Management and yield impact of the greenhouse whitefly (Trialeurodes vaporariorum) on California strawberries

Abstract

Reductions in strawberry yields were observed in association with infestations of the greenhouse whitefly, Trialeurodes vaporariorum (Westwood). The magnitude of yield impact is estimated using data from a field experiment evaluating nine management approaches for the greenhouse whitefly on strawberries, var. Camarosa. A range of effectiveness and yields was found. Imidacloprid (Admire) applied at transplanting was found to provide the greatest effect on adult whitefly densities. Pyriproxyfen (Esteem) had no immediate effect on adult density but reduced nymphal densities over time. Pairing the use of these products at transplant (Admire) and early spring (Esteem) provided the greatest reduction in whitefly density observed relative to an untreated control. Reductions in strawberry yields were found to increase as whitefly densities grow or as populations persist over time. For example, the estimates from our analysis suggest that at 20 weeks after planting, an average whitefly population may reduce average weekly yields in an untreated field by ≈80 g/plant.