An EAMU has been issued for the use of Serenade ASO (Bacillus subtilisstrain QST 713) as a post-harvest drench treatment for the control of Botrytis cinereain outdoor cabbage before storage.
The loss of Rovral WG (iprodione) in June was a major blow for cabbage growers as it had significantly reduced wastage and trimming losses due to Botrytisin long term stored cabbage. Following on from AHDB funded work by Dr Richard Colgan at the Natural Resources Institute in project FV430, further work was initiated at the Allium & brassica Centre (ABC) in 2017/18 under the SCEPTREplus programme, to find alternatives.
One of the parameters measured was loss of marketable heads due to Botrytis. The ABC’s Andy Richardson says the research showed loss of marketable yield – 40% in the untreated water control – reduced by 10-15 % with Serenade ASO treatment.
“This is a big reduction in wastage and shows that Serenade can do the same job as previous standard Rovral WG. In addition there are significant labour savings to be had from not trimming 10-15 % of heads only to find they’re unmarketable and have to be disposed of.”
The EAMU specifies that the treatment solution must not exceed 3% i.e. 30 ml of product per litre of spray solution. The maximum application rate is 20 litres of solution (600ml product) per tonne of cabbages. There is no minimum utilisation interval between application and removal from store whereas for Rovral WG it was eight weeks.
Andy highlights the importance of the environmental protection requirements on the EAMU. Application to cabbages must only take place where any product runoff from the crates/storage bins and spray equipment washings can be contained (e.g. on a biobed or bunded residue collection area). All dilute pesticide waste of must be disposed of safely and legally’.
Bayer has advised that there are no known compatibility issues mixing Serenade ASO with SL567a (metalaxyl-M) for control of Phytopthoraand mixtures of the two products are used in other crops with no reduction in efficacy.
This EAMU application was submitted by the BGA/AHDB based on Dr Colgan and the ABC’s results and issued on 11thOctober with EAMU number 2825 of 2018.