The Occurrence And Control Of Potato Late Blight In Central Region Of Gansu Province

Wheat,rice,corn and potatoes are among the world food crops.In Gansu province,potatoes are planted as three food crops and economic crops.In recent years,as Gansu province membrane double deals with information technology promotion,the potato planting area of about 10 millionmu,the 14 cities(state)of 61 counties have grown,fresh potato yields more than 22.5 million tons,among the top of the country.However,the occurrence and harm of pests and diseases of potato late blight seriously affect the healthy development of potato industry in our province.The central region of Gansu province,Including 8 areas of huining,lintao,longxi,zhangxian,linxia,tianzhu,kongtong,zhuang lang,is the potato producing,therefore,we choose the potato late blight occurrence regularity in this research,summarizes the extraction is feasible and effective prevention measures and method,the purpose is to promote the healthy and stable development of potato industry in Gansu province,promote the farmers' income and the government decision-making to provide the reference.This research mainly based on Gansu province plant protection station providing relevant data of potato late blight,refer to the development of Gansu yearbook,Gansu rural yearbook and Gansu potato late blight monitoring and early warning system and other data released by the official web site,use of Excel for mapping and scheduling.From different point of view about the present situation of Gansu potato late blight occurred in central region of Gansu province,field change rules and chemical control effect are studied,and put forward a series of concrete Suggestions on prevention and control.The main results are as follows:(1)The potato late blight has occurred in eight counties and districts in central region of Gansu province.The disease began in late May,and ended in late September and early October.The disease occurred during the whole potato growth period with the change of the number of pathogenic bacteria.There are some differences in the development of potato late diseases in different areas,but there are some similarities in the development of diseases in the same area.The average generation of potato late blight in central region of Gansu province is around 8 generations,infection cycle 3-13 times,3-36 times of infection.The incidence is more common,the degree of infection is moderate.(2)The potato late blight in the field of fashion movement in an s-shaped curve,,and the development of the disease is obvious as such Four phases: Hyphae incubation period,Central strain stage,Extended period and Recession.After the potato seedling(5 / late month-6/ early month)to the flowering period(6 / midmonth-7/ latemonth),Most plots don't see any symptoms,A central strain was found in the potato phase(7 / late month-8/ early month).The potato plants and leaves around the central strain were alternated with rainfall,cloudy weather,and drought,and the disease presents such development process: Infecting-Extending-Shrinking-Sick again.(3)By 12 common fungicides pesticides in Gansu province market comparison experiment was carried out in three groups,found the selected bactericide for prevention and control of potato late blight has certain effect,but there is a big difference between the control effect of different drugs,part of the drug control effects between different concentrations have bigger difference.There are a variety of antiseptic agents in the test that are better than the antiseptic effect of single fungicide.Experiments on potato late blight prevention effect is good to have: antivirus alum 400 times liquid,big treasure,more than 500 times liquid,86.8% ray WP700 times liquid,80% of net WP500 times faster and 70% c,zinc WP300 times liquid and liquid silver Farley SC400 times the six kinds of agents,these agents on potato late blight control effect can be up to 58.64 ~ 80.95%..(4)The potato planting area in the central region of Gansu province is larger,farmers in order to minimize losses,achieve the goal of high production and efficiency,the central region of Gansu province should be studied as early as possible for prediction method,promoting advanced potato planting and late blight prevention techniques.Around according to the seeding time,and climate factors,combined with the potato late blight epidemic law field,strain in the center of the hyphae incubation period and the period using efficient protective fungicide,efforts to do a good job of disease prevention,strive for in front of the potato piece of bulking stage will disease killed in the bud.When the field chooses to use the agent,according to the local specific situation,the control experimental group's geography,climate and soil conditions,choose the effective potion suitable for the region.When using this test suggested that 6 kinds of fungicides,should try to combine the advanced agricultural technology,applying fertilizers,resultant force,before the onset of applying protective agent,after the onset of use protective effect,tag,in a variety of absorption of effective drugs,in order to achieve the best control effect,get the highest yield.