Investigation On The Occurrence Regularity Of Corn Field Major Diseases And Pests And Pesticide Screening In South Of Hebei Province Under The New Cultivation System

The investigation of the occurrence regularity of maize diseases and insect pests and it’s insecticides and fungicides selection were very important to guide maize production.The main research content of this thesis included two aspects.The first was to investigate the occurrence of pests and diseases.The second was for the occurrence of pests and diseases for pharmaceutical screening experiments.This experiment was conducted in the experimental field and indoor laboratory of Handan Academy of Agricultural Sciences,after nearly 12 months of experimental investigation and pesticide screening.Using sampling methods,corn fields were randomly grouped,pupa quantity was investigated by turning soil.The number of larvae was obtained by stripping the whole plant and ear of corn.Adult populations were investigated by trapping,including overwintering base,number of eggs,and disease occurrence rule.Finally,the occurrence regularity of corn borer,peach borer and corn big spot disease under current farming methods was summarized.Specific research results were as follows:(1)There weae more corn borer during the overwintering period.During the whole growth period of maize,the overwintering generation of corn borer caused great harm to maize plants.Temperature had a significant effect on the growth and reproduction of the overwintering corn borer.Based on the control effects of the three agents in this study on corn borer,sprayed 562.5g/hm~280%flubentranamide and 750g/hm~280%flubentranamide had the best control effect on corn borer.(2)Peach borer in maize field in southern Hebei region mainly harms ear of maize.Integrated laboratory and field tests on the control effect of peach moth,sprayed 20%chlorananthramide suspension 3000 times agent had the best control effect on peach moth.(3)The incidence of corn northern leaf blight would increased gradually with the growth period of maize.Severe early onset could lead to severe later disease.The prevention and control of maize big spot disease should be carried out in the early stage of maize.Large corn spot disease could cause maize yield reduction of 1.2-10.2%.Based on preliminary screening and rescreening tests,7 kinds of control agents for big spot disease were screened out,they were mizunamine,benzoyl methyclic azole,fluoxazole,diphenylamine,dinium oxazole,and pyrazole ether ester.