Chloroxynil
Chloroxynil is a postemergent benzonitrile herbicide, used to control broad leaved weeds on cereal crops. It was manufactured by Rhone-Poulenc and May & Baker, and is now considered obsolete, though its usage may continue.
Chloroxynil was developed as a variant of bromoxynil, which is identical except for bromines replacing chloroxynil's chlorines. A 1972 study found chloroxynil less injurious to alfalfa and red clover, but also less potent at controlling broadleaf weeds.
Chloroxynil's MoA inhibits electron transfer in the photosystem II receptor. Its HRAC group is Group C, C3 or 6.Genetic engineering
Chloroxynil can greatly improve the speed and efficiency of agrobacterium-mediated transformation of plants. Compared to the control, acetosyringone was 6 times faster, and chloroxynil was 60 times faster. Chloroxynil's related herbicides were also tested: bromoxynil was 18 times faster than control but caused plant damage, and ioxynil showed no significant improvement.Soil behaviour
In soil, chloroxynil lasts about a month in aerobic soil, or about two weeks in anaerobic soil. Sunlight can photochemically degrade it, by splitting off the chlorine atoms.Application
Chloroxynil was used on wheat, barley, oats, lucerne, sorghum and fax, to control pigweed, mayweed, knotweed, shepherd's purse, goosefoot and stinkweed.