The Occurrence And Controlling Of Weeds In Cotton Field Under Drip Irrigation In Shihezi

Cotton is an important economic crop at a position which can not be replaced in the national economy of China,Xinjiang is one of the most important cotton production base in China,its output accounts for more than 62.5% of the country.In recent years,with the drip irrigation technology promoted and crop layout changed,the occurrence of weeds seriously threatened the yield and quality of cotton.In order to provide theoretical basis and technical reference for cotton production and weed control in Xinjiang.The occurrence of weed community and crop smothering in cotton field were studied,the number,species,relative abundance,field density and field coverage of weeds were investigated,the indoor fungicides screening of herbicides aiming at the main weed Solanum and the safety evaluation of soil treatment herbicides were researched.The main results are as follows: 1 The weed species of drip irrigation cotton are 9 families and 15 species.Mainly weeds were broadleaf weeds,mainly in Convolvulaceae,Chenopodiaceae and solanaceous weeds;relative abundance of weeds over 43% were barnyardgrass,Solanum nigrum;the occurrence frequency of weeds more than 90% were bindweed,Setaria and barnyard weeds;the average density is higher than that of 1 line /m2 were purslane,Solanum nigrum and barnyard weeds.2.After treated by Glyphosate,clethldim and three fluorine sulfonylurea,3 kinds of protective enzymes respectively showed the different trends,among the different.Because of the protective stress response,there will be an increased first and then decreased of CAT;At the beginning of a period of time,POD will maintain a relatively stable stage,the protect enzyme and antioxidant effect appeared in the last;Due to pesticide spraying,SOD will be greatly inhibited,especially cotton Jie,three fluorine sulfonylurea in the recommended concentrations,there is a big decrease and increased slowly in late period.3.The safety test of soil treatment herbicides on cotton seedlings showed that after treated by 48% Butralin EC,50% acetochlor and 33% EC pendimethalin EC,the cotton seedling roots were swelling compared with the control;After treated by 24% oxyfluorfen EC,the root swelling phenomenon wasn't appeared,but the same as the other three agents,the length of root and fresh weight were lower than that of the control;The content of MDA was significantly higher than the control,and the seedling injury was stronger by the concentration.