VG04013 White Blister – Risk Forecasting

White blister predictive model is based on weather conditions experienced by the crop.

Growers can use this approach to reduce the number of chemical applications needed to control the disease.

• Control of white blister before it gets established in the crop
• Determines the time to look for white blister in the crop
• Fungicides can be applied when they will have the maximum efficacy
• Avoidance of weekly spraying of crops for white blister control
• Time irrigation to minimise the duration of leaf wetness

BrassicaSpot is a computer based, disease-forecasting system for some fungal diseases and insect pests of brassicas.

Over half of UK growers now use this model to time their fungicide sprays for white blister control.

The model predicts the risk of white blister infection periods for broccoli and other vegetable brassica crops using weather data such as temperature, leaf wetness, relative humidity and rainfall.

The model indicates the time to inspect crops for white blister and, depending on the results, a decision is made whether or not to spray.

The BrassicaSpot model was evaluated in two trials at Dandenong and Werribee, Victoria, during autumn and winter 2005.

In both trials white blister was kept in check using only 1-4 chemical applications compared with up to 8 applications under a conventional spray program.

The model was an excellent decision support tool that helped to reduce the applications of fungicides for crop protection.