2018 ASHS Annual Conference

Sustainable production of strawberries (Fragaria x ananassa) is challenged in Alabama due partly to the relatively restricted arsenal of effective chemistries for pest control. The objective of this study was to evaluate the effectiveness of pre-plant herbicides (four labeled for use and one not labeled for use) in strawberry production in order to develop recommendation for growers. A study was established at the Chilton Research and Extension Center (CREC) in Clanton, AL on a fine sandy loam. Planting rows were prepared and herbicide treatments applied on 4 Oct. 2016. Rows were set on 1.8 m centers. Black plastic and drip irrigation were installed. Plants were set in double rows within a plot (0.9 m x 6 m) at a spacing of 35 cm. Pre-plant herbicides applied were bicyclopyrone (not labeled for use in strawberries) at a rate of (123 g ha^-1), Blazer Ultra (0.3 L • ha^-1), Devrinol (1.5 L • ha^-1), Sinbar (17 L • ha^-1), and Spartan 4F (0.5 L • ha^-1). An untreated control plots were included. Plugs of ‘Camarosa’ strawberry plants were planted on October 17, 2017. Treatments were planted according to a randomized complete block design with four replications. An analysis of variance was performed on all responses using PROC GLIMMIX in SAS version 9.4 (SAS Institute, Cary, NC). Early and total season marketable yield per plot and individual berry weight were analyzed using the normal probability distribution. Percent weed cover of plots treated with Devrinol (18 %) was similar to the untreated control. Bicyclopyrone (12 %), Spartan 4F (10.5%) and Sinbar (9.7 %) were similar in weed cover but had a lower percentage of weeds than all other treatments. Early season yields were highest in plots treated with Sinbar (941 g/plot). Other herbicide treatments produced early season yields similar to the untreated control. Total season yield of Sinbar (1,126 g/plant) was similar to Spartan 4F (986 g/plot), Devrinol (1,041 g/plot), and Blazer Ultra (1,053 g/plot). Plots treated with Sinbar produced total season yields that were higher than the untreated control plots (872 g/plot). Individual berry weight from plots treated with Sinbar were numerically higher than all other treatments but there were no significant differences found among treatments. Cull weight of plots treated with Sinbar (353 g/plot) differed significantly from those treated with Devrinol (270 g/plot) and byclopyrone (216 g/plot) but similar to all other herbicide treatments and the untreated control. Total season cull weight was similar among all treatments with the exception of bicyclopyrone, which was statistically lower than all other treatments. Bicyclopyrone was also effective in controlling weeds; however, it is not labeled for use in strawberries and strawberry plants in plots treated with bicyclopyrone were stunted and chlorotic. Sinbar and Spartan 4F were among the most effective in controlling weeds. Sinbar was effective in encouraging the production of the highest yields during the early and late seasons.