Crop desiccation is used as a pre-harvest herbicide and harvest aid on cereal crops including wheat and oats and on oil seed rape. As a systemic herbicide it is not a true desiccant as it can take weeks rather than days for the crop to die back after application. In the UK, it began to be applied to wheat crops in the 1980s to control perennial weeds such as common couch which was very effective and meant that sowing of the next crop could occur sooner. Use as a harvest aid in the UK increased after the introduction of strobilurin fungicides which
Crop circle Crop circle A crop circle or crop formation is a pattern created by flattening a crop, usually a cereal. The term was first coined in the early 1980s by Colin Andrews. Crop circles have been described as all falling "within the range of the sort of thing done in hoaxes" by Taner Edis, professor of physics at Truman State University. Although obscure natural causes or alien origins of crop circles are suggested by fringe theorists, there is no scientific evidence for such explanations, and all crop circles are consistent with human causation. A person who studies crop circles is known