Phoma Risk is Still High
PRESSURE FROM phoma disease infection in oilseed rape remains high, with some fields set to need a second fungicide treatment this season, warns ADAS disease control expert Peter Gladders.
Inspect crops treated 4-6 weeks ago for new infections, he advises.
High numbers of spores continue to be caught on most ADAS monitoring sites, prompting the Syngenta Phoma Advance Warning System (SPAWS) to issue a high risk notice for all growers this week (Nov 22).
Thresholds for small or backward crops, or those with a canker resistance of 6 or less, should be cut to 10% of plants infected, or 5% if spray delays likely.