Differences in Tolerance of Broccoli and Cabbage Cultivars to Clomazone Herbicide

Abstract

<jats:p>Clomazone herbicide is registered for cabbage (<jats:italic>Brassica oleracea</jats:italic> Capitata group) in the United States but not for other crop groups within the species. Greenhouse and field experiments were designed to compare the tolerance of broccoli (<jats:italic>B. oleracea</jats:italic> Italica group) and cabbage cultivars to clomazone to assess its potential for weed management in broccoli. Four broccoli cultivars (Captain, Green Magic, Legacy, and Patron) and four cabbage cultivars (Bravo, SC 100, Stone Head, and Vantage Point) were evaluated in all experiments. In a greenhouse experiment where seedlings were transplanted into potting medium containing clomazone at 0, 1.0, 2.0, and 4.0 parts per million (ppm), ‘Bravo’ cabbage was most susceptible. Its injury ratings and shoot weight reduction at 1.0 ppm were similar to ratings and shoot weight reduction for the other cabbage cultivars at 4.0 ppm. Among the broccoli cultivars, Patron was highly susceptible, exhibiting injury and shoot weight reduction similar to Bravo. Green Magic was the most tolerant broccoli cultivar, and it exhibited injury and growth reduction similar to the tolerant cabbage cultivars. In a field experiment where clomazone was applied pretransplanting at 0.25, 0.5, and 1.0 lb/acre, 0.25 lb/acre caused moderate chlorosis to the susceptible cultivars, Bravo and Patron. At 0.50 and 1.0 lb/acre, most cultivars exhibited chlorosis at 2 weeks after transplanting (WAT); however, tolerant cultivars recovered and injury was often not observed at 6 WAT. At 1.0 lb/acre, chlorosis persisted until maturity on ‘Bravo’ and ‘Patron’ foliage. Clomazone did not reduce mean broccoli head weight or the percentage of plants producing market-size heads. Mean cabbage head weight for ‘Bravo’ was reduced by clomazone at 1.0 lb/acre. This study indicates that the variability in clomazone tolerance among broccoli cultivars may be similar to that among cabbage cultivars and suggests that the herbicide can be used safely on tolerant broccoli cultivars at rates that are recommended for cabbage.</jats:p>

Banana Pepper Response and Annual Weed Control with S-metolachlor and Clomazone

“…This chloroacetamide herbicide is applied PRE to preformed beds before laying polyethylene mulch, or it may be used PRE in bare-ground culture (Bangarwa et al 2009). Clomazone (Command, 3ME herbicide label, FMC Corporation, Agricultural Products Group, 1735 Market St, Philadelphia, PA 19103), an herbicide from the isoxazolidinone family, provides residual control of several important annual grass and broadleaf weeds and is an important herbicide for weed management in peppers and other vegetable crops (Harrison and Farnham 2013).…”

Plasticulture banana pepper response to clomazone applied pretransplanting

“…The clomazone recommended use rates for all crops are based on soil type and crop tolerance (Harrison and Farnham 2013). In Indiana, clomazone is currently registered for use in bell pepper as a pre-transplanting application at rates from 280 to 1,120 g ai ha -1 (Anonymous 2021).…”