Evaluation of Preemergence Herbicides in Vegetable Crops

In an effort to identify new herbicides for vegetables crops, broccoli (Brassica oleracea) cantaloupe (Cucumis melo), carrot (Daucus carota), head lettuce (Lactuca sativa), bulb onion (Allium cepa), spinach (Spinacia oleracea) and processing tomato (Lycopersicon esculentum) were evaluated in the field for tolerance to eight herbicides. The following herbicides and rates, expressed in a.i. lb/acre, were applied preemergence: carfentrazone, 0.05, 0.1, 0.15 and 0.2; flufenacet, 0.525; flumioxazin, 0.063, 0.125 and 0.25; halosulfuron, 0.032 and 0.047; isoxaben, 0.25 and 0.50; rimsulfuron, 0.016 and 0.031; SAN 582, 0.94 and 1.20 and sulfentrazone, 0.15 and 0.25 (1.000 lb/acre = 1.1208 kg(.)ha(-1)). Tolerance was evaluated by measuring crop stand, injury and biomass. Several leads for new vegetable herbicides were identified. Lettuce demonstrated tolerance to carfentrazone at 0.05 and 0.10 lb/acre. Cantaloupe and processing tomato were tolerant of halosulfuron at 0.032 and 0.047 lb/ acre. Broccoli, cantaloupe and processing tomato were tolerant of SAN 582 at 0.94 lb/acre. Broccoli and carrot were tolerant of sulfentrazone at 0.15 lb/acre.