Generation of residue, efficacy and crop safety data for pesticide minor-use permit applications – Captan fungicide
Horticulture Australia and the Australian Vegetable industry are seeking a permit for captan (various formulations) for the control of grey mould (Botrytis cinerea) in cucumber, capsicums, chilli peppers and leafy lettuce crops in protected cropping situations for use in all states. Grey mould is a common fungal disease in capsicum, cucumber, chilli and leafy lettuce crops grown in protected cropping systems. It can affect plants at most stages of production. Affected fruits and other plant parts become water logged and soft and are quickly covered by a thick grey mould. Botrytis can also cause secondary rots on vegetables in storage or transit to market. High humidity conditions within greenhouse structures contribute to the spread of the disease. There are limited products available for hydroponic growers to use for controlling this disease in their growing systems. The main aim of this permit application is to ensure that hydroponic growers of cucumber, capsicums, chilli peppers and leafy lettuce have an effective tool for controlling grey mould in their crops. This study was conducted to determine the residue levels of captan fungicide in leafy lettuce, cucumber, capsicum and chilli following three foliar applications of a product containing captan 900 g ai/kg as the only active ingredient. Applications were applied at 7 day intervals. Twelve trials were conducted in major growing regions in Queensland and Northern New South Wales. Trials were conducted in the field and under protected cropping situations. Specimens were collected at 0, 3, 7 and 10 days after the third and final application. Collected specimens were then analysed to determine the level of captan residue. The analytical study was conducted in two stages, with specimen homogenisation carried out upon specimen receipt; and extraction, purification and instrumental analysis at the analytical facility of AgriSolutions Australia Pty Ltd. A new permit application has been supplied to Growcom for submission to the APVMA along with a copy of the study report on the field and analytical components of the project which will be used as part of a minor-use permit application to the APVMA. The outcome of this project is residue data and analysis to support a minor use permit application to be lodged with the APVMA. If approved, an effective fungicide will be available for use by protected cropping vegetable grower for the control of Grey Mould.