Chloroxynil is a postemergent

benzonitrile Benzonitrile is the chemical compound with the formula , abbreviated PhCN. This aromatic organic compound is a colorless liquid with a cherry or almond like odour. It is mainly used industrially to produce the melamine resin precursor benzoguanam ...

herbicide Herbicides (, ), also commonly known as weed killers, are substances used to control undesired plants, also known as weeds.EPA. February 201Pesticides Industry. Sales and Usage 2006 and 2007: Market Estimates. Summary in press releasMain page f ...

, used to control broad leaved

weed A weed is a plant considered undesirable in a particular situation, growing where it conflicts with human preferences, needs, or goals.Harlan, J. R., & deWet, J. M. (1965). Some thoughts about weeds. ''Economic botany'', ''19''(1), 16-24. Pla ...

s on cereal

crop A crop is a plant that can be grown and harvested extensively for profit or subsistence. In other words, a crop is a plant or plant product that is grown for a specific purpose such as food, Fiber, fibre, or fuel. When plants of the same spe ...

s. It was manufactured by Rhone-Poulenc and

May & Baker May & Baker was a British chemical company founded by John May and William Gerrard Baker in Wandsworth, London in 1839. They initially specialized in the manufacture of chemicals derived from mercury and bismuth. Over the years they diversified ...

, and is now considered obsolete, though its usage may continue. Chloroxynil was developed as a variant of

bromoxynil Bromoxynil is an organic compound with the formula HOBr2C6H2CN. It is classified as a nitrile herbicide, and as such sold under many trade names. It is a white solid. It works by inhibiting photosynthesis. It is moderately toxic to mammals. It ...

, which is identical except for bromines replacing chloroxynil's chlorines. A 1972 study found chloroxynil less injurious to

alfalfa Alfalfa () (''Medicago sativa''), also called lucerne, is a perennial plant, perennial flowering plant in the legume family Fabaceae. It is cultivated as an important forage crop in many countries around the world. It is used for grazing, hay, ...

and

red clover ''Trifolium pratense'' (from Latin prātum, meaning meadow), red clover, is a herbaceous plant, herbaceous species of flowering plant in the bean family, Fabaceae. It is native to the Old World, but planted and naturalised in many other regions ...

, but also less potent at controlling broadleaf weeds. Chloroxynil's

MoA Moa are extinct giant flightless birds native to New Zealand. Moa or MOA may also refer to: Arts and media * Metal Open Air, a Brazilian heavy metal festival * MOA Museum of Art in Japan * The Moas, New Zealand film awards People * Moa ...

inhibits electron transfer in the photosystem II receptor. Its HRAC group is Group C, (Australia) C3 (global) or 6 (numeric).

Genetic engineering

Chloroxynil can greatly improve the speed and efficiency of agrobacterium-mediated transformation of plants. Compared to the control,

acetosyringone Acetosyringone is a phenolic natural product and a chemical compound related to acetophenone and 2,6-dimethoxyphenol. It was first described in relation to lignan/phenylpropanoid-type phytochemicals, with isolation from a variety of plant sour ...

was 6 times faster, and chloroxynil was 60 times faster. Chloroxynil's related herbicides were also tested:

was 18 times faster than control but caused plant damage, and

ioxynil Ioxynil is a Postemergence, post-emergent selective nitrile herbicide. It is used in Australia, New Zealand and Japan to control broadleaf weeds via the inhibition of photosynthesis. It is used notably on onion crops, among others, normally at 300� ...

showed no significant improvement.

Soil behaviour

In soil, chloroxynil lasts about a month in aerobic soil (soil with sufficient oxygen to support microbial activity), or about two weeks in anaerobic soil. Sunlight can

photochemical Photochemistry is the branch of chemistry concerned with the chemical effects of light. Generally, this term is used to describe a chemical reaction caused by absorption of ultraviolet (wavelength from 100 to 400 nm), visible (400–750&nb ...

ly degrade it, by splitting off the chlorine atoms.

Application

Chloroxynil was used on

wheat Wheat is a group of wild and crop domestication, domesticated Poaceae, grasses of the genus ''Triticum'' (). They are Agriculture, cultivated for their cereal grains, which are staple foods around the world. Well-known Taxonomy of wheat, whe ...

barley Barley (), a member of the grass family, is a major cereal grain grown in temperate climates globally. It was one of the first cultivated grains; it was domesticated in the Fertile Crescent around 9000 BC, giving it nonshattering spikele ...

oat The oat (''Avena sativa''), sometimes called the common oat, is a species of cereal grain grown for its seed, which is known by the same name (usually in the plural). Oats appear to have been domesticated as a secondary crop, as their seeds ...

lucerne Lucerne ( ) or Luzern ()Other languages: ; ; ; . is a city in central Switzerland, in the Languages of Switzerland, German-speaking portion of the country. Lucerne is the capital of the canton of Lucerne and part of the Lucerne (district), di ...

sorghum ''Sorghum bicolor'', commonly called sorghum () and also known as great millet, broomcorn, guinea corn, durra, imphee, jowar, or milo, is a species in the Poaceae, grass genus ''Sorghum (genus), Sorghum'' cultivated for its grain. The grain i ...

and fax, to control

pigweed Pigweed can mean any of a number of weedy plants which may be used as pig fodder: * ''Amaranthus'' species ** ''Amaranthus albus'', white pigweed, tumble pigweed ** '' Amaranthus blitoides'', prostrate pigweed ** '' Amaranthus californicus'', Cali ...

mayweed Mayweed is a common name for two different species of flowering plants and also a name commonly used for several genera of the tribe Anthemideae whose species are currently in a flux of renaming: Species with the common name of mayweed: :'' Anthemi ...

knotweed Knotweed is a common name for plants in several genera in the family Polygonaceae. Knotweed may refer to: * ''Fallopia'' * ''Persicaria'' * ''Polygonum'' * ''Reynoutria'' ** ''Reynoutria japonica'' or Japanese knotweed, a highly invasive species in ...

shepherd's purse ''Capsella bursa-pastoris'', known as shepherd's purse or lady's purse because of its triangular flat fruits, which are purse-like, is a small annual and ruderal flowering plant in the mustard family (Brassicaceae). Scientists have referred to ...

goosefoot ''Chenopodium'' is a genus of numerous species of perennial or annual herbaceous flowering plants known as the goosefoot, which occur almost anywhere in the world. It is placed in the family Amaranthaceae in the APG II system; older classifica ...

and stinkweed.

References

External links

* {{Herbicides Benzonitriles Phenols Chloroarenes Group 6 herbicides Post-emergent herbicides