the wilt- the country’s export crops. 95% susceptible varieties. However, of national production comes from many of the sandy soils of the the area south of Lake Victoria, WCGA are infested with root-knot bounded on the east by the nematode (Meloidogyne Serengeti National Park and in the incognita), and where this parasite west by the highlands on the occurs together with the wilt borders with Rwanda and Burundi, pathogen, susceptibility to known as the western cotton- fusarium wilt is increased. growing area (WCGA). Cotton is Following the liberalization of the the main source of income for Tanzanian cotton sector in 1993, many rural families in the WCGA. restriction of the movement of seed Fusarium wilt (caused by Fusarium cotton across ginnery zone and oxysporum f.sp. vasinfectum) was breeding zone boundaries has first noted in Tanzania in 1954. ceased, and phytosanitary control It is the most important disease of measures against the spread of cotton in Tanzania, and is now fusarium wilt have become difficult widely distributed in the WCGA. to apply. Since the 1960s attempts have The last fusarium wilt survey was been made to control and contain conducted in 1988, when the spread of the disease through it appeared that the disease was the use of resistant varieties and continuing to spread. The aim of phytosanitary measures to reduce SELECTED PUBLICATIONS the project described here was to the risk of distributing infected seed improve understanding of the for planting. Resistance to wilt has ELDON, S. and HILLOCKS, R.J. (1997) effects of liberalization on cotton The effect of reduced phytoalexin produc- been an important selection production in general and, more tion on the resistance of upland cotton to criterion for varieties intended for specifically, on the potential for verticillium and fusarium wilts. Annals of the northern zone, but has not spread of fusarium wilt, and to Applied Biology 129: 217–225. been required for the unaffected improve knowledge of farmers’ southern zone. The wilt-resistant perceptions of the disease, thus KATSANDONIS, D. (1999) The nema- varieties carry codes with odd contributing to the design of a tode-enhanced susceptibility to fusarium numbers, currently UK77 and management system for fusarium and verticillium wilt of cotton. PhD the- UK91, whereas wilt-susceptible wilt which takes account of the sis, Department of Agriculture, Univer- varieties carry codes with even new realities in a deregulated sity of Reading, UK. numbers, currently UK74 and UK82. industry.

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Table 1. Fusarium wilt incidence recorded on required where the seed crop is grown only on ibushi soils. different soil types The project also conducted Fields with extensive surveys in the cotton seed Soil type fusarium wilt (%) multiplication areas around Lake Kyoga in Uganda. Both verticillium Lusenje (grey sand – sandy loam) 69 wilt and the fusarium wilt/root-knot Nduha ( brown sandy loam) 67 nematode complex were found. Itogolo (grey sandy clay) 50 Verticillium wilt was found on the Ibushi (grey – brown calcareous clay loam) 33 clay soils in Apac district, while Mbuga (black cracking clay) 0 fusarium wilt/root-knot nematode was found on the sandy soils, mainly in Pallisa and Kamuli. There is a need in Uganda to begin ACHIEVEMENTS with both the fusarium wilt fungus screening for resistance to root-knot and root-knot nematode. Although nematode, as it was rare to find Surveys confirmed that fusarium fusarium wilt has been reported fusarium wilt in the absence of the wilt is widespread in the northern from a limited number of sites in nematode. zone of Tanzania’s WCGA. With the southern zone of the WCGA, the exception of parts of cotton is grown on clay and In Tanzania, the project originally Sengerema District, where the grey calcareous soils in much of this planned to conduct a survey for sandy soils are particularly condu- zone. It was confirmed in pot fusarium wilt across the whole cive to wilt, disease incidence was experiments that the ibushi soils of the WCGA, relying partly on generally below 5%. This reflects (calcareous) are particularly non- questionnaires administered the success of the resistant variety conducive to fusarium wilt, but are by extension staff. This was UK 77. Where disease incidence still fertile. If further spread of abandoned for two reasons: earlier was 10% or above, the wilt was fusarium wilt is to be prevented, surveys show that fusarium wilt is associated with root-knot nema- a seed multiplication system is so widespread in the northern zone tode. This suggests that fusarium that the whole area should wilt management in the now be regarded as unsuit- areas already infested with able for seed multiplication; the wilt pathogen and root- and owing to the large knot nematode will require number of villages that selection for nematode each extension worker has resistance. to cover, it is doubtful that The main factors influencing negative records could be the spread of fusarium wilt relied upon. Instead, an were identified. The indication of the rate of pathogen is seedborne and, spread was obtained from at present, planting seed is the records of previous derived from farmers’ crops. surveys which were Previous phytosanitation conducted in 1969, 1979 measures are now ineffec- and 1988. The number of tive as a result of deregula- villages with fusarium wilt tion: the cotton buying posts increased by 30 between were identified as the point 1969 and 1979, and by at which potentially infected 59 between then and 1988. seed cotton is mixed with In 1979 there were no non-infected seed cotton, records of wilt in the and also where wilt-resistant southern zone of the and wilt-susceptible WCGA; even in 1988 varieties were being mixed. there were only a few localized incidences. Fusarium wilt is confined to However, any presence the sandy soils in the WCGA of fusarium wilt in the (Table 1). Much of the Figure 1. Sketch map showing the western cotton- southern zone has serious cotton-growing land in the growing area (WCGA) in western Tanzania and the implications, as varieties northern sector of the boundary between the northern zone (closest to Lake grown in the zone are not WCGA, closest to Lake Victoria) where fusarium wilt is prevalent and the selected for resistance Victoria, is already infested southern zone where it is mainly absent. to wilt.

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for the production of certified seed Table 2. Farmer recognition infested with the wilt fungus and of fusarium wilt symptoms in which seed production is root-knot nematode. separated from crop production An IPM system for fusarium wilt Number of as a whole. The project has shown that the ibushi soils are non- management would have the Location respondents % following components. conducive to fusarium wilt, and Own fields 70 78 seed multiplication schemes should • Certified seed production Other fields 12 13 be sited on these soils. The one system to prevent disease Neither 8 9 proviso is that a disease known spread through infected seed. as ‘Lubaga wilt’ appears to be Total 90 100 • Consider moving to a single- prevalent on ibushi soils – more variety breeding programme. work is required on the (as yet The single variety should be The information from these surveys unknown) cause of this disease, wilt resistant. The only justifica- was combined with information and whether or not it may be provided by the Tanzania Cotton tion for continuing the two- seedborne. Lint and Seed Board in order to variety system would be that tabulate wilt distribution according the fusarium wilt-susceptible Table 3. Farmer perceptions to District boundaries. Previously, alternative was consistently of causes of fusarium wilt the information on wilt distribution higher yielding in the southern symptoms was collected by ginnery zone. zone and had a significantly higher ginning out-turn. This made sense prior to market Number of liberalization, when there was only Cause respondents % • Varietal resistance: UK77 has one ginnery per zone and restric- good wilt resistance but tions were in place on the move- Insect pests 16 15 requires improved resistance to ment of seed cotton across ginnery Pest problems 1312 root-knot in order to maintain zone boundaries. Now that the Termites 6 6 resistance levels on soils private sector has constructed new Drought 16 15 heavily infested with the ginneries, there are several ginnery Rain related 8 7 nematode. zones with more than one ginnery, Fertilizer/ and seed cotton is marketed across excessive rainfall 1 1 both ginnery and zonal boundaries. Low fertility 1 1 FUTURE The cotton buying posts are now Not known 47 44 situated according to District Total 108 100 Further work is required in two boundaries. areas: However, a separate, certified seed- • The outputs from the present Variety mixing could be avoided production system will not be project with respect to seed by converting to a single-variety without a cost: farmers will need to transmission of fusarium wilt system and growing only the latest be paid a premium to produce a should be developed further by fusarium wilt-resistant variety in seed crop, and ginning companies assisting the Tanzania Cotton both northern and southern zones will need to be compensated for the of the WCGA. If it is deemed Lint and Seed Board to prepare revenue lost from not being able to necessary to retain a two-variety a plan for a seed multiplication use the seed for oil extraction. system, then the problem could system that can provide high- quality seed free of seedborne still be circumvented if planting Similar problems with the risk diseases. seed is not derived from the main of spreading fusarium wilt on crop. planting seed were identified • Management of fusarium wilt in in Uganda, but to a lesser extent: While recognizing the problem, areas infested with both the wilt farmers and other stakeholders in this country the problem could pathogen and root-knot nema- surveyed had a poor understanding be addressed by ceasing to use the tode requires the wilt-resistant of the causes of fusarium wilt areas of sandy soil for seed multi- varieties to have improved (Tables 2 and 3), and none at all plication. But selection for resist- resistance to the nematode. of nematodes. Farmers therefore ance to fusarium wilt is not The cotton research stations cannot be expected to implement practised in Uganda, and the best at Ukiriguru control measures. Likewise, cotton approach to control of the fusarium in Tanzania and Serere in buyers and ginning companies in wilt/root-knot nematode complex Uganda require assistance to the deregulated cotton industry would be to begin selection for develop screening methods to cannot be expected to implement resistance to root-knot nematode produce varieties resistant to phytosanitary measures. The spread from the stage of single plant root-knot nematode. of fusarium wilt on seed can only selection, followed by testing in the be controlled by having a scheme later generations in a sick plot

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Assessment of major soilborne pests of the multi-purpose agroforestry tree Sesbania sesban, and the development of IPM strategies

R6736 Sesbania sesban is one of the main agroforestry tree crops being promoted in Africa to improve soil fertility by nitrogen fixation, and to provide fodder for livestock. However, the J. Bridge, M. Kenis CABI Bioscience, Ascot, UK species is subject to pests and diseases, and has been little studied in the past. This project has identified the main soilborne (and other) pests of Sesbania in eastern and southern M.R. Rao Africa, and developed and promoted practical pest management strategies. Farm surveys International Centre for Research in identified three leaf beetles, Mesoplatys ochroptera, Exosoma sp. and Ootheca sp., as Agroforestry (ICRAF), Nairobi, Kenya major insect pests, and two root-knot nematode species, Meloidogyne incognita and F. Kwesiga M. javanica, as major nematode pests of Sesbania in Africa. Sesbania nursery beds in farms ICRAF – Southern Africa Regional and research stations were found to be commonly infested with root-knot nematodes. The Programme, Harare, Zimbabwe root-knot nematodes are particularly damaging in loamy sand soils in Zambia, Malawi and P. Mafongoya Tanzania, especially where nematode-susceptible crops such as tobacco or solanaceous ICRAF – Agroforestry Research Project, vegetables are also grown. Recommendations have been produced for the integrated and Msekera Research Station, Chipata, practical management of the major pests to assist in the more sustainable and productive Zambia use of Sesbania by smallholders in agroforestry systems. R. Otsyina ICRAF – Agroforestry Research Project, Shinyanga, Tanzania ISSUES ACHIEVEMENTS B.R. Critchley The increased use of nitrogen-fixing Natural Resources Institute (NRI), leguminous species of trees to INSECTS University of Greenwich, UK improve soil quality is a major Surveys showed that soil insects component of the development and October 1996–March 2000 were less important than previously promotion of agroforestry systems thought. Whitegrubs (Scarabaeidae) in Africa, particularly by the may occasionally cause some International Centre for Research in damage to the rooting system Agroforestry (ICRAF). One of the in some regions (such as Kenya), main agroforestry tree crops being but were rarely found in Zambia. promoted in Africa is Sesbania Termites are often cited by farmers sesban, a fast-growing, nitrogen- as a major problem in legume fixing tree with good quality leaf SELECTED PUBLICATIONS fallows, including Sesbania, but biomass which is traditionally in most cases they were found BRIDGE, J. (2001) Plant parasitic grown in Africa and is acceptable attacking dead or dying trees. nematodes of agroforestry trees. to farmers for improving soil fertility Agroforestry Today (in press). and providing fodder for livestock. In contrast, three leaf beetles CRITCHLEY, B.R., ABRAHAM, Y., Sesbania is being recommended as appeared to be major pests of PRICE, N. and DESAEGER, J. (1999) a short-duration improved fallow Sesbania fallows: Mesoplatys Sesbania sesban: Results of an insect crop to replenish soil nutrients and ochroptera, Exosoma sp. and pest survey conducted in smallholder thus improve yields of sequentially Ootheca sp. The three species are farmers’ fields in western Kenya, grown food crops, particularly particularly damaging to young October–November 1996. NRI Report maize. seedlings and, when the attack No. 2411. Chatham, UK: Natural The promotion of Sesbania as an occurs early in the year, can Resources Institute. improved fallow has been restricted seriously hamper their establish- ment. Exosoma and Ootheca occur SHIRIMA, D.S., OTSYINA, R., partly because the tree is suscepti- sporadically, particularly in Zambia MWAGENI, W.P. and BRIDGE, J. (2000) ble to soilborne pests, in particular and Malawi, whereas M. ochroptera Effect of natural and Sesbania fallows to the root-knot nematodes, is a very abundant and frequent and crop rotations on incidence of root- Meloidogyne spp. Problems had pest of Sesbania throughout eastern knot nematodes and tobacco produc- arisen concerning the establishment and southern Africa. Therefore tion in Tabora, Tanzania. International and subsequent growth of Sesbania, work focused on M. ochroptera Nematology Journal 10: 49–54. and ICRAF has reported a complete failure of Sesbania (thought to be and its control in improved fallows. SILESHI, G., KENIS, M., OGOL, due to nematode attack) in Rwanda C.K.P.O. and SITHANANTHAM, S. and Malawi. Until the beginning of The following aspects of (2001) Studies on predators of this project there had been no M. ochroptera were investigated Mesoplatys ochroptera Stal in Sesbania- concerted programme directed at through farm surveys, laboratory planted fallows in Eastern Zambia. the identification and management experiments and field trials: general BioControl (in press). of pests of Sesbania. biology and ecology of the beetle;

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lishment and had a greater ability Table 1. Main insect species observed on S. sesban in improved to withstand pest attack. fallows in Kenya (K), Malawi (M), Tanzania (T) and Zambia (Z) A range of other insect and nema- Species Importance* Country tode pests occurred with Sesbania Root feeders but were not of major significance Schizonycha sp. (Col.: Scarabaeidae) 1 K (see Tables 1 and 2), including an Trochalus sp. (Col.: Scarabaeidae) 1 K important nematode pest of maize, Trunk/root feeders Pratylenchus zeae. Other potential Amitermes evuncifer Silvestri (Iso: Termitidae) 1 T pests of Sesbania recorded in- Ancistrotermes latinotus Holmgren 1 T (Iso: Termitidae) cluded fungal pathogens of the Macrotermes spp. (Iso: Termitidae) 1 K genus Fusarium. Microtermes luteus Harris (Iso: Termitidae) 1 T M. subhylinus Silverstri (Iso: Termitidae) 1 K RECOMMENDATIONS Odentotermes badius (Haviland) 1 K (Iso: Termitidae) Pseudacanthotermes spp. (Iso: Termitidae) 1 K Information from field trials in Defoliators Zambia and experiments in the UK Exosoma sp. (Col.: Chrysomelidae) 2 M, Z with the insect and nematode pests Mesoplatys ochroptera Stal 3 K, M, T, Z enabled practical recommenda- (Col.: Chrysomelidae) tions to be made. Although Ootheca sp. (Col.: Chrysomelidae) 2 M, Z nematodes are important pests of Euproctis rubricosta Fawc. (Lep.: Lymantriidae) 1 M, Z Undetermined tortricid (Lep. Tortricidae) 1 Sesbania, they can be managed by Sap suckers farmers by relatively simple and Anoplocnemis curvipes (F.) (Het.: Coreidae) 1 T, M, Z practical means. Brachyplatys testudonigra F. (Het.: Plataspidae) 1 M, Z Hylda patruelis Stal (Het.: Tettigometridae) 1 M, Z • Maize can be successfully Nezara viridula L. (Het.: Pentatomidae) 1 M, Z grown in rotation as Sesbania Aphis fabae Scopoli (Hom. :Aphididae) 1 M, Z does not support the nematode Lipaleyrodes sp. (Hom.: Aleyrodidae) 1 M, Z pest of maize and, conversely, Flower feeders Haplothrips gowdeyi Franklin (Thys.: Thripidae) 1 K maize is a non- or poor host of Megalurothrips sjostedti (Tryboom) 1 K, T, M, Z root-knot nematodes. (Thys.: Thripidae) Mylabris dicincta Gerst. (Col.: Meliodae) 1 M, Z • Resistance to nematodes and Seed feeders insects was not found and Acanthoscelides obtecus (Say) (Col.: Bruchidae) 1 M, Z therefore was not an option, Callobruchus sp. (Col.: Bruchidae) 1 K but avoiding nematodes and Undetermined eurytomid (Hym.: Eurytomidae) 1 M, Z insects are appropriate meas- *Importance: 3 = serious damage frequently observed; 2 = serious damage occasionally observed; ures: avoiding crops in rotations 1 = frequently found species not presently considered as a serious pest of Sesbania. which are highly susceptible to Only insects for which damage has been observed are listed. root-knot nematodes and using nematode-free seedlings are the natural control in fallows and todes, and was only seriously most effective management natural habitats; influence of damaged when high soil measures that can be taken. cultural practices on beetle populations were present. Growth populations; resistance/tolerance of Sesbania was correlated with the • Greater attention to nursery of S. sesban to M. ochroptera; and extent of root galling. beds earlier in the season is a possibilities of using plant extracts simple, practical and effective None of the Sesbania lines was as repellents or biopesticides. means of producing seedlings Future work should focus on the resistant to the nematodes, includ- ing one from Tanzania which was free of nematodes. Mesoplatys two other beetle species, Exosoma could also be a problem starting sp. and Ootheca sp., of which very reported to have resistance in the nurseries. Insect adults, little is known. (‘Tabora 026’). egg masses and larvae can be Nematodes could be eliminated hand picked and destroyed on NEMATODES from nursery beds to produce seedlings before transplanting Both root-knot nematode species, healthy seedlings, and greater from nurseries to the field. M. incognita and M. javanica, were attention to nursery beds earlier pathogenic to S. sesban but in the season is a simple, practical • When Sesbania fallows are variations occurred between and effective means of producing cleared, this should be done different country isolates and clean seedlings. Older seedlings before the onset of the rain to species. Sesbania was relatively than previously recommended prevent the overwintering tolerant of low numbers of nema- were significantly better at estab- beetles from breeding.

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Table 2. Plant parasitic Instead, farmers may plant acceptable management methods. nematodes associated with another non-host fallow tree Growing a number of different S. sesban in eastern and such as Tephrosia vogelii. One nitrogen-fixing trees as mixed southern Africa year without Sesbania on-farm fallows is a developing trend being should be enough to reduce introduced to farmers, and the Species Status local populations to an accept- effects of these mixtures of plants able level. on pests and diseases require Criconemella curvata investigation. • In the absence of S. sesban, Criconemella sphaerocephala Mesoplatys breeds on other A possible new disease, which we Helicotylenchus wild Sesbania species. Weeding refer to as ‘drying disease’, was pseudorobustus out these species will reduce seen on Sesbania and Tephrosia Hemicriconemoides cocophillus Hemicycliophora sp. insect numbers, but must be in Zambia. The diseased material Meloidogyne incognita done before flowering and seed collected from the trees yielded Meloidogyne javanica * dispersal. two separate species of Fusarium; Paratrichodorus sp. the nature and cause of this disease These measures for farmers to Pratylenchus zeae * needs to be verified and manage- manage the nematode and insect Rotylenchulus parvus * ment methods developed. More pests of Sesbania and to increase Rotylenchulus variabilis * widely, fungal pathogens are nitrogen fixation and subsequent Scutellonema brachyurus largely unknown or neglected on maize growth were recommended Scutellonema clathricaudatum agroforestry crops, and need to be through ICRAF, and information Scutellonema magniphasmum investigated and their relative Scutellonema unum to produce advisory leaflets was importance determined. Tylenchorhynchus spp. provided. Xiphinema sp. Several ecological aspects of FUTURE M. ochroptera remain unknown, *Major parasitic species in particular the natural control of Following reports that other the beetle on wild S. sesban. • As most insects overwinter in or agroforestry tree crops, including The two other major defoliators, around adjacent older Sesbania Tephrosia vogelli and Acacia spp., Exosoma and Ootheca, are still fallows, with heavy infestations are also susceptible to root-knot very poorly understood, and of Mesoplatys beetles it is nematodes, there is a need to several aspects of their biology recommended not to plant investigate the nematode damage need to be studied before develop- Sesbania in the following year, to these other tree crops with the ing control measures. The possible especially on adjacent fields. aim of developing and promoting insecticidal or repellent properties of Tephrosia vogelii and Gliricidia sepium merit further investigation.

Left, a 2-year-old healthy experi- mental plot of Sesbania sesban, Msekera, Zambia; below, Sesbania fallow with severe root knot, Tanzania. Inset: severe root knot galls on Sesbania

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Development of appropriate management systems for hymenomycete disease of perennial crops

R6628 Diseases caused by Ganoderma and related pathogens cause significant losses of oil palm and other perennial crops, including coconut and tea, in Asia. Development of J. Flood CABI Bioscience, Egham, UK appropriate integrated management systems in successive plantings of crop monocultures is currently hampered by a limited knowledge of the different hosts, the mechanisms of Universiti Putra Malaysia (UPM), disease establishment, and the influence of environmental factors. Techniques developed Malaysia through a previous project were used to determine the extent and variability of populations Palm Oil Research Institute of Malaysia of Ganoderma in oil palm and coconut cropping systems in Malaysia and Indonesia, as (PORIM), Malaysia well as in coconut crops in Sri Lanka and India. Limited studies of a tea cropping system were also conducted. The project sought to determine how the fungus survives between Ebor Research Station, Sime Darby, Malaysia crops; to use biodegradation to eliminate infective inoculum in crop debris; to study the influence of environmental factors on disease development, including the effect of United Plantations, Malaysia soil amendments on root colonization and pathogen survival; and to produce an Forestry Research Institute of Malaysia Asian research network to facilitate the exchange of new knowledge and appropri- (FRIM), Malaysia ate management strategies. Boh Tea Plantations, Malaysia Bah Lias Research Station (BLRS), ISSUES very significant impact in Indonesia Sumatra, Indonesia as this country moves from first Palm-oil production is a major planting to successive replantings. Biotechnology Research Unit for Estate source of export revenue for several Linked with replanting is the issue Crops, Bogor, Indonesia countries in South-East Asia. The of environmental sustainability – if Indonesian Oil Palm Research Institute palm-oil industry employs thou- replanting becomes uneconomic (IOPRI), Sumatra, Indonesia sands of people, and the crop is then further areas of primary forest Coconut Research Institute (CRI), also an important source of income will be cleared for first plantings. Lunuwila, Sri Lanka for smallholder farmers – independ- Thus the management of Gano- ent smallholders represent about derma is a key issue for environ- Coconut Research Station, Tamil Nadu 10% of the area under cultivation mental sustainability. In addition, Agricultural University (TNAU), India in Malaysia, with a further 40% of other smallholder perennial crops, April 1995–August 1999 the land area being cultivated by notably coconut, are also affected smallholders within Federal and by Ganoderma diseases: in India State Land Schemes. Particularly in and Sri Lanka coconuts are affected Indonesia, oil-palm production has by a stem bleeding disease caused created cash economies in areas by Ganoderma, and some losses that would otherwise have little of tea plantings also occur in prospect of income for the rural Malaysia. poor. The fungal disease basal stem Techniques developed through a rot (Ganoderma) can be very previous project (R5325) were used damaging, with a greatly shortened here to determine the extent and economic life to the planting which variability of Ganoderma popu- will then entail costly replanting. In lations in oil palm and coconut Malaysia, the expected economic cropping systems in Malaysia and life of an oil palm planting is 25 Indonesia, as well as in coconut years, but losses to Ganoderma crops in Sri Lanka and India, to basal stem rot of up to 85% of the determine the means of spreading. stand have been recorded within Limited studies of a tea cropping SELECTED PUBLICATIONS 15 years of planting. In Sumatra, system were also conducted. losses of up to 50% of the oil palm FLOOD, J., BRIDGE, P.D. and HOLDER- stand are often seen by the time the NESS, M. (2000) Ganoderma Diseases of ACHIEVEMENTS palms are only half-way through Perennial Crops. Wallingford, UK: CABI their normal economic life. Small- Publishing. In oil palm, debris from previous holders are particularly vulnerable plantings was shown to be a MILLER, R.N.G., HOLDERNESS, M., to the high cost of replanting. Also, significant source of fungal inocu- BRIDGE, P.D., CHUNG, G.F. and with each replanting the disease lum. Previously this debris was ZAKARIA, M.H. (1999) Genetic diversity becomes progressively worse, so burned, but management practices of Ganoderma on oil palm plantings. replanting needs to be done more now commonly involve excavation Plant Pathology 48: 595–603. frequently. This is likely to have a of the stumps and trunks, which is

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could be coupled with the short FUTURE fallow system as recommendations to smallholders. It was concluded at the 1998 Workshop that much basic science Understanding the pathogen’s still needs to be done, including biology using biochemical and investigation of host responses and molecular methods is essential to the mechanisms of pathogenicity exploring the disease in the field. and associated enzymatic degrada- Variability studies indicate that the tion (these aspects would be useful Ganoderma associated with both to plant breeding and to Thanjavur wilt in India is different biodegradation). Breeding for from that isolated from oil palms resistance and the development and coconuts in Malaysia and of robust techniques of screening, Indonesia. In Sri Lanka, the level of including a sound method of variability in the pathogen popula- artificial inoculation which would tion was much lower than in South- allow the mass screening of East Asia, with the same genotype germplasm, was considered a high being found several kilometres priority. Enzymatic degradation apart and in several species of studies are also a top priority. Fungal brackets of Ganoderma palms, whilst in Malaysia each Individual organisms have been palm contained an individual shown to be capable of degrading very costly and is usually genotype. Early indications suggest components of the oil palm beyond the means of smallhold- debris, but combinations should ers. Cheaper, easier manage- be studied to produce a compat- ment of the debris is required. ible cocktail of degraders, as is One possible approach is by seen with the natural successions biodegradation of the debris on trunks and stumps in the field. using microorganisms. A survey Enzymatic breakdown also has of potential antagonists was enormous scope for useful by- conducted in South-East Asia products such as ruminant feeds and the biodegradative ability and materials for the building of isolates tested, demonstrating industry. the feasibility of this approach; further work is required on this, As well as coconut and oil palm particularly in the field. Another cropping systems, future studies Fallen palm due to basal stem rot approach takes advantage of the should include other systems fact that diseased palm stumps such as tea and forest systems. appear to lose their infectivity over two types of Ganoderma may be Ganoderma and related species are time: smallholders may be able to present in coconuts in Sri Lanka. likely to affect forestry species in practise a short fallow system to the region, particularly some timber The enhancement of skills among species such as Acacia, as succes- reduce the inoculum between oil scientists from a number of countries palm crops. Coconut stumps also sive replants progress. The interre- in the region has been a key feature lationships between isolates from represent a hazard to new plantings of the project. Training attachments of oil palms, and their removal also forestry species and palms should were provided at CABI Biosciences be investigated. Some of these represents considerable outlay for for counterpart scientists from the smallholders (and estates). Further aspects are currently being studied three countries under study. Informal in Papua New Guinea under a investigation of the biodegradation networking has facilitated exchange of coconut debris is also needed. European Community (EC) - funded of ideas throughout the project, project. These studies would also be useful while the Second International to smallholders throughout Asia. Workshop on Ganoderma Diseases The success of the regional network of Perennial Crops in 1998 enabled should be continued, following Soil amendments, notably calcium a research framework developed at nitrate, organic matter and antago- the transfer of technologies to those best placed to use them within the the 1998 Workshop. A programme nistic microorganisms such as region. of adaptive research on the Trichoderma, have resulted in management of Ganoderma reduced disease in glasshouse A research network, instigated by disease of oil palm to operate as a trials. Field testing is in progress the First International Workshop regional programme in South-East and continues to demonstrate some (1994) and promoted by the Asia, building on the outputs of the benefit of amendments. The use of project, has progressed well, with current DFID-funded project, is organic amendments to encourage positive feedback from the collabo- under development with collabora- antagonists to reduce the inoculum rating institutions. tors from the region.

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Coconut diseases of uncertain etiology

R6604 Yellowing, wilting and decline diseases of coconuts in South-East Asia have been increas- ing in incidence over recent decades. In many cases the cause of these diseases remains P. Jones undefined. Because coconut production is central to the rural economy in many areas of Institute for Arable Crops Research (IACR), Rothamsted, UK South-East Asia, it is becoming increasingly important to identify the causes of these dis- eases as a first step towards developing appropriate crop protection practices for small- April 1996–September 1998 scale growers. The effect of these coconut wilt diseases is to seriously reduce the income of smallholder families. There appears to be a lack of coordinated coping strategies, and little incentive for the introduction of alternative crops. Activities under this project fo- cused on monitoring the spread and attempting to identify the causal organisms of the coconut diseases in Indonesia known as Natuna wilt or Kalimantan wilt; the Indian dis- ease coconut (root) wilt or Kerala wilt; and that in Sri Lanka commonly called leaf scorch decline. Preliminary results indicate that the Indonesian diseases are caused by the same phytoplasma.

ISSUES diseases in Africa (Cape St Paul wilt in Ghana, and coconut lethal In various regions of South-East decline in Tanzania) have also been Asia there is an increasing inci- associated with phytoplasma dence of failure in coconut for pathogens. At least three diseases unexplained reasons. For example, in India and South-East Asia have in a village in central Kalimantan, been attributed to phytoplasmas Indonesia, it was reported that in despite some symptom differences 1990 an unidentified disease from lethal yellowing. affected ~1% of coconut palms; by 1996 this had reached 10%, and NATUNA WILT/KALIMANTAN production had probably fallen by WILT 30% as the best-producing trees were affected. In Indonesia, a lethal disease of coconuts has been known for some In both Natuna and parts of years on Natuna Island in the south Kalimantan, Indonesia, the China Sea, and recently an out- economy is completely geared to break was reported to have the production of copra: farm destroyed over 2000 ha of mature SELECTED PUBLICATIONS families depend almost entirely for coconut palms in central their cash needs on coconut, which Kalimantan. In central Sulawesi, a ALLORERUNG, D., HARRIES, H., JONES, also provides employment to the yellowing disorder of coconut P. and WAROKKA, J.S., eds (1999) Pro- landless and land-poor population. palms has also been reported, and ceedings of the International Workshop In Sri Lanka, following land the symptomatological and on Lethal Diseases of Coconut caused by reforms, coconut production is epidemiological similarities Phytoplasma and their Importance in predominantly in the hands of between these disease outbreaks Southeast Asia. Jakarta, Indonesia: APCC. smallholders, and there are well suggest that they may be caused by developed markets not only for the same or similar groups of JONES, P., CRONJE, C.P.R. and WAROKKA, copra, but for fibres, charcoal, pathogens. J.S. (1999) Investigations into coconut dis- activated carbon and increasingly, eases of uncertain aetiology in Indonesia. desiccated coconut. Small-scale KERALA WILT (COCONUT ROOT In Proceedings of the 5th International farmers have no effective coping WILT) Conference on Tropical Plant Protection strategies to deal with these in the Information Age, 15–18 March diseases, and few see an alternative In India, at least two diseases of 1999. Kuala Lumpur, Malaysia: MAPPS, to growing coconut. uncertain etiology have been pp. 39–42. tentatively associated with Since 1972, lethal yellowing phytoplasmas: tatipaka disease in TYMON, A.M., JONES, P. and HARRISON, disease of coconut in the Carib- Andhra Pradesh, and coconut root N.A. (1998) Phylogenetic relationships of bean and the Americas has been wilt or Kerala wilt in the southern coconut phytoplasmas and the develop- associated with a phytoplasma parts of Kerala and Tamil Nadu ment of specific oligonucleotide PCR (microscopic organisms formerly states. Kerala wilt causes significant primers. Annals of Applied Biology 132: known as mycoplasma-like losses and has been the subject of 437–452. organisms or MLOs), and related extensive investigation; electron

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In Indonesia, Natuna wilt (above) and Kalimantan wilt (right) tend to affect palms >10 years old, but symptoms have been observed on palms as young as 7 years. Palms that are not in bearing are not affected by the disease. Symptoms include wilting and drooping of lower fronds, progressing from the oldest to the youngest leaves. Affected leaves lose their sheen before changing colour from green to brown. There is no pronounced yellowing stage on Natuna Island (although this is seen in Kalimantan wilt, possibly being a genetic trait rather than a response to infection), and there is no necrosis/blackening of unopened or immature inflorescences. Nut production ceases with the appearance of symptoms

Leaf scorch decline (Sri Lanka) is seen in palms >20 years old, and the course of the disease can take up to 6 years before the palm dies. It first appears as a scorching of the tips of lower fronds. It then progresses along the pinnae to the mid-rib and from the lower to the upper fronds. There may be curling of the frond. The youngest fronds often Coconut root wilt disease in India (above) is remain green, even in initially seen in flaccid leaflets which curve advanced stages of disease, downwards, giving a rib-like appearance to the but they are shorter and frond. There may be yellowing of the crown. thinner in appearance than those of healthy trees. Affected fronds remain There may be some nut fall, but a reduction in attached to the trunk for longer than normal. There is a rapid tapering of the the number and size of nuts is more usual. The trunk, affected palms produce fewer and smaller inflorescences, and nuts are palm does not die, but examination of the roots elongated. Eventually the crown diminishes and falls off. The root system shows that there can be extensive rotting of the decays giving a fibrous appearance; fewer secondary roots are seen, but root system and a lack of new growth laterals proliferate and then decay rapidly

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microscopy evidence associates established to study the spread of Indonesia in February 1998. a phytoplasma with Kerala wilt- Kalimantan wilt, and the extent of If losses on the scale of those infected coconut and arecanut the current outbreak was mapped. experienced in Africa and the palms, and there are claims for the Caribbean are to be avoided in There are no symptom similarities remission of symptoms following Indonesia, then the initial results between the wilt diseases in the application of tetracycline from this project will need to be Indonesia and Kerala wilt (India) antibiotics. The symptoms of Kerala applied in a more comprehensive and leaf scorch decline (Sri Lanka). wilt, however, are quite different action. However, there are some similari- from those of lethal yellowing. ties between the Indian and Sri SPREAD Palms decline in production over Lankan diseases. The main differ- many years, and the disease is not A study was carried out on the ence is that Kerala wilt does not kill regarded as lethal. Unlike lethal epidemiology of Kalimantan wilt. the palms, while leaf scorch yellowing, root wilt disease spreads Over one year of study the percent- decline kills the palm but is more rather slowly and reports of its ages of trees showing symptoms sporadic than any of the other transmission by a lace bug are at approximately doubled. The diseases studied. A study was odds with the confirmed vectors of greatest number of new symptom instigated at the Coconut Research all other phytoplasma diseases. appearances occurred in a fairly Institute, Sri Lanka to chart the narrow time window (August– spread of leaf scorch decline as LEAF SCORCH DECLINE October), suggesting that infec- previous records were sparse. tion of the palms may have taken In Sri Lanka, leaf scorch decline is Tetracycline antibiotic therapy trials place in a similarly narrow time a sporadic problem and causes were set up in central Kalimantan frame. This should help with losses in coconut production. and Sri Lanka to obtain more future studies on potential Again, palms usually decline over evidence on whether the diseases vectors of the disease. a long period, but unlike root wilt are caused by phytoplasmas. disease, they eventually die. Phytoplasma DNA was successfully FUTURE A more rapid, premature decline amplified from diseased coconut condition has been observed since Priorities for follow-up in Indonesia palms with Natuna wilt, 1994 in which palms die within include: Kalimantan wilt and Sulawesi 2 years of the onset of symptoms. • confirm the phytoplasma yellows. Amplified phytoplasma The present status of leaf scorch etiology by continuing epidemi- DNA was compared by digestion decline is not well documented ology and therapy trials; obtain with restriction endonucleases. and few investigations into possible corroborating evidence of Restriction fragment-length pathogens have been made. phytoplasma infection by polymorphism (RFLP) profiles electron microscopy Identification of the pathogen is suggested that two different an essential first step in the devel- phytoplasmas were present. • use molecular techniques to opment of scientifically based refine a diagnostic test for the The phytoplasma origin of the sustainable crop protection three diseases, and use in products was further confirmed by measures. The project therefore conjunction with epidemiologi- DNA sequencing. No phytoplasma aimed to identify the pathogens cal data to identify a possible DNA was amplified from Kerala associated with these coconut vector diseases of uncertain etiology or wilt, leaf scorch decline or prema- • look for local resistance to origin in Indonesia, India and ture decline-affected coconuts, and diseases by following up seed- Sri Lanka. no pathogens of a virus-like or viroid-like nature could be found. garden experiments in Natuna ACHIEVEMENTS Island Scientists from all three national PATHOGEN STUDIES institutes (Research Institute for • develop farmer coping strate- gies that are sustainable. Surveys in Indonesia (Natuna Island Coconut and Palmae, Indonesia; and central Kalimantan), India and Coconut Research Institute, CRI, In India, molecular biology Sri Lanka collected and compared Sri Lanka; and Central Plantation capabilities are being introduced symptom information (see illustra- Crops Research Institute, CPCRI, at CPCRI. These should be used to tions), and obtained samples for India) were trained at Rothamsted, provide corroborating evidence for molecular analysis. UK in molecular detection the transmission trials. technologies. The disease symptoms of Natuna In Sri Lanka, the Coconut Research wilt and Kalimantan wilt are very Results from the project were Institute should continue to monitor similar, if not identical. In central discussed at the International the spread of leaf scorch decline Kalimantan a variant of Kalimantan Coconut Biotechnology Sympo- and premature decline, and con- wilt, which exhibited a yellowing sium, Merida, Mexico, 1997 and tinue with the antibiotic therapy of the foliage as well as a wilt, was publicized through an international trials, with penicillin included as an observed. Experimental plots were workshop held in Manado, additional antibiotic.

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Development of pheromones for management of coconut pests in Sri Lanka

R6929 The red palm weevil (Rhynchophorus ferrugineus) and the rhinoceros beetle (Oryctes rhi- noceros) are the two most important pests of coconuts in Sri Lanka and most of South-East D.R. Hall Natural Resources Institute (NRI), Asia. Current methods of control are only partially satisfactory, and there are fears that University of Greenwich, UK infestation levels will increase dramatically following the recent banning of the insecticide monocrotophos. This project provided the basis for development of mass trapping with Champa Rajapakse pheromone-baited traps for control of these pests, as has been successful with a related Coconut Research Institute (CRI), species in Central America. This technology will be environmentally acceptable and Sri Lanka appropriate for use in developing countries. December 1996–June 1997

ISSUES a basis for environmentally benign, R. ferrugineus at the Coconut appropriate methods for control of Research Institute (CRI) in Coconut palms and their many these pests. Sri Lanka has been initiated, and products contribute 19% of four members of the CRI have agricultural GNP in Sri Lanka, the ACHIEVEMENTS been trained in aspects of majority being for domestic pheromone research. consumption but also contributing Male-produced aggregation 3.6% of total exports. It is estimated Improved slow-release dispensers pheromones have been reported for that the industry also provides for the pheromones of both both these species. The current employment for more than 135,000 R. ferrugineus and O. rhinoceros project has established the persons. The two most important have been developed and proven pheromone blend produced by chronic insect pests are red palm in the field. R. ferrugineus from Sri Lanka. weevil, Rhynchophorus A new minor component has been ferrugineus, and rhinoceros beetle, FUTURE identified, and the roles of the Oryctes rhinoceros, with infestation minor components are being Coconut growers in Sri Lanka are levels often 10% or greater. investigated in the field. already aware of the possibilities The larvae of the palm weevil bore of pheromone trapping as a result into the crown and trunk causing The major component was con- of the CRI’s extension work, and death of the tree. Rhinoceros firmed to be (4S*,5S*)-4-methyl-5- the CRI cannot meet demand for beetle attacks the growing point nonanol (ferrugineol), as reported the traps. and leaves, causing reduction previously. in yield and secondary infections Work is in progress at CRI to One of the minor components was by fungal rots. complete optimization of the identified as the corresponding pheromone blend for Current methods of control involv- ketone, 4-methyl-5-nonanone R. ferrugineus and investigate the ing application of tar or oil to stems (ferrugineone), but it was present at importance of natural and to prevent egg-laying, injection of <1% of the major component, synthetic food attractants. stems with insecticide, and removal much less than the 5–10% reported of infested palms are only partially previously. Further assistance is required: satisfactory, and there are fears that A new minor component was • to secure supply of the infestation levels will increase identified as (3S*,4S*)-3-methyl-4- synthetic pheromone for dramatically following the recent octanol, which has not been R. ferrugineus locally in ban in Sri Lanka of the commonly reported previously for this species. Sri Lanka; used organophosphate insecticide monocrotophos. A fourth EAG-active component was • to develop a cheaper synthesis identified as 2-hydroxy-3-butanone for the pheromone of The aim of this project was to (acetoin), a fermentation product of O. rhinoceros; develop and promote methods for sugarcane. Production of this control of rhinoceros beetles and • to demonstrate that the coincided with the period during weevils by developing pheromone pheromone traps can be used which sugarcane is reported to be trapping systems for R. ferrugineus to control R. ferrugineus and attractive to the weevils. and O. rhinoceros appropriate for O. rhinoceros and establish use in Sri Lanka. These will provide Production of the pheromone of the necessary parameters.

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Nematode resistance in bananas

R6391 All types of banana (Musa) are susceptible to damage caused by plant parasitic nema- todes, the most important of which are the banana burrowing nematode Radopholus S.R. Gowen University of Reading, UK similis and the root lesion nematodes, Pratylenchus spp. Nematode resistance in bananas is not common, and this project set out to identify sources of resistance (or tolerance) in S. Sathiamoorthy the wider Musa germplasm. The results obtained show that there is resistance to both Tamil Nadu Agricultural University nematode species in some cultivars, but not in any that are widely grown commercially. (TNAU), Coimbatore, India Cultivars showing resistance have less lesioning on their roots, and nematode populations October 1995–December 1999 are significantly lower than on susceptible plants. Immunity to infection is not known. The rate at which nematodes multiply is lower on the ‘resistant’ cultivars. A new result was the discovery that R. similis is more damaging nematode-for-nematode than P. coffeae; when inoculated with similar numbers, the former caused greater loss of fresh root and shoot weight. Biochemical analyses have shown that the resistant cultivars have higher concen- trations of phenolic compounds such as tannins, or that greater quantities of phenolics develop following infection. These contributions towards understanding the mechanisms of resistance (or decreased susceptibility) will assist banana improvement programmes to select for these attributes in cultivars and synthetic hybrids.

SELECTED PUBLICATIONS ISSUES This project was set up to seek sources of resistance to nematodes BINKS, R.H. (1996) Aspects of biochemi- Nematodes were recognized as in the Musa germplasm that had cal resistance in Musa spp. Nematropica, major pests of banana in relatively not hitherto been tested. The 26: 243. recent times. In the 1950s severe information gained can be used by COLLINGBORN, F.M.B. and GOWEN, crop losses (over 50%) were the international and national S.R. (1997) Screening of banana cultivars experienced in commercial planta- banana improvement programmes, for resistance to Radopholus similis and tions in the Caribbean and Latin for example in India, Honduras, Pratylenchus coffeae. InfoMusa 6: 3. America resulting from nematode Cameroon and Brazil, and the root damage, which predisposes International Institute of Tropical COLLINGBORN, F.M.B., GOWEN, S.R. banana plants to topple. It is likely Agricultural (IITA) programmes in and MUELLER-HARVEY, I. (2000) Inves- that this coincided with the change Nigeria and Uganda. All of these tigations into the chemical basis for nema- of cultivar made necessary by the programmes seek to improve yields tode resistance of roots from three Musa epidemic of fusarium wilt known as and sustainability of bananas for cultivars in response to Radopholus similis Panama disease which destroyed the the smaller banana producers by infection. Journal of Agricultural and Food hitherto principal export clone Gros developing new cultivars with pest Chemistry 48: 5297–5301. Michel. The replacement Cavendish and disease resistance and good FOGAIN, R. and GOWEN, S.R. (1998) clones were used for their immunity agronomic and culinary qualities. Yangambi km5 (Musa AAA, Ibota sub- to the disease. It can be hypoth- group): a possible source of resistance to esized that during the period of ACHIEVEMENTS Radopholus similis and Pratylenchus rapid multiplication and distribu- A diverse selection of cultivars, goodeyi. Fundamental and Applied tion of the Cavendish clones, the diploids, triploids and tetraploids, Nematology, 21: 75–80. burrowing nematode Radopholus some inedible wild seed-forming similis was also distributed on SHANTHI, A., SATHIAMOORTHY, S., types (Musa acuminata and infested planting material. JOHNSON, N., GOWEN, S.R. and M. balbisiana), and some grown for cooking rather than as sweet SOORIANATHASUNDARAM, K. (1998) There is a long history of banana Response of certain banana cultivars and dessert fruit have been evaluated. breeding, but success in terms of The principal research activity has hybrids to the burrowing nematode and new varieties being adopted for root-knot nematodes under glasshouse been to compare the reaction to widespread cultivation has been nematode attack measured in terms conditions. Meeting of the Afro-Asian slow to happen. This is largely due Society of Nematologists, April 1998, of lesion development, nematode to the problem of incorporating abundance and plant growth Coimbatore, India. essential qualities into varieties that response. Other features that SHANTHI, A., SATHIAMOORTHY, S., meet the criteria for grower/ contributed to the assessment JOHNSON, N., GOWEN, S.R. and consumer acceptability concerning included the growth of the root SOORIANATHASUNDARAM, K. (1998). flavour and cooking quality. The system, the anatomy of the roots, Field screening of synthetic hybrids for challenges are easier now that and biochemical differences in nematode resistance. Meeting of the Afro- banana breeders are selecting for roots between cultivars. It has been Asian Society of Nematologists, April uses other than the international found that resistance/decreased 1998, Coimbatore, India. trade in dessert fruit. susceptibility to nematodes is

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The diversity of fruit within Musa. present in the Musa germplasm. tions to withstand nematode attack Some of the many cultivars grown When challenged with nematodes, and produce acceptable yields of in southern India may be less some cultivars contained the fruit. The root health of bananas is susceptible to nematodes but their development of the nematode critical because, in extreme cases, use and distribution is quite population when compared to the crop losses result from plants limited. The inclusion of some of some susceptible cultivars. None falling over, with consequent total these cultivars in banana improve- was immune to attack, but root loss of fruit. Some cultivars have a ment programmes is desirable, but lesions were fewer or contained proportionally larger root system the beneficial effects of including fewer nematodes. any resistance traits in new varieties will be a medium-term This feature was found in some (10-year) objective. diploid cultivars, and these can be used in banana improvement There is a diversity of germplasm schemes. The genetic basis for this in India, much of which has not resistance (or resistance to other yet been fully evaluated. However, diseases) has not been determined, the major constraint is the high mainly because of the practical incidence of virus infection in the difficulties in banana breeding. wild (and synthetically produced) The heritability of these traits is varieties. Until advances can be still unknown. made in virus elimination, the widespread exchange of these Differences in root anatomy could R. similis, the banana burrowing nematode under-exploited materials will be be associated with the decreased (~0.7 mm long, 0.03 mm wide). restricted. This situation underlines rate of nematode reproduction in the serious nature of the banana some cultivars. The amounts of viruses and the priority that should than others, which may explain the aerenchyma or respiratory tissue be given to their elimination from field tolerance, but from a crop with air spaces in the root cortex plants as well as their epidemiology. differ between cultivars: those that improvement standpoint may be are less susceptible to nematodes less attractive if such varieties are Contemporaneous research have less aerenchyma. Similarly, intrinsically less productive in (R6583) suggests that there is quite the amounts of phenolic com- terms of size of fruit and exportable wide genetic (pathogenic) variabil- pounds, such as tannins and yield. ity between nematode populations, flavonols, were found to be even from within one country. If different. In resistant cultivars FUTURE such variability is normal, it may higher levels were encountered, require that more in-country particularly after challenge by The results from this project have evaluations be made with nematodes. demonstrated that there are Musa selected cultivars. Future work cultivars that are less susceptible to with the same cultivars at different Root vigour can account for nematodes than the standard sites in Uganda may help to tolerance to nematodes, allowing cultivars currently grown widely for disclose if such variability has field bananas grown under field condi- subsistence and local markets. significance.

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Identification, vector relationships, epidemiology and control of virus and bacterial diseases of banana

R6579 The Asia–Pacific region, including the Philippines, is the centre of diversity for bananas and plantains, and is therefore also a centre of diversity for many of the pathogens attack- L. Kenyon Natural Resources Institute (NRI), ing this family. Banana viral and bacterial diseases, particularly banana bunchy top virus University of Greenwich, UK and the bacterial diseases Moko and Bugtok, are major constraints to banana production by both commercial and small-scale growers throughout the region. This project built on L.V. Magnaye, L Herradura earlier efforts to obtain information on the insect vectors of these diseases and their move- Philippines Department of Agriculture, ments, and hence on the pattern and rate of spread of the diseases. An improved under- Bureau of Plant Industry (BPI), Davao, standing of disease increase and spread has allowed the formulation of more relevant Mindanao, Philippines control strategies. Project findings have been disseminated to local small-scale growers April 1996–February 1998 and extension agents in the southern Philippines, and other promotional pathways (such as a comic strip publication) are being pursued.

ISSUES Philippines, and on the factors influencing their pattern and rate of Banana is the most important fruit spread. species in South-East Asia, ranking first in the Philippines, Indonesia ACHIEVEMENTS and Thailand in both area planted and production. As well as being BANANA BUNCHY TOP VIRUS locally important to smallholders, banana is one of the most impor- A study of smallholder banana tant export crops in the Philippines. growers’ perceptions of banana As a vegetatively propagated crop, diseases and their knowledge and banana is particularly susceptible understanding of currently recom- to accumulation of virus diseases. mended control practices was Banana bunchy top virus (BBTV) continued. Most farmers had heard was ranked by the International of bunchy top virus but did not Network for the Improvement of SELECTED PUBLICATIONS recognize it until the disease was at Banana and Plantain (INIBAP) as an advanced stage; young infected the most important virus disease of KENYON, L. (1996) Epidemiology of suckers were completely over- banana in the region, and has the virus diseases affecting banana. Presented looked. Other less damaging potential to cause major losses, as at Sixth RAC Meeting, INIBAP, Asia and viruses (banana bract mosaic virus occurred in the 1920s in Australia, Pacific Network, Tiruchirapalli, India, and cucumber mosaic virus) and more recently in the early September 1996. generally were not recognized. 1990s in Pakistan. Banana bract Farmers were confused over the KENYON, L. (1997) Banana Streak mosaic virus is also becoming different control measures used for Badnavirus. FAO/CABI Plant Quarantine increasingly important in the different diseases, and there was no Virus Identification Sheet. Wallingford, Philippines and on the Indian clear extension message. The UK: CAB International. subcontinent. In addition, diseases recommended control measures of caused by the bacterial pathogen KENYON, L. (1997) Banana Bunchytop roguing bunchy top-infected plants Ralstonia (Pseudomonas) Nanavirus. FAO/CABI Plant Quarantine were not followed adequately, solanacearum (Moko and Bugtok) Virus Identification Sheet. Wallingford, even when farmers were aware of can devastate crops, sometimes UK: CAB International. them, as they tended to leave part causing total collapse of young, of the infected root mats and young fast-growing plants within one KENYON, L., BROWN, M. and KHONJE, P. suckers in the ground after the week. (1997) First report of Banana Bunchy Top infected mother plant had been Virus in Malawi. Plant Disease 81: 1096. The aim of this project was to build removed. Farmers were unaware SMITH, M.C., HOLT, J., KENYON, L. and on the findings of a previous that this provided a source of FOOT, C. (1998) Quantitative epidemi- project (R5234; see Research disease inoculum which could then ology of banana bunchy top virus disease Highlights, 1989/95) to obtain be spread to other plants. Even the and its control. Plant Pathology 47: more information on the epidemi- farmers who knew that bunchy top 177–187. ology of these diseases in the was a virus spread by aphids, and

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Left, local banana growers during field demonstrations at the project workshop

Right, a young banana plant already severely affected by BBTV

readily observe aggregation of glyphosate into the base of the bunchy top virus infections, pseudostems of the mother plant indicating that some secondary and suckers – was a more efficient spread of the disease was occur- means of eradication than the ring. Alate (winged) banana aphids common practice of roguing. (Pentalonia nigronervosa), the Information on the epidemiology vectors of bunchy top virus, were who had good contact with of bunchy top virus was obtained caught most frequently on yellow extension staff, did not appear to by compiling disease incidence sticky traps between ground level be aware of the risks of leaving data from commercial banana and 1 m above ground level in the infected suckers in the farm. New farms in the Davao city region. experimental plots of banana. planting material usually came From these data, models of a However, BBTV incidence and rate from the farmer’s existing plants, bunchy top virus disease epidemic of spread were not readily associ- or was bought from neighbouring were developed, incorporating the ated or correlated to aphid abun- farms. Tissue-cultured material two key features of an epidemic in dance. generally was not available to a plantation in the Philippines: an individual farmers. Where it was Preliminary results suggested that exponential increase in disease available it was often planted in the ‘vampire’ method – whereby incidence over 10 years (Fig. 1), amongst infected plants, and most infected banana mats were and a declining gradient of inci- of the benefits of clean planting destroyed by driving split bamboo dence from the outside edge of the material were soon lost. skewers soaked in the herbicide plantation to the centre. A non- During the preceding project (R5234) three trial sites, each consisting of at least 600 virus- indexed banana plants, were established. This project continued to monitor the trial sites, both visually and by enzyme-linked immunosorbent assay (ELISA), for infection and spread of bunchy top virus. Climatic records were kept for each site, and the number and type of aphids caught in yellow pan traps at each site were also recorded. Despite following the routine management practice of digging out infected plants and replacing them with healthy ones, the incidence of bunchy top virus gradually increased at all three Figure 1. Original data and fitted regression of the number of banana bunchy sites. However, only at one site was top-diseased plants (natural log transformed) removed each month from the incidence sufficiently high to a banana plantation in the southern Philippines

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infecting strains of the bacterium were isolated from individuals of the banana thrips (Thrips hawaiiensis) and of an unidentified dipteran fly caught on Bugtok-infected bunches of cooking banana. So far no consistent differences between the Bugtok and Moko strains of R. solanacearum have been identified at the nucleic acid level; however this is still under investigation. SUMMARY Shortfalls have been identified in the current control practices for BBTV-infected suckers emerging from the mat of a banana plant that bunchy top virus and in farmers’ has not been properly destroyed: a potent source of virus for infecting understanding of the disease neighbouring plants process, and methods to improve these have been devised. A comic- strip publication in the local dialect spatial and a spatial model were Aphis gossipii and Rhopalosiphum on the control of banana bunchy developed; analysis of the two maidis. Banana bract mosaic virus top disease has been produced, models showed that for disease is only distantly related to abaca and an end-of-project workshop, incidence to increase exponentially mosaic potyvirus. held at the Bureau of Plant Indus- over time, the rate of disease tries Davao station in August 1997, MOKO progress could be dependent either was attended by over 50 small- on internal spread and roguing rate During experiments to try to scale banana growers and field (proportion of diseased plants identify the putative insect vectors of workers from the Davao region. In removed and replaced per unit Ralstonia solanacearum, banana- addition, the capability of the time), or on the rate of Philippine Bureau of Plant increase of external inocu- Industry for research on the lum pressure. The spatial detection and identification, model was also used to vectors and control practices explore a variable roguing for virus and bacterial diseases rate across blocks. of banana (and other crop Simulations indicated that plants) has been strengthened, this may produce small and diagnostic tests for gains over the adoption of identification of banana a constant roguing rate over diseases transferred. all blocks, but would be risky because a slight shift in roguing emphasis can result FUTURE in a dramatic increase in disease. Further research is required to determine if the findings of BANANA BRACT MOSAIC this project are applicable to VIRUS other banana-growing regions The incidence of banana of South-East Asia. Further bract mosaic also appeared work is also needed to evaluate to be on the increase in the the alternative control practices Philippines. Transmission resulting from this project. studies (in association with a UNDP-funded project) A similar study has recently showed that banana bract been initiated on the epidemi- mosaic virus is most effi- ology of banana streak ciently transmitted by the badnavirus in Uganda (R7529), banana aphid Pentalonia and there is a further need for nigronervosa, but can also The comic-strip publication, written in the local dialect, such a study on banana bract be transmitted by the aphids on the control of banana bunchy top disease mosaic potyvirus in India.

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Investigation of the Rhizoctonia sheath disease complex in rice

R6643 Rhizoctonia sheath disease, caused by a complex of three related fungi, is one of the most significant constraints to rice production in Asia. Development of effective M.A. Rutherford and sustainable control measures has been hampered by a poor understanding of the CABI Bioscience, Egham, UK pathogens involved, and of the effects of environmental and management factors on these H.C. Turner pathogens and how they interact. The specific and sub-specific diagnostic tools devel- Natural Resources Institute (NRI) , oped through this project should provide the key to resolving these uncertainties University of Greenwich, UK and developing optimal sustainable methods for disease control in the future. U.D. Singh Central Rice Research Institute (CRRI), Cuttack, India ISSUES These include mapping of species distributions, which would help in April 1996–March 1999 Sheath blight is a disease of rice planning how and where to plant caused by the fungal pathogen different resistant rice lines, and Rhizoctonia solani which affects assessment of different rice varie- the lower part of the leaf. It causes ties’ resistance to the three significant crop losses in many Rhizoctonia species individually rice-growing areas of South and and in combination, thereby South-East Asia, and its impact improving the productivity: on rice production in the region investment ratio for small-scale is increasing due to wider use farmers and contributing to of high-yielding varieties and a reduction in rural poverty. increased fertilizer application. It is now ranked as one of the two The aim of this project was to major rice disease problems in characterize the nature of the many countries. Rhizoctonia disease complex (R. solani, R. oryzae and Earlier work on characterizing and R. oryzae-sativae) in rice-based developing appropriate disease cropping systems, and to use this management strategies for sheath information as a basis for develop- blight (R5535 and R5922; see ing morphological, biochemical Research Highlights 1989–95) and molecular techniques for demonstrated the need for diagnos- identifying the causal agents at an tic methods to detect and discrimi- early stage of disease development, nate between R. solani and two leading to improved disease other Rhizoctonia species, diagnosis and management. R. oryzae and R. oryzae-sativae, which also cause sheath blight-like ACHIEVEMENTS lesions on the rice crop. The three species produce very similar Comprehensive culture collec- symptoms on the rice sheath, may tions of strains of R. solani, SELECTED PUBLICATIONS coexist as a disease complex, and R. oryzae and R. oryzae-sativae collectively cause considerable collected from specific cropping JOHANSON, A., TURNER, H.C. yield losses in rice in Asia. systems in South and South-East MCKAY, G.J. and BROWN, A.E. (1998). Sheath spot, caused by R. oryzae, Asia have been established in the A PCR-based method to distinguish and aggregated sheath spot UK and India. fungi of the rice sheath-blight complex, (R. oryzae-sativae), are generally A number of approaches were Rhizoctonia solani, R. oryzae and not considered to be as widespread developed in the UK to assess R. oryzae-sativae. FEMS Microbiology or economically important as variation within and between Letters 162: 289–294. sheath blight, but the three related Rhizoctonia species at the genetic TURNER, H.C., SINGH, U.D., RUTHER- diseases have been incorrectly level (Table 1). These methods FORD, M.A., BANNIZA, S., JOHAN- diagnosed in many cases. A lack included analyses of genetic SON, A., DAVIES, D and BRIDGE, P.D. of techniques for detecting and variation in ribosomal DNA (1999). Detection and differentiation of differentiating the individual (rDNA) and the subsequent Rhizoctonia species causing sheath pathogens has impeded the development of species-specific diseases of rice crops: application of development and specific targeting PCR primers targeting this region, a new approach. Rice Biotechnology of sustainable and appropriate and analyses of variation in Quarterly 38. disease management practices. mitochondrial DNA (mtDNA)

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with subsequent development of disease complex of rice in South The findings strongly suggest that DNA probes for use in Southern and South-East Asia. It has, for our understanding of the relative blots. example, reinforced suspicions that importance of R. solani, R. oryzae- R. solani is a causal agent of rice sativae and R. oryzae in the region, From the above work a range of sheath blight throughout India. of their interactions with each other tools has been developed that can It has also revealed the presence and with climatic factors, and of rapidly identify the Rhizoctonia of R. oryzae as a rice pathogen their responses to cropping species present in diseased rice in India for the first time. The three practices, is more limited than sheaths. These will permit the species exhibited geographic and previously assumed. More impor- tracking of sub-specific populations tantly, measures currently applied of these pathogens through the ecological specificity, differed to control sheath diseases of rice development and spread of sheath in growth response to temperature may be inappropriate. disease epidemics in the field. in culture, showed differential Preliminary application of these virulence on rice and differed The effect of temperature on tools during the project has in their tolerance to the fungicide growth of the three species provided greatly improved insight carbendazim, which is widely used observed in this work suggests that into the components of the sheath in India to control sheath blight. they may be adapted to quite

Table 1. Summary of suitability of techniques for differentiation and diagnosis of R. solani, R. oryzae-sativae and R. oryzae at species and sub-species level

Suitable for diagnosis of:

Species Notes Technique groups Species Sub-species (+ benefit; – limitation)

Morphological √√+ Can be conducted with minimal technological input characterization – Requires isolation of the pathogen(s), (time-consuming, plus a risk of preferential isolation) – Requires experienced personnel for reliable identification

Species-specific √ + No fungal isolation required PCR primers + Identification achieved within 48 h

Restriction √√+ Differentiation of Rhizoctonia species possible in most fingerprinting of cases rDNA + Permits tracking of individual strains – Requires isolation of the pathogen – Species designation not 100% reliable

mtDNA analysis √ + Permits tracking of individual strains – Pathogen isolation required

Immunological √ + Rapid confirmation of Rhizoctonia infection without detection pathogen isolation – Differentiation between Rhizoctonia species not reliable – commercially available ‘Agri-screen’ also give a positive reading for S. hydrophilum infections

Biochemical √√+ Permits differentiation of intraspecific groups of strains and characterization possibly individual strains + Many techniques relatively simple to perform – Pathogen isolation and prior identification to genus is required

Fungicide √ + Differentiation of Rhizoctonia species possible resistance – Pathogen isolation and prior identification to genus is required

Temperature √ + Differentiation of Rhizoctonia species possible tolerance – Pathogen isolation and prior identification to genus is required

Pathogenicity √ + Lesion appearance is easily identifiable for the Rhizoctonia testing group – Requires isolation of the pathogen

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different ecological FUTURE conditions. The more rapid growth of A proposed further study R. oryzae-sativae and will determine sources R. oryzae at two tempera- of inoculum and mode ture extremes (10 and of transmission o 35 C, respectively) may of Rhizoctonia diseases indicate species-based within local rice-cropping differences in optimal systems, and investigate climatic conditions for the effects of farm inoculum persistence and management practices epidemic development. on pathogen inoculum The ability of R. oryzae sources, levels and to maintain growth across transmission, and disease a wide range of tempera- development. The study tures, its less aggressive will provide an accurate nature on the rice plant assessment, under and its resistance to the specific cropping condi- fungicide carbendazim tions, of the population suggest that, of the three dynamics during the species, it is best adapted course of disease estab- ecologically. The current lishment and spread, and perception of R. oryzae will clarify the potential as a ‘less significant’ importance of primary rice pathogen may be and secondary sources due to a lack of aware- of inoculum. Outputs will ness, or the fact that it is permit the identification an emerging pathogen of conditions and under the current cropping practices that intensification of rice most effectively restrict production. In either disease development and case, it appears to have spread, by reducing the greatest potential as or eliminating potential a future major constraint sources of inoculum and to rice production. restricting subsequent pathogen dissemination. The tools developed Sheath blight, caused by Rhizoctonia solani, on paddy rice Final results of the study through this project now in Asia will aid the formulation make it possible to obtain a better • identification of environmental of clear recommendations for crop understanding factors determining the relative management which will minimize of these problems and to provide significance of the three species losses due to Rhizoctonia diseases key information for the develop- under various agro-ecological in rice cropping systems. ment of control measures. Areas conditions; A number of centres – the Central where these tools should prove Rice Research Institute, the Directo- invaluable include: • determining effects of cultural crop management practices on rate of Rice Research, Govind • identification of the predomi- pathogen prevalence and Ballabh Pant University of Agricul- nant sources of pathogen disease development. ture and Technology, Haryana inoculum in the field Agricultural University and (e.g. detection in soil, circum- Broader use of the technologies Tamil Nadu Rice Research Institute venting the need for isolation); developed by the project will (India); National Institute of Plant enhance our understanding of the Protection (Vietnam); China Rice • mapping of species distributions diseases so that more appropriate Research Institute; Crop Diseases to facilitate optimal deployment management practices can be Research Institute (Pakistan); and of resistant rice lines; developed and effectively applied. the Institute of Agriculture and In the longer term this will lead to Animal Science (Nepal) – have • assessment of rice germplasm in cost-effective reductions in losses expressed significant interest terms of resistance to the three resulting from these diseases, an in using these technologies Rhizoctonia species, both improvement in rice yields and to support ongoing studies of rice individually and enhanced sustainability for small- sheath diseases in their respective in combination; holder farmers in Asia. countries.

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Epidemiology and management of rice tungro virus disease

R6519 Rice tungro disease is one of the most important constraints to rice production in inten- sively cultivated, irrigated areas in South and South-East Asia. It is a highly destructive T.C.B. Chancellor, J. Holt, L. Kenyon, H. Warburton, N.P. Hartanto disease, and resource-poor farmers can suffer serious loss of income if their crops are Natural Resources Institute (NRI), affected. Tungro, a virus disease with an insect vector, is difficult to control, and manage- University of Greenwich, UK ment strategies have traditionally relied on heavy insecticide usage, with adverse effects on human health and the environment. This project aimed to reduce yield losses and to O. Azzam, R.C. Cabunagan, protect farmers’ income in intensive rice-cropping systems by developing and promoting K.L. Heong sustainable strategies for management of tungro disease. The project has identified appro- International Rice Research Institute (IRRI), Los Baños, Philippines priate methodologies to reduce yield losses due to tungro in endemic areas, and to pro- tect farmers’ incomes from the drastic loss of income that results from a serious attack of X.H. Truong the disease. The key management option is the deployment of new disease-resistant vari- Philippine Rice Research Institute, eties. This offers the most practical and sustainable approach in endemic areas. Two tungro- Muñoz, Philippines resistant varieties identified through the project were released in 1999 in Indonesia. One T. Ganapathy of these varieties, Tukad Unda, was quickly adopted by farmers and was grown on 10 000 Tamil Nadu Agricultural University ha. One tungro-resistant variety has been approved for regional release in the Philippines (TNAU), Coimbatore, India and others are being used in resistance breeding programmes in India. January 1996–September 1999 ISSUES inputs; as a result of the lack of effective control measures and high Rice tungro disease emerged as yield losses, farmers have been a serious problem for rice farmers caught in a debt cycle from which in the 1960s, as a result of the they cannot easily escape. intensification of rice production during the Green Revolution. Results of a previous project Major outbreaks occurred through- (R5243) showed that tungro out South and South-East Asia, incidence is not directly related causing serious production losses to insect abundance, and that the over wide areas. Large-scale widely used threshold-based epidemics have become less recommendations for control by frequent but still occur: in 1995, insecticides could not be justified. SELECTED PUBLICATIONS for example, a tungro outbreak Research on disease dynamics occurred in central Java, Indonesia, revealed that secondary plant-to- AZZAM, O., CABUNAGAN, R.C. and affecting an estimated 18 000 ha plant spread by leafhopper vectors CHANCELLOR, T.C.B. (2000) Methods of rice and resulting in major plays an important role in tungro for Evaluating Resistance to Rice Tungro economic losses for resource-poor epidemiology. Disease. IRRI Discussion Paper Series farmers and for the country as No. 38. Makati City, Philippines: Interna- a whole. Developing rice varieties with tional Rice Research Institute. resistance to the rice tungro The dynamics of tungro disease are spherical virus, rather than to the HOLT, J. and CHANCELLOR, T.C.B. extremely complex and, until insect vector, has the potential (1999) Modelling the spatio-temporal de- recently, remained poorly under- to dramatically reduce tungro ployment of resistant varieties to reduce stood. Consequently there was no incidence by preventing secondary the incidence of rice tungro disease in clear strategy to manage the spread. The most effective way a dynamic cropping system. Plant Pathol- disease, and many of the control to control tungro was found to be ogy 48: 453–461. measures implemented were not through tactical measures such inappropriate and ineffective. NATH, P.D., KENYON, L., BARTOLOME, as applying insecticides or remov- The use of varieties with resist- V.I., MCLAREN, G. and AZZAM, O. (2000) ing infected rice plants, but rather ance to the leafhopper vector has Simple serological assays for detecting using a strategic approach involving been successful in reducing rice tungro viruses. Journal of Food and the use of virus-resistant varieties tungro incidence, but this Agricultural Immunology 12: 139-151 and the manipulation of planting resistance has not proved to be dates. TIONGCO, E.R., CHANCELLOR, T.C.B., durable. Farmers have been VILLAREAL, S., MAGBANUA, M. and forced into relying on insecti- This project has built on the TENG, P.S. (1998) Roguing as a tactical cides, even though they know previous findings, with the aim of control for rice tungro virus disease. that this approach had limited developing and promoting sustain- Journal of Plant Protection in the Tropics efficacy. Many rice farmers able tungro disease management 11: 45–52. depend on credit to purchase strategies.

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performance of promising virus- resistant lines in farmers’ fields. Replicated field plots were planted with a virus-resistant or virus- tolerant line, a leafhopper vector- resistant line, and a variety chosen by the farmer and grown in the rest of his or her field. Leafhopper vector numbers, tungro disease incidence and grain yield were recorded. The trials enabled farmers to discover for themselves the value of virus-resistant varieties and to appreciate that insecticide sprays were not needed, even when large numbers of leafhoppers were present in the crop. In one trial Figure 1. Mean tungro incidence and infection with rice tungro bacilliform in the Philippines, the collaborating (BB) and spherical (SS) viruses in advanced breeding lines and varieties at two farmer bulked up seed of the virus- sites in the Philippines and one in Indonesia in replicated field trials (1998) resistant line IR69705-1-1-3-2-1, and renamed it Line 386. Through ACHIEVEMENTS sian variety, Utri Merah. These lines a process of exchange and sale consistently showed strong resist- among farmers and traders, Line DURABLE RESISTANCE ance to tungro disease at all trial 386 became widely adopted in sites. Moreover, IR69726-116-1-3 North Cotabato and the neighbour- Advanced breeding lines with has an excellent plant type, which ing province of Maguindanao. resistance to rice tungro viruses is attractive to rice farmers in In view of the spontaneous uptake developed at the International Rice Indonesia and the Philippines, and of Line 386, the Philippine Rice Research Institute (IRRI) were has good eating quality and high Research Institute decided to give selected and evaluated in the yield potential. Some of the it their official blessing and distrib- greenhouse and in multilocation advanced breeding lines tested uted seeds to farmers under the field trials in India, Indonesia and showed good resistance at some name Matatag 3. This informal the Philippines. Figure 1 illustrates sites, but only moderate resistance process of seed dissemination also the performance of four advanced at others. This shows the value occurred in Tamil Nadu with breeding lines at sites in the of multilocation testing, which is IR68305-18-1 which was taken up Philippines and Indonesia essential for the development by farmers and subsequently in relation to leafhopper-resistant of successful resistance deployment entered in the State multilocation (IR62) and tungro-susceptible strategies. yield trials. (IR64) check varieties. Lines IR69705-1-1-3-2-1 and IR69726- On-farm trials were conducted A simple, reliable and relatively 116-1-3 have virus resistance in North Cotabato, Philippines and low-cost prototype diagnostic kit derived from a traditional Indone- Tamil Nadu, India to assess the for rice tungro bacilliform virus was developed. This should greatly facilitate the resistance breeding work undertaken by researchers in national agricultural research programmes. Previously, research- ers had to rely on symptom expres- sion alone and this did not allow them to identify resistance to the individual viruses. The kits will also be useful to agricultural extension staff for early and rapid identifica- tion of tungro outbreaks. Test kits were evaluated by selected partici- pants at an international workshop on tungro management conducted in November 1998. The method On-farm trial in North Cotabato, Philippines: yellow areas, ‘farmer choice’ was then refined and further field (tungro-susceptible) variety showing almost 100% tungro incidence; green evaluation was done in Bangladesh areas, leafhopper- and virus-resistant lines showing very low tungro levels and the Philippines.

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MODELLING STUDIES constrained by insufficient and identifying virus-resistant advanced irregular water supplies. However, breeding lines appropriate for Modelling studies were carried out at a workshop held in Midsayap, particular geographical locations to investigate the dynamics of Philippines in December 1998, the project has laid the basis for disease spread between rice fields. a commitment was made by farmers, this approach to be implemented. A lattice model was developed agricultural extension officers, local Two lines, IR68305-18-1 (Tukad to examine how the spatio- government units and the National Unda) and IR69726-116-1-3 temporal deployment of resistant Irrigation Authority to improve the (Tukad Petanu) were released varieties could reduce the inci- scheduling of irrigation water in the in 1999 as approved varieties by dence of rice tungro disease. The municipality. If successful, this the Indonesian government. Tukad model was also used to assess would serve as a model for other Unda was grown on 10 000 ha how changes in the synchrony areas. Reports from Midsayap in Bali and showed good resistance of planting dates affected the in the 1999 wet season indicate to tungro disease. Line IR69726-29- incidence of tungro. Figure 2 shows that a tighter scheduling of irriga- 1-2-2-2 was approved for regional that where planting dates are highly staggered, it is extremely difficult to reduce tungro incidence through cultural measures. However, in situations where the variation in planting dates is not so great, a relatively small move towards synchrony results in a big reduction in tungro disease.

EXTENSION Surveys of farmers’ perceptions of tungro disease and their current control practices were used to develop extension methodologies for improved tungro management. Two training courses in the identifi- cation and management of rice tungro disease were devised for Figure 2. The impact of changes in planting date synchrony depends on the agricultural extension officers and current level of planting synchrony (standard deviation of planting) and the for rice farmers. Courses were fallow period between successive rice crops. The appropriateness of recom- conducted in North Cotabato and mending synchrony changes can thus be evaluated for specific cases Tamil Nadu. Selected agricultural extension officers subsequently tion water was achieved, resulting release by the Philippine Seedboard trained groups of about 30 rice in more synchronous planting and in April 2000, and IR68305-18-1 farmers in three villages in North low tungro incidence. has been entered in the cooperative Cotabato and two villages in Tamil yield trials in Tamil Nadu, India. The success of the training led to Nadu. On-farm trials were used The development of a simple and the production of two training in the training to demonstrate the reliable diagnostic kit has provided manuals in tungro identification advantages of resistant varieties and rice breeders with a valuable tool and management aimed at rice to enable farmers to identify tungro to utilize this resistant material farmers and extension workers, disease, tungro vectors and their in their own breeding programmes. respectively. These manuals were natural enemies. There is strong demand for the kit, used in a training programme and researchers and agricultural Information obtained from focus conducted by IRRI in June 2000 extension officers from Bangladesh, group surveys conducted 2 years in Iloilo, Philippines, where a serious India, Indonesia and the Philippines after the training showed that tungro outbreak was recorded. farmers retained the main messages have been trained to use it. The promoted during the courses. The FUTURE project has contributed to a new spontaneous adoption of virus- emphasis on strategic measures for resistant lines by farmers before Durable resistance to rice tungro tungro management in recommen- clearance for varietal release disease offers the most practical, dations promoted by national indicates the potential for their cost-effective and environmentally agricultural extension agencies. This widespread uptake. Farmers sound way to stabilize yields and has led to a reduced emphasis on understood the importance of protect farmers’ income in inten- insecticide-based tungro control synchronizing planting dates to sive production systems where the strategies, with consequent benefits reduce tungro incidence, but were disease is a major problem. By for human health and the environment.

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Application of mating disruption to control yellow rice stem borer in India

R6739 Demand for rice production in developing countries is expected to increase by 1.8% per A. Cork year – this demand can be satisfied only by increased productivity. In many of the rice- Natural Resources Institute (NRI), growing regions of Asia, and particularly in India, the most economically important insect University of Greenwich, UK pest is the yellow stem borer, Scirpophaga incertulas. Where yellow stem borer is a peren- nial pest of economic importance, even with the use of cultural practices and tolerant J. Naidu varieties to suppress pest populations, expensive and environmentally damaging chemi- Sarada Valley Development, Samithi, cal control may be the only course presently available to rice producers. Control of lepi- India dopterous pests by the mating disruption technique, in which mating is suppressed by K.V. Prabhakar permeating the air around a crop with female sex pheromone, is now well established in Sri Vidya Trust, Anakapalle, India a wide range of crops. A controlled-release formulation has previously been developed October 1996–September 1999 and successfully field-tested in India for use in controlling yellow stem borer by mating disruption. A second control technology, mass trapping, was subsequently developed in- dependently by the Directorate of Rice Research. The project described here worked closely with smallholder rice cultivators to investigate whether these technologies could provide a practical and viable crop protection strategy.

ISSUES tion and through subsequent groundwater contamination. The demand for rice production Insecticides can also cause a in developing countries is expected resurgence of secondary pests by to increase by 1.8% per annum. killing predators and parasites that There is little land left to develop would normally control them. in South Asia – in fact the amount During the rainy season insecti- of land available for agricultural cides are generally ineffective as use is likely to fall because of water levels cannot be controlled increased urbanization. To consoli- and pesticides are leached out into date recent gains in productivity, the groundwater. many Asian countries have In contrast, pheromones (chemicals recognized the importance of secreted by insects that affect encouraging sustainable produc- members of the same species) are tion that puts a value on the species-specific, have no adverse SELECTED PUBLICATIONS environmental, social and effects on the environment, are economic costs of current rice unaffected by rainfall, and would CORK, A., DE SOUZA, K., KRISH- cultivation practices. Excessive be fully compatible with an NAIAH, K., ASHOK REDDY, A. and use of fertilizers and pesticides integrated pest management (IPM) ZAINULLABUDDIN, S. (1998) Season- could be reduced by adopting approach to controlling rice pests long control of yellow stem borer, need-based use of these inputs, in both dry- and wet-season crops. Scirpophaga incertulas (Lepidoptera: yielding an estimated saving By permeating the air with a Pyralidae) by mating disruption with the of up to US$2.5 bn. synthetic blend of female natural ratio of pheromone components. pheromone components, male Bulletin of Entomological Research 88: The yellow stem borer, Scirpophaga moths are prevented from 109–116. incertulas, is a major insect pest of following odour trails of rice in Asia, and chemical control CORK, A. (1998) Pheromones for con- pheromone released by females. is generally regarded as being the trol of yellow stem borer in India: does This results in a reduced level only option. The systemic insecti- mating disruption meet the needs of the of mating, or mating disruption, cides available to smallholders in rice cultivator? In Proceedings of the Sixth that can lead to a significant India, such as phorate and Australasian Applied Entomological reduction in the larval population carbofuran, are relatively cheap Research Conference, September/Octo- of the next generation and hence and readily available but are ber 1998, Brisbane, pp. 304–313. a reduction in the damage invariably toxic to a wide range of sustained by a crop. CORK, A. and HALL, D. (1998) Applica- organisms apart from the target tion of pheromones for crop pest man- pests. The indiscriminate use of A pheromone has been developed agement in the Indian sub-continent. Jour- such insecticides exposes people for yellow stem borer (R5297; see nal of Asia–Pacific Entomology, and domestic animals to these Research Highlights 1989–95). On- 35–49. compounds, both during applica- farm development trials, conducted

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by researchers using prescribed a wider scale. Ideally, validation NGO staff and labourers recruited protocols and teams of labourers, should take place in the context from participating villages were have demonstrated that yellow of currently used farmers’ prac- trained to collect field data and stem borer can be effectively tice, with no financial or other assist social anthropologists in controlled by mating disruption inputs that might influence the interviews with farmers, with with synthetic sex pheromones outcome of the process. In an varying levels of success. Inter- (R5747). Mating disruption can attempt to conform to this views with farmers generated provide control in areas as small as strategy the project worked important background informa- 1 ha on smallholder rice cultiva- closely with farmers in establish- tion on farmers’ understanding tors’ fields in a range of agro- ing mutually suitable conditions of pests and existing pest control climatic zones of India, but is for field trials. Farmers were strategies. There was little local effective on a larger understanding of scale. Yields may be the concept of increased by 50–75% natural predators. compared to untreated Farmers generally controls, and by 10% sprayed a range of compared to plots pesticides when treated with insecti- they saw any cides. In separate trials insects in the rice the Directorate of Rice field. All insects Research (DRR) were assumed to demonstrated that be harmful, and no mass trapping with distinction was synthetic pheromone made between the was also efficacious. damage caused by Mass trapping involves fungi, bacteria, or catching male moths viruses, or that in pheromone-baited caused by insects. traps to reduce the Farmers applied ability of female moths between one and to mate and lay fertile seven applications eggs. The aim of the of pesticide per current project was to Farmers engaged in attaching Selibate® YSB pheromone dispensers to season depending validate these tech- bamboo sticks on the season and nologies as a viable village sampled. crop protection The average cost of one pesticide strategy amongst smallholder rice encouraged to continue with application was comparable to the cultivators. their existing farming practices, cost of applying mass trapping to the only exception being that control yellow stem borer for the farmers participating in the trials ACHIEVEMENTS whole season. Thus if yellow stem would not spray pesticides in borer was perceived as a potential The challenge facing this project trial fields, a condition to which threat to a crop, mass trapping was the validation of yellow stem they initially agreed. borer pheromone technology by would represent a cost-effective means of control. However, these means of voluntary on-farm trials Four villages were selected for on- low costs were only possible with a group which constitutes the farm trials. The farmers in these because of indigenous production dominant rice farming community villages identified the damage of traps and lures; the formulation in India – small-scale subsistence caused by stem borers as a major farmers. A prerequisite for the used for mating disruption is problem affecting their rice, and currently manufactured in the UK successful application of mating were prepared to participate in disruption and mass trapping was and is subject to an import tax of trials to test the new technologies 50% that makes its use in India the use of large areas of rice, and under offer. Villagers selected since most of the rice grown in prohibitively expensive. groups of farmers who would India is cultivated in small plots of provide blocks of land for the trials For a range of reasons most farmers approximately 0.4 ha or less, this and they applied the pheromone were unwilling to refrain from required effective community under the direction of participating using pesticides in trial areas. The participation to be fully successful. NGOs. Farmers later indicated that constant use of pesticides by most Validation is a fundamental step the application of pheromone traps farmers compromised their before a science-led technology and dispensers was not a burden ability to test the technology on can be released and promoted on for them. offer effectively. In no field trial

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have been compensated for any loss to their yield caused by using pheromones instead of pesticides. Other lessons learned included: • a need for effective and rapid communication among stakeholders in order to build an effective partnership in farmer participatory projects • researchers should be sensitive to farmers’ comments and respond to their suggestions • despite farmers’ assurances, they are not necessarily prepared to risk their liveli- hoods to test new technologies • IPM component technologies can be tested by farmers only A farmer and children walking to fields to ‘plant’ the pheromone dispensers if adequate provision is made to address other crop protection was pesticide use sufficiently to achieve control, but as this was issues restricted to allow farmers to fully more labour-intensive than their appreciate the impact of the new conventional practice they did not • intermediaries need to have the control technologies on stem act on the advice. capability of providing partici- borer damage. While it would pating farmers with training in seem desirable to have initially Pheromone technology presents an crop protection and other IPM- developed the pheromone interesting case concerning gender related issues technology under tests with the and pest management practices. same level of farmer participa- It is not exactly clear why although • the problem to be addressed in tion, it was evident from these the concept of pheromone technol- the project has to be of suffi- trials that this would not have been ogy was introduced to both men cient importance to farmers for possible without of some form of and women, only men took them to fully participate in the compensation package being responsibility for its practical evaluations. agreed. application. If men are convention- ally responsible for applying A range of factors appear to have pesticides because of the health FUTURE influenced the farmers’ behaviour risks to women, then pheromone in the context of this project and technology offers an opportunity During the course of the project, should be taken into account in for increasing women’s involve- efforts were made to encourage future projects. These include ment in pest management strategies companies known to be involved indigenous beliefs about pests; as it does not pose a threat to in the production of biorational aversion to risk; lack of understand- human health. If other factors were control technologies to consider ing of the new technology; and influencing men’s control over pest producing and marketing poor communication of the project management technologies, then pheromone products for control aims and approach by intermediar- involving women in the decision- of yellow stem borer, and repre- ies. Other constraints were also making process on the choices of sentatives from two such compa- found to affect farmers’ adoption of and need for pest control interven- nies attended the project workshop. new practices, for example, farmers tions becomes a more complex Given the high level of interest in in Kakinada were well aware that task. the Indian Council of Agricultural they were applying too much Research (ICAR) and associated pesticide, and this was borne out The project raised important issues institutes, and a positive response by the low incidence of almost all concerning farmer participatory from industry, it is conceivable that arthropod species in field samples. validation methods. Providing a major effort will be launched The resulting loss of predators from farmers with demonstration trials through the Government system the rice fields subsequently resulted would have helped them to see to promote mass trapping of yellow in high planthopper populations. how the technology would benefit stem borer as part of an IPM The farmers had been instructed on them. Alternatively, farmers using package of technologies for how best to spray the planthoppers their own land for the trials could controlling rice pests.

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The Pakistan–UK fruit fly project

R6924, R7447 Fruit flies, principally Bactrocera spp., are serious pests of fruit and vegetables in Pakistan, causing annual losses of nearly US$200 million. The aim of this research was to develop J.D. Mumford, J. Stonehouse, D. Huggett cost-effective and accessible technologies for the assessment and control of fruit fly dam- Imperial College of Science, Technology and Medicine, UK age in Pakistan. Two control methods, the bait application technique and the male annihi- lation technique, were assessed: overall average reductions in infestation losses ranged A. Poswal, R. Mahmood from 75 to 100%, and these methods were as good as, if not better than, cover sprays, to CABI Bioscience, Rawalpindi, Pakistan which they are decidedly preferable for reasons of cost, safety and environmental con- A.H. Makhdum tamination. As well as reductions in fruit infestation, the trial data show increases in the CABI Bioscience, Mardan, North West overall density of fruit production, suggesting that percentage infestation data of sampled Frontier Province (NWFP), Pakistan fruit have underestimated true economic losses.The findings of this research will improve Z.M. Chaudhary the volume and quality of fruit production, and thus incomes and nutrition, in ways that Agriculture Extension Department, Rahim are cost-effective, accessible and environmentally benign. Yar Khan, Punjab, Pakistan K.N. Baloch Agricultural Extension Service, Dera Ismail Khan, NWFP, Pakistan ISSUES which use less than 10% of the G. Mustafa pesticide in the cover sprays Ayub Agricultural Research Institute, Pakistan is a predominantly currently in widespread use. Faisalabad, Punjab, Pakistan agricultural country. Its population September 1997–February 2000 is growing at the fastest rate of any major Asian nation, and is pro- ACHIEVEMENTS jected to become the world’s third Fruit fly losses were assessed in largest by 2050. It will therefore be SELECTED PUBLICATIONS farmers’ fields of guava, melon, necessary to maximize farm yields jujube and mango in four areas per unit area, and to develop high- STONEHOUSE, J.M., MUMFORD, J.D. under different control regimes, value crops such as fruit. Tephritid and MUSTAFA, G. (1998) Economic losses by the percentage season-end fly fruit flies, principally Bactrocera to Tephritid fruit flies (Diptera: Tephritidae) infestation of sampled fruit, and the spp. (previously called Dacus spp.), in Pakistan. Crop Protection 17: 159–164. density of fruit on trees relative to are estimated to cause annual those fallen to the ground. AFZAL, M., MAHMOOD, R. and STONE- losses of nearly US$200 million at In guava, infestation was 80% HOUSE, J.M. (2001) Soaked-wood killer farm level, including 15% of in unprotected orchards, 40% in an blocks for MAT fruit fly control in Paki- mangoes (annually $40 million), orchard protected by cover sprays, stan. In: Price, N. (ed.) Proceedings of the 35% of guavas ($46 million) and and 17% in orchards protected by Symposium on The Fruit Flies of the In- 35% of melons ($46 million). Fly BAT; fruit on trees per unit volume dian Ocean Region, Mauritius, June attacks have led to the virtual of tree canopy were 51.5% of the 2000. Port Louis, Mauritius: Ministry of abandonment of guava cultivation total in unprotected and 59.7% Agriculture, Food Technology & Natural in Sind and, together with apricot, in BAT orchards. In jujube, infesta- Resources/Indian Ocean Commission/EU in the Islamabad/Rawalpindi area. tion was 43% in unprotected and Indian Ocean Regional Applied Fruit Fly The principal pests are in the 3% in BAT orchards, and 3.7% of Research Programme (in press). species or species complexes of the unprotected and 12.7% of BAT- HAI, M.A., MAHMOOD, R. and STONE- oriental fruit fly B. dorsalis, the protected fruit remained on the HOUSE, J.M. (2001) Fruit flies in plums peach fruit fly B. zonata, and the tree. In melon, fly infestation was in North-West Frontier Province: devel- melon fly B. cucurbitae. There is 26% in unprotected and 3% in BAT opment, attack and drop. In: Price, N. a need for more complete informa- fields. Fifteen farmer-managed trials (ed.) ibid. (in press). tion on which flies are found found BAT-treated melon fields where: in general the distribution of yielded 36% more than unpro- MAHMOOD, R., BALOCH, K.N., fly species, and their movements tected. In all trials, farmers gave MAKHDUM, A.H., CHAUDHARY, Z.M., within Pakistan with seasonal very favourable reports of BAT. MUSTAFA, G. and STONEHOUSE, J.M. changes in weather and vegetation Smaller-scale trials on luffa and (2001) Fruit flies in Pakistan: damage and fruiting, are incompletely mapped. persimmon were inconclusive, control in farmers' fields. In: Price, N. (ed.) This research aimed to quantify probably due to late starts. MAT by ibid. (in press). levels and patterns of damage, and wood blocks soaked in lure mixed ZIA, Q., MAHMOOD, R. and STONE- to assess the prospects for two with insecticide is less expensive, HOUSE, J.M. (2001) Laboratory and field control methods, the bait applica- cumbersome and time-consuming tests of home-made baits of animal pro- tion technique (BAT) and male than the plastic traps in current use. tein. In: Price, N. (ed.) ibid. (in press). annihilation technique (MAT), In late-season mango, percentage

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A ber (jujube) orchard in Khanpur, Punjab, March 1999, the site of an informal, farmer-managed trial of protein bait sprays against fruit flies. This farmer tried a single BAT spray instead of his usual three cover insecticide sprays; the first cover spray was ineffective (it may have washed off in rain), and the bait spray was so successful that the other insecticide sprays were abandoned. The fruit yield was so high that the tree branches were bowed and even broken by the weight

infestation before harvest was 20% return from control measures killed, calibrated to total kill by in an unprotected plot and 0% in regardless of the intensity of fly a descending tier of increasingly one protected by soaked blocks; attack. wider bags to allow the fall of dead 43.8% of fruit were on the tree in flies away from the killing point to In a separate experiment monitor- unprotected orchards, and 46.7% be mathematically modelled. ing the development of infestation in MAT orchards. Attacks by fruit Assessed by both methods, BAT in plum orchards, attack was flies in early-season mango were with a home-made meat broth had predominantly during early limited, but also reduced. approximately 71% of the effective- ripening of fruit, and tended to the ness per unit volume of commer- The overall average reductions in west-facing parts of trees, possibly cial protein hydrolysate, and infestation losses implied by these because they are sunlit when flies application by brushes was as trials were 75% for guava by BAT, are active at dusk. Fly attacks were effective as by a sprayer, although 93% for jujube by BAT, 86% for on 23% of fruit in unprotected there may be a substantial health melon by BAT, and 100% for plots and 13% in protected plots, risk from the mixing of insecticide mango by MAT. If the estimated and additionally fruit in unpro- with a meat broth, which is savings obtained by these experi- tected plots were significantly prepared in a way similar to a food ments are applied to the loss likelier to fall from the tree prema- product. Soaked wood MAT blocks, estimates above, the resulting turely, even though not visibly on average, killed over three times annual gross savings (excluding attacked, and these falls took place more flies and lasted over twice as costs) at farm level for the whole before the main period of fly long as the plastic lure-baited traps of Pakistan would be $40 million oviposition. Attacked fruit devel- currently recommended and used in mangoes, $35 million in guavas oped to the point of disintegration in Pakistan. and $40 million in melons, or $115 slightly more quickly than million annually for these three unattacked fruit. More mature, FUTURE crops. developed fruit were not more This work is still very much in likely to be attacked by flies. The distribution of attacks was also progress, with Pakistani partners assessed in these trials. Fly maggots Modifications of BAT and MAT engaged in substantial research were not evenly distributed among were evaluated in laboratory and work, including further field trials, fruit, but clustered in relatively few field studies on the effectiveness studies on the male annihilation heavily infested fruits, differing sig- of individual ‘killing points’ of bait technique, and an expansion of the nificantly from a Poisson (random) or lure by recovering flies attracted programme of informal, farmer- distribution. But the number of and killed. Laboratory studies were managed trials. Information about maggots per infested fruit remained in choice chambers specially the project’s activities, findings and relatively constant, so that the developed by this project for recommendations has been frequency of fruit infested was assessment of the relative attraction distributed to participating exten- a direct function of the total and killing power of BAT mixtures. sion services, and to officials at number of maggots present, Field studies were by catching bags senior levels in the Pakistan suggesting a constant economic below killing points to record flies Agricultural Research Council.

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Sustainable management of the whitefly, Bemisia tabaci, and tomato leaf curl virus (ToLCV) on tomato in India

R6627 The whitefly Bemisia tabaci is currently the most serious pest of tomato in India, causing direct damage as well as transmitting tomato leaf curl virus. J. Colvin Natural Resources Institute (NRI), When populations of the whitefly are high, over 90% of plants can become University of Greenwich, UK infected, resulting in yield losses that may reach 100%. Farmers surveyed did not recognize the whitefly as the source of the virus disease, and responded V. Muniyappa by applying pesticides which are both costly and, in this case, ineffectual. University of Agricultural Sciences, A number of options for alternative pest management strategies were studied. Bangalore, India New tomato lines resistant to the virus disease were developed, and show the D. Moore most promise for sustainable control. This was the output in which tomato CABI Bioscience, Ascot, UK farmers expressed the greatest interest. April 1996–March 1999 ISSUES of Agricultural Sciences, Bangalore (UASB) initiated a research pro- In the recent past, over-reliance gramme to introduce ToLCV on conventional insecticides resistance genes into edible in vegetable and cotton production tomatoes through conventional has resulted in the evolution plant breeding techniques. of several new, highly resistant biotypes of whitefly (Bemisia The aim of this project was to tabaci). These ‘aggressive’ strains develop and promote sustainable outcompete the original biotypes, and cost-effective management are highly mobile and, worldwide, practices for the tomato pest cause hundreds of millions of B. tabaci and the virus disease pounds worth of damage annually. ToLCV, thereby improving both The development of alternative the quantity and quality of Indian management practices is vitally tomato production. The project important both to prevent the builds on previous work on evolution of more aggressive insecticide-resistant whitefly biotypes, and to cope with those in Pakistan (R5699; see Research already in existence. Highlights 1989–95). In India, tomato is both a high- ACHIEVEMENTS value crop which is exported to the Middle East, and an important RESISTANCE SCREENING subsistence vegetable grown Resistance to ToLCV is an mainly by women. Bemisia tabaci extremely important component is currently the most serious pest, of the IPM recommendations causing direct damage as well as for tomato production. transmitting tomato leaf curl virus (ToLCV). When whitefly Screening in both the glasshouse populations are high, over 90% and field was carried out during SELECTED PUBLICATIONS of plants can become infected, five field seasons and several very resulting in a yield loss of 40–100%. promising lines are being devel- RAMAPPA, H.K., MUNIYAPPA, V. and oped. F lines currently in the field Disease symptoms are particularly 5 COLVIN, J. (1998) The contribution severe if the plants are infected have shown excellent resistance of tomato and alternative host plants at an early stage of development. and will be rescreened in the next to tomato leaf curl virus inoculum With associated risks to both their field season when they will pressure in different areas of south health and the environment, experience the most intense India. Annals of Applied Biology, 133: farmers currently use large quanti- disease pressure. 187–198. ties of costly broad-spectrum Seven genotypes which performed insecticides in increasingly unsuc- HOLT, J., COLVIN, J. and MUNIYAPPA, V. well with respect to fruit yield and cessful attempts to control B. tabaci (1999) Identifying control strategies for other horticultural characters were and ToLCV. tomato leaf curl virus disease using selected for further field trials (see an epidemiological model. Journal In response to this potentially Table 1). The opinions of tomato of Applied Ecology 36: 625–633. devastating problem, the University growers were obtained during the

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However, augmentation of benefi- Table 1. Fruit characteristics of selected ToLCV-resistant lines cial insects did produce an TLB increase in the final tomato yield No. Fruit characters which was achieved without applying any chemical sprays. 111 Round shaped, slightly less than medium sized fruits, good yielding This finding is important in that 119 Round shaped, medium sized fruits (70–90 g), deep red, high yielding 122 Round shape, more than medium sized fruits, deep red colour, high it demonstrates the value of at least yielding, more foliage preserving the complex of benefi- 129 Oblong shape, light red, nipple at the basal end of the fruit, high yielding; cial insects within the crop, as they good in other characters such as fruits / cluster, more foliage etc, except also prevented any other major the shape of the fruits insect pests such as Helicoverpa 130 Round shaped, medium sized fruits, high yielding 134 Oval shaped, medium sized fruits and deep red colour, high yielding and armigera from causing damage. good taste This work was carried out by 148 Oval shape, deep red above, medium sized fruits, good yielding Mr Venkatesh towards his PhD.

MYCOPESTICIDES end-of-project farmer-field day/ E. adrianae and Eretmocerus workshop. The farmers evaluated mundus. Among many predators Fungal isolates were collected both F lines by considering resistance found in tomato fields, Axinoscymnus from the field and from the Institute 5 to ToLCV, foliage of plants, fruit puttarudriahi was very common. of Mycology, Chandigargh, India, bearing, size of the fruit, shape Colonies of several species were and mass-produced for field trials. of the fruit, transportability, market- established and the insects were The pathogens Beauveria bassiana ability, firmness of fruit and mass-reared. These were then used and Verticillium lecanii performed thickness of the skin and taste in a mass-release experiment to well, and B. bassiana gave similar of the fruits. At least two of the determine whether they could be yield results to the currently lines looked very promising and used to control the B. tabaci popu- recommended conventional also fulfilled the farmers’ horticul- lation and influence ToLCV spread. insecticide Hostathion (triazophos). tural requirements. The B. bassiana treatment using Unexpectedly, the numbers of material that was mass-produced These seven ToLCV-resistant immature B. tabaci developing at UASB gave better results than genotypes will go on to on the tomato crop before release the commercially available multilocation on-station trials in the were relatively low. The beneficial mycopesticide Biorin. Bangalore area. This work is insects which feed and develop planned for the next phase of the on the immature stages of B. tabaci In the laboratory, bioassays showed project. This is the first time systemic had a limited effect on the B. tabaci that both B. bassiana and V. lecanii ToLCV resistance has been success- population within the tomato crop, were very effective against all stages fully introduced into tomato lines and there was almost no effect on of B. tabaci except the egg. A major with acceptable horticultural the spread of ToLCV. This was limitation was that they also characteristics in India, and the found to be because almost all the attacked parasitized B. tabaci demand for these new varieties from spread of ToLCV into a susceptible nymphs and the adult stages all stakeholders is clearly evident. tomato crop is caused by virus- of beneficial insects; in this regard their effect was not unlike a broad- The use of these genotypes will be carrying adult B. tabaci coming spectrum conventional insecticide, a sustainable resource for poor into the crop from outside. This and widespread use would probably farmers as, unlike hybrid varieties, finding has both increased our affect the local silk industry. Other they are true-breeding and seeds understanding of the pathosystem, limitations were that efficacy would can be collected for use in the and aided the formulation of be reduced by fungicides which are following season. Further benefits sustainable IPM recommendations. often sprayed by farmers, and include cost savings from the The data showed that tomato yields control is currently not noticably reductions in pesticide use, and disease spread were similar better than achieved with a conven- improvements to farmers’ health, in the treated and control plots. tional insecticide, which may and reductions in environmental In plots where beneficial insects impede its adoption by local pollution and pesticide residues were released, the yield was just farmers. This work was carried out in tomato-based products. significantly higher, although this by Dr Anita Cherian towards her PhD. result is hard to explain in terms PARASITOIDS AND PREDATORS of disease progression within the SIMULATION MODEL Insects attacking B. tabaci, both crop. These results suggest that parasitoids and predators, were given the effort involved in the mass Epidemiological data were collected collected in Karnataka, identified production of predators and and incorporated into a mathemati- and mass-produced for field trials. parasitoids, the returns to be cal model that was used to assess The parasitoid species identified obtained in terms of increased and identify potential novel control included Encarsia transvena, tomato yield are neligible. techniques. Those that increased

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and decreased the vector emigration 11.5% of farmers did think that ingredients; for example, a few and immigration rate, respectively, insects were involved in causing or were using mixtures of very similar had the greatest potential for spreading the disease, but only four chemicals. Few non-chemical pest reducing the spread of the disease farmers knew that whiteflies were management methods were (see Selected publications). the disease vector. reported by farmers. Farmers’ stated methods of control- Other farmers were said to be the FARMERS’ PERCEPTIONS AND ling ToLCV were based on using main source of information on MANAGEMENT PRACTICES chemicals. However, many were farming; over half the farmers ob- aware that infected tomato plants tained information from pesticide A large survey was carried out of did not recover after spraying. dealers, particularly on which farmers’ perceptions and manage- Other diseases reported included chemicals to buy. The media was ment practices related to B. tabaci leaf spots, wilt, blight, various another important resource. and ToLCV, and the socio-eco- forms of rots, powdery mildew Extension staff were not seen as the nomic factors affecting the adop- and damping off. Fruit borers and main source of information by most tion of new varieties and IPM leaf miners were also important farmers. management strategies. The study pests. consisted of group and individual Farmer field trials were carried out discussions with farmers, plus Questions on general pesticide use looking at the effect of netting- a structured questionnaire survey revealed that the application of covered nurseries. All the farmers of 174 farmers in 15 locations. chemicals was the most commonly experienced increased yield due ToLCV was known by a variety reported pest management practice, to the netting and felt that it was of local names. Approximately and farmers sprayed up to 25 times a good technique. They were also 97% rated ToLCV as their most in a season with a mixture of very keen to obtain ToLCV-resistant important tomato disease, but they chemicals. Only one farmer said he varieties. were largely unaware that it was did not apply chemicals. Over 75% transmitted by B. tabaci. Most of farmers knew the brand names RECOMMENDATIONS associated the disease with hot of the chemicals they were using Recommendations for pest man- weather, and thought that high but it was not clear how many agement practices were formulated temperature was the cause. knew much about the active in the light of the project’s experi- mental results and farmers’ views. How can Tomato Leaf Curl Disease be prevented? An information leaflet containing In the nursery: the IPM recommendations has been published in Kannada, the Use a nylon net to cover the seedbed and stop whitefly from reaching the local language of Karnataka State, seedlings South India, and has been given Use a small (40) mesh nylon net to researchers, extension workers Make a frame to support the net and farmers. This leaflet continues to be freely available. Cover the seedbed completely, making sure there are no gaps where the whitefly could enter FUTURE Make sure there are no holes in the net To prevent the whitefly reaching the seedlings, do not raise the sides of the net The project’s IPM recommenda- at any time tions have been given to UASB’s In the main field: Directorate of Extension and the State Horticultural Department for No chemical can cure a plant once it is sick with Tomato Leaf Curl Disease dissemination. In the next phase However, spraying with insecticide can kill the whitefly and therefore delay the (R7460) it is intended that the spread of the disease from one plant to another ToLCV-resistant genotypes will Spray within 3 days after transplanting with an approved insecticide such as undergo multilocation and farm Confidor (or Hostathion) trials. If these are successful, these Alternatives to conventional insecticides are Neem, Neem extract (Neemark) genotypes will be officially and mycopesticides such as Biorin released for general cultivation Spray again 8 days after transplanting in Karnataka. It is highly probable that these genotypes could also be Note: Fungicides (for example Dithane) will have no effect on Tomato Leaf Curl grown in other parts of India. Disease Ultimately there will be benefits in Spraying late in the season (after 35 days after transplanting) will have no other regions where B. tabaci and effect on Tomato Leaf Curl Disease ToLCV cause serious losses: North Africa, the Middle East, the Carib- Translated excerpt from IPM recommendations distributed to farmers in Karnataka bean and Central/South America.

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Use of insect viruses to control Helicoverpa

R5540, R7004 The widespread appearance in the late 1980s of resistance to chemical pesticides by the American bollworm (Helicoverpa armigera) means that the pest now poses a major threat D. Grzywacz to food security and farm incomes in India and elsewhere in South Asia. An alternative to Natural Resources Institute (NRI), synthetic chemical insecticides is the use of indigenous natural control agents. The most University of Greenwich, UK promising of these is a virus, the H. armigera nuclear polyhedrosis virus (NPV). Strains of R.J. Rabindra this highly specific virus isolated from India are infective and lethal to this pest, yet are Tamil Nadu Agricultural University completely safe for man, animals and even other insects. Attempts to promote the use of (TNAU), Coimbatore, India biological pesticide products from NPV in India began in the early 1980s, but were held back by the poor quality and unreliability of locally produced NPV pesticides. Earlier January 1993–March 1997 projects have provided training courses for local scientists and commercial producers in April 1997–March 1998 improved production and quality control techniques. Since then, commercial production has expanded rapidly and a marked improvement in the quality of products has been seen. The first regulations incorporating NPV products under the Pesticides legislation and setting national standards in India will be enacted in 2000, and continue the ongoing effort to improve the quality of locally produced biological pesticides. The projects de- scribed here have built on earlier efforts to lay the groundwork for in-country researchers to develop effective biological pesticides, as well as helping to establish a new biotechnol- ogy industry producing cheap and safe pest control products.

ISSUES overuse of pesticides. In addition to the damaging environmental effects A major problem in the whole of of pesticide overuse, the costs of southern Asia is the widespread crop protection are higher for small- appearance in key pests of resist- scale farmers who often have to ance to chemical insecticides. borrow to pay for inputs. If serious Among the most important pests crop losses occur despite their efforts, SELECTED PUBLICATIONS showing resistance is the podborer farmers are often left with debts. or American bollworm, JENKINS, N.E., GRZYWACZ, D. and Helicoverpa armigera. This is a An alternative to chemical control COLLINS, S.A. (2000) Quality Control – major pest of cotton, legumes such is the use of natural control agents. assurance of product performance. as chickpea, gram and pigeonpea, The most promising is a specific Biocontrol Science & Technology and vegetables including tomatoes insect virus pathogenic to 10: 753–777. and chillies. The International H. armigera: the nuclear polyhedrosis Crops Research Institute for the virus (NPV). The H. armigera NPV JONES, K.A., ZELAZNY, B., KETUNUTI, Semi-Arid Tropics (ICRISAT) and a (HaNPV) is under development as a U., CHERRY, A. and GRZYWACZ, D. number of national agricultural commercial biopesticide in a (1998) World survey of insect viruses: SE research services have identified number of countries including the Asia and the Western Pacific. In: Hunter- H. armigera as the single most UK, USA, Australia and Thailand. Fujita, F.R., Entwistle, P.F., Evans, H.F. and damaging insect on cotton and Work carried out at Tamil Nadu Crook, N.E. (eds) Insect Viruses and Pest legumes in the Indian subcontinent Agricultural University (TNAU) in Management Theory and Practice. New and the major pest constraint to India prior to 1992 had shown that York: John Wiley& Son. increased production. It is also an HaNPV was a potentially viable important pest in other south Asian KENNEDY, J.S., RABINDRA, R.J., crop protection agent, but they countries. SATHIAH, N. and GRZYWACZ., D. (1999) lacked the expertise to produce The role of standardisation and quality Currently on much of the Indian standardized, stable formulations of control in the successful promotion of subcontinent only the young larvae the NPV that would be appropriate NPV insecticides. In: Ignacimuthu, S. and less than 7 days old are at all for farmers. Their product was a Alok, S. (eds) Biopesticides in Insect Pest susceptible to insecticides. To simple liquid suspension which, if Management. New Delhi: Vedam Books, control this pest, farmers must spray not stored in a deep freezer, pp. 170–174. crops as often as every week during fermented giving it a highly offen- RABINDRA, R.J., GHEETA, N., JAYARAJ, the growing season, often spraying sive odour which seriously discour- S., GRZYWACZ, D. and BROWN, M. mixtures of pesticides at two to aged many farmers. The absence of (1998) Evaluation of cross infectivity of three times the recommended dose standardized, stable formulations of insect viruses to Helicoverpa armigera in an attempt to overcome the pest HaNPV and the resulting variability (Hbn). Pest Management in Horticultural resistance. This strategy is often was also identified by farmers as a Ecosystems 3: 61–65. ineffective and results in serious major problem.

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Left, workers in India are trained in the production of virus formulations; above and right, spray application of HaNPV in the field

This project builds on previous Staff were trained both laboratory, the production target of work developing NPV formulations in the UK and at TNAU, and the a stockpile of 100 ha of HaNPV (R5268/69/70; see Research first profiles were produced in India was not met in full. However by Highlights 1989–95), and studies of in March 1995. Although most of starting work in temporary facilities mass production in vivo and field the equipment and consumables a stock of NPV for 70 ha was testing in Thailand (R5290). The were initially supplied from the UK, produced. aims were to set up a new insect considerable efforts have been HaNPV formulations from this virus formulation facility at TNAU made to identify local sources to project are the first NPV products to produce improved standardized ensure sustainability. with guaranteed activity available formulations of HaNPV; to equip, in India. These have been used in commission, and train staff for a A database of NPV profiles and a IPM trials at TNAU, and NPV DNA analysis laboratory to enable gene bank of standard strains was formulation was supplied in 1995 NPVs to be identified to strain also set up, and it is intended that to the legumes IPM project based at level; to train staff in NPV formula- this work will continue. The ICRISAT. In addition, NPV has been tion procedures and commission laboratory profiles any insect virus made available for crop protection an NPV formulations laboratory at on request, and a number of trials at the Central Institute of TNAU; to train staff in quality research and extension groups have Cotton Research, Coimbatore, control procedures and set up a already utilized this diagnostic and the Banaras Hindu University quality control laboratory; to build service, either to identify potential (BHU), Varanasi, India. up a stock of 100 ha equivalent of pathogens or to check the purity of HaNPV; to provide NPV and NPV products they intend to use. One serious limitation is the problem of NPV mass production. technical assistance for use in the Setting up the DNA laboratory The methods currently in use at IPM cotton trials being undertaken posed some unexpected technical TNAU, while they produce a very at ICRISAT in 1995 to demonstrate difficulties. The main problem was good quality product, are far too new H. armigera management that the electrical power supply time-consuming and expensive to strategies to farmers (R6734; see was prone to severe voltage be the basis of a commercial mass- page 95); and to hold a training fluctuations and frequent power production system. Two Govern- course at ICRISAT, Patancheru for cuts. Voltage fluctuations mean ment of India projects at TNAU local commercial virus producers most modern microprocessor- aimed to develop a practical and extension service personnel. controlled molecular biology system but have so far been The emphasis on NPV processing apparatus is unable to function; unsuccessful. One of the most and formulation was designed to power cuts make long electro- important outputs has been for complement two major Govern- phoresis runs and cold storage TNAU to produce high-purity NPV ment of India-funded projects to difficult. It was therefore necessary for distribution to commercial develop improved NPV production to select simple, mechanically producers as seed stock. This has techniques. controlled equipment that can directly improved the poor quality tolerate these power fluctuations; to of NPV previously sold by commer- provide battery back-up; and to ACHIEVEMENTS cial producers. adopt practical measures such as The DNA analysis laboratory was storing sensitive restriction en- The provision of NPV to CGIAR commissioned in March 1995. This zymes in insulated labtop coolers centres, NARS, Indian Council of is the first laboratory dedicated to inside freezers. Due to delays in Agricultural Research (ICAR) and insect virus identification in India. building the new quality control agricultural extension service staff

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has provided high-quality NPV biocontrol research programme, a effective, and Government regula- formulations for the use of re- series of national trials of NPV on tory agencies lacked the technical searchers and agricultural extension legumes is being run at TNAU. This know-how to test products. workers in India for the first time. will provide an opportunity to test The provision of certified pure This should promote the use of the recommendations for NPV use strains of NPV from TNAU as the biopesticides, with a consequent on a national scale using improved seed stock for commercial produc- reduction in pesticide use leading field trial protocols. The ICRISAT tion has improved the quality of to reduced costs to farmers, and legumes programme has proposed Indian-produced NPV environmental and health benefits. further collaboration with TNAU/ biopesticides. Following the work NRI to continue this work by Glasshouse trials indicated that of these projects the biological developing new NPV biopesticide while the current recommended pesticides sector in India expanded formulations for control of a application rates were justified on rapidly after 1996, and by 1998 33 number of other target pests, tomato and pigeonpea, on cotton companies, state enterprises or including Amsecta albistriga and the recommended rate might be other organizations had been Maruca testulalis. reduced, and on chickpea it was registered with the government of not effective. The objective of a India as suppliers of H. armigera further 1-year project (R7004) was NPV pesticides. Many of these had thus to carry out field trials on the sent staff to the training courses application efficacy and persist- funded by the CPP during 1994–96 ence of HaNPV on these crops in to promote improved production India, obtaining quantitative field and quality control techniques. data for the first time. Some NGOs and farmers’ groups have established simple, low-tech Application and persistence trials production of viruses as a small- were completed on cotton (in scale cottage industry. In Thailand, collaboration with project R6734; A range of HaNPV products are too, commercial biopesticide see page 95), tomato, chickpea and now commercially available, and a products have been registered and pigeonpea. This work confirmed number are being marketed via the are now on sale to farmers. that the efficacy and persistence of Internet. HaNPV in the field is significantly FUTURE affected by the nature of the crop, In 1999 the CPP funded a further and this effect needs to be quanti- The viral diagnostic facility and study of the biopesticides sector in fied before recommendations can database for HaNPV and other NPVs India and Thailand (R7299), to help be developed. While the prospects will be of major assistance in promote the improved uptake and for succesful use of NPV on tomato development of new and improved marketing of biological pesticides. are good, its use on cotton may be strains for IPM of H. armigera and An initial survey has confirmed the more problematic as higher applica- other pests. There is an agreement in successful development of local tion rates are needed for good larval place to use the facilities of the DNA production in both countries, and kills. Its use on chickpea and laboratory to support a DFID-funded will go on to look at the socio- pigeonpea will need further consid- project based at Kerala Research economic, regulatory and technical eration, the former because of Station on the development of NPV factors that contribute to successful doubts about its effectiveness, and for control of the teak defoliator, uptake. This will identify environ- the latter because of poor persist- Helicoverpa pura (R6295). ments and policies that encourage ence. Before NPV use on these The quality control facility at TNAU the use of biopesticides and crops is promoted to farmers, field provides a model for a national stimulate the establishment of local trials should be carried out in a standards laboratory for viral production. The information number of different climatic zones in biopesticides. The work on deter- generated will be disseminated to India to validate the proposed mining the scope of the problem of producers, state organizations, application rates. bacterial contamination in HaNPV agricultural extension services, will underpin setting national The new formulations laboratory scientists and NGOs in both standards for NPV products in enables Indian researchers to countries to further stimulate India. produce and test new NPV formu- adoption of biological pesticides. lations with the aim of improving Prior to this project, training for The lessons learned will also be of the storage, persistence and rain- commercial and other producers of value to other developing countries fastness of the NPV. The provision NPV was one of the most important in Asia and Africa where the of these high-quality NPVs has needs. Many producers lacked the development of local biopesticides stimulated ICRISAT in developing knowledge to produce consistent has the potential to provide poor HaNPV as an IPM agent for a quality products. As a result the farmers with cheap control tech- number of key legume crops. As quality of NPV products varied niques against insect pests resistant part of the Indian Government’s wildly and many were totally in- to conventional chemicals.

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Detection, identification and epidemiology of mycoplasma-like organ- isms (MLOs) associated with little leaf of sweet potato (Ipomoea batatas)

R5881, R5885 Little leaf, witches’ broom or ‘ishuku-byo’ disease of sweet potato is widespread in Asia, South-East Asia, Australia and the western Pacific, and on occasion can lead to almost M.F. Clark Horticulture Research International total yield loss. This project has improved knowledge of the diversity and host range of the (HRI), East Malling, UK disease, allowing local cultivars with stable disease resistance to be identified for immedi- ate use by local farmers. Infected planting material is important in the dissemination of S.J. Eden-Green little leaf mycoplasma, and practical diagnostic techniques have been developed which Natural Resources Institute (NRI), will be of value primarily to international and local crop protection programmes con- University of Greenwich, UK cerned with developing management strategies for the disease. In the long term the benefi- December 1993–November 1996 ciaries will be sweet potato smallholder farmers in the region.

ISSUES ACHIEVEMENTS discriminate among different phytoplasmas, and is recom- Of the world’s root and tuber crops, Detailed information was obtained mended only for detecting the sweet potato is second in impor- on the geographic distribution of the presence of phytoplasma. tance only to white potato, and disease, and on the molecular and 97% of world production is from serological characteristics of isolates A plate-capture PCR (PC-PCR) developing countries. Sweet potato from different geographic regions procedure was developed as a little leaf mycoplasma, caused by a and their cross-reactions with other simple, sensitive and rapid method mycoplasma-like organism (MLO), related phytoplasmas. This informa- for detecting phytoplasma in plant has been recorded on the crop in tion was used to develop rapid, or insect extracts. As with the DAPI more than 12 countries throughout sensitive screening procedures for staining procedure, this test is not Asia and the Pacific. Leaves are use by field operatives and research able to discriminate among yellowed and significantly reduced technicians. different phytoplasmas. However, in size, resulting in weak, stunted when necessary the amplification plants with few or no harvestable Polyclonal antibodies have been product can be analysed further tubers. Yield losses of 30–90% have produced to a New Caledonia using fingerprinting techniques been recorded, and are particularly sweet potato little leaf isolate (NC1), such as restriction fragment length severe in dry years. Infected and oligonucleotide-specific polymorphism (RFLP). planting material is important in the primers (SP3A/4B) for use in PCR dissemination of little leaf myco- investigations were obtained from a FUTURE plasma, and as the pathogen has a random-cloned DNA fragment. Information on the spread of the very long latent period – up to 283 Detection of field infection was disease from weeds and in sweet days by graft transmission – possible by ELISA using potato planting material will infected planting material can NC1polyclonal antibodies, but was allow improved phytosanitary appear healthy, making detection not reliable or consistent. ELISA is practices to be introduced to difficult. not recommended as a method of farmers through the International screening for infection. Not all Potato Center (CIP) and, in SELECTED PUBLICATIONS sweet potato little leaf isolates could particular, its South-East Asian be detected by PCR with SP3A/4B Program for Potato Research and CROSSLEY S.J. and CLARK M.F. (1996) primers, so the use of these primers Development (SAPPRAD), A plate capture PCR method for to detect sweet potato little leaf in regional programmes and na- epidomiological studies with sweet potato field samples is unreliable and is not tional extension officers. little leaf and other phytoplasma diseases. recommended. The procedures and reagents Proceedings of the BCPC Brighton Crop A simple, rapid screen for the developed will be useful to any Protection Conference, 571–576. presence of phytoplasma in sweet future investigations on the epide- MINUCCI, C., RAJAN, J. and CLARK, M.F. potato samples comprised (i) miology of the disease. The PC- (1996) Differentiation of phytoplasmas as- squashing tissue between glass PCR procedure is being evaluated sociated with sweet potato little leaf dis- slides, (ii) adding two drops of the in a separate project (R7318) to ease and other phytoplasmas in the faba DNA stain DAPI, and (iii) examining improve field testing and identifica- bean phyllody cluster. In: Diagnostics in the squash by UV fluorescence tion of corn stunt spiroplasma and Crop Production, BCPC Symposium Pro- microscopy. The phytoplasmas maize bushy stunt phytoplasma in ceedings No. 65. Farnham, UK: BCPC: show as brightly fluorescing spots in the corn stunt disease complex in 61–66. the phloem cells. This test cannot Mexico.

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Sustainable insect pest management in Indian cotton

R6734, R6760 Throughout the cotton-growing areas of India, intensified production, increased use of D.A. Russell, J. Cooper, D. Overfield irrigation and the excessive use of pesticides have led to the major cotton pests evolving Natural Resources Institute (NRI), resistance to the chemicals used against them: for example, resistance to common University of Greenwich, UK pyrethroids used in bollworm control can reach close to 100% by the end of the cotton R6734 season in heavily sprayed areas. This resistance encourages the application of more and A. McCaffery stronger insecticides, leading to a classic ‘pesticide treadmill’. Two related projects, fo- Reading University, UK cusing on southern India (R6734) and the irrigated cotton-growing systems of the Punjab K. Kranthi, Dr Surulivelu (R6760*) have developed and tested integrated pest management (IPM) packages of meth- Central Institute of Cotton Research ods that reduce the need for insecticides. Using the recommended IPM methods, farmers (CICR), Coimbatore, India encourage the build-up of the bollworm’s natural predators, and target limited sprays of A. Regupathy recommended insecticides on the pest only when absolutely necessary. The results have Tamil Nadu Agricultural University been dramatic. Reduced costs of production and increased yields of cotton resulted in (TNAU), Madurai, India massively increased incomes to farmers. In the last (1998/99) season, farmers using the D. Jadhav IPM package in southern India achieved average profits of £176 per ha, compared with International Crops Research Institute £38 per ha for other farmers. Farmers’ strong enthusiasm generated by these results for the Semi-Arid Tropics (ICRISAT), attracted widespread coverage by local news media, and this in turn has fuelled strong Patancheru, India demands for expansion into other districts. Use of the recommended IPM package has R6760 already reduced hazards to the environment and human health, and improved the profit- J. Singh, A.S. Sohi Jr, D.S. Brar, ability and reliability of cotton harvests for hundreds of poor rural families dependent on S.K. Kapoor, D. Singh, N. Sharma, the cotton crop. The future widespread adoption of these methods now seems assured, P. Sarao, R.S. Malhan and will have a major and sustainable impact on improving the livelihoods of small-scale Punjab Agricultural University (PAU), farmers, on human welfare and on the environment. Ludhiana, India I. Denholm, M.Cahill Institute for Arable Crops Research ISSUES continued to buy more toxic (and (IACR) Rothamsted, UK expensive) chemicals and to spray India produces 2.5 million tons of P. Elangovan ever more frequently, but with Tamil Nadu Agricultural University cotton each year, sustaining the decreasing effectiveness. The cost (TNAU), Madurai, India livelihoods of over 17 million of chemicals has pushed farmers people. Most are poor farmers who October 1996–March 1999 into dramatically increasing spirals must support their families on less of debt: in 1986/87 this drove than 2 ha of land. For these hundreds of farmers to suicide – smallholders the cotton crop is often by drinking the very pesticide often the only source of income for SELECTED PUBLICATIONS which had brought them to the food, medicines, education and brink of desperation. KRANTHI, K.R., RUSSELL, D.A., shelter. Unfortunately cotton crops WANJARI, R., MANOJ, K., MUNJE, S., have become less and less viable, The aim of this work was to LAVHE, N. and ARMES, N. (2001) In-sea- partly because of the increasing develop and demonstrate alterna- son changes in resistance of insecticides cost of pest control which accounts tives to the current over-reliance on in Helicoverpa armigera Hubner (Lepi- on average for more than 40% of conventional pesticides without doptera: Noctuidae) in India. Journal of the cost of growing the crop. compromising cotton production, through the development of Economic Entomology (in press). Without chemicals, farmers face Integrated Pest Management (IPM) devastating attacks of pests such as RUSSELL, D.A., KRANTHI, K.R., methods for an area-wide approach the voracious cotton bollworm SURULIVELU, T., JADHAV, D.R., to cotton pest management. REGUPATHY, A. and SINGH, J. (2000) caterpillar (Helicoverpa armigera), Developing and implementing insecticide which not only ruins their cotton ACHIEVEMENTS resistance management practices in cot- but also attacks their food crops. R6734 ton ICM programmes in India. Proceed- The threat of cotton bollworm has ings of the Brighton Crop Protection Con- Effective components of IPM in dramatically increased in recent ference – Pests and Diseases, 205–212. cotton, explored on a small scale years because of intensified land under a preceding project (R5745), RUSSELL, D.A., SINGH, J., JADHAV, use. In addition, poor spraying were refined and developed into a D.R., SURULIVELU, T., REGUPATHY, A. techniques and over-use of chemi- package. The use of appropriate and KRANTHI, K.R. (2000) Management cals have made the pest resistant to agronomy and resistant cotton of insecticide resistant Helicoverpa most available insecticides. Seeing varieties and seed treatments to armigera (Lepidoptera: Noctuidae) in cot- their crops devastated by bollworms, protect against sucking pests ton in India. Pp. 679–688 in: Gillam, F. and desperate to salvage something allowed the use of pesticides to be (ed.) Proceedings of the World Cotton from their losses, farmers have delayed as long as possible, taking Conference–2; New Frontiers in Cotton Research, Athens, September 1998. *Project R6760 was jointly funded by the DFID Natural Resources Systems Programme.

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damaging and can minimize the Table 1. Results of trials by 1600 farmers in risk of developing further insecti- 23 villages in four states cide resistance. This represents a Tamil Andhra considerable step forward in the Nadu Pradesh Maharashtra Punjab provision of much more economi- cally acceptable cotton pest control Reduction in which also addresses environmen- pesticide use (%) 46 69 92 29 tal and human health concerns. Reduction in health hazard* (%) 77 89 92 48 R6760 Yield increase (%) 17 25 70 49 Studies of 260 farm households in 13 villages within the Punjab cotton belt showed that cotton maximum benefit from beneficial Pradesh and 42% in Tamil Nadu, yields and gross revenues per insects. When insecticides were with equal or enhanced yields. hectare have been declining across necessary, the results of the the belt since at least 1994. Over These very positive results were resistance monitoring programme the same period, insecticide use supported by the provision of and the study of mechanisms has increased by 22% and the costs advanced equipment to detect of resistance and of field efficacy of spraying by 50%. As a result mechanisms of nerve insensitivity against the different insect pests most farmers are making a loss on to the Central Institute of Cotton provided the rationale for the cotton. There are biological reasons Research (CICR) Nagpur which, choice of materials and the timing for this – unseasonal rains and with the ICRISAT and Tamil Nadu and sequences of chemical exceptionally high outbreaks of Agricultural University (TNAU) applications. Simple pest manage- cotton bollworm and whitefly have laboratories, undertook the regular ment guides were developed for contributed. There are also social weekly resistance (and thus the states of Maharashta, Andhra reasons: the intensification of insecticide efficacy) monitoring on production, the move to irrigation, Pradesh and Tamil Nadu. which the pest management and the use of input levels that Extension of the work of the Interna- programme was built. Nerve damage both groundwater and the tional Crops Research Insitute for insensitivity has now been demon- viability of the agricultural system. the Semi-Arid Tropics (ICRISAT) strated to be a major mechanism of Although farmers’ educational laboratory to cover whitefly resistance in India. A technical background was correlated with (Bemisia tabaci) showed, for the bulletin produced by the project, improved yields, the clearest first time in India, that whitefly had the Podborer Newsletter, has correlation was with the quantity of developed resistance to the chronicled these advances and insecticide used. The yield increase bollworm chemicals chlorpyrifos raised awareness and understanding with increased insecticide use did and acephate (organophosphates) of the problems and their solution not, however, translate into higher and cypermethrin (pyrethroid) amongst India’s scientific commu- profit margins because of the costs chemicals, but that whitefly were nity. A practical training workshop of inputs. Agricultural advice is still susceptible to the widely used in insecticide resistance monitoring strongly concentrated with the sucking pest products. These results and management was run at CICR commission agents, who are also were incorporated into the control on semi-commercial lines. The the vendors of insecticide, which is programme. production of two fast-selling often poorly formulated and usually editions of a detailed cotton IPM Making full use of farmer and sold on credit. Increasing insecticide brochure aimed at farmers in Hindi, village participatory methods, these Marati, Tamil and now Punjabi has use is selecting strongly for evolved management schedules were helped to implant the messages. resistance to the main chemicals extended into single villages in the used against both bollworm three states in 1997. These resulted The project has unequivocally (cypermethrin, fenvalerate, in an average of 40% reduction in demonstrated that, with careful quinalphos and endosulfan) and insecticide use and a 20–40% design supplemented by a detailed whitefly (cypermethrin, acephate increase in the value of the yield, understanding of insecticide and chlorpyrifos). This was well turning a marginal crop into a resistance patterns, effective and documented through the measure- profitable one. Following end-of- economic IPM programmes can be ments made in the project- season farmers’ field days and developed and extended. Insecticide supported laboratories at Punjab excellent media coverage, in the use can be delayed, with consequent Agricultural University (PAU), with 1998 season this work was ex- environmental and biodiversity resistance to common pyrethroids panded to 13 villages and over 600 benefits. Scouting for pest infesta- used in bollworm control rising to farmers. Utilizing local people as tions can form an effective basis for close to 100% by the end of the effective extension agents, insecti- decisions on interventions, and the cotton season. This resistance cide use was reduced by over 92% resulting pattern of insecticide use encourages the application of more in Maharashtra, 69% in Andhra can be much less environmentally and stronger insecticides and their

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mixtures to control the resistant pests. government partially adopted these ways to tackle these production This situation is exacerbated by the practices in five villages and constraints. Pest management fact that whitefly are the vectors achieved 10–20% yield improve- decision recommendations have for the debilitating cotton leaf curl ments. The work stimulated great been developed and demonstrated virus disease (CLCuV). Epidemio- interest in the region. that are based on better under- standing of both biological and logical studies demonstrated the In the 1998 season an attempt was socio-economic factors. These range of crop and weed alternative made to implement all aspects of recommendations have been shown hosts for CLCuV and identified a the cotton management plan to to greatly reduce the costs and number of tolerant cotton varieties, over 1000 farmers in 10 contiguous environmental impact of control, of which LH 1556, F 846 and LHH villages of the Lumbi block in the and to increase cotton yields by 144 appeared to have the other cotton belt, as an initiative of the over 50% for participating farmers, agronomic characters suited to Chief Minister of Punjab. Good even in the two worst pest attack conditions in the Punjab. seeds, fertilizer, good pesticides years on record. The PAU now has and timely irrigation were promised The project used the knowledge the proven capacity to monitor in addition to field support and gained from these studies to insecticide resistance in the two most mobility. For a variety of reasons, construct a ‘best-bet’ package of important species of cotton pest. practices for the cotton farmer. This these non-project inputs either did strategy included the use of not materialize or were partially FUTURE In 1999, the CPP promoted these positive results in India by helping to train industry and government agri-business stakeholders in the principles and practices of appro- priate cotton IPM. Recognising the potential of these improved pest control methods, the Indian Ministry of Agriculture is now funding promotion of IPM in 500 villages in the 20 major cotton districts which account for 80% of the total insecticide used on cotton in India. The Government of India has agreed to provide 30 million rupees (about £450 000) over 3 years Significant inputs are being provided Farmers in Tamil Nadu discuss IPM with extension workers from the pesticide, fertilizer and seed industries. The value of this appropriate short-stature, sucking provided in this, the worst year on work has been recognised in pest- and CLCuV-tolerant varieties record for high pest levels and low a major collaborative project at appropriate spacings; the use cotton production across the funded by the Common Fund for of insecticides only when specific Punjab. Farmers were demoralized Commodities (CFC), DFID CPP and pest thresholds were exceeded; and spraying rose amongst the the governments of China, Pakistan and a sequence of single insecti- participants despite a determined and India (2000–2004) and the cide active ingredients which effort by PAU and project staff. insecticide industry’s Resistance maximized efficacy against the pest However, the use of undesirable Action Committee. This new work complex and minimized further pesticide mixtures and pyrethroids will deepen our understanding resistance development. The was reduced by half and the yields of the technical constraints to the materials to be used and their were 49% higher than that of non- best use of insecticides for cotton sequence depended on the severity participants. As a result this pest control, and will make the and nature of the pest complex provided marginal profitability benefits of the earlier work avail- at the time. rather than significant loss to the able to many millions of cotton This strategy was demonstrated in participators. The need for careful growers across Asia. The findings the 1997 season in farmer-partici- insecticide use and active manage- of the projects from 1993 onwards patory work in two villages. ment of resistance is now appreci- are being used to inform the curri- Insecticide use was reduced by ated by all stakeholders. culum-building exercises of the 40% and yields increased by 38% The project has successfully European Community’s Asian in a season otherwise disastrous in identified the pest management Cotton Farmer Field School project the surrounding areas due to issues within the Punjab that are which is active in Bangladesh, unseasonal heavy rains and very contributing to the decline of China, India, Pakistan, Vietnam and high bollworm attack. The Punjab cotton production, and has found the Philippines.

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Use of pheromones in insect pest management on cotton

R5272 Cotton is the major export crop of many developing countries. Insect pests are a major cause of yield losses, and worldwide more insecticide is applied to cotton than to any D.J. Chamberlain, L.J. McVeigh, other crop. Pheromones provide a means of monitoring and control of insect pests. They D.R. Hall, D.I. Farman Natural Resources Institute (NRI), are not toxic to animals or plants, and are specific for the target pest. As such, they are University of Greenwich, UK compatible with all other methods of pest control and thus provide ideal components of integrated pest management programmes which aim to provide cost-effective, sustain- Z. Ahmed able control of pests with minimal use of conventional insecticides. This project arose Central Cotton Research Institute from previous work in Egypt and Pakistan which had demonstrated the possibility of con- (CCRI), Multan, Pakistan trolling pink bollworm (Pectinophora gossypiella) with pheromones. As well as pink April 1992–March 1996 bollworm, the main insect pests in Pakistan include spiny bollworm (Earias insulana), spotted bollworm (E. vittella) and American bollworm (Helicoverpa armigera). The aim of this project was to develop improved methods for management of insect pests in cotton production systems. The project aimed to develop and validate integrated strategies for controlling the pest complex on cotton in Pakistan based on application of pheromones for monitoring and control of bollworm pests.

ISSUES pesticide use were not achieved due to the need to use pesticides to SELECTED PUBLICATIONS Pakistan is the world’s fourth largest control other cotton pests, particu- cotton producer. Cotton is responsi- larly Earias insulana and CHAMBERLAIN, D.J. (1994) Phero- ble for more than 60% of export E. vittella. Following the identifi- mones: a potential weapon in helping to earnings, provides 55% of domestic cation and synthesis of the overcome Pakistan’s cotton pest prob- edible oil, and is the basis for an female sex pheromones of lems. Cotton Time 2: 9–11. industry employing 12.5 million Earias spp., small plot trials HALL, D.R. et al. (1994) The use of people. In Pakistan the area under indicated that these bollworms pheromones for mating disruption of cotton has more than doubled could be controlled by a single, cotton bollworms and rice stemborer in over the past 40 years, and early season application of their developing countries. In: Proceedings of productivity has increased from combined pheromones. Brighton Crop Protection Conference – 157 (1947/48) to 769 (1991/92) This project aimed to develop Pests and Diseases. Farnham: BCPC, kg/ha. Much of this increase in improved methods for management pp 1231–1238. productivity occurred during the 1980s as a result of increasing of insect pests in cotton production CHAMBERLAIN, D.J. and AHMAD, Z. use of chemical pesticides. Since systems by developing and (1997) Predicting infestation levels and 1991/92, productivity fell to 487 validating integrated strategies spray timing for the control of the Ameri- kg/ha in 1993/4, to a large extent for controlling the bollworm pest can bollworm, Helicoverpa armigera due to outbreaks of leaf curl virus complex on cotton in Pakistan, Hübner (Lepidoptera: Noctuidae) from transmitted by whitefly, and to based on the application of catches in pheromone baited traps in increasing prevalence of the pheromones for monitoring and cotton in Pakistan. The Pakistan Cottons.. American bollworm, Helicoverpa control. armigera. The increased incidence CHAMBERLAIN, D.J. (1996) Integrated of these pests is attributed to ACHIEVEMENTS pest management in cotton production destruction of beneficials by misuse All trials were carried out in in Pakistan. In: Cotton connection: of pesticides, and both whitefly and farmers’ fields rather than on a towards sustainable cotton production. H. armigera from Pakistan have research station, involving the end- Hamburg: Pesticide Action Network, Ger- been shown to be highly resistant users of the technology in the many, pp. 63–71. to the commonly used insecticides. trials at an early stage. Flooding CHAMBERLAIN, D.J., MCVEIGH, L.J., Pheromone formulations to control in 1993/94 did not affect appli- CRITCHLEY, B.R., HALL, D.R. and pink bollworm (Pectinophora cation of pheromone, but greatly AHMAD, Z. (1994) The use of pheromones gossypiella) were previously reduced the effectiveness of to control three species of bollworm in Pa- developed by NRI and successfully insecticide applications and kistan. In: Constable, G.A. & Forrester, evaluated in Pakistan in collabora- hence worked to the benefit of N.W. (eds) Challenging the Future: Pro- tion with the Pakistan Central the project; however an abnor- ceedings of the World Cotton Research Cotton Committee at the Central mally severe outbreak of Conference. Melbourne, Australia: Cotton Research Institute, Multan. H. armigera in 1994/95 necessi- CSIRO, pp. 419-422. However, significant reductions in tated applications of insecticide

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Left, pink bollworm caterpillars on cotton

Right, Selibate pheromone formulation on cotton

that reduced the information applied at rates as low as 250 uptake pathways in Pakistan. The available from the pheromone trials point sources/ha and 40 gm UK-based commercial companies and hence was unfavourable to the a.i./ha, is effective against Agrisense-BCS and International project. P. gossypiella; Pheromone Systems (IPS) Ltd provided formulations for evalua- The major results of this work were: • studies of the distribution of tion free or at cost, and will be H. armigera eggs and larvae on • separate, single applications of responsible for commercializing cotton plants emphasized the either of two different, commer- the products. cially available pheromone importance of timing any insecticide application against formulations against FUTURE P. gossypiella and Earias spp. the young larvae when they are can virtually eliminate the need still exposed on the leaves; The manufacturers have now for application of insecticide • there is a significant correlation modified the formulation to release against these species; between pheromone trap a higher proportion of active • trials with pheromone against catches of H. armigera male ingredient, and two pheromone P. gossypiella showed that this moths and oviposition by female formulations have been regis- species was better controlled H. armigera on the following tered for use against pink than with insecticide, and that day, such that pheromone trap bollworm in Pakistan and are numbers of beneficial arthro- catches can be used as an aid now available commercially pods were greatly increased in to scouting for this pest; there. This work is being carried a normal season, greatly forward by the Pakistan Ministry of • the African spiny bollworm Agriculture. reducing the need for insecti- E. biplaga was observed for the cide application against Earias first time as a pest of cotton In the Punjab, a province-wide spp. and H. armigera (although outside Africa, and a fruit pest, network of over 3000 pheromone the pheromone of Earias spp. is Dichocrocis punctiferalis, was traps has been used to monitor still expensive and is not yet also seen causing significant Helicoverpa over a 3-year period, readily available); damage on cotton; the latter and recently similar networks of • combined with a single applica- could be important when traps for pink bollworm and Earias tion of insecticide against cotton fields are near to fruit have been established. sucking pests, this approach orchards. Following on from this research, provides a realistic IPM Work was carried out in close pheromones are now being programme; collaboration with the Pakistan evaluated for potential control of a • the ‘Selibate’ formulation, Central Cotton Committee and the range of pests on other crops developed at NRI and commer- Central Cotton Research Institute, including sugarcane and brinjal cialized by Agrisense-BCS, Multan, who will provide the main (aubergine).

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A biocontrol strategy for management of the alien perennial weed Mikania micrantha in tree crop-based farming systems in India

R6735 Mikania micrantha, or mile-a-minute weed, is an invasive weed that smothers tree and other crops in homegarden production systems in the tropical moist forest regions of S.T. Murphy, C.A. Ellison CABI Bioscience, Ascot, UK India. The project sought to assess and develop the potential for management of this weed through biological control utilizing fungal pathogens, in particular exotic pathogens as S.V. Sankaran classical biological control agents, and also native pathogens. Exotic biocontrol agents, Kerala Forest Research Institute (KFRI), once they have become widespread, have the potential to reduce the abundance of the Peechi, India weed, providing a self-perpetuating, long-term sustainable management option for the July 1996–June 2000 M. micrantha problem. A number of potential biocontrol agents were collected within the weed’s centre of origin; from these an isolate of the rust fungus Puccinia spegazzinii from Trinidad was selected for detailed assessment, and shows great promise as a biocontrol agent. Exotic biological control agents require little or no input from resource-poor farm- ers, and are environmentally benign. Local marginal and smallholder farmers will benefit from increased yields and decreased labour costs.

ISSUES homegardens are interdispersed with multipurpose trees including In the moist tropical forest region of teak, casuarina and Ailanthus. the Western Ghats in southwest Coconut is the major crop in the India, agroforestry is the principal lowland areas (less than 80 metres). form of agriculture. The type of Cultivation cost has always been system depends on the type of a primary factor in the economics community and can range from of homegardens, particularly for semi-permanent holdings of hill marginal and smallholder farmers. tribes to the more common Weeds, in particular, form a major permanent holdings or proportion of cultivation costs. ‘homegardens’ characteristic of the Over the past few decades the region. The term homegarden refers invasive weed Mikania micrantha to the intimate association of tree has spread throughout the southern crops, multipurpose trees and part of the Western Ghats, causing shrubs with annual and perennial severe damage to several tree SELECTED PUBLICATIONS crops and livestock within the crops, multipurpose trees and compounds of individual houses. In seasonal crops (such as cassava COCK, M.J.W., ELLISON, C.A., EVANS, the state of Kerala, for example, and yam). The weed is known as H.C. and OOI, P.A.C. (1999) Can failure most homegardens (about three- ‘mile-a-minute’: young plants grow be turned into success for biological quarters) belong to marginal extremely quickly (8–9 cm in 24 h), control of mile-a-minute weed farmers with less than 1.5 hectares and use trees and crops to support (M. micrantha)? In: Proceedings of X of land, and a further 35% to their growth; the weed rapidly International Symposium on Biological smallholders with 1.5–5 hectares. forms a dense cover of entangled control of Weeds. Bozeman, Montana, stems bearing many leaves, USA. 4–14 July 1999. Both food and commercial crops are grown throughout the Western smothering and choking crop IIBC (1997). Invasive Weed Alert! Ghats, but the cropping pattern plants and penetrating tree crowns. M. micrantha or Mile-a-minute Weed. differs depending on geography. There is also evidence from studies International Institute of Biological For example, in the highlands on rubber in Malaysia that the Control, Ascot, Berkshire, UK (Factsheet). (above 750 metres) coffee, tea and weed can retard plant growth, cardamom are predominantly probably through the production REID, A. and MURPHY, S.T. (1999). of chemicals. Biogeographic fine-tuning helps weed cultivated; bamboo and reed are biocontrol. Biocontrol News & Informa- also harvested from the natural Mikania micrantha is a native of tion No. 20. Pp 51-54. CABI Bioscience forests by local tribes. The mid- South and Central America and the UK Centre (Ascot), Berkshire, UK. lands (80–750 metres) are an area Caribbean, and was probably intro- of intensive cultivation, where duced intentionally into north- SANKARAN, K.V. (1988). Control of mile- crops such as banana, plantain, eastern India as a non-leguminous a-minute weed. Evergreen No. 40 cashew, coconut, arecanut, cocoa, ground cover for crops. It is also (March). p 14. Kerala Forest Research cassava, yam, ginger, pepper and suggested that it may have been Institute, Peechi, Kerala, India. vegetables are grown. These introduced during the Second World

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War for camouflaging purposes. The project aimed to assess the range and economic impact of the weed, and to develop a management strategy based on biological control utilizing fungal pathogens. ACHIEVEMENTS The range of M. micrantha is now mapped in the Western Ghats. Twenty-eight permanent sample plots have been established in Kerala. The weed is present in most of Kerala and is now moving northwards into Karnataka. Signifi- cant impacts of M. micrantha in tree crop/agroforestry systems have been confirmed. Crops particularly affected include banana, coconut, coffee, cocoa, cassava, pineapple, ginger and teak. Intensive weeding of M. micrantha has now become necessary to reduce its effect on productivity, resulting in the escalation of production costs. In evergreen forests, infestation by M. micrantha is on the increase, which affects harvesting by tribals of reeds, bamboo and other non- wood forest products. The status of M. micrantha in northeastern India has also been assessed. The main impact is on tea production. Herbicide residues on tea have resulted in some exports being rejected by Western Europe. Surveys for potential exotic fungal revealed only nine minor fungal DNA analyses indicate that the pathogens were carried out in pathogens, none of which was weed population probably origi- Brazil, Mexico, Trinidad and Costa found to be damaging, thus these nates from Central America rather Rica; 29 suspected fungal patho- local pathogens were inappropriate than elsewhere in the indigenous gens were recorded, of which four for mycoherbicide development. range from Mexico to Paraguay, are considered to have most The exotic rust fungus Puccinia therefore this area has been of potential as classical biological spegazzinii was selected for particular interest. control agents. Surveys in India detailed assessment; eleven isolates

Figure 1. Effects of a. temperature, and b. dew period on the infection of Mikania micrantha by Puccinia spegazzinii

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(KFRI) staff have been trained in ecological and socio-economic survey techniques for alien invasive species. Also patholo- gists from KFRI and the Indian Council of Agricultural Research (ICAR) were trained in classical biological control and mycoherbicide development and application, through training attachments at CABI Bioscience. A national workshop was held at KFRI in November 1999, which produced recommendations for a further research phase; support was also expressed for the introduction P. spegazzinii as a biocontrol agent for the weed. An alert sheet (left) was prepared and distributed to KFRI and other relevant organizations. Once KFRI had determined that the front of the weed invasion lay at the border between Kerala and Karnataka, copies of the alert sheet were also given to the Karnataka Forest Department based in Bangalore. FUTURE The national workshop recom- mended that the project be fol- lowed up by: • development of an implementa- tion phase involving farmer validation of the integrated weed management programme • an application should be made have been collected, Mikania species. A microscopic for the introduction of the and the high biocontrol potential of analysis was undertaken of these M. micrantha-specific exotic an isolate of this pathogen from species and a range of other test rust fungus P. spegazzinii Trinidad has been confirmed in the species. The results revealed that in quarantine labs of CABI all cases fungal spore germination • further ecological and socio- Bioscience. The life cycle of the and/or penetration was inhibited by economic studies are needed rust has been elucidated, and some the test plants and no infection on M. micrantha, in particular of the factors affecting successful occurred. This confirms that the on dispersal, prediction of infection of M. micrantha have rust is highly specific and therefore spread, modelling, and ecologi- been determined (Figure 1). likely to be acceptable as cal and socio-economic impact on agroforestry farming systems It is essential that exotic biocontrol a biocontrol agent. agents are carefully screened for A protocol for the introduction • adaptation of the integrated any effect on the local flora, and of exotic fungal pathogens was weed management technology particularly on crop plants. Fifty- discussed and agreed with relevant for use and implementation in five species were screened for institutions. For this protocol, the the northeastern states of India infection by P. spegazzinii, and high specificity and biocontrol There is no written protocol for the none was infected despite consist- potential of P. spegazzinii has been introduction of biological control ent infection of M. micrantha demonstrated, and support for agents for weeds into India, controls. Chlorotic spots were introduction from all collaborators particularly pathogens; this is now observed on Helianthus annuus has been confirmed. being revised and the Mikania and Eupatorium canabum, and project is contributing to the necrotic spots on two other Kerala Forestry Research Institute process.

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Pest constraints affecting tree crops in Bolivia

R6820 Tree planting for farmers and local communities is common in many development pro- grammes. Bolivia has many projects working in rural development forestry – a catch-all E. Boa CABI Bioscience, Egham, UK term used to describe anything from agroforestry to small-scale reforestation. In Bolivia, rural development forestry uses exotics and valuable native species, and encompasses January–March 1997 forest species, multipurpose trees and fruit trees. All have an important value to local communities. A mechanism is needed for assessing and monitoring the health of these trees, and to provide technical support and advice on managing diseases. Such services do not exist at present in Bolivia. The cataloguing of a series of tree diseases and damage by this project therefore represents a significant advance on previous knowledge.

ISSUES species observed (Table 1). The A general guide has been prepared results emphasized that the to Diagnosis of Diseases and The purpose of this short project importance of a pest constraint can Damage on Trees. Copies, was to investigate the pest con- be defined from different perspec- in English and Spanish, have been straints affecting tree crops in tives. Two examples at opposite distributed to main collaborators selected agroforestry schemes in ends of the spectrum include sika (see Bibliography on CD). Bolivia; to identify suitable research sika (lepidopterous larvae) on approaches to manage these Schinus molle, probably of minor FUTURE constraints; and to explore partner- economic importance but of This work has been continued ships between institutes and significant concern to foresters and in a further 1-year study (R7479), organizations to tackle problems local communities; and a spectacu- in collaboration with with CIAT relating to tree health. lar rust on Inga cylindrica which is and CARE Sucre, involving a more ACHIEVEMENTS of biological interest, is not detailed look at the tree pests recognized by local people, yet in two departments of Bolivia, Work was carried out in collabora- could pose a problem in the future. Santa Cruz and Sucre. The study tion with five key institutions: the Between these two extremes lie has identified fruit trees as the most UNDP Programme on Forests problems of unequivocal impor- important perennial component of (PROFOR); University of the Beni; tance, such as dothistroma blight agroforestry systems, in particular Silsoe Hillsides Project; CARE on pines and tristeza and gummosis citrus and peaches. No systematic Amboró Project; and the Interna- on citrus. The causes of these effort has been made to diagnose tional Center for Tropical Agricul- diseases are well known and the causes of ill-health, and the aim ture (CIAT). Samples of pests and advice on their management is of this work is to determine which diseases were collected, and a large available. However, there is pests are most important. Weak photographic record of symptoms confusion about the extent of the research capacity is being strength- compiled. citrus diseases, how to differentiate ened, and community-based Key pest problems were identified the reported two leading diseases, approaches are being used to re- on many of the important tree and their geographic distribution. solve technical and scientific gaps.

Table 1. Important diseases of trees noted in Bolivia

Type Host Problem

Tree crops Bixa orellana (urucú) Sudden death - possible new and potentially serious disease Citrus spp. Tristeza and gummosis - well known diseases but diagnosis difficult Community forest trees Eucalyptus spp. Psyllid attack Foliage blights (to be confirmed) Cerambycid, probably Phoracantha semipunctata Pinus spp. Dothistroma blight Seedling blight (undiagnosed) Schizolobium amazonicum (cerebó) “Elephant’s foot” disease (basal swelling; undiagnosed) Rural development trees Polylepis incanae (kewiña) Seedling blight (undiagnosed) Schinus molle (molle) Psyllid attack Seedling blight (possibly Alternaria) Lepidopterous larvae (sika sika) Spartium junceum (retama) Mildew

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Improved ecological and economic recommendations for the control of Hypothenemus hampei in coffee in Mexico

R6812 The coffee berry borer is the most serious pest of coffee in many of the major coffee- A. Leach, J. Mumford producing countries. Losses can be severe, ranging from 50–100% of berries attacked if no Centre for Environmental Technology, control measures are applied. Even if borers do not destroy the berries, the damage caused Imperial College of Science, Technology produces poor quality coffee, and damaged berries are difficult to market. A computer and Medicine, UK program modelling the production of berries in the field and the dynamics of the pest, first J. Barrera developed in Colombia, was extended by this project to coffee production in Mexico. This El Colegio de la Frontera Sur (ECOSUR), model has achieved a high level of complexity in its short development, and covers a broad Chiapas, Mexico range of pest management aspects and their implications under the varying conditions and January–March 1997 cultivation practices in Mexico. It can be used to predict the consequences of different man- agement decisions in the context of the current coffee market in Mexico. ISSUES The scolytid beetle Hypothenemus Applications of pesticide or Combined strategies, including hampei, the coffee berry borer, Beauveria (a fungus that attacks efficient harvesting and well timed presents a threat to the viability some insect pests, including sprays or repasé, are far more likely of coffee growing in many coun- H. hampei) work only when the to be effective against the broca than tries. Coffee is a major crop in pest, which breeds within coffee single approaches, although they Mexico, and in 1995 the Mexican berries, is exposed to external may not be economically feasible. government began a programme to conditions. The model demonstrates It was not possible to build a model provide US$80 million in credit to that injudicious pesticide applica- that encapsulates all aspects of the 260 000 small-scale coffee growers tions against the broca are uneco- berry borer’s dynamics in so short a (accounting for 92% of growers) to nomic. However, well applied period. There are other factors to improve cultural practices. With sprays between 6 and 20 weeks include in future modelling efforts, higher domestic producer prices, after a major flowering (and for example, more detailed descrip- growers have improved cultural particularly between 7 and 15 tions of the dynamics of the broca practices and expanded the use of weeks) are likely to be efficacious in berries on the ground, and of inputs, mostly to control coffee rust and cost-effective. aestivation in berries both in the and H. hampei (colloquially Efficient harvesting reduces the tree and on the ground. A parasitoid known in Mexico as the broca). availability of berries for attack and model was not specifically included While overall coffee production removes a considerable part of the because a simulation model of in Mexico is increasing, it is broca population from the field, and these complex three-way interac- declining in the southern states should be conducted from the first tions was neither possible in a which are badly affected by the broca. year after pruning onwards. spreadsheet model, nor necessary ACHIEVEMENTS For the rainfall and flowering pattern given the relatively low success of in Mexico, repasé (post-harvest the parasitoid species currently The existing computer program was being applied. However, the model improved in terms of the flexibility clearing of berries of all ages) is a very effective way of reducing the can provide support for scientists of the management actions and developing biocontrol strategies by local cropping systems that could broca population. This technique is currently rarely used except in some assisting in the design of parasitoid be tested; quality payment systems release experiments, and also in the of the more commercial, organic were added; and the overall interpretation of data generated by operations. Badly timed sprays and function and structure were im- field trials. proved. This was followed by a inefficient repasés represent a worse review of the outputs with collabo- return for the farmer than the ‘harvest FUTURE rators and the coffee industry. only’ option. Interest in use of the model has Recently, major buyers in the south The model illustrates some impor- been stimulated through demon- have begun to pay more for robusta tant points, summarized below. strations to staff from El Colegio de type coffee than for arabica (a very la Frontera Sur (ECOSUR), Texas The flowering pattern and berry rare occurrence). Cultivation of A&M University, the US Depart- production induced by the rainfall robusta coffee extends the time that ment of Agriculture, the Interna- in southern Mexico limit the ripe berries are available to broca tional Institute of Biological Control damage inflicted by the borer. attack, reducing the period that is (CABI Bioscience), Zamarano Pan- This is principally because of the free of ripe berries from 5 to 2 American Agricultural College, 5-month berry-free period between months. The model demonstrates farmers from Union Regional January and April/May. the implications of this in terms of Productores de Café Tacana, potential future damage by the Nestlé plc, and the International Publications: see Bibliography on CD. broca. Coffee Organisation.

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Development of an integrated management strategy for itchgrass in maize-based cropping systems in selected areas of Latin America

R6690 Itchgrass (Rottboellia cochinchinensis) is a tropical weed of maize, sugarcane, rice and other crops which has been introduced to the New World relatively recently and is par- C.A. Ellison, R.H. Reeder, CABI Bioscience, Ascot, UK ticularly severe there. This project continued to test previously developed, sustainable methods for itchgrass management in farmers’ fields in Costa Rica, Mexico and Bolivia. M.C. Smith, C.R. Riches Specific research aimed to improve knowledge of the biology and importance of itchgrass, Natural Resources Institute (NRI), and address the best combinations of planting density and timing of cover crops to allow University of Greenwich, UK effective weed suppression while maintaining profitable grain yields. Interactions between B.E. Valverde, E. Bustamante the three key species of the production system (maize, itchgrass and the cover crop CATIE (Tropical Agricultural Center for Mucuna) have been well characterized and demonstrated to collaborating growers in Research and Higher Education), Costa Rica. A mycoherbicide has been developed that may have potential for integrating Turrialba, Costa Rica in the overall control strategy, and a classical biocontrol agent (head smut) studied. As it April 1995–March 1999 is not yet possible to release head smut in the field, a modelling exercise was carried out, and the results confirm that a biocontrol agent which prevents seed production in itchgrass SELECTED PUBLICATIONS could have a significant impact on itchgrass populations. Overall, the project has contrib- uted important management alternatives for one of the most troublesome weeds in tropi- REEDER, R.H., ELLISON, C.A. and THO- cal America, that should allow sustainable control with reduced environmental impact. MAS, M.B. (1996) Population dynamic aspects of the interaction between the ISSUES that little viable seed remained after weed Rottboellia cochinchinensis 12 months in the soil, underlining Itchgrass (Rottboellia cochin- (itchgrass) and the potential biological the importance of prevention of chinensis) is a pantropical agricul- control agent Sporisorium ophiuri (head seed set in the weed’s management. smut). In: Proceedings of the IX Interna- tural weed that is increasing its tional Symposium on Biological Control range at an alarming rate. It is Sustainable methods for managing of Weeds (Moran, V.C. and Hoffman, J.H., native to the Old World, but was itchgrass in the seasonally dry eds). University of Cape Town, pp. 205– probably introduced at the begin- Pacific and humid tropical Atlantic 211. ning of the 20th century to the New regions of Costa Rica were further World, where infestations are now developed and began field testing SANCHEZ-GERITA, V. (ed.) (1999) considered to be the most severe. under R6047 (see Research Control Biológico de Rottboellia This could be due to a number of Highlights 1989–95); results cochinchensis. Turrialba, Costa Rica: factors including better compatibil- demonstrated the usefulness of CATIE. ity with the climate; man’s activities combining in-crop herbicides, VALVERDE, B.E., MERAYO, A., spreading the grass; favourable control of residual plants during FONSECA, J.F., ALVAREZ, T. and RICHES, agronomic practices; and the the off season, and zero tillage. C.R. (1999) Validation of integrated meth- absence of co-evolved natural Early planting of Mucuna and ods to control itchgrass (Rottboellia enemies. In Central America Canavalia ensiformis gave good cochinchinensis) in corn with subsistence itchgrass infests both annual and ground cover, suppressed itchgrass growers in Costa Rica. WSSA Abstracts 39: perennial crops, and has been and increased maize yields. In 308. reported to cause significant yield initial validation plots, despite ZÚÑIGA, C., SÁNCHEZ-GARITA, V., losses in maize, sugarcane, upland higher initial costs farmers per- BUSTAMANTE, E. and CERVANTES, M. rice, beans and sorghum. Infesta- ceived the control methods (2000) Selección de patógenos nativos de tions can result in up to 80% crop developed by the project very Costa Rica para el control biológico de loss, or even abandonment of favourably. agricultural lands. Rottboellia cochinchinensis (Selection of A promising area of research is the native pathogens of Costa Rica for bio- Previous studies and surveys use of fungal pathogens to control logical control of Rottboellia cochin- conducted in Costa Rica docu- itchgrass. Both mycoherbicide and chinensis). Revista Manejo Integrado de mented the importance of itchgrass classical biological approaches Plagas 57: 49–53. and the need to develop suitable have been investigated in Costa ZÚÑIGA, C., SÁNCHEZ-GARITA, V., and economically feasible control Rica (R6047) and the UK (R5883). BUSTAMANTE, E. and CERVANTES, M. alternatives for small-scale farmers. Since many farmers currently use (2001) Uso de herbicidas como agentes Initial research demonstrated that chemical herbicides, adopting de predisposicin de Rottboellia cochin- effective in-crop control was mycoherbicides as an environmen- chinensis al ataque de patgenos nativos essential for maintaining low levels tally benign alternative should be a (Herbicides as predisposition agents of of the weed, but that planting in useful approach. The use of a Rottboellia cochinchinensis to native zero tillage and prevention of seed classical biological control agent is pathogen damage). Revista Manejo set during the fallow period were considered to be of direct value to Integrado de Plagas (in press). also important. It was also shown farmers as they do not cost farmers

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time or money. These organisms maize rows as a cover crop; and performed with stress factors to target areas not typically tended by prevention of itchgrass seed set in increase the severity of the patho- farmers (fallow fields, roadsides the fallow period. Pendimethalin gens. To identify the stress factors and headlands), and weeds that effectively controlled itchgrass at that could improve the effective- escape the control measures used the onset of validation plots and ness of native pathogens, trials by farmers (such as weeds between allowed the establishment of the were conducted with shading, crop plants within a row), all of cover crop during the first maize flooding and sublethal doses of which constitute an important crop. At all sites itchgrass densities many herbicides including source of seed for re-infestation. were lower in validation plots than pendimethalin and nicosulfuron. in growers’ fields, and infestation Good results were observed with Previous investigations had levels decreased over the years haloxyfop methyl. In order to identified two exotic pathogens of with integrated management. evaluate the native itchgrass R. cochinchinensis with potential In general, yields (maize and dry pathogens under field conditions, as classical biocontrol agents for beans, planted as a rotation crop trials were conducted in five maize Costa Rica: a head smut, in one of the sites) were higher in plots located in Guanacaste, Sporisorium ophiuri; and a rust, validation plots at all locations and Costa Rica. The pathogens applied Puccinia rottboelliae. The dynamics over all cropping seasons; however as mycoherbicides were tested in of the itchgrass–head smut system soil fertilization regimes differed water or formulated with canola oil were explored in a previous project between validation and growers’ and Tween 40, and inoculated after using a modelling approach plots and, in some cases, improved the application of sublethal doses (R6003; see Research Highlights maize varieties were used in of haloxyfop methyl. 1989–95) . This work suggested validation plots. Soil core samples that a very high annual infection The results showed that both taken each year at the beginning rate (>85%) would be required for pathogens in combination with the of the cropping season revealed the smut to be effective as the sole two lowest herbicide doses (1 and substantial reductions in the agent of control. However, the 1.5 ml/l) caused the death of itchgrass soil seed bank in valida- smut cannot be released in 15–25-day-old seedlings, depend- tion plots. Costa Rica until host specificity ing on the environmental condi- tests are completed. Partial budget analyses demon- tions. Under field conditions the strated that integrated itchgrass best results were observed with The aim of this project was to build management was economically lower doses. Individual pathogens on the achievements of previous feasible for smallholders. were more effective than a mixture. work in order to improve methods Combining the pathogen formula- for managing itchgrass in maize by A validation plot was also estab- tion with a Mucuna cover crop did developing an integrated manage- lished in Oaxaca, Mexico in 1998 not improve itchgrass control. ment strategy and disseminating but included only minimum tillage the results to target farmers in and the use of pendimethalin to The mycoherbicide component Costa Rica, Mexico and Bolivia. reduce the initial itchgrass infesta- requires the implementation of a tion. Nevertheless, this validation validation stage, in different areas ACHIEVEMENTS plot was always less infested with and for a minimum of 2 years. itchgrass than the commercial one. Virulent isolates are available for Field research over two years in which other formulations need to Costa Rica showed that mucuna Preliminary screening of cover be tested. The stability of pathogen suppressed R. cochinchinensis, crops for itchgrass management virulence should be evaluated over but lower maize grain yields were was conducted at El Vallecito time. Experiment Farm in Santa Cruz, obtained if maize was grown in The potential of head smut as a association with the ground cover Bolivia. Promising species were Dolichos lab lab, Canavalia classical biocontrol agent for use in crop Mucuna at 50 000 plants/ha, an integrated management strategy especially when the cover crop ensiformis and Mucuna (Stizolobium) cinereus. against itchgrass in Costa Rica was was planted simultaneously with investigated. A comprehensive maize. However, itchgrass itself In addition, information on host-range screening programme decreased maize yield by about itchgrass density-dependent was undertaken using a 46%. mortality and seed production Madagascan isolate of the smut. under field conditions at two The results show that the smut is Three-year validation plots in locations in Costa Rica was extremely host-specific, as none farmers’ fields in Costa Rica generated to support modelling of the 49 species/varieties of evaluated the integration of no- studies. graminaceous test plants became tillage; use of a selective herbicide infected. (pendimethalin) in the first season During the first two years of to lower the initial density of research, native pathogens with Electrophoretic techniques were itchgrass; planting of velvetbean biocontrol potential were identified used to characterize the genotypic (Mucuna deeringiana) between and greenhouse experiments variation of itchgrass biotypes.

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Figure 1. Structure of the model of the itchgrass life cycle showing flows between the state variables (seedbank, itchgrass seedlings per m2, N ; itchgrass plants per m2, N ; seed production per m2) and parameters (proportion of seed germinating from the seed bank each season, g; i,t t proportion of seed lost per season, d; density-independent seedling mortality rate, s; degree of density dependence in seedling survival, m; seeds produced per plant in the absence of competition, w ; degree of density dependence in seed production, a; proportion of seed grain m incorporated into the new seed bank, r)

The results suggest that the biotypes microscope studies indicated that head smut and itchgrass is stable form a narrow genetic base with sporidia (propagative spores) may over a wide range of values for the greater than 80% similarity. This also be involved in the disease smut. The ability to reduce popula- high degree of similarity can be process, however no smutted plants tion density to a low, stable related to the inbreeding nature of were achieved through sporidial equilibrium density is one of the the weed, and to the relatively inoculations. requirements for a good biological recent expansion of its geographic Because release of the head smut is control agent. range. Itchgrass biotypes can be not yet possible, an existing model broadly grouped according to their was adapted to explore itchgrass FUTURE geographic origins. Latin American population dynamics in maize- biotypes form two distinct groups, based cropping systems in The results of all this work have indicating that these populations Costa Rica. The effects of the head been submitted as part of a dossier probably arose from a relatively smut, on its own and in combina- on the biological control potential small number of introductions. tion with suppressive cover crops, of head smut to the Costa Rican Neotropic invasions of the weed were explored. A simple simulation plant health authorities. On the appear to have mainly been from of smut population dynamics was basis of this information an Africa, although biotypes in Brazil incorporated later. The interaction assessment was made by the and Colombia probably originated of smut and cover crop depends on Costa Rican Sanidad Vegetal on the in Asia. This genetic homogeneity how they are modelled, and hence risks of introducing the smut into suggests that the smut should infect on how biocontrol with the smut is the New World, and permission the majority of Latin American implemented. Under a purely was granted (1999) for the importa- biotypes, some of which would be natural infestation the cover crop tion of the smut. However, they new associations. affects smut reproduction as well as were keen to introduce it first into the itchgrass, and therefore reduces quarantine in Costa Rica, and to Molecular characterization of a undertake selective host specificity range of smut genera was also effectiveness of the smut. However, when smut infection was modelled screening prior to field releases. undertaken. The genus Sporisorium The screening is to be conducted at could be readily distinguished as a constant proportion of itchgrass plants each season (for example by the Tropical Agricultural Center for from other smut genera, and this Research and Higher Education should enable the Madagascar augmentation or if applied as a mycoherbicide), then the smut in (CATIE) in a specially converted strain to be fingerprinted if the need screenhouse. Bulking up of should arise to track the fungus in combination with a cover crop could be highly effective. Results inoculum prior to field release will the environment. In addition, smut also be undertaken in this facility. pathotypes from Africa and Asia also suggest that under a natural The introduction and successful could be separated. infestation of smut there can be a trade-off between infectivity, establishment of head smut will Infection studies showed that only reproductive rate, and mortality rate potentially help in the management the teliospores (resting spores) of in the soil which should be consid- of R. cochinchinensis and thus lead the smut induced infection. ered in selecting effective smut to a reduction in the infestation and Laboratory and scanning electron strains. The interaction between spread of this weed.

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Management of herbicide-resistant weeds of rice in Bolivia, Mexico and Central America

R6652, R6793 Rice production costs in Latin America have increased as control of the annual grass weed junglerice (Echinochloa colona) has become increasingly difficult due to the evolution of C.R. Riches Natural Resources Institute (NRI), herbicide-resistant populations. Rice weed management in the region has become de- University of Greenwich, UK pendent upon herbicides, and it is vital that growers adopt a rational herbicide resistance management programme based on affordable options, including rotation of herbicides to J.C. Caseley reduce selection pressure, to ensure that rice production remains competitive with im- Institute for Arable Crops Research (IACR), ported supplies. A competitive rice industry will also safeguard employment opportunities. Long Ashton Research Station, UK This project has built on previous work to contribute further to an understanding of the B.E. Valverde resistance problem, and has demonstrated options for resistance management in both dryland CATIE (Tropical Agricultural Center and flooded rice cultures. Equally important has been the contribution to raising aware- for Research and Higher Education), ness of the resistant weed problem in Central American, Bolivian and Mexican agricultural Turrialba, Costa Rica systems. April 1996–June 1999 ISSUES enzyme aryl acylamidase, which is responsible for detoxification of the Weed management in Latin American herbicide. It was demonstrated that rice production systems is heavily propanil-resistant biotypes could be dependent on herbicide applica- controlled by mixtures of the tions, with propanil being the usual herbicide with synergists contain- choice for post-emergence control ing carbamates and mono-oxygen- of the important annual grass ase inhibitors, while integrated junglerice (Echinochloa colona), approaches using herbicides with as well as other grasses and several alternative modes of action, and broad-leaved weeds. Previous work combinations of pre-planting and undertaken by the Tropical Agricul- in-crop weed control, were tural Center for Research and demonstrated in the field in Costa Higher Education (CATIE), Costa Rica in dry seeded upland rice. Rica (R5884; see Research High- lights 1989–95) confirmed that The aims of the project described SELECTED PUBLICATIONS repeated use of propanil has led to here were to complete the develop- KIM, D.S., CASELEY, J.C., BRAIN, P., the evolution of propanil-resistant ment and field validation RICHES, C.R. and VALVERDE, B.E. (2000) populations of junglerice. By 1995, of junglerice management strate- Rapid detection of propanil and resistant populations infested an gies in upland rice, to investigate fenoxaprop resistance in Echinochloa estimated 70% of the major rice- modifications of the system colona. Weed Science 48: 695–700. producing areas of Costa Rica, in flooded rice, and to extend the El Salvador, Guatamala, Nicaragua collaboration to institutions RICHES, C.R., KNIGHTS, J.S., CHAVES, and Panama. In addition to using in Bolivia and Mexico. The project L., CASELEY, J.C. and VALVERDE, B.E. higher application rates of propanil, was therefore designed to provide (1997) The role of pendimethalin in the growers have responded to the an understanding of the status integrated management of propanil-resist- evolution of resistance by adopting of herbicide resistance in rice- ant Echinochloa colona in Central late post-emergence applications of cropping systems in Bolivia and America. Pesticide Science 51: 341–346. fenoxaprop-p-ethyl, but populations Mexico, and to recommend VALVERDE, B.E., CHAVES, L., GARITA, of E. colona have evolved resist- appropriate weed management I., RAMÍREZ, F., VARGAS, E., CARMIOL, ance to this graminicide within systems for the prevention and J., RICHES, C.R. and CASELEY, J.C. (2001) three seasons of its use in Costa Rica. management of resistance. Modified herbicide regimes for propanil- An important aim was to raise Collaboration between CATIE, awareness of the resistance resistant Echinochloa colona control in Costa Rica, the Institute for Arable rice. Weed Science 49 (in press). problem among growers, farm Crops Research (IACR), Long advisers and the pesticide industry VALVERDE, B.E., RICHES, C.R. and Ashton Research Station and in collaborating countries. CASELEY, J.C. (2000) Prevention and man- Natural Resources Institute (NRI) in agement of herbicide resistant weeds in projects R5226 (see Research ACHIEVEMENTS rice: experiences from Central America Highlights 1989–95) and R5473 Surveys in Mexico revealed the with Echinochloa colona. San Jose, Costa resulted in the discovery that the presence of propanil-resistant Rica: Crop Protection Association of Costa propanil resistance mechanism in junglerice (Echinochloa colona). Rica. E. colona is an elevated level of the Propanil resistance was not found

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and increased grain yields. Herbi- growers, extension staff, herbicide cide options for flooded rice were manufacturers’ technical and sales also demonstrated at sites representatives, researchers, in Costa Rica. students and government officials in Central America, Bolivia and Although it proved impossible to Mexico through a series of publica- improve propanil activity on tions and presentations at seminars junglerice using additional or conferences. A workshop surfactant in the tank mix, this attended by delegates from six approach was successful in countries in Latin America was glasshouse trials with fenoxaprop. organized by the project in Costa Additional surfactant did not lead Rica, to provide a forum for raising to increased damage to rice when awareness of herbicide resistance Junglerice (Echinochloa colona) used with fenoxaprop in the field, in weeds and to disseminate infesting rice but in two field trials in Costa Rica findings. junglerice control was not in Bolivia, probably due to improved. Propanil has been Staff of herbicide manufacturers a different rice production and local sales outlets play an system. However, populations important role in Central and of the grass Eriochloa punctata, South America in providing which are resistant to ACCase- advice to growers. The project inhibiting herbicides including has therefore placed emphasis fluazifop-butyl, were described on increasing awareness of from soya/rice systems herbicide resistance within the in Bolivia. industry by inviting staff to seminars, field days and Laboratory and glasshouse workshops. The industry has work in the UK led to the also been well represented at development of a range the conferences attended by of rapid diagnostic tests for project staff. This will also be propanil and fenoxaprop-p one important target audience resistance in junglerice over Research and extension staff from Bolivia, Mexico and of the project publication a range of growth stages. across Central America meet in Costa Rica in July 1998 Prevention and management of These tests use a variety of to discuss herbicide resistance management in rice herbicide resistant weeds in plant organs – seeds, seedlings, rice, published and circulated tillers and stem nodes – and a useful herbicide in rice systems in collaboration with the Crop require a minimum of facilities and because of the relatively wide Protection Association of Costa Rica. equipment. The seedling test was spectrum of species controlled. validated on plants taken from the Use of propanil in mixture with FUTURE field in Costa Rica. a synergist, either piperophos Lessons have been learnt from Field trials in Costa Rica investi- or anilophos, was shown to be the propanil-resistance story gated the management of resistant a further effective option for sites which it is hoped will influence junglerice populations by the where resistant populations future weed management deci- integration of pre-plant and in-crop of junglerice are found. sions to allow important herbi- control options. Timely stubble Graminicides which are selective cides a long life, as growers take incorporation after harvest was in rice against E. colona, but which action to prevent further not effective, but long-term trials have different modes of action to resistances developing. demonstrated that control of the propanil and fenoxaprop, have an initial junglerice flush before Internationally, the true extent of important role to play in manage- planting, by chemical or mechani- herbicide resistant rice weed popu- ment of resistant populations cal means, and improved in-crop lations is unknown, but important in high-potential rice production control with alternative herbicides, cases are recognized in the USA systems. Additional work was can serve as the basis for integrated and the Far East. The approach carried out (project R6793) to management of herbicide-resistant taken by the project and the weed assess the activity of recently junglerice in rain-fed rice. management strategies that have developed and registered rice A number of graminicides with been developed therefore have herbicides on glasshouse-grown alternative modes of action to a wider relevance to the major junglerice, and effective treatments propanil and fenoxaprop, including rice-producing areas of the world were selected for field trials in quinclorac, pendimethalin and where herbicide use either is Costa Rica. bispyribac-sodium, also controlled already intensive, or is increasing resistant junglerice in field trials Project results were disseminated to due to labour and other costs.

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Improved monitoring of conventional and microbial pest management sprays

R6620 While integrated pest management is being adopted in many developing countries, con- ventional pesticides are likely to continue to play a major role in crop protection for the H. Dobson Natural Resources Institute (NRI), foreseeable future. Pesticides are often poorly managed and applied, resulting in ineffi- University of Greenwich, UK cient and uneconomic usage, environmental and human health problems, build-up of pest resistance, and excessive residues in produce. When mismanaged they may also prevent April 1996–March 1999 the activity of important natural control agents in the cropping ecosystem. These problems are often difficult to relate in a quantifiable way to the pesticide management regimes in use due to the lack of appropriate technologies. To address these problems, this project has developed a range of techniques to monitor the processes and the consequences of spraying ISSUES practices. Crop production is expanding and efficiencies for a range of very small with a known quantity of the pesti- intensifying in peri-urban regions droplet sizes and low wind speeds cide, was developed to test the volati- of many developing countries, with were measured, and these data can lity of ultra-low-volume formulation. corresponding increases in the use be used to correct field drift sample The final component related to the of pesticides. The limited area of data to give quantitative assessments distribution of nuclear polyhedrosis productive land in peri-urban areas of drift through human habitations, virus (NPV) particles in spray puts pressure on farmers to maxi- natural enemy refugia and ecologi- droplets. These particles infect mize yields through very intensive cally sensitive areas. certain insect pests when sprayed agriculture, which is often charac- An attempt was made to develop onto crop surfaces, and can be terized by high pesticide use, a rapid method for quantifying used instead of conventional threatening the welfare and volumes of deposited spray directly chemical pesticides. A method was livelihood of inhabitants as well as from visual interpretation of two- developed to visualize deposited the long-term welfare of the dimensional deposit patterns on droplets of spray formulation at the environment, and resulting in the target plant surfaces. When tested, same time as the NPV particles rejection of export crops due to the variability in correlations within them, and a series of trials excessive pesticides. Information on between apparent deposit and carried out to assess distribution best spray practice is often not actual volume was too great to uniformity. A disproportionate available to farmers. justify pursuing the technique — number of particles were found There is a need for feedback on the the great range of microstructures in the larger-sized droplets. This fate of sprayed products on the and surface characteristics between has implications for the type of plant, on the soil, and travelling out different crop types, and even within spray equipment and nozzle of the target area as drift. Newer individual plants, made universal performance required for the microbial insecticides pose similar correction factors unreliable. application of microbial pesticides. application and monitoring The third component of the project problems, and also present addi- looked at methods for tagging spray FUTURE tional challenges related to non- formulations for later recovery and uniform distribution of microbial Some of the outputs of this deposit analysis. Ideal performance particles in the droplets. Accuracy project have already contributed characteristics were established for of application is particularly to more effective sampling dye tracers, and one of the princi- important with microbial pesticides: of sprays, both in large-scale pal limiting characteristics – they must be ingested or come into migratory pest control operations photostability – was tested for four direct contact with their hosts to be and in smallholder horticultural promising visible dyes and three effective, and this must occur soon production systems. For example, fluorescent dyes in a sunlight after application due to their short the deposition and drift sampling simulator. On the basis of results, field persistence. techniques were used in quality conclusions were drawn as to which monitoring of aerial spraying dyes suit which modes of use. ACHIEVEMENTS against the migratory locust In ultra-low-volume spraying, the in Madagascar. Thus the project Four simple spray samplers likely to oil-based droplets must remain contributes to the overall goal be able to capture the very small airborne for many seconds without of promoting pest management droplets found in drift were selected significant reduction in size. methods which will allow higher and tested in a specialized wind- A simple laboratory method, yields to be produced in a manner tunnel facility. Their collection involving sequential weighing that is safe to operators, communi- Publications: see Bibliography on CD. of a series of filter papers wetted ties and the environment.

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Acronyms and abbreviations

ACMV African cassava mosaic virus AfFOResT African Farmers’ Organic Research and Training, Zimbabwe Agritex national agricultural extension service, Zimbabwe APAARI Asia-Pacific Association of Agricultural Research Institutions ARI agricultural research institute/advanced research institute ASARECA Association for Strengthening Agricultural Research in Eastern and Southern Africa (Uganda) AVRDC Asian Vegetable Research and Development Center, Taiwan BACTID bacterial identification system (NRI) BAT bait application technique BBTV banana bunchy top virus BHU Banaras Hindu University, India BLRS Bah Lias Research Station, Indonesia Bt Bacillus thuringiensis CABI Centre for Agriculture and Biosciences International CATIE Centro Agronomico Tropical de Investigacion y Enseñanza (Tropical Agricultural Center for Research and Higher Education), Costa Rica CBSD cassava brown streak disease CBSV cassava brown streak virus CCRI Central Cotton Research Institute, Pakistan CFC Common Fund for Commodities CGIAR Consultative Group on International Agricultural Research CIAT Centro Internacional de Agricultura Tropical (International Center for Tropical Agriculture) CICR Central Institute of Cotton Research, India CIMMYT Centro Internacional de Mejoramiento de Maiz y Trigo (International Maize and Wheat Improvement Center) CIP Centro Internacional de la Papa (International Potato Center) CMD cassva mosaic disease CORAF Conseil ouest et centre Africain pour la recherche et le développement agricoles, Senegal CORNET Coffee Research Network (East and Central Africa) CPP Crop Protection Programme (DFID) CPCRI Central Plantation Crops Research Institute, India CRF Coffee Research Foundation, Kenya CRI Coconut Research Institute, Sri Lanka CRRI Central Rice Research Institute, India CSIR Council for Scientific and Industrial Research, Ghana DFID Department for International Development, UK (formerly ODA) DRR Directorate of Rice Research, India DRSS Directorate of Research and Specialist Services, Zimbabwe EC European Commission ELISA enzyme-linked immunosorbent assay ECLO Emergency Centre for Locust Operations (FAO) FAO Food and Agriculture Organization of the United Nations FCRDI Food Crops Research and Development Institute, Sri Lanka FOSEM Food Security and Marketing for Smallholder Farmers network, Uganda FRIM Forestry Research Institute of Malaysia GNP gross national product GRAV groundnut rosette assistor luteovirus GRV groundnut rosette umbravirus HaNPV Helicoverpa armigera NPV HRI Horticulture Research International, UK IACR Institute for Arable Crops Research, UK ICAR Indian Council of Agricultural Research ICIPE International Centre for Insect Physiology and Ecology, Kenya ICOSAMP Information Core on Southern African Migrant Pests ICRAF International Centre for Research in Agroforestry ICRISAT International Crops Research Institute for the Semi-Arid Tropics IDEA Investment in Developing Export Agriculture (USAID) IFAD International Fund for Agricultural Development IITA International Institute of Tropical Agriculture INGER International Network for Genetic Evaluation of Rice

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INIBAP International Network for the Improvement of Banana and Plantain IOPRI Indonesian Oil Palm Research Institute IPM integrated pest management IPMSA Integrated Pest Management Strategy Area IPS International Pheromone Systems Ltd IRRI International Rice Research Institute KARI Kenya Agricultural Research Institute KFRI Kerala Forest Research Institute, India KIOF Kenya Institute of Organic Farming MALNR Ministry of Agriculture, Livestock and Natural Resources (Tanzania) MAT male annihilation technique MLO mycoplasma-like organism MSVD maize streak virus disease NAARI Namulonge Agricultural and Animal Production Research Institute (Uganda) NARL National Agricultural Research Laboratories (Kenya) NARS national agricultural research system NARSIS Natural Resources Information System (DFID) NARO National Agricultural Research Organization (Uganda) NDVI normalized difference vegetation index NGO non-governmental organization NPV nuclear polyhedrosis virus NRI Natural Resources Institute, UK NRIL Natural Resources International Limited, UK NRSP Natural Resources Systems Programme (DFID) OB occlusion bodies ODA Overseas Development Administration, UK (now DFID) PAU Punjab Agricultural University, India PCR polymerase chain reaction PEDUNE Protection ecologiquement durable du niébé—Swiss Development Corporation-Funded project in West Africa PORIM Palm Oil Research Institute of Malaysia PPRI Plant Protection Research Institute, South Africa PROFOR UNDP Programme on Forests PSRP Plant Sciences Research Programme (DFID) PVC poly vinyl chloride PxGV Plutella xylostella granulosis virus RAMSES Reconnaissance and Management System of the Environment of Schistocerca RAPD random amplified polymorphic DNA RLD Rural Livelihoods Department (DFID) RT-PCR reverse transcriptase polymerase chain reaction RYMV rice yellow mottle virus SACCAR Southern African Centre for Co-operation in Agricultural Research, Botswana SADC Southern Africa Development Community SAPPRAD Southeast Asian Program for Potato Research and Development (CIP) SARRNET Southern African Roots and Tubers Research Network SPCSV sweet potato chlorotic stunt closterovirus SPVD sweet potato virus disease SWARMS Schistocerca Warning Management System TARO Tanzanian Agricultural Research Organization TNAU Tamil Nadu Agricultural University, India ToLCV tomato leaf curl virus UAS University of Agricultural Sciences, Bangalore, India UNDP United Nations Development Programme UNPP Uganda National Potato Programme UNBRP Uganda National Banana Research Programme UPM Universiti Putra Malaysia UV ultra-violet VLR vertical-looking radar WARDA West Africa Rice Development Association WCGA western cotton-growing area, Tanzania WECARD West and Central African Council for Agricultural Research and Development

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Project list 1996–2000

R No. PROJECT TITLE DATES LOCATION Page

R5272 Use of pheromones in insect pest management in cotton 1992–1996 Pakistan, Egypt, 98 China R5445 Field demonstration of vertical-looking radar as a cost- 1992–1996 Mauritania 42 effective, automatic monitor of desert locust migration R5540 The improvement of insect virus application for control 1993–1997 India 91 of Helicoverpa armigera in India R5735 Control of yam diseases in in Nigeria 1992–1996 Nigeria 8 R5881 Detection and identification of mycoplasma-like 1993–1996 Indonesia, Solomon 94 R5885 organisms (MLOs) associated with little leaf of sweet Islands, Papua New potato (Ipomoea batatas) Guinea R6006/7CB Adaption of novel techniques for the detection and 1994–1996 Tanzania, Uganda, 32 characterization of the fungi causing fusarium wilt and Kenya Sigatoka leaf spots of banana and plantain R6008CB Sustainable agriculture in forest margins in Bolivia: 1996–1999 Bolivia weed science component R6009CB Management of rice nematodes in West Africa 1994–1996 Ghana 38 R6115 Development of pheromones for monitoring and control 1996–1997 Uganda of sweet potato weevils Cylas brunneus and C. puncticollis R6391 Development of nematode resistance in bananas and 1995–1999 India 72 plantains R6392 Control of water hyacinth in the Shire River, Malawi 1995–1999 Malawi 7 R6519 The epidemiology and management of rice tungro virus 1996–1998 India, Indonesia, 80 disease in relation to the ecology of the leafhopper Philippines vectors R6520 Molecular and biochemical techniques for identification 1995–1998 Tanzania, Malawi 29 and characterisation of Ralstonia solanacearum and other plant-pathogenic bacteria R6521 Detection and identification of phytoplasmas 1996–1997 Ghana 46 (mycoplasma-like organisms, MLOs) in putative insect vectors of lethal yellowing-like diseases in Africa R6579 Identification, vector relationships, epidemiology and 1996–1999 Philippines 74 control of virus and bacterial diseases of banana R6580 Non-chemical management of banana nematodes in 1996–2000 Uganda East Africa R6581 An investigation into the epidemiology and control of 1996–1999 Tanzania, Kenya fungal pathogens of sorghum in semi-arid production systems in East Africa R6582 Epidemiology, toxicology and management of the maize 1996–2000 Kenya, Malawi ear-rot complex in African farming systems R6583 Analysis of the pathogenic variability and genetic 1996–2000 Ghana, Uganda diversity of the plant-parasitic nematodes Radopholus similis, Pratylenchus coffeae and P. goodeyi on bananas and plantains in East and West Africa R6604 Investigation of lethal coconut diseases of uncertain 1996–1998 Indonesia, India, 68 etiology Sri Lanka R6611 Biological control of root-knot nematodes 1996–1999 Ghana, Pakistan R6614 Control of African cassava mosaic virus 1996–1998 Uganda, Tanzania 15 R6615 Investigation of biorational methods for control of insect 1996–1999 Kenya 53 pests of vegetables in Kenya

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R No. PROJECT TITLE DATES LOCATION Page

R6616 Pest management in horticultural crops: integrating 1996–1999 Kenya 50 sustainable pesticide use into biocontrol-based peri- urban production systems R6617 Identification, characterisation and epidemiological 1996–1999 Uganda, Tanzania, 10 studies of the whitefly-borne component of sweet potato Nigeria virus disease complex in Africa R6620 Improved monitoring of conventional and microbial 1996–1999 Zimbabwe 110 pest management sprays R6627 Sustainable management of Bemisia tabaci and tomato 1996–1999 India 88 leaf curl virus (ToLCV) on tomato in India R6628 Development of appropriate management systems for 1995–1999 Indonesia, India, 66 hymenomycete diseases of perennial crops Malaysia R6629 Biological control of bacterial wilt disease of potato in 1996–2000 Pakistan, Kenya Kenya and Pakistan R6642 The development of management strategies for maize 1996–1999 Uganda 21 streak virus disease R6643 Investigation of the Rhizoctonia sheath disease complex 1996–1999 India, Philippines 77 in rice R6651 Functional diversity of Phaseolus bean mixtures in 1996–1998 Tanzania 18 East Africa R6652 Management of herbicide-resistant weeds in rice in 1996–1999 Mexico, Bolivia, 108 Bolivia, Mexico and Central America Costa Rica R6653 Development of integrated management strategies for 1996–2000 Uganda 20 soil insect pests of maize-based smallholder cropping systems in Uganda R6654 Integrated control of Striga in Tanzania 1996–1999 Tanzania 2 R6655 Zimbabwe: moisture conservation through improved 1996–1999 Zimbabwe 4 weed management in Savannah cropping systems R6656 Evaluation of the significance and potential for control 1996–1998 Ghana 47 of mistletoe in cocoa and citrus R6657 Integrated food crops systems project: crop protection 1996–1999 Ghana 49 component–develop/promote improved methods for the control of weeds, insect pests, diseases and nematodes in market gardening and commercial horticultural enterprises in Brong Ahafo Region, Ghana R6658 Epidemiology and crop loss assessment of rice 1996–1997 Ghana, Côte d’Ivoire, 38 nematodes in West Africa Burkina Faso, Togo, Guinea R6659 Development of pheromone traps for monitoring the 1996–1999 India, Nigeria, 56 legume pod borer Maruca testulalis (M. vitrata) Sri Lanka, Taiwan R6690 The development of an integrated management strategy 1996–1999 Bolivia, Mexico, 105 for Rottboellia cochinchinensis (itchgrass) in maize- Costa Rica based cropping systems in selected areas of Latin America R6691 Control of yam diseases in forest margin farming 1996–2000 Ghana 8 systems in Ghana R6692 Novel techniques for detection and characterisation of 1996–1997 Tanzania, Uganda, 32 fungi causing fusarium wilt and Sigatoka leaf spots of Kenya banana and plantain in East Africa R6693 The chemical ecology and mating behaviour of the 1996–2000 Ghana, Niger, millet pests Coniesta ignefusalis and Heliocheilus Nigeria albipunctella R6694 Identification of resistance in major nematode pests of 1996–2000 Ghana, Nigeria yams (Dioscorea) in West Africa R6695 Developing strategies for the control of Parthenium 1996–2000 India weed in India using fungal pathogens R6733 An investigation into the biology, epidemiology and 1996–1999 Tanzania, Kenya 24 management of finger millet blast in low-input farming systems in East Africa

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R No. PROJECT TITLE DATES LOCATION Page

R6734 Development of an area-wide strategy for management 1996–1999 India 95 of insecticide-resistant cotton pests in southern India R6735 The development of a biocontrol strategy for the 1996–2000 India 100 management of the alien perennial weed Mikania micrantha HBK (Asteraceae) in tree crop based farming systems in India R6736 The assessment of major soilborne pests of the multi- 1996–2000 Kenya, Zambia, 63 purpose agroforestry tree, Sesbania sesban, and the Malawi development and promotion of integrated pest management strategies R6737 Management of Cyperus in smallholder farming systems 1996–2000 Ghana on vertisols and vertic clay soils R6738 Identification and characterisation of key screening sites 1996–1999 Ghana, Nigeria, for blast and scald resistance in West Africa Côte d’Ivoire R6739 Application of mating disruption to control yellow rice 1996–1999 India 83 stem borer in India R6746 Entomopathogenic baculoviruses for control of the 1996–2000 Tanzania African armyworm, Spodoptera exempta, in Tanzania R6760 A systems approach to sustainable insect pest 1996–1999 India management in irrigated cotton in India R6761 Integrated management of the fusarium wilt/root-knot 1996–2000 Tanzania 60 nematode disease complex on cotton R6762 Decision tools to aid armyworm surveillance and 1996–1999 Tanzania outbreak prediction R6763 The epidemiology of rice yellow mottle virus disease in 1996–1999 Tanzania 35 rice farming systems in Tanzania R6764 Environmentally acceptable crop protection strategies 1997–2000 Zimbabwe based on the improved use of pesticides and adoption of integrated pest management strategies by smallholder farmers in Zimbabwe R6765 Control of cassava virus diseases in coastal coconut- 1996–1999 Malawi, Tanzania 13 based farming systems in Tanzania R6766 Epidemiology and population structure of Phytophthora 1996–2000 Indonesia species causing diseases of coconut in Indonesia R6782 Development of coffee IPM components in Kenya 1996–1999 Kenya 59 R6788 Development of an outbreak forecasting tool for the 1997–2000 Senegal, Niger, Senegalese grasshopper, Oedaleus senegalensis, using Chad, Cameroon, satellite and ecological data Mali R6793 Selection of herbicides for use in the management of 1997 Central America 108 propanil and fenoxaprop-P resistant Echinochloa colona in direct seeded rice R6794 Investigation of banana leaf speckle in Africa 1997 Kenya, Uganda, 31 Cameroon R6795 Isolation, identification and culture of indigenous 1997 Kenya entomopathogenic nematodes and preliminary investigations into their use for control of insect pests of peri-urban agriculture R6796 An investigation to elucidate the basis of resistance in 1997 India, Bangladesh wild and cultivated species of chickpeas to botrytis grey mould, Botrytis cinerea R6797 Development of pheromone traps as a component of an 1997 Malaysia, India IPM approach to control of cabbage webworm, Hellula undalis R6807 An investigaton of pesticide and microbial interactions 1996–2000 Malawi on coffee as a means of developing an IPM strategy for economically important coffee pests in smallholder farming systems in Malawi

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R No. PROJECT TITLE DATES LOCATION Page

R6809 Statistical analyses of locust movements and their 1996–1998 Sub-Saharan Africa 44 determinants R6811 Groundnut rosette disease epidemiology 1996–1999 Malawi 27 R6812 Improved ecological and economic recommendations 1997 Mexico 104 for the control of Hypothenemus hampei in coffee in Mexico R6820 Pest constraints affecting tree crops in Bolivia 1997 Bolivia 103 R6822 Identification of the factors that lead to changes in 1996–1999 Sub-Saharan Africa 43 desert locust populations at the beginning and end of recession periods R6823 Models of Quelea movements and improved control1996–1999 Namibia,45 strategies Mozambique, Angola, Malawi, Botswana, Zimbabwe, South Africa, Swaziland, Zambia R6835 Evaluate plate capture PCR (PC–PCR as a rapid 1997 Mexico detection procedure for screening maize plants for infection by maize bushy stunt phytoplasma and corn stunt spiroplasma in Mexico R6921 Improved methods for the management of Striga: 1997–2000 Tanzania, Kenya 1 nitrogen, tolerance, screening and cultural practice R6924 Fruit and vegetable pest control in Pakistan 1997–1999 Pakistan 86 R6928 Development of pheromones for management of coffee 1997 India white stemborer, Xylotrechus quadripes R6929 Development of pheromones for management of red 1996 Sri Lanka 71 palm weevil and rhinoceros beetle on coconuts in Sri Lanka R6940 Analysis of plant quarantine pest risks for Tanzania 1997 Tanzania R6941 The use of composted urban wastes in integrated pest 1996–1998 Ghana management systems to control pests and pathogens in peri-urban agriculture R6944 Development of improved IPM technologies for dry 1997 India season (rabi) vegetables in the Sunderbans coastal saline zone of eastern India R7004 The improvement of insect virus application for control 1997–1998 India 91 of Helicoverpa armigera in India R7065 Modelling the performance of the barrier control 1998–2000 Madagascar 40 technique for locust and grasshopper control to maximise their efficiency and minimise their environmental effects R7071 Development of improved pest control technologies 1997–2001 India for dry season vegetables in the coastal saline zone of north-eastern India R7189 Cultivar competitiveness and interactions with on-farm 1998–2001 Côte d’Ivoire, Ghana, seed priming for integrated weed management Philippines, India, Bangladesh, Zimbabwe R7246 Development of pheromones for management of coffee 1998–1999 India, Malawi white stemborer, Xylotrechus quadripes R7247 Entomopathogenic viruses for control of the legume pod 1998–1999 West Africa borer, Maruca vitrata (Fabricius) (= M. testulalis Geyer) (Lep: Pyralidae) in West Africa R7248 Analysis of a host specificity gene in vascular bacterial 1998–1999 Global pathogens of banana and plantain R7249 Development of mycoinsecticides and pheromones for 1998–2001 Ghana cocoa mirids R7266 Development and evaluation of a pilot field handbook 1998–1999 Zimbabwe, Kenya 48 on natural enemies of vegetable pests in Kenya and Zimbabwe

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R No. PROJECT TITLE DATES LOCATION Page

R7267 Principal pod-boring pests of tropical legume crops: 1998–2001 India, Niger, Brazil, economic importance, taxonomy, natural enemies and Malawi control R7296 Pest and natural enemy interactions in low input 1998–2001 Bangladesh cropping systems R7299 An evaluation of the promotion and uptake of microbial1998–1999 Thailand, India, pesticides in developing countries by resource-poor United Kingdom farmers R7317 The invasion mechanism of endophytic Beauveria 1999 West Africa bassiana isolates into maize plants for protection against stem-borer larvae in Africa R7318 Variability within maize bushy stunt phytoplasm in 1998–1999 Mexico Central America R7325 The development of integrated weed management 1999–2002 Bolivia strategies for hillsides in the valleys of Cochabamba R7326 Control of Phytophthora megakarya diseases of cocoa 1999–2002 Ghana with phosphonic acid R7331 Minimising the economic and sociological impact of 1999–2001 India, Bangladesh Phalaris minor in rice/wheat ecosystems R7337 The optimisation and dissemination of a molecular 1999–2000 Global identification module for Phytophthora species R7345 Management of weedy rices 1999–2002 Ghana, Mali, Tanzania R7346 Evaluation of the effects of plant diseases on the yield 1999–2002 India and nutritive value of crop residues used for peri-urban dairy production on the Deccan Plateau in India R7347 Fate of herbicide residues in irrigated rice systems 1999–2000 India, Pakistan, Bangladesh R7377 Development of sustainable weed management systems 1999–2002 India in direct seeded, irrigated rice R7401 Improving production in the Teso farming system 1999–2002 Uganda through the development of sustainable draught animal technologies R7403 Pest management in horticultural crops: an integrated 1999–2002 Kenya, Zimbabwe approach to vegetable pest management with the aim of reducing reliance on pesticides in Kenya R7404 Socioeconomic study of the uptake of herbicide 1999–2000 Kenya, Uganda technology in maize cropping systems R7405 Development of weed management in maize-based 1999–2002 Kenya, Uganda cropping systems R7428 Biology and control of armoured bush crickets in 1999–2002 Southern Africa southern Africa R7429 The development of management strategies for maize 1999–2000 Uganda streak virus disease R7441 Development of pheromone trapping for monitoring 1999–2002 Ghana, Benin and control of the legume podborer, Maruca vitrata (syn. testulalis) by smallholder farmers in West Africa R7445 Groundnut rosette disease management 1999–2002 Uganda, Malawi, Mozambique, Zimbabwe, Nigeria, Mali, Burkina Faso, Niger R7447 Fruit and vegetable fly management in Pakistan 1999 Pakistan 86 R7449 Development of biorational brassica IPM in Kenya 1999–2002 Kenya R7452 Characterisation of the causal virus of pigeonpea 1999–2002 India, Nepal sterility mosaic disease: a step towards attaining sustainability of pigeonpea production in the Indian subcontinent R7460 Sustainable management and molecular 1999–2002 India characterisation of Bemisia tabaci and tomato leaf curl virus (ToLCV) on tomato in India (phase II)

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R No. PROJECT TITLE DATES LOCATION

R7462 The development of integrated management systems for 1999–2002 Bolivia the control of pests and diseases in the potato farming systems of the Mesothermic Valleys of Bolivia R7471 Developing weed management strategies for rice-based 1999–2002 Bangladesh cropping systems in Bangladesh R7472 Integrated management of root-knot nematodes on 1999–2002 Kenya vegetables in Kenya R7473 Weed management options for seasonally inundated 1999–2002 Zimbabwe land in semi-arid Zimbabwe R7474 Weed management options for cotton-based systems of 1999–2002 Zimbabwe, Zambia the Zambezi valley R7478 Management strategies for banana streak virus: variation 1999–2000 Uganda, Rwanda of BSV in Uganda as an adjunct to diagnosis and epidemiology R7479 Assessment and significance of tree pests in Bolivia 1999–2000 Bolivia R7488 Study of factors affecting the uptake and adoption of 1999–2000 Uganda outputs of crop protection research in banana-cropping systems in Uganda R7489 Study of factors affecting the uptake and adoption of 1999–2000 Kenya, Uganda outputs of crop protection research in maize systems in East Africa R7490 Integrated pest and soil fertility management 1999–2000 Kenya, Tanzania R7491 Nacobbus aberrans and weeds in Bolivian potato fields: 2000 Bolivia environmental consequences of current and future nemotode control options R7492 Promotion and technical support for methods of 1999–2002 Uganda, Tanzania controlling whitefly-borne viruses in sweet potato in East Africa R7499 Crop protection research methodologies for agroforestry 1999–2000 Nepal systems R7500 Analysis of farmers’ decision-making in pest 1999–2000 India, Kenya, Uganda management R7503 Integrating pest management and soil fertility 1999–2000 Ghana management R7504 Study of factors affecting the uptake and adoption of 1999–2000 Ghana, Nigeria outputs of crop protection research on yams in Ghana R7505 Strategies for the sustainable deployment of cassava 1999–2002 Uganda, Tanzania, mosaic disease-resistant cassava in eastern Africa Kenya, Rwanda R7506 Review of technical and institutional options for 1999–2000 India sorghum grain mould management and the potential impact on the poor R7512 Factors affecting update and adoption of outputs of crop 1999–2000 Kenya protection in peri-urban vegetable systems in Kenya R7513 Factors affecting uptake and adoption of outputs of crop 1999–2000 India, Bangladesh, protection in vegetable systems in India, Bangladesh Nepal and Nepal R7518 Promotion of sustainable control of covered kernel smut 1999–2002 Kenya, Tanzania, of sorghum through broadening the cropping base Uganda R7529 Management strategies for banana streak virus; 1999–2002 Uganda, Tanzania, epidemiology, vector studies and control of banana Kenya, Rwanda, streak virus in East Africa highland bananas Burundi R7552 Strategies for development and deployment of durable 1999–2002 Ghana, Côte d’Ivoire blast resistance in West Africa R7561 Factors affecting uptake and adoption of crop protection research in rice systems in West Africa (Ghana) 2000 Ghana R7563 Management of cassava brown streak disease and 2000–2002 Tanzania, mosaic disease in eastern and southern Africa Mozambique, Malawi R7564 Striga on cereal crops in East Africa 2000–2003 Tanzania

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R No. PROJECT TITLE DATES LOCATION

R7565 Participatory breeding of superior, mosaic disease- 2000–2003 Ghana resistant cassava R7566 Management strategies for maize grey leaf spot 2000–2003 Zimbabwe, Kenya, (Cercospora zeae-maydis) in Kenya and Zimbabwe Swaziland R7567 Integrated management of banana diseases in Uganda 2000–2002 Uganda R7568 Characterisation and epidemiology of root rot diseases 2000–2003 Uganda, Congo, caused by Fusarium and Pythium spp. in beans South Africa R7569 Participatory promotion of disease-resistant and farmer- 2000–2003 Tanzania acceptable phaseolus beans in the southern highlands of Tanzania R7570 Determining the nature and function of crop associated 2000–2003 Côte d’Ivoire, biodiversity for sustainable intensification of rice-based Vietnam, Bangladesh production systems R7571 Management of virus diseases of important vegetable 2000–2003 Kenya crops in Kenya R7572 Management of key insect pests of sorghum in southern 2000–2003 Southern and and eastern Africa: developing IPM approaches with eastern Africa expert panels R7576 Factors affecting uptake and adoption of outputs of 2000 India research systems in India R7579 Strategies for forage production and erosion control as 2001 Bolivia a complement to hillside weed management R7585 Use of transgenic pest-resistant crops in developing 2000 Bolivia, Côte d’Ivoire, countries India R7587 Field guide and posters of key natural enemies of 2000–2001 Zimbabwe vegetable pests in southern and eastern Africa: production and dissemination in Zimbabwe R7778 Rice sheath blight complex caused by Rhizoctonia 2000–2003 Bangladesh species: pathogen epidemiology and management strategies R7779 Forecasting outbreaks of the brown locust in 2000–2003 Angola, Botswana, southern Africa Lesotho, Mozambique, Namibia, South Africa, Zambia, Zimbabwe R7796 Cassava brown streak virus, virus isolates and the 2000–2001 Tanzania, Malawi, application of the diagnostic test Uganda, Kenya, Mozambique R7813 Sustainable control of the cotton bollworm, Helicoverpa 2000–2004 India, Pakistan, armigera, in small-scale production systems China R7818 Development of biologically-based control strategies for 2000–2003 Zambia, Tanzania environmentally sustainable control of red locust in central and southern Africa R7821 IPM promotion in pigeonpea 2000–2001 India R7858 Promoting potato seed-tuber management for increased 2000–2001 Kenya, Uganda, ware yields in Kenya, Uganda and the Republic of South Africa South Africa R7876 Investigations into the epidemiology of Kalimantan wilt 2001–2003 Indonesia of coconuts in Indonesia R7885 Promoting the adoption of improved disease and pest 2000–2002 Nepal, India management technologies in chickpea by poor farmers in mid hills and hillside cropping systems in Nepal R7890 Establishment of an information core of southern 2001–2002 South Africa, Angola, African migrant pests (ICOSAMP) Botswana, Lesotho, Malawi, Mozambique, Namibia, Swaziland, Tanzania, Zambia, Zimbabwe

119 DFID CROP PROTECTION PROGRAMME

Addresses of main participating institutions

African Farmers’ Organic Research and Training Agronomy Institute (AfFOResT) PO Box CY550 PO Box CY 301 Causeway Causeway, Harare Harare Zimbabwe Zimbabwe Tel: 00 263 4 336130 Fax: 00 263 4 726911 Asian Vegetable Research and Development Center (AVRDC) E-mail: [email protected] Africa Regional Programme PO Box 10 Agricultural Extension Department Duluti Rahim Yar Khan Arusha Punjab Tanzania Pakistan Tel: 00 255 57 504323/508491 Fax: 00 255 57 504270 Agricultural Extension Service Bannu Road Asian Vegetable Research and Development Center (AVRDC) Ismail Khan PO Box 42 North West Frontier Province (NWFP) Shanhua Pakistan Tainan 741 Taiwan Agricultural Research and Training Centre, Ilonga Tel: 00 886 6 583 7801 Kilosa Fax: 00 886 6 583 0009 c/o Ministry of Agriculture and Cooperatives E-mail: [email protected] Tanzania Bah Lias Research Station (BLRS) Agricultural Research and Training Centre, Kilombero, PTPP London Ifakara PO Box 1154, c/o Ministry of Agriculture and Cooperatives Medan 20011 Tanzania North Sumatra Indonesia Agricultural Research and Training Centre, Naliendele Tanzanian Agricultural Research Organization (TARO) Biotechnology Research Unit for Estate Crops PO Box 509 Jl. Taman Kencana No 1 Mtwara Bogor 6151 Tanzania Indonesia

Agricultural Research and Training Centre, Ukiriguru Boh Tea Plantations TARO No 9 Persiaran Hampshire PO Box 1433 off Jalan Ampang Mwanza 50450 Kuala Lumpur Tanzania Malaysia Tel: 00 60 3 2164 6555 Agricultural Research and Training Centre, Uyole Fax: 00 60 3 2164 6610 TARO E-mail: [email protected] PO Box 400 Mbeya Bureau of Plant Industry (BPI) Tanzania Davao National Crops Research and Development Centre Agritex (Institute of Agricultural Engineering) Bago-Oshiro PO Box BW 330 Mintral Borrowdale Davao City Harare Mindanao Zimbabwe Philippines Tel: 00 263 4 860019 Tel: 00 63 82 293 0107 Fax: 00 263 4 860136 Fax: 00 63 82 293 0107

120 DFID CROP PROTECTION PROGRAMME

CABI Bioscience (Ascot) Central Institute of Cotton Research (CICR) Silwood Park Regional Station Buckhurst Road Coimbatore 641 003 Ascot Maharashtra Berks SL5 7TA India UK Tel: 00 44 1491 829136 Central Rice Research Institute Fax: 00 44 1491 829123 Cuttack 753006 Orissa CABI Bioscience (Egham) India Bakeham Lane Tel: 00 91 671 21887 Egham Fax: 00 91 671 31613 Surrey TW20 9TY UK Coconut Research Institute (CRI) Tel: 00 44 1784 470 111 Bandirippuwa Estate Fax: 00 44 1784 470 909 Lunuwila Sri Lanka CABI Bioscience Tel: 00 94 31 5300 Africa Regional Centre Fax: 00 94 31 7195 PO Box 633, Village Market Nairobi Coconut Research Station Kenya Tamil Nadu Agricultural University (TNAU) Tel: 00 254 2 521450 Coimbatore Fax: 00 254 2 522150 Tamil Nadu India CABI Bioscience Tel: 00 91 422 440045/441238 PO Box 8 Rawalpindi Coffee Research Foundation (CRF) Pakistan PO Box 4 Tel: 00 92 51 423210 Ruiru Fax: 00 92 51 451147 Kenya Tel: 00 254 151 54027/48 CABI Bioscience, Mardan, Pakistan Fax: 00 254 151 54133 c/o CABI Bioscience, Rawalpindi, Pakistan Council for Scientific and Industrial Research (CSIR) CABI Bioscience PO Box 32 Opposite I-A Accra Data Gunj Ghana Bakhsh Road Tel: 00 233 21 777651-4 PO Box 8 Fax: 00 233 21 777655 Satellite Town Pakistan Department of Crop Production and Forestry Tel: 00 92 51 929 0332 Fax: 00 92 51 451 147 Ministry of Agriculture E-mail: [email protected], [email protected] Private Bag 0033 Gaborone CATIE (Tropical Agricultural Center for Research and Botswana Higher Education) Tel: 00 267 720968 7170 Turrialba Fax: 00 267 328965 Costa Rica Tel: 00 506 56643 Directorate of Environmental Affairs Fax: 00 506 56006 Ministry of Environment and Tourism Windhoek Central Cotton Research Institute (CCRI) Namibia Old Shujabad Road Tel: 00 264 61 249015, Multan Fax: 00 264 61 240339. Pakistan Tel: 00 92 61 545361/71 Dodoma District Extension Officer Fax: 00 92 61 543245 c/o Ministry of Agriculture and Cooperatives E-mail: [email protected] Tanzania

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Ebor Research Station Institute for Arable Crops Research (IACR) Sime Darby Plantations Rothamsted PO Box 7202 Harpenden 40706 Shah Alam Herts AL5 2JQ Malaysia UK Tel: 00 44 1582 763133 El Colegio de la Frontera Sur (ECOSUR) Fax: 00 44 1582 760981 Apt Postal 36 30700 Tapachula Institute for Arable Crops Research (IACR) Chiapus Long Ashton Research Station Mexico University of Bristol Long Ashton Entomology Section Bristol BS18 9AF Ayub Agricultural Research Institute Tel: 00 44 1275 392181 Faisalabad Fax: 00 44 1275 394007 30281 Punjab International Centre for Research in Agroforestry (ICRAF) Pakistan Headquarters United Nations Avenue Food Crops Research and Development Institute (FCRDI) PO Box 30677 Maha Illuppallama Nairobi Sri Lanka Kenya Tel: 00 252 2 521450 Forestry Research Institute of Malaysia (FRIM) Fax: 00 252 2 521001 Kepong 52109 Kuala Lumpur ICRAF–Southern Africa Regional Programme, Harare, Malaysia Zimbabwe Tel: 00 60 3 634 2633 c/o ICRAF Headquarters, Nairobi Fax: 00 60 3 636 7753 E-mail: [email protected] ICRAF–Agroforestry Research Project, Msekera Research Station, Chipata, Zambia Hombolo Research Station, Dodoma c/o ICRAF Headquarters, Nairobi c/o Ministry of Agriculture Tanzania ICRAF–Agroforestry Research Project, Shinyanga, Tanzania Horticultural Research Institute (HRI) c/o ICRAF Headquarters, Nairobi Wellesbourne Warwickshire CV35 9EF Indonesian Oil Palm Research Institute (IOPRI), Sumatra UK c/o Jl. Brigjen Katamso 51 Tel: 00 44 1789 470382 Medan 20158 Fax: 00 44 1789 470552 Indonesia

Horticulture Research International (HRI) International Crops Research Institute for the Semi-Arid East Malling Tropics (ICRISAT) Headquarters Near West Malling Patancheru 502 324 Kent ME19 6BJ Andhra Pradesh Tel: 00 44 1732 843833 India Fax: 00 44 1732 849067 Tel : 0091 40 3296161 Fax : 0091 40 3241239 Horti-Tengeru E-mail: [email protected] Ignas swai Arusha, International Crops Research Institute for the Semi-Arid Tanzania. Tropics (ICRISAT) Tel: 00 255 57 4232 Chitedze Agricultural Research Station E-mail: [email protected] PO Box 1096 Lilongwe Imperial College of Science, Technology and Medicine Malawi Exhibition Road Tel: 00 265 707297 London SW7 2BX Fax: 00 265 707298 UK Telex: 44466 UNDP MI Tel: 00 44 20 7589 5111 E-mail: [email protected]

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International Institute of Tropical Agriculture (IITA) Kwame Nkrumah University of Science and Technology Headquarters Kumasi PMB 5320 Ashanti Ibadan Ghana Oyo State Tel: 00 233 51 60334 Nigeria Telefax: 2555 UST GH Tel: 00 234 2 241 2626 Fax: 00 234 2 241 2221 Malawi Fisheries Department E-mail: [email protected] PO Box 593 Website: www.cgiar.org.iita Lilongwe Malawi International Institute of Tropical Agriculture (IITA) BP 08-0932 Ministry of Agriculture, Livestock Development and Cotonou Marketing Republic of Benin PO Box 30028 Nairobi International Institute of Tropical Agriculture, Cameroon Kenya c/o IITA, Nigeria Ministry of Agriculture and Cooperatives International Rice Research Institute (IRRI), Los Baños PO Box 2066 c/o IRRI, Manila Dar es Salaam PO Box 933 Tanzania 1099 Manila Tel: 00 255 051 865323 Philippines Fax: 00 255 051 865312 Tel: 00 63 2 818 1926 Fax: 00 63 2 891 1292 Natural Resources Institute (NRI) University of Greenwich Kenya Agricultural Research Institute (KARI) Central Avenue National Agricultural Research Laboratories (NARL) Chatham Maritime, Chatham Waiyaki Way Kent ME4 4TB PO Box 14733 UK Nairobi Tel: 00 44 1634 883422 Kenya Fax: 00 44 1634 880077/88 Tel: 00 254 2 444249 Fax: 00 254 2 444144 Namulonge Agricultural and Animal Production Research Institute (NAARI) KARI Regional Research Centre, Kisii PO Box 7084 c/o KARI Headquarters Kampala Nairobi Uganda Tel/Fax: 00 256 41 341554 Kawanda Agricultural Research Institute PO Box 7065 Ornithological Research Unit Kampala Department of National Parks and Wildlife Management Uganda Bulawayo Tel: 00 256 41 567708 Zimbabwe Fax: 00 256 41 567649 Palm Oil Research Institute in Malaysia (PORIM) Kerala Forest Research Institute (KFRI) PO Box 10620 Peechi 680 653 50720 Kuala Lumpur Thrissur District Malaysia Kerala India Philippine Rice Research Institute Tel: 00 254 2 444249 Munoz Fax: 00 254 2 444144 Maligaya Nueva Ecija Kizambani Research Station, Ukiriguru, Mwanza Philippines c/o Ministry of Agriculture and Cooperatives Tel: 00 63 4456 112/258/277 Tanzania Fax: 00 63 4456 113

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Plant Protection Division Silsoe Research Institute Ministry of Agriculture, Livestock and Natural Resources Wrest Park (MALNR), Zanzibar Silsoe c/o Ministry of Agriculture and Cooperatives Bedford MK45 4HS Tanzania UK Tel: 00 44 1525 860000 Plant Protection Research Institute (PPRI) Fax: 00 44 1525 860156 PO Box CY 550 Causeway Sri Vidya Trust Harare Devipuram (via N. Doddi) Zimbabwe Anakapalle Andhra Pradesh Punjab Agricultural University (PAU) 531 002 Ludhiana 141004 India Punjab India Sugarcane Research Institute, Kibaha Tel: 00 91 161 401960 c/o Ministry of Agriculture, Livestock and Natural Fax: 00 91 161 400945 Resources Tanzania Quelea Research Unit Plant Protection Research Institute (PPRI) Tamil Nadu Agricultural University (TNAU) PO Box 3474 Coimbatore Parklands 2121 Tamil Nadu Pretoria India South Africa Tel: 00 91 422 440045/441238

Sokoine University of Agriculture Uganda National Banana Research Programme (UNBRP) PO Box 3021 Kawanda Agricultural Research Institute Morogoro PO Box 7065 Tanzania Kampala Tel: 00 255 56 4978 Uganda Fax: 00 255 56 4088 Tel: 00 256 41 567158 Fax: 00 256 41 566381 Sarada Valley Development E-mail: [email protected] Indian Council of Agricultural Research (ICAR) Directorate of Rice Research (DRR) University of Agriculture Rajendranagar Makurdi Hyderabad 500 030 PMB 2373 Andhra Pradesh Nigeria India Tel: 00 234 44 33204 Tel: 00 91 40 245120 Fax: 00 91 40 245308 University of Agricultural Sciences Bangalore 560 065 Selian Agricultural Research Institute (SARI) Karnataka PO Box 6024 India Arusha Tel: 00 91 80 3332442/ 3330153 Tanzania Tel: 00 255 57 250510/1/2 University of Bristol E-mail: [email protected] 30 Bristol Avon BS1 2EE Serere Agricultural and Animal Research Institute (SAARI) UK PO Soroti Tel: 00 44 117 928 9000 Uganda Tel: 00 256 45 61192 Fax: 00 256 45 61444 E-mail: [email protected]

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University of Edinburgh United Plantations Berhad (Institute of Cell, Animal and Population Biology) Jenderata Estate Ashworth Laboratories 3600 Teluk Intan The King’s Buildings Perak Edinburgh EH9 3JT Malaysia UK Tel: 00 44 131 650 1000 Universiti Putra Malaysia Fax: 00 44 131 650 6564 43400 UPM Serdang, Selangor Darul Ehsan University of Ghana Malaysia PO Box 44 Tel: 00 6 3 9434419 Legon Fax: 00 6 3 9434419 Accra E-mail: [email protected] Ghana WARDA (West Africa Rice Development Association) University of Nairobi 01 BP 2551 PO Box 30197 Bouaké Nairobi Côte d’Ivoire Kenya World Vision International University of Reading PO Box 157 Whiteknights Quelimane PO Box 217 Mozambique Reading Tel: 00 258 421 3807 Berkshire RG6 6AH Fax: 00 258 421 2136 UK Tel: 00 44 118 987 5123 ZIP Research (now African Farmers for Research and Fax: 00 44 118 931 4404 Training - AfFOResT) E-mail: [email protected] PO Box CY301 Website: www.reading.ac.uk Causeway Harare University of Sheffield Zimbabwe The Firth Court Tel: 00 263 4 336301 Western Bank Sheffield West Yorkshire S10 2TN UK Tel: 00 44 114 222 2000

125 Perspectives on Pests 7/4/01 6:14 PM Page 1

selected CPP/IPMSA publications,CD-ROM 1989-2001Includes of

ESETVSO ET 1996–2000 PERSPECTIVES ON PESTS PERSPECTIVES ON PESTS

This report highlights achievements from research carried out between 1996 and 2000 under the Crop Protection Programme (CPP) of the UK’s Department for International Development Achievements of research under the UK (DFID). The programme focuses on generating and promoting knowledge to improve pest, disease and weed management in cropping systems that are relevant to poor people. The CPP Department for International Development’s and its predecessor, the Integrated Pest Management Strategy Area (IPMSA), have funded over 350 research and dissemination projects since the inception of the IPMSA in 1989. Crop Protection Programme, 1996–2000

The work of the programme is guided by DFID’s Renewable Natural Resources Research Strategy, which has as its objective the generation and application of new knowledge which will benefit the livelihoods of poor people. The programme is managed on behalf of DFID by Natural Resources International Limited, a specialist research and development management company.

Perspectives on Pests presents the work and findings of CPP-funded research in sub-Saharan Africa, South Asia and South America. The report begins with an overview of how crop protection research relates to poverty alleviation, sustainable livelihoods and environmental issues. Summaries of selected research projects outline the background to each project, the key findings, and current and potential uptake of the technologies developed. A full listing of all CPP projects undertaken between 1996 and 2000 is given, as well as contact information for the main organisations participating in the research. Also provided (on CD-ROM) is a bibliography Natural Resources International Limited of publications generated by the programme since 1989.

Perspectives on Pests is intended to be of use to technical specialists and non-specialists alike, and should be of interest to researchers, research managers and policy-makers in the field of crop protection.

CROP PROTECTION PROGRAMME

This publication is an output from the DFID Crop Protection Programme for the benefit of developing countries. The views expressed are not necessarily those of DFID.