MONITORING STRAWBERRY PESTS AND DISEASES: PRACTICAL APPLICATIONS FOR DECISION MAKING

Leaf samples were examined for the presence of two-spotted spider mite, strawberry mite, powdery mildew and leaf spot diseases. Timing of control of grey mould was successful by means of the warning device. Beating tray sampling was an effective method for determining the presence of strawberry blossom weevil and leaf beetles. Monitoring capsid bugs was problematic because they often flew into the field at the beginning of flowering when no effective insecticides were available. It was concluded that repeated sampling can give an early warning of capsids before full bloom.

Prognosis of economic losses is based on the number of pests recorded per plant. Other necessary data from the field include the mean number of flowers per plant and the number of plants per ha. Previous data on the mean levels of injury caused by the key pests to buds, flowers and berries, on the number of developing berries per truss, on the mean weight of berries and on the effect of treatments, are needed for decision making. Monitoring should be timed according to the phenology of the cultivar and life cycle of insects, and the prevailing weather. The sampling route should cover the whole field adequately, and any areas of special interest should be sampled separately. The risk of poor decision making can be minimized by increasing the frequency of sampling and the number of plants sampled.

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