Improving lettuce insect pest management - NSW and QLD
Dr Sandra McDougall
NSW Department of Primary
Industries
Project Number: VG01028
VG01028
This report is published by Horticulture Australia Ltd to pass on information concerning horticultural research and development undertaken for the vegetable industry.
The research contained in this report was funded by Horticulture Australia Ltd with the financial support of the vegetable industry, Syngenta, Convenience Foods Pty Ltd, South Pacific Seeds, Organic Crop Protectants Pty Ltd and the NSW Department of Primary Industries.
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© Copyright 2006
FINAL REPORT
VG01028
Improving lettuce pest management –
NSW and SE Queensland
30 November 2005
Sandra McDougall et al.
NSW Department of Primary Industries
ISBN 0 7347 1691 5
- Project No:
- VG 01028
Principal Investigator: Contact Details:
Dr Sandra McDougall National Vegetable Industry Centre NSW DPI PMB, Yanco NSW 2703 (02) 6951 2728 (02) 6951 2692 fax 042 740 1466 mob
Project Team:
NSW DPI: QDPI:
Sandra McDougall, Andrew Creek, and Tony Napier, John Duff
Report Completed:
October 2005
Statement of purpose: This report is a summary of the research and extension work conducted by the project team on lettuce pest management.
Funding:
The researchers acknowledge the financial support for this project from NSW DPI, QDPI, Horticulture Australia, AUSVEG, South Pacific Seeds and Convenience Foods. Financial support for the 2nd & 3rd Australian Lettuce Industry Conferences, which were organized as part of this project also came from: Abbe Corrugated, Bejo Seeds, Boomaroo Nurseries, City of Wyndam, Dupont, Freshcuts, GSF, Henderson Seed Group, Landpower, Melbourne Markets, New Holland, Perfection Fresh, Rijk Zwaan, Syngenta Seeds, TotalPak Solutions, Tripax Engineering, Vegco, Withcott Seedlings and Yates (Enza Zaden).
Disclaimer:
Any recommendations contained in this publication do not necessarily represent current HAL Limited policy. No person should act on the basis of the contents of this publication, whether as to matters of fact or opinion or other content, without first obtaining specific, independent professional advice in respect of the matters set out in this publication.
VG 01028: Improving lettuce pest management in NSW and SE QLD
MEDIA SUMMARY............................................................................................................................................... 1 TECHNICAL SUMMARY..................................................................................................................................... 2 INTRODUCTION................................................................................................................................................... 3
LETTUCE INDUSTRY .............................................................................................................................................. 3 INTEGRATED PEST MANAGEMENT......................................................................................................................... 3 PROJECT DIRECTION .............................................................................................................................................. 3 EFFICACY TRIALS .................................................................................................................................................. 4 TRIAL PRODUCTS................................................................................................................................................... 7
FIELD TRIAL REPORTS ................................................................................................................................... 11
SAP-SUCKING INSECTS INSECTICIDE EFFICACY TRIAL, SPRING 2002 (LEETON RS, NSW) ................................... 12 SAP-SUCKING INSECTS INSECTICIDE EFFICACY TRIAL, AUTUMN 2003 (GATTON, QLD)...................................... 16 APHID SOIL DRENCH EFFICACY TRIAL, SPRING 2003 (YANCO, NSW).................................................................. 23 APHID INSECTICIDE EFFICACY TRIAL, SPRING 2003 (YANCO, NSW)................................................................... 29 SAP-SUCKING INSECTS INSECTICIDE EFFICACY TRIAL, AUTUMN 2004 (GATTON, QLD)...................................... 35 APHID SOIL DRENCH EFFICACY TRIAL, SPRING 2004 (HAY, NSW)...................................................................... 42 HELIOTHIS INSECTICIDE EFFICACY TRIAL, AUTUMN 2002 (GATTON, QLD) ........................................................ 49 HELIOTHIS INSECTICIDE EFFICACY TRIAL, AUTUMN 2003 (HAY, NSW).............................................................. 54 HELIOTHIS INSECTICIDE EFFICACY TRIAL, SPRING 2003 (YANCO, NSW)............................................................ 59 NPV SPRINKLER EFFICACY TRIAL SEPTEMBER 2004 (YANCO, NSW) ................................................................. 64 HELIOTHIS NPV SPRAY EFFICACY TRIAL, SPRING 2004 (YANCO, NSW)............................................................. 72
POT TRIAL REPORTS ....................................................................................................................................... 80
PARTICLE FILM EFFICACY TRIAL, WINTER 2002 (YANCO, NSW) ........................................................................ 81 APHID INSECTICIDE EFFICACY TRIAL, SPRING 2002............................................................................................. 83 APHID SEEDLING DRENCH EFFICACY TRIAL, WINTER 2004 (YANCO, NSW)........................................................ 85 APHID SOIL & CELL DRENCH EFFICACY TRIAL, SPRING 2004 (YANCO, NSW)..................................................... 91 APHID SOIL DRENCH EFFICACY TRIAL, WINTER 2005 (YANCO, NSW) ................................................................ 96 POLYHOUSE HELIOTHIS INSECTICIDE EFFICACY TRIAL I, WINTER 2003 (YANCO, NSW) .................................. 101 POLYHOUSE HELIOTHIS INSECTICIDE EFFICACY TRIAL II, WINTER 2003 (YANCO, NSW) ................................. 105 POLYHOUSE HELIOTHIS INSECTICIDE EFFICACY TRIAL III, WINTER 2003 (YANCO, NSW)................................ 109 POLYHOUSE HELIOTHIS NPV EFFICACY TRIAL, SPRING 2003 (YANCO, NSW).................................................. 113 POLYHOUSE HELIOTHIS EFFICACY TRIAL, SPRING 2003 (YANCO, NSW) ......................................................... 116
BEST MANAGEMENT OPTIONS (BMO) TRIALS...................................................................................... 119
SUMMARY ......................................................................................................................................................... 119 ICEBERG LETTUCE BMO, SPRING 2003 (HAY, NSW)........................................................................................ 121 ICEBERG LETTUCE BMO II, SPRING 2003 (HAY, NSW) .................................................................................... 127 ICEBERG LETTUCE BMO, SPRING 2003 TRIAL 1(COWRA, NSW) ...................................................................... 132 ICEBERG LETTUCE BMO, SPRING 2003 TRIAL 2 (COWRA, NSW) ..................................................................... 138 ICEBERG LETTUCE BMO, SPRING 2003 TRIAL 3 (CANOWINDRA, NSW) ........................................................... 145 LETTUCE BMO COMPARISON, AUTUMN 2004 (HAY, NSW) ............................................................................. 151 LETTUCE BMO CASE STUDY, AUTUMN 2004 (HAY, NSW)............................................................................... 157 SEEDED ICEBERG LETTUCE BMO COMPARISON, WINTER 2004 (HAY, NSW).................................................... 162 TRANSPLANTED LETTUCE BMO COMPARISON, WINTER 2004 (HAY, NSW) ..................................................... 169 BEST MANAGEMENT OPTIONS (BMO) TRIAL, SPRING 2003 (LOCKYER VALLEY, QLD)................................... 176 EFFICACY TRIALS DISCUSSION.......................................................................................................................... 180
OTHER TRIALS................................................................................................................................................. 183
EVALUATING LETTUCE VARIETIES, SPRING 2002 (CENTRAL WEST NSW)....................................................... 183 STICKY TRAP COMPARISON, 2004 (HAY, NSW) ............................................................................................... 187 COMPARISON OF MONITORING METHODS (HAY, NSW).................................................................................... 189
TECHNOLOGY TRANSFER ........................................................................................................................... 194
VG 01028: Improving lettuce pest management in NSW and SE QLD
INTRODUCTION.................................................................................................................................................. 194 ACTIVITIES ........................................................................................................................................................ 194
EVALUATION.................................................................................................................................................... 200
LETTUCE IPM SURVEY SE QLD GROWERS (2005)............................................................................................ 204 LETTUCE IPM SURVEY 2005............................................................................................................................. 212
RECOMMENDATIONS .................................................................................................................................... 220 APPENDICES ..................................................................................................................................................... 221
APPENDIX 1 CONFERENCE PROGRAM................................................................................................................ 222 APPENDIX 2 LETTUCE INDUSTRY RESEARCH & DEVELOPMENT PRIORITIES ..................................................... 224 APPENDIX 3 2ND LETTUCE INDUSTRY CONFERENCE EVALUATION ................................................................... 230 APPENDIX 4 LETTUCE SURVEY OF CURRENT INSECTICIDE PRACTICES ............................................................... 232 APPENDIX 5 LETTUCE GROWER / CONSULTANT SURVEY (2002)....................................................................... 242 APPENDIX 6 3RD LETTUCE INDUSTRY CONFERENCE PROGRAM .......................................................................... 243 APPENDIX 7 3RD LETTUCE INDUSTRY CONFERENCE PRIORITIES ........................................................................ 251 APPENDIX 8 3RD LETTUCE INDUSTRY CONFERENCE PARTICIPANT EVALUATION............................................... 252 APPENDIX 9 3RD LETTUCE INDUSTRY CONFERENCE COMMITTEE EVALUATION................................................. 261 APPENDIX 10 LETTUCE INSECT PEST MANAGEMENT SURVEY FORM ................................................................ 270
VG 01028: Improving lettuce pest management in NSW and SE QLD
Media Summary
New options for managing insect pests in lettuce have been developed and lettuce growers have been assisted in adopting an Integrated Pest Management (IPM) approach. Australian lettuce growers have been assisted in preparing for the arrival of the new pest, Currant Lettuce aphid into their growing areas and those affected by the pest’s arrival have been assisted in it’s management.
The initial 3 year lettuce integrated pest management (IPM) project (VG98048) focused on managing the key pest, heliothis. One species of this pest group, like most key pests, had developed resistance to the insecticides used to control it. Although growers still got some control using the old chemistry, chemical failures had become more common. An IPM approach seeks to utilize both beneficial insects and selective pesticides that have less negative impact on beneficals to assist in managing pests. In an IPM system, crops are monitored and attention is paid to cultural control practices such as removing weeds that host diseases or pests.
This project continued working with growers to improve understanding of an integrated pest management approach, to recognize pests, beneficials, diseases and disorders in their lettuce crops, and learn from each other through lettuce industry conferences. The field identification guide was produced as a reference that growers’ and industry people can continue to refer to.
Following VG98048 heliothis and other caterpillars could effectively be managed by relying on beneficial insects and using new generation insecticides or some biological products. However, towards the end of VG98048 silverleaf whitefly moved into SE Queensland lettuce producing areas causing considerable damage. The currant-lettuce aphid devastated the NZ lettuce industry just after this project began in 2002 and arrived in Tasmania (Mar 2004) 14 months before this project finished. Western flower thrips also moved more into field grown lettuce crops causing considerable damage by spreading tomato spotted wilt virus. These sapsucking insects were the focus of trials for new insecticides throughout this project. Some work also continued to test insecticides for heliothis management. There are some products, particularly some soil or seedling drenches that showed very good control of aphids and leafhoppers. A smaller group reduced whitefly numbers and data was inconclusive or variable on thrips control.
Western flower thrips appears to be a major impediment to adoption of IPM in lettuce in South and Western Australia. The lack of IPM consultants in most lettuce growing areas is also a major impediment to adoption. Like heliothis, these new pests of lettuce: silverleaf whitefly, western flower thrips and currant-lettuce aphid have developed resistance to most chemicals that has been used against them intensively. Therefore developing an integrated approach that relies on more than just a single chemical to manage each pest is as important as ever.
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VG 01028: Improving lettuce pest management in NSW and SE QLD
Technical Summary
A biointensive IPM strategy should be more effective and resilient in the long term in managing pests than reliance on a few regularly applied broad spectrum insecticides. Developing a biointensive IPM strategy for an industry and having an industry adopt a biointensive IPM strategy is a slow and potentially complicated business.
This project screened the efficacy of 23 new products and some novel applications of old chemistry against various sap suckers and/or lepidoptera. A variety of polyhouse pot and field trials were conducted. Some trials were conducted on field stations (Yanco and Gatton) and some were conducted in commercial lettuce growers fields. In trying to tie together the various combinations of new chemistry ‘best management option’ (BMO) trials were conducted. Some BMOs were incorporated into replicated small plot trials, some were as unreplicated commercial-scale trials paired to ‘grower controls’.
For aphid management the neonicotinyl insecticides were effective as as foliar (acetamiprid, clothianidin and thiacloprid), soil or seedling drenches (imidacloprid, thiomethoxam and clothianidin) and/or granular band applications (thiomethoxam). Seedling drenches were quickest to take effect. Soil or seedling drenches and granular band killed aphids for life of crop/trial at recommended rates but for a shorter period at lower rates. Foliar sprays had knockdown and some residue for a week or so.
In trials where leafhoppers were present neonicotinyl insecticides were effective, and also had some reduction on Rutherglen bugs and mirids. Thrips activity was mixed between trials and products. Imidacloprid reduced whitefly numbers, however acetamiprid seemed to promote development of whitefly. Pirimicarb and dimethoate used as soil or seedling drench had good activity although serious phytotoxicity problems were noted at higher rates of dimethoate. Pymetrozine as a foliar spray was slow to show activity, reducing for aphid and leafhopper numbers but not whitefly or western flower thrips. Pyriproxyfen as a foliar showed no western flower thrips activity but reduced whitefly egg production. Of the experimental foliar products DC068 showed aphid and leafhopper activity for 2 weeks, and DC027 showed some thrips but not whitefly activity. MTI446 as a furrow spray not properly tested.
Parrifin oil, SilicaK, Natrasoap, kaolin and azadiractin showed no aphid activity. DC041, S1812, emamectin benzoate and methoxyfenozide were all effective against heliothis, although prodigy is slower to act. Emamectin and S1812 were good at controlling lucerne leafroller (LLR), although the lower rate of S1812 was not as good at getting LLR in lettuce heads. The heliothis virus products Gemstar® and Vivus® did eventually kill virtually all heliothis, however many larvae continued to feed for days and in some cases weeks. BMO trials were variable in methodology and results but tended to give reasonable control. However BMOs proved to be more costly when compared to the ‘grower’ control.
Raising awareness of IPM with growers was facilitated via field days, workshops, the bimonthly newsletter, training of an IPM scout in one region, and two national lettuce industry conferences. Identification of pests, beneficials, diseases and disorders was assisted with the production and distribution to all lettuce growers a field identification guide for lettuce.
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VG 01028: Improving lettuce pest management in NSW and SE QLD
Introduction
Lettuce Industry
The Australian lettuce industry produces between 100,000-150,000 tonnes of lettuce valued around $100 million annually (ABS, Catalogue 7121.0). Average yields are approximately 22.6 tonnes per hectare (AUSVEG 2005). Lettuce is produced in all states with Queensland producing the most (35%) followed by Victoria (28%), NSW (17%), WA (11%), SA (6%) and Tasmania (3%).
Lettuce production can be classified into ‘head’, ‘fancy’, and ‘baby-leaf’ lettuce. It can be grown in fields or hydroponically. It can be sold on the ‘fresh’ market or processed. Data is not readily available for the breakdown of the different lettuce sectors.
Processing of head lettuce involves washing and shredding for fast food or restaurant sectors. Processing of baby-leaf usually involves washing and bagging for the restaurant or retail sectors. Head lettuce sold on the fresh market usually is sold with some wrapper leaves still attached but if bagged the wrapper leaves are removed. Similarly wrapper leaves are removed from head lettuce sold to the processing sector.
Integrated Pest Management
Integrated Pest Management (IPM) is a strategy which seeks to integrate all available knowledge to best manage pests and diseases. Definitions of IPM vary as do IPM strategies for different crops and for similar crops in different regions. Nevertheless, there are many similar elements to all IPM strategies. The debate tends to rage around which tools or elements are the minimum necessary to be called an IPM practitioner, for in reality there is an IPM spectrum. The beginning of the spectrum is debatable and the end is farm planning that minimises pests, maximises beneficials and rarely requires pesticide applications, and when they are needed biological pesticides are preferred.
Developing an IPM system for a crop requires building up the knowledge base of what pests, diseases and beneficials are in the system. Also understanding their interactions and impacts on the crop. It requires getting access to more specific pesticides that are ‘softer’ on beneficial insects, or getting access to varieties that are resistant to pests or diseases. It requires developing crop monitoring techniques or strategies that are time and cost effective and where possible, developing action thresholds or information on when intervention is required.
Project direction
Prior to the first lettuce IPM project VG98048 growers had no access to ‘soft’ chemistry. All but a few growers were spraying on a calendar basis and few could identify their key pests and even fewer knew what other insects or diseases could help manage those pests. In VG98048 emphasis was put on regular monitoring of a range of lettuce crops to understand what pests,
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VG 01028: Improving lettuce pest management in NSW and SE QLD
diseases and beneficials were in the system. Generating efficacy data to assist in registration of new ‘IPM-friendly’ pesticides for the key pest, Heliothis, and to develop greater knowledge in how these pesticides might be best used in lettuce was also a key focus. Workshops and an IPM Information Guide were produced to help growers and consultants learn what pests, beneficials and diseases were found in lettuce crops and what their management options might be. Information was gathered to help better target pesticides to the vulnerable life stages of the pest. Trials were conducted to improve spray application with modified overhead booms, air assist or CDA sprayers. Towards the end of the project other sap-sucking insects were causing problems in the lettuce industry. Silverleaf whitefly had arrived in SE Queensland, growers in the central west of NSW were experiencing trouble with aphid or thrips transmitted viruses and growers in Sydney basin were seeing more problems with thrips. VG01028 was funded to continue the insect pest work and look more broadly than just Heliothis.