Efficacy evaluation of a mixture combining flumioxazin and flufenacet for weed control in strawberry seedling nurseries

The study aims to clarify the optimal ratio of the mixture of flumioxazin and flufenacet, and its efficacy and safety against weeds in strawberry seedling fields. The whole-plant bioassay using the Gowing method was conducted under greenhouse conditions to evaluate the joint action of flumioxazin and flufenacet and identify the optimal mixture ratio. Subsequently, efficacy and phytotoxicity trials were carried out both under controlled conditions and in the field. The optimal ratio for the combination of flumioxazin and flufenacet is 1:4 (6%+24%). A flumioxazin·flufenacet 30% SC based on this ratio exhibited GR₉₀ values ranging from 124.94 to 139.76 g a.i./hm² for Echinochloa crusgali (L) Beauv., Setaria viridis (L.) P. Beauv., Eleusine indica (L.) Gaertn., Commelina benghalensis L., Amaranthus blitum L., Stellaria media (L.) Vill., Portulaca oleracea L., and Cyperus iria L. The treatment has no significant negative effect on the growth of strawberry seedlings, with selectivity indexes greater than 7.2. When applied as a pre-emergence soil treatment at rates of 225 g a.i./hm² or higher, the flumioxazin·flufenacet 30% SC provided >97% control of E. crus-galli, S. viridi, A. blitum, S. media, and C. iria at 30 days after application. Both plant-count and fresh-weight control efficacies remained above 95% at 60 days after application, with no observable phytotoxicity to strawberry seedlings. A single pre-emergence application of the flumioxazin and flufenacet mixture effectively controls weed infestations in strawberry nursery fields and is safe to strawberries.