A decade of integrated pest management (IPM) in brassica vegetable crops Ð the role of farmer participation in its development in Southern Queensland, Australia

S. Heisswolf1, B.J. Houlding2, and P.L. Deuter1 1Department of Primary Industries Queensland, PO Box 245, Gatton QLD 4343, Australia 2Cooperative Research Centre for Tropical Pest Management, PO Box 245, Gatton QLD 4343, Australia.

Abstract In the mid 1980’s, management of Diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), in brassica vegetable crops was at crisis level with spray failures prevalent across the industry in Southern Queensland. Insecticide resistance to synthetic pyrethroids was identified in 1986, and resistance monitoring between 1988 and 1992 showed that problems also existed with carbamates, organochlorines and some organophosphates. A resistance management strategy was implemented in 1988 with the widespread support of industry. This strategy resulted in a summer production break, improved spray application, an understanding of resistance and the need for insecticide rotation on farm. Development work with Bacillus thuringiensis (Bt), crop scouting, shelterbelts and natural enemies of pests expanded the emerging integrated pest management (IPM) system over the next few years. A joint project between Australia and China to improve IPM in brassica vegetable crops commenced in 1995. The aim of the project is twofold; to expand the tools base available to growers by investigating critical areas within the IPM system (pest forecasting, monitoring, action thresholds, spray application, natural enemies, decision aids); and to continue industry participation in the development of practical IPM systems, using action learning and adult education principles. This paper gives an overview of the research, development and extension work with pest management in brassica vegetable crops in Southern Queensland over the last ten years. In particular it discusses the evolution of Integrated Pest Management (IPM) systems in the region and examines the changing role of farmers in developing these systems for managing and avoiding insecticide resistance in P. xylostella.

Key words: IPM, implementation, brassicas, Australia

Introduction (Lepidoptera: Plutellidae), cabbage white butterfly, The brassica industry of Queensland is worth Aus$24 Pieris rapae (Linnaeus) (Lepidoptera: Pieridae), centre million, which is 19% of the Australian industry. grub, Hellula hydralis (Guenee) (Lepidoptera: Eighty percent of the crop is sold on the domestic Pyralidae), cabbage cluster caterpillar, Crocidolomia market, with the remainder exported to Hong Kong, pavonana (Fabricius) (Lepidoptera: Pyralidae), cluster Singapore and Japan (Australian Bureau of Statistics, caterpillar, Spodoptera litura (F.) (Lepidoptera: 1993). The major brassica vegetable crops grown are Noctuidae), and Helicoverpa spp. (Lepidoptera: cabbages, cauliflower and broccoli with Brussels Noctuidae). Aphids can be pests of seedlings or a sprouts, Chinese cabbage and other Chinese leafy contaminant of produce but generally do not cause vegetables being minor crops. A total of 2 300 hectares severe damage to the crop. of brassicas are produced per annum (Australian P. xylostella is the most difficult pest to manage, Bureau of Statistics, 1993). The average property size largely due to its resistance to a range of commonly is 50 hectares. used insecticides, however C. binotalis and H. hydralis The major production region is the Lockyer have the potential to cause more significant damage if Valley, a river system about 100 km inland. Planting not controlled in early season crops. of crops begins in February (late summer) and weekly Traditionally, brassica vegetables were grown year or fortnightly plantings are made until early spring round in the Lockyer Valley and growers schedule (September) with last harvests in late spring (end of sprayed for pests once per week throughout the October). Summer production occurs at higher production season. Since the mid 1980s when P. altitudes further inland in the Granite Belt region. xylostella resistance to pyrethroids was first reported Limited areas of brassica vegetable crops are also (Wilcox, 1986) and resistance in carbamate, grown near the coast, north and south of Brisbane. organophosphate and organochlorine insecticides was A suite of lepidopterous pests attack brassica identified (Hargreaves, 1994, pers comm.), vegetable crops in Queensland. These include the Queensland growers have gradually included pest diamondback moth, Plutella xylostella (L.) monitoring, Bacillus thuringiensis var. kurstaki (Btk),

228 Proceedings: The Management of Diamondback Moth and Other Crucifer Pests a production break, rotation of insecticides and months of the year. The strategy was aimed at all improved spray application in their pest management primary producers in the region (Deuter, 1989). regime. A logo for the strategy was developed and Several factors facilitated this change in pest pesticide resellers were asked to colour-code management practice. Spray failures and crop plough- insecticide containers according to insecticide groups. outs were the trigger for developing and implementing A series of articles was published in the local media alternative methods of pest management as scheduled and extensive publicity about the strategy was applications of insecticides were no longer reliable. maintained for two years after its launch. (Deuter and Up until the late 1980’s, growers were largely Twine, 1988; Deuter, 1989). Growers meetings and interested in research focussed on efficacy of insect identification workshops were held to encourage insecticides, however the control crisis mobilised grower adoption of the strategy (Deuter, 1989). industry and government to search for alternative Operating costs for activities were shared by industry approaches to DBM management and all sectors of and organisations involved in promoting the strategy. the industry participated in implementation. The A survey to determine the level of adoption of opportunity was also taken to develop an alternative the strategy was conducted in 1990. Data was gathered approach to research and extension which did not rely using a questionnaire to interview four groups of on the transfer of technology extension model people; broccoli growers, local pesticide resellers, crop (Chambers and Jiggins, 1987). Continued participation consultants and company field officers (Heisswolf, by all sectors of the industry was seen as a key to 1992). successful implementation of research and development results within the farming system and Reducing reliance on conventional pesticides (1990 extension activities were structured using the concepts to 1995) of action learning (Kolb, 1984; McGill and Beaty, The second project aimed to further reduce reliance 1992; Heisswolf, 1995) and adult education on conventional insecticides by developing alternative (Brookfield, 1986; Tennant, 1991). pest management techniques within an IPM The progression of IPM in brassicas in framework and focussing on the cropping systems Queensland can be divided into three discrete but level rather than the individual pest level. Research overlapping projects. and extension activities involved a series of ¥ 1988 to 1990 Ð Development and implementation demonstration plantings at a local research station and of an insecticide resistance management strategy on commercial farms in the Lockyer Valley. This work based on rotation of insecticide groups by was funded by the vegetable industry, state and federal exclusion. Techniques which developed from this governments. Unsprayed plantings of brassica strategy included a production break, pest vegetables were also established to collect data on the monitoring and improved spray application. abundance of pests and beneficials over three seasons ¥ 1990 to 1995 Ð A project designed to reduce and insecticide resistance levels in P. xylostella reliance on conventional insecticides by focussing continued to be monitored. on the cropping systems level of pest management Thirty-six demonstration plantings were and introducing Btk into the developing IPM established between 1990 and 1993 at the local system. research station and over 50 commercial brassica ¥ 1995 to 1998 Ð This project builds on the existing plantings were assessed on farm from 1992 to 1995. IPM system and includes research, development Data collected included pest activity, yields and quality and extension components. of harvested product. Results were used to recommend improvements to the farmer’s pest management regime Materials and Methods with particular emphasis on spray decision making. Resistance Management Strategy (1988 to 1990) Apart from the intensive work with grower The initial response to the crisis caused by insecticide cooperators, farm walks and field days were used to resistance in P. xylostella was the development of a demonstrate results in commercial crops. Numerous resistance management strategy based on rotation of articles were also published in local media and industry insecticide groups. It was used in three valleys in South publications describing project progress and East Queensland, hence its name, the 3 Valley Strategy. recommendations from this work. The strategy was launched in August 1988. It was developed by a small group of people from various Improving IPM in brassicas (1995Ð1998) organisations and the concept for the strategy received The third project aims to build on the existing IPM widespread support from all sections of the industry system. It includes a research and development including local growers, agrichemical companies, component which focuses on problem areas such as pesticide resellers and crop consultants. Its primary insecticide spray coverage, pest monitoring protocols, objective was to reduce the rate of increase of action thresholds, natural enemies particularly insecticide resistance in P. xylostella and Helicoverpa parasitoids, and development of decision-making tools. sp. by asking growers to voluntarily exclude a The project also includes an implementation particular insecticide group from use in particular component with emphasis on extension methodologies useful to IPM implementation.

Pesticide resistance mechanisms and resistance management strategies 229 The project commenced in July 1995. It is a aware of predators and parasites in their crops. Since collaborative research and development project 1990, the use of monitoring and Btk by Southern between Queensland and China funded by the Queensland brassica vegetable growers has increased Australian Centre for International Agricultural substantially (Deuter et al., 1992) indicating that Research (ACIAR). Objectives for the Queensland demonstration plantings, field days, on farm trial work, component of the project evolved from a problem availability of decision aids and continued publicity definition workshop (Deuter and White, 1995) held about IPM have been successful tools for by the Cooperative Research Centre for Tropical Pest implementing new pest management practices. Management (CTPM) at which farmers, consultants, By 1995, the focus had changed from scheduled scientists, extension staff, industry, chemical company spraying of conventional insecticides to a more staff were represented. complex system which combined a range of pest A team approach was adopted with team members management techniques. These include: holding skills in entomology, taxonomy, pesticide ¥ cultural control methods (production breaks, crop application methodology, extension and IPM hygiene), development. The broad skills base of the team should ¥ crop monitoring to improve decision making, contribute towards a systems approach to IPM in ¥ strategic applications of insecticides (biological brassica vegetables. The process also encourages and conventional), considerable grower contribution to the project with ¥ protection of local natural enemies by using pest their views playing a significant role in determining specific insecticides whenever possible the direction of research. Industry participation is encouraged through on farm trial work, collaborative Improving IPM in brassicas planning and conduct of trial work and field days using The successful implementation of IPM techniques adult education and action learning principles. These discussed above has led to a receptive environment principles have also been used to structure six monthly for integrating research results from the ACIAR project review meetings of the project team. into the existing pest management system. Close interaction with farmer cooperators will continue to Results be critical in refining IPM systems at the farm level The Resistance Management Strategy and for highlighting specific research needs and An evaluation of the 3-V strategy two years after implementation constraints. Grower cooperators are development revealed that within the first year, 70% more proactive in their approach to pest management of broccoli growers had used the strategy; but 12 to and are actively involved in assisting the ACIAR team 18 months later this implementation rate had dropped realise project milestones. to 35%. Key factors for achieving a relatively high rate of adoption were extensive publicity and industry Discussion support. Factors leading to the decline of the strategy Much has been written in the past few years about the included a perceived inflexibility of the strategy, and transfer of technology (TOT) model of extension and a lack of continuing publicity. It is important to point its limitations in implementing complex systems or out that of the 35% of farmers who continued using concepts such as IPM. Tait (1983), Chambers and the strategy, most had adapted the strategy to suit their Jiggins (1988), Vanclay and Lawrence (1994) state that particular farming enterprise (Heisswolf, 1992). the traditional TOT model relies on a top down The evaluation also showed that by 1990, farmer approach in which scientists develop methods and and industry awareness of responsible insecticide use technologies which are disseminated by extension and pest management techniques such as a break in agencies for adoption by farmers; and that this production over summer, improved spray application, extension model is inappropriate in many instances. pest monitoring and strategic applications of Btk had Petty (1994) argues that participative methods of increased (Deuter et al., 1992). enquiry are required to develop sustainable farming practices so that local people are able to develop Reducing reliance on conventional pesticides farming systems which suit their particular needs and Monitoring of resistance of a range of insecticides from conditions. A respect for knowledge, experience and 1988 to 1992 showed that P. xylostella was relatively expectations of farmers is considered critical for insensitive to methomyl, carbaryl and endosulfan and participatory research and extension (Chin et al., 1992; as a result the organochlorine and carbamate groups McDonald and Glynn, 1994). of insecticides were no longer recommended. An Traditionally the main barriers to adoption were apparent stabilisation of resistance levels occurred in considered to be farmer attitudes and lack of permethrin after the introduction of a summer break knowledge rather than logical decision making by in 1990 (Heisswolf and Hargreaves, 1994). farmers on the usefulness of a particular technology Demonstration plantings showed that brassica (Vanclay and Lawrence, 1994) but it appears that that vegetable production with significantly reduced input the reasons for non adoption are more complex. of conventional insecticides was possible using pest A recent survey of crop consultants in the United monitoring and Btk. This system minimised hazardous States indicates that lack of viable nonchemical tactics, effects on natural enemies and farmers became more potentially lower yields and quality, higher costs, need

230 Proceedings: The Management of Diamondback Moth and Other Crucifer Pests for higher management skills and lack of information farm trial work demonstrating the Btk/monitoring are the major limitations of IPM adoption (Ferguson system were key elements in achieving adoption of et al., 1996). Tait (1983) suggests that poor marketing these two techniques. With reduced input of of research products is a contributing factor in non conventional insecticides, natural enemies were seen adoption of IPM and survey work by Wearing (1988) more frequently in crops and farmers became more showed that an IPM program must be marketed and receptive to methods which would help protect natural adapted to suit local conditions in an effort to compete enemies and further decrease insecticide use. with pesticides. The participatory problem specification workshop Lack of a crisis with existing pest management (Deuter and White, 1995) in 1995 assisted in the techniques is also listed as a major obstacle to IPM development of the ACIAR project and utilised farmer implementation by Wearing (1988) and Vanclay and and industry knowledge and experience. Farmer Lawrence (1994) outline several additional factors participation will continue through the use of adult which lead to resistance or reluctance to change education and action learning to plan and conduct on including conflicting information, loss of flexibility, farm trial work and field days. This will ensure that a complexity and/or incompatibility with other aspects two way flow of information and ideas between the of farm management and personal objectives. project team and industry occurs throughout the life Over the past decade, our approach has been to of the project. actively encourage industry participation in combating The future holds many challenges for IPM in the insecticide resistance problem. The process of brassica vegetables in Southern Queensland. Research developing IPM systems and appropriate extension and extension efforts are seen as one source of processes has been evolutionary and highlight the information for improving IPM systems and importance of the issues discussed above. participatory processes will enable the project team The development of insecticide resistance in to tap into farmer and industry experience and so DBM and resultant spray failures and crop plough- remain responsive to changes in farmer needs. outs in the late 1980’s provided the necessary crisis Participatory processes ensure ownership of problems and accelerated the search for alternatives to and opportunities and provides a mechanism for insecticides. Resistance management became a priority contributing towards solutions. not only for government but industry and farmers who were unable to rely on their usual pest management Acknowledgments technique; scheduled applications of insecticides. This, A key to the success of IPM implementation has been combined with industry and farmer involvement in the willingness of growers to contribute their time and developing the strategy provided a receptive expertise in the planning and conduct of projects. environment for implementation. Financial support from the Department of Primary The review of the strategy in 1990 highlighted Industries Queensland, the Queensland Fruit and the importance of marketing. Widespread support of Vegetable Growers, the Horticultural Research and the strategy combined with an aggressive publicity Development Corporation, the Australian Centre for campaign placed additional pressure on farmers to International Agricultural Research and the consider the strategy as an appropriate part of their Cooperative Research Centre of Tropical Pest pest management system. As publicity and industry Management has also been critical to the success of support for the strategy decreased, farmer usage also IPM development in the Southern Queensland brassica decreased, with lack of flexibility given as a major vegetable industry. factor in discontinuing use of the strategy (Heisswolf, 1992). References By this time, additional techniques which evolved Australian bureau of statistics (1993) Agricultural Industries from the strategy were being utilised, including a Financial Statistics, Australia 1992Ð93, cat. no. 7507.0, summer production break, improved spray application Canberra, Australia. and pest monitoring. Industry and farmers had adapted Brookfield, S. D. (1986). Understanding and Facilitating Adult Learning. Jossey-Bass Publishers, San Francisco, the strategy to fit their farming systems. IPM U.S.A. technology is not static but must be modified and Chambers, R. and Jiggins, J. (1987). Agricultural research improved as new management tools become available for resource-poor farmers Part I: transfer-of-technology (Chin et al., 1992). and farming systems research. Agricultural The demonstration plantings and on farm trial Administration and Extension 27: 35Ð52. work from 1990 to 1995 promoted the strategic use of Chin, H.; Othman, Y., Loke, W. H. and Rahman, S. A. (1992). Btk and pest monitoring under commercial conditions. National integrated pest management in Malaysia. In: From a farm management point of view, Btk use is Integrated Pest Management in the Asia-Pacific Region not radically different from conventional insecticides (ed. P.A.C. Ooi et al.) pp. 255Ð266. Oxon: CAB International and Asian Development Bank. Ð both are applied through spray equipment Ð although Deuter, P. L. (1989). The development of an insecticide Btk requires higher managerial skills to achieve resistance strategy for the Lockyer Valley. Acta comparable results. Btk was in a good position to Horticulturae 247: 267Ð272 compete with conventional insecticides. A concerted marketing effort by Btk suppliers and participatory on

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