Efficiency And Low Toxicity Chemicals Laboratory Screening And Field Application For Pears Rot

China is one of the important origin of pear,and the world's largest pear-producing country.Pears rot,known as pear cancer,is one of the major disease of pears for its widespread occurrence and difficult to cure.It occurred in China's northeast,northwest and the Yellow River region,it mainly hazards pear branches and also could be harmful to leaves and fruits.It can cause damage to the big sticks,whole plant and plots of pears.Currently,the mainly method to prevent and cure pear rot is applying chemicals after curettage lesion.It has good control effect and very low disease recurrence rate after use of Asomate at early time.However,it was strong toxicity,high residue,strong sensitization and irritation,damage to people and the environment,and if Asomate was long-term use,it would cause pollution orchard,thereby affecting the growth of trees.Currently,organic arsenic insecticides has been disabled.The species of pear rot prevention Pharmacy are messy on the market,so it is necessary to screen efficiency,low toxicity,and better control effect of chemicals to replace organic arsenic insecticides.We selected seven chemicals registered for Pears rot and three chemicals non-registered for Pears rot,evaluated for its Protective and therapeutic effects on Pears rot in vitro.It showed that NAA and humic acid copper sulfide works best to pear rot prevention.We selected methylthio NAA,humic acid copper sulfide and sim bacteria amine acetate to conduct field efficacy trials,the test results are consistent with the interior.Therefore,NAA and humic acid copper sulfide can be used as the preferred controlling pear rot agents.