Clomazone

Clomazone is an agricultural herbicide, and has been the active ingredient of products named Command and Commence. The molecule consists of a 2-chlorobenzyl group bound to a nitrogen-oxygen heterocycle called a isoxazolidinone. It is a white solid.
Clomazone was first registered by the USEPA on March 8, 1993, and was commercialized by FMC Corporation. It is used for broadleaf weed control in several crops, including soybeans, peas, maize, rapeseed, sugar cane, cassava, pumpkins and tobacco. It may be applied pre-emergence of incorporated before planting the crop. Clomazone is relatively volatile and vapors induce striking visual symptoms on non-target sensitive plants. Clomazone undergoes biological degradation, exhibiting a soil half life of one to four months. Adsorption of the herbicide to soil solids slows degradation and offgassing. Encapsulation helps reduce the compound's volatility and therefore reduces off-target damage to sensitive plants.
Clomazone suppresses the biosynthesis of chlorophyll and other plant pigments.