Disease pressure is building on brassica crops, with significantly high levels of Ringspot spores being picked up in monitoring traps across east Lincolnshire, reports Andy Richardson of the Allium and Brassica Centre.
The capture of high levels of spores in several traps, combined with weather conducive to infection indicates a high risk of infection in these areas, according to the Brassica Alert web site and text messaging service. "Any crops that have not received a suitable fungicide in the past 14 days should be treated as soon as possible," advises Mr Richardson.
Furthermore, White Blister remains at high risk, as a consequence of extended periods with wet leaves. Crops must be regularly inspected and treated at the first signs of disease, he adds.
The advance warning of impending disease attack given by Brassica Alert can really help growers to time applications of Amistar Top when they will have the greatest effect, according to Jon Ogborn of Syngenta. "Amistar Top has proven highly effective in controlling all the key brassica crop diseases, especially the most damaging Ringspot. Amistar gives good protection against White Blister, although Folio Gold is advised for best curative action if it is established in the crop."
"Amistar Top will also effectively deal with the threat of Phoma from cankers on old oilseed rape stubble, which are already primed by the wet weather and threaten very early infection," he adds. Although Phoma is not typically a key concern to field brassica growers, the unprecedented early start of spore release and the potential for a prolonged season of infection could pose a risk this year.
Mr Ogborn highlights the optimised combination of azoxystrobin and difenoconazole in Amistar Top gives outstanding disease protection, as well as curative control of early infection and the benefit of all important enhanced green leaf retention for brassica growers. The pre-formulated product also gives cost savings over an equivalent tank-mix of the two components.
