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.
M.J. Haar, S.A. Fennimore, M.E. McGiffen, W.T. Lanini, and C.E. Bell
Grant R. Manning and Steven A. Fennimore
Methyl bromide has been the foundation of chemical weed control in strawberry (Fragaria ×ananassa) in California for over 40 years. The impending phaseout of methyl bromide may leave strawberry producers dependent on less efficacious alternative fumigants for weed control. The use of herbicides to supplement fumigants is a potential weed control strategy for strawberry. A 2-year field study was conducted in California to evaluate 10 herbicides as possible supplements for methyl bromide alternative fumigants. Herbicides were applied immediately after transplanting (immediate posttransplant), and 3 weeks after transplanting (delayed posttransplant). Napropamide applied immediate posttransplant was included as a commercial standard. Immediate posttransplant treatments that were safe in strawberry include carfentrazone at 0.075 and 0.15 lb/acre (0.084 and 0.168 kg·ha-1), flumioxazin at 0.063 lb/acre (0.071 kg·ha-1) and sulfentrazone at 0.175 and 0.25 lb/acre (0.196 and 0.28 kg·ha-1). Triflusulfuron at 0.016 lb/acre (0.017 kg·ha-1) was the only delayed posttransplant treatment with acceptable selectivity. Among the selective herbicides applied immediate posttransplant, flumioxazin and napropamide provided the most consistent control of bur clover (Medicago polymorpha) and shepherd's purse (Capsella bursa-pastoris). Triflusulfuron applied delayed posttransplant did not significantly reduce bur clover densities, but did reduce shepherd's purse densities.
Timothy L. Grey, Mark Czarnota, Thomas Potter, and B. Todd Bunnell
‘TifEagle’ bermudagrass to seven plant growth regulators HortScience 39 1759 1762 Mueller, T.C. Shaw, D.R. Witt, W.W. 1999 Relative dissipation of acetochlor, alachlor, metolachlor and SAN 582 from three surface soils Weed Technol. 13 341 346 Nelson, L