Study On Weed Infestation And Control Technique In Cotton Regions Of Changde Area

Three experiments in this article were conducted to reseach Weed community, Population structure,occurrence and distribution pattern,control technique in cotton regions of changde Area through chemical methods and investigation.1.we investigate the weed community,generation pattern,population structure, occurrence and distribution pattern in cotton regions of changed area using an inverted W-Pattern with 9 sampling points.The results showed that there was 62 species and 23 section of mail weed in changed cotton area.Based on the analysis of weeds U(%),MD(%),F(%),MDR,MDKandRA.2.The dominant species are Digitaria sanguinalis,persic,Acalypha australis,Echinochloa crusgalli,Mazus japonicus,Ecliptaprostrata,Setaria viridis,Portulaca oleracea,Eleusine indica and Leptochloachinensis,it is difficulty control.3.Nine herbicides to the stems and leaves have been tested for controlling cotton weed.The results showed that the efficiency of killing weeds can reach 80%t and effect of yield increase is remarkable.4.Seven soil-applied herbicides and two mixed have been tested for controlling cotton weed.The results showed that the efficiency of killing weeds can reach 70%.5.In recent years,the development cotton has made great progresses,but The weeds are serious.Under the condition of understanding the kind,quantity and occurrence law of weeds,the control technique and strategies have been reviewed in this part,the author hope it is helpful to research and production.