POST weed control atop the bed during strawberry production is limited to hand weeding, clopyralid, and acetyl CoA carboxylase inhibitors. Identification of additional modes of action is desirable to increase available options for producers and alleviate herbicide resistance concerns. The study objective was to screen sulfonylurea herbicides for safety of strawberry coordinated with efficacy against Carolina geranium. Herbicide treatments included metsulfuron-methyl, flazasulfuron, foramsulfuron, thifensulfuron-methyl, trifloxysulfuron-sodium, and rimsulfuron. Strawberry plants were heavily damaged by all herbicides apart from foramsulfuron. Although the strawberry plant was dramatically affected by the evaluated herbicides, demonstrating strong epinasty, there were no differences in resultant biomass at 31 d after treatment (DAT) compared to controls. Carolina geranium was severely injured by metsulfuron-methyl, flazasulfuron, and thifensulfuron-methyl, and moderately injured by foramsulfuron. There were consistent reductions in biomass by 31 DAT by metsulfuron-methyl and flazasulfuron. Overall, metsulfuron-methyl and flazasulfuron are suitable candidates for Carolina geranium control in row-middles. Foramsulfuron is a suitable candidate for additional field-based screening for utility in POST use in strawberry production atop the bed. Consideration toward doses, surfactants, timings, and cultivar tolerance may be necessary to minimize injury as observed in the greenhouse (15% to 20%).

Broadleaf infestations interfere with Florida strawberry production. Broadleaf POST herbicide options applied atop the crop are limited to synthetic auxins and not suitable for conventional multi-cropping and organic systems. Reducing light access and interception during weed emergence may reduce interference. Light-limited growth of two problematic broadleaves, black medic and Carolina geranium, and the most commonly grown strawberry cultivar (‘Florida Radiance’), were examined in the greenhouse. The experimental design was completely randomized, and the trial was repeated. Black medic was susceptible to reductions in incoming solar radiation, wherein reducing the daily maximum available light from 331 to 94 µmol m−2 s−1 reduced leaf number and area by 93% and 89%, respectively. Carolina geranium growth was less susceptible to reduced-light treatments, with leaf area and number each reduced by 66% when light was reduced from 331 to 94 µmol m−2 s−1. Belowground, Carolina geranium biomass was similarly reduced between the 331 and 94 µmol m−2 s−1 treatments. Strawberry was relatively tolerant to shading at 155 µmol m−2 s−1, but further reductions did increase mortality. Shade-induced weed suppression is a promising alternative strategy for conventional and organic Florida strawberry production. Targeted application during periods of weed emergence may play a role within integrated pest management strategies. This approach is most feasible for black medic management but may be useful for Carolina geranium in concert with other strategies.