Occurrence and Chemical Control Status of Weeds in Wheat Field in Sichuan Province

Sichuan Province is located in the southwest China,it crossed over climate zones from subtropical to subfrigid.Winter wheat occupied the main part among wheat crops growing in Sichuan Province,only a small part of spring wheat and barley distributed in this province.The whole planting area of wheats is about 1.333 million hm2,the weeds occurrenced area is above 1.067 million hm2.At present,the area of chemical control is over 60% of the total wheats cultivated area.The weeds types in wheat field in Sichuan Province consists of above 80 species,which belongs to about 20 families respectively,mainly distributed in the family of Poaceae,Asteraceae,Cruciferae,and Caryophyllaceae.Because of cropping system change and continuous use of same kind of herbicides for many years,the change of weeds population and succession of community in farmland accelerated.The herbicide types used also developed from a few old types to above 20 types at present,especially brought in some new safe and high efficiency types of herbicide including tribenuron-methyl,fenoxaprop-p-ethyl,and clodinafop-propargyl,which basically meeted the needs of weeds chemical control in wheat field in Sichuan Province.