The UK Agricultural and Horticulture Development Board (AHDB) has launched an enhanced sclerotinia risk alert service before spraying blooming oilseed rape to help growers.

Sclerotinia is a fungal disease that can reduce the yield of affected plants by up to 50%, and to combat it, the timely use of appropriate preventive sprays is necessary.

To help farmers in terms of using sprays, AHDB has improved its web service using its WeatherHub page, which means that warnings can be included in even more sites.

The web-based tool uses a simple traffic light system to highlight areas of the UK where current weather conditions or are projected to be suitable for the causative agent of sclerotin infection that affects crops: Green - no warning about the risk of infection; Amber - a forecast of a condition approaching the launch of warnings about the risk of infection and Red - a forecast of warnings about the risk of infection.

Oilseed rape is most at risk of infection when the relative humidity exceeds 80% and the air temperature is 7 ° C or higher for over 23 hours.

Katherine Garman, director of disease research at AHDB, explained that since fungicides are used as a protective agent, they should be applied immediately before the risk of infection warning, if you start earlier, this may increase the need for further treatment.