Tim Lacey, Bayer's product manager for biologicals, told delegates at the Horticultural Development Company and British Carrot Growers Association technical seminar in Peterborough (26 March) that trials data for Serenade showed strong activity against cavity spot.
Across four 2013-14 UK trials, 10 litres per hectare of Serenade reduced disease incidence as well as or more effectively than the conventional standard metalaxyl-M. Two Dutch 2013-14 trials saw Serenade substantially outperform the standard.
He explained that Serenade is a liquid formulation of the Bacillis subtilis strain QST713 that has anti-fungal, antibacterial and plant health promotion characteristics. The strain works by growing a biofilm on roots that "outcompetes a lot of the bad guys in the soil".
Efforts are now focusing on fine-tuning the application method. Lacey said: "Applications trials in 2014 indicated that the most practical and effective Serenade applications were either at drilling in the rows or at the typical metalaxl-M timing - cotyledon to one true leaf. In all cases, a small amount of rain or irrigation after application was highly beneficial."