Potatoes in field© Tim Scrivener

The blight monitoring season is officially under way for potato growers with the publication of the first online forecast.

The first 2017 edition of BlightCast from Syngenta dropped into subscriber’s inboxes on Friday morning, and offers growers the opportunity to study risk periods for the next five days using either the traditional Smith Period or the new Hutton Criteria.

Blight is the single biggest disease threat to potato growers, and industry best practice recommends taking a preventive approach, with sprays timed to protect leaves ahead of high-risk weather events.

See also: How improved blight forecasts will benefit spud growers

According to the new Hutton Criteria, a risk event is two consecutive days where the minimum air temperature is 10C and there is a minimum of six hours with a relative humidity of at least 90%.

The forecast for the next five days shows a low risk of a blight across all the forecasting models, and predicts that there will be spraying opportunities on all days except Sunday 30 April and part of Monday 1 May.

Growers can sign up for a BlightCast service by visiting the Syngenta website. Alternatively they can use the AHDB Potato “Fight Against Blight” service.