Compensatory ability of strawberries to bud and flower removal: Implications for managing the strawberry bud weevil (Coleoptera : Curculionidae)

The strawberry bud weevil, Anthonomus sgnatus Say, is considered a major pe st of perennial matted row strawberry plantings in the eastern United State s with an economic threshold of 2 clipped buds per meter row. No relationsh ip was found between the number of naturally clipped buds per meter (range, 0-20) and subsequent yield over 2 field seasons for the strawberry cultiva r 'Earliglow' indicating the potential for compensatory fruit production. I n field experiments, flower buds or open flowers were removed by hand and t he impact on yield for 3 strawberry cultivars measured. For the cultivar 'J ewel', removal of all primary or secondary buds did not result in a signifi cant decrease in yield relative to control plots, although the removal of a ll tertiary plus higher order buds did result in a significant decrease. Fo r 'Seneca' and 'Kent', removal of all primary, secondary, or tertiary buds did not significantly decrease yield compared with control plots. Compensat ion to bud removal was achieved by increasing fruit weight of remaining bud s and increasing the number of higher order buds matured. When similar trea tments were applied to flowers, we observed a negative impact on yield for all 3 cultivars. In 1996 we assessed the benefit of treating for strawberry bud weevil when injury reached the economic threshold at 7 commercial stra wberry operations in upstate New York. Untreated plots had significantly mo re clipped buds per meter than treated plots (13 versus 4), however, there was no difference in yield.