The humid weather conditions have proved to be an ideal environment for white blister at every one of the sites monitored in Lincolnshire by Syngenta's Brassica Alert pest and disease warning service - prompting it to rate the white blister threat as "red" for high risk.
Andy Richardson of the Allium & Brassica Centre advised growers to take action now to minimize the development of these pests and diseases. He said: "If there is a disease risk present, growers need to be taking mitigating action." White blister, he added, needed to be treated with an appropriate fungicide, such as Folio Gold, as soon as symptoms were seen.
Thrips and Silver Y moth have also been identified as "red" or high risk on every one of the Brassica Alert's monitoring sites - with diamondback moth at the amber moderate risk level. This means that more than 150 thrips and 20 Silver Y moths have been caught in each of the traps, along with 10-20 diamondback moths.
Jon Ogborn of Syngenta said: "The Brassica Alert warnings are a timely indication to look out for the first signs of caterpillar damage. Hallmark Zeon applications targeted for Silver Y moth have proven effective and will control diamondback moth caterpillars too."
- For the free Brassica Alert service, see www.tiny.cc/syngenta.