Common name: clomazone U.S. trade name: COMMAND

Clomazone [pre-emergent (PRE)]
on wild mustard (Brassica kaber).
Note the bleached white appearance of cotyledons

Clomazone (PRE) on tomatoes


Clomazone (PRE) on redroot pigweed
(Amaranthus retroflexus)



 Clomazone (PRE) on grass weeds including
barnyardgrass (Echinochloa crusgalli),
yellow foxtail (Setaria glauca) and
large crabgrass (Digitaria sanguinalis)
Clomazone (PRE) on various crops including
corn, soybean, alfalfa and winter wheat
Clomazone (PRE) on corn



Chemical Name:
2-[2-chlorophenyl)methyl]-4,4-dimethyl-3-isoxazolidinone.

Chemical Family:
Isoxazolidinone (none generally accepted).

Chemical Structure:

WSSA resistance group:
13.

Crop/non-crop registration:
Soybean, peppers, pumpkins, peas.

Sensitive weeds:
Annual grasses and BLW (broadleaf weeds): barnyard grass, Panicum spp., crabgrasses, velvetleaf, common ragweed, lambsquarters.

Application method:
PPI or PRE.

Absorption & Translocation:
Not highly absorbed when foliar applied;readily absorbed by roots and emerging shoots (grass coleoptile and broadleaf hypocotyl) and is translocated to foliage via xylem.

Mode of action:
Not completely understood; but thought to inhibit the isoprenoid pathway.

Metabolic pathway inhibited:
Inhibition of the isoprenoid pathway stops production of among other things gibberellin, plastoquinone, carotenoids, and the phytol tail of chlorophyll.

Basis of selectivity:
Metabolized to non-toxic compounds by tolerant species.

Symptoms:
Susceptible seedlings typically emerge from treated soil, but are bleached white and become necrotic after a few days.

Residuality:
Intermediate (1- 4 months); decreasing persistence in sandy loam soils compared with silt loam or clay loam soils.

Toxicity:
Oral LD50 = 2077 mg/kg - moderately toxic (COMMAND = 2343 mg/kg - moderately toxic).

Additional comments:
Susceptible species in later growth stages may exhibit foliar bleaching when treated POST or when exposed to vapor drifting from nearby treated areas.