The effect of irrigation on terbacil tolerance in field-grown strawberry

Abstract

Field experiments were conducted in newly planted strawberry (Fragaria xananassa) with terbacil applied at rates of 0 to 6.4 oz/acre a.i. either 4 days after planting but before appearance of new growth, or at the three-leaf stage. Irrigation of 0.4 inch was applied to half of the plots immediately after application of terbacil. Injury was greater when terbacil was applied before new growth than when applied at the three-leaf stage. Injury symptoms increased linearly with terbacil rate. Irrigation immediately following terbacil application reduced injury relative to non-irrigated plots. Weed control was reduced when terbacil was applied at the three-leaf stage than when applied before new growth. Irrigation did not reduce weed control. Herbicide injury symptoms were not detected the spring following terbacil application. Fruit yield was not affected by herbicide and irrigation treatments applied the previous year. The combination of low rates of terbacil, 0.8-1.6 oz/acre a.i., followed by irrigation to remove the herbicide from foliage is a safe option that growers can use to improve weed control and reduce hand weeding costs in the planting year.