Workshop to develop research, development and extension priorities for nematode control in vegetable crops Frank Hay University of Tasmania Project Number: VG05026 VG05026 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. All expressions of opinion are not to be regarded as expressing the opinion of Horticulture Australia Ltd or any authority of the Australian Government. The Company and the Australian Government accept no responsibility for any of the opinions or the accuracy of the information contained in this report and readers should rely upon their own enquiries in making decisions concerning their own interests. ISBN 0 7341 1424 9 Published and distributed by: Horticultural Australia Ltd Level 1 50 Carrington Street Sydney NSW 2000 Telephone: (02) 8295 2300 Fax: (02) 8295 2399 E-Mail: [email protected] © Copyright 2006 Final Report for Horticulture Australia Ltd. Project VG05026 Workshop to develop research, development and extension priorities for nematode control in vegetable crops. October 2006 Dr. Frank Hay Tasmanian Institute of Agricultural Research, University of Tasmania Cradle Coast Campus, P.O. Box 3523, Burnie, Tasmania, Australia 7320. Horticulture Australia Ltd. Project VG05026 Workshop to develop research, development and extension priorities for nematode control in vegetable crops. October 2006 Contact details for project leader: Dr. Frank Hay (Research Leader Vegetable Group), Tasmanian Institute of Agricultural Research, University of Tasmania Cradle Coast Campus, P.O. Box 3523, Burnie, Tasmania, Australia 7320. Purpose of project: This workshop involved a gathering of vegetable nematologists and industry representatives to discuss and formulate future research, development and extension priorities in vegetable nematology. Funding: This project was facilitated by Horticulture Australia Ltd., in partnership with AUSVEG and funded by the National Vegetable Levy with matching funding from the Australian Government. Disclaimer: Any recommendations contained in this publication do not necessarily represent current Horticulture Australia Ltd. policy. No person should act on the basis of the contents of this publications, 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. Table of contents Media summary ..................................................................................... i Technical summary.............................................................................. iii Part 1. Workshop and recommendations 1. Introduction .......................................................................................1 2. The importance of plant parasitic nematodes to vegetable production. ..................................................................2 3. Current status of nematode control in vegetable crops in Australia.......................................................................................5 4. Nematodes of importance to vegetable crops in Australia. ..............6 5. Previous research in vegetable nematology in Australia................11 6. Identification of nematodes .............................................................14 7. Example of successful management of nematodes through a change in the farming system........................................................17 8. Potential strategies for managing nematodes in vegetable production .....................................................................22 9. Options for the management of nematodes in the Australian vegetable industry .........................................................................37 10. Workshop recommendations ........................................................41 11. Conclusions ..................................................................................50 Acknowledgements.............................................................................51 References .........................................................................................52 Appendices .........................................................................................55 Part 2. Literature review: Management of nematodes in vegetable production. 1. Introduction................................................................................. 60 2. The importance of plant-parasitic nematodes to vegetable production .............................................................. 61 3. Nematodes of importance to vegetable production .................... 65 4. Quantifying nematode populations ............................................. 90 5. Modelling nematode population dynamics................................ 118 6. Resistant varieties .................................................................... 120 7. Fallow (bare fallow and break crops)........................................ 122 8. Planting or harvest date............................................................ 143 9. Nematicides.............................................................................. 145 10. Biological control ..................................................................... 158 11. Farming systems suppressive to plant-parasitic nematodes ............................................................................. 164 12. Gaps in knowledge/technology................................................ 169 13. Conclusions............................................................................. 175 References .................................................................................... 176 Final report for Horticulture Australia Ltd. Project VG 05026 Workshop to develop research, development and extension priorities for nematode control in vegetable crops Part 1 – Workshop and recommendations i Media summary Plant-parasitic nematodes have been estimated to cause annual farm gate losses in Australian vegetable crops of $9.0 M in carrot, $3.0 M in lettuce, $12.1 M in potato and $10.6 M in tomato, with significant losses likely in other crops such as brassica. In general the vegetable industry has become reliant upon chemical fumigants and nematicides for nematode control. However, there is continual pressure on availability of these chemicals due to environmental and health concerns and due to the development of soils with capacity for enhanced biodegradation leading to poor efficacy. For example, Bayer (USA) has announced the voluntary withdrawal from production of one of the most commonly used nematicides in the vegetable industry (fenamiphos) in 2007. It is therefore timely to reassess nematode management strategies in vegetable crops. A workshop involving 21 nematologists, agronomists and industry personnel was held on 10-11th July 2006 to discuss and formulate future research, development and extension priorities in vegetable nematology resulting in the following recommendations: 1. Prepare extension material for use by growers and consultants to improve the way nematodes are managed in the vegetable industry. Currently there is no Australian-produced guide to help vegetable growers manage nematode problems. 2. Demonstrate the value of rotation crops for root-knot nematode (Meloidogyne spp.) control in various vegetable-growing regions of Australia. Root knot nematode is the major nematode pest of vegetable crops. Cover crops such as forage sorghum have proven effective in some vegetable growing regions due to its resistance to the common species of root-knot nematode. There is a need to demonstrate its use in other regions and identify alternative cover crop species where it is not suitable. 3. Establish regionally-based, multi-disciplinary research groups to develop sustainable farming systems and soil management practices for local vegetable industries and ensure that there is adequate ii nematological input into each research group. Farming systems which enhance biological activity in soil through practices such as minimum tillage, crop rotation, green manuring, organic amendments and organic mulches have been demonstrated to result in soils which are suppressive to nematodes and other soil borne pathogens. The challenge is to further develop and increase the adoption of such systems. 4. Enhance the adoption of DNA technologies for identifying and quantifying nematodes. DNA technologies offer considerable advantages over conventional methods for identifying and quantifying nematodes. Commercial tests are available for nematodes of importance to the cereal industry. Much of the ground-work has been completed for nematodes of interest to the vegetable industry, however there is a need to further develop and commercialise such tests. 5. Increase the number of nematologists working in the vegetable industry and ensure that programs are in place to provide the industry with nematological expertise in the long term. Investment in vegetable nematology has been minimal over the last 15 years. Given the size of the industry and the importance of nematodes there is a need to increase R,D&E effort. In addition, nematology training has been depleted in recent years and several nematologists are due for retirement which will lead to a serious skill shortage. 6. Support basic research that has the potential to lead to