Crop desiccation little or no advantage in doing so. Glyphosate was found in 5–15% of cereal crop samples tested in the UK between 2000 and 2004, although never exceeding the Maximum Residue Level of 20 mg/kg. A survey of British wheat in 2006–8 found average levels of 0.05–0.22 mg/kg with maximum levels of 1.2 mg/kg. In July 2013 Austria banned the use of pre-harvest glyphosate citing the precautionary principle. In April 2015 an oat buyer in Western Canada announced that it was refusing oats in which pre-harvest glyphosate had been used. Crop desiccation Pre-harvest crop desiccation (also siccation) refers to the application
Cover crop ("Sinapis alba") and radish ("Raphanus sativus"). They can be grown after a main (cereal) crop and trap nematodes, for example the beet cyst nematode and Columbian root knot nematode. When grown, nematodes hatch and are attracted to the roots. After entering the roots they cannot reproduce in the root due to a hypersensitive resistance reaction of the plant. Hence the nematode population is greatly reduced, by 70-99%, depending on species and cultivation time. Other cover crops are used to attract natural predators of pests by providing elements of their habitat. This is a form of biological control known as habitat