Study On The Integrated Control Of Soybean Sclerotinia Stem Rot Caused By Sclerotinia Sclerotiorum

The soybean sclerotinia stem rotis a infective disease caused by Sclerotinia sclerotiorum (Lib.)deBary,and is a cosmopolitan soybean disease that can cause serious losses in yield.In overseas,the soybean sclerotinia stem rot mainly distributed in Brazil,Canada,America, Hungary,Japan and India. In China,it mainly distributed in soybean production areas of north china,east china,southwest china and northeast china. In Heilongjiang Province of northeast china soybean production areas,the incidence of soybean sclerotinia stem rot is increasingly serious when entering the 80`s,the incidence rate are increased from 5% to 20%~30%,the most serious incidence rate of the field are more than 50%,even nil production. Recent years,with the constant enlargement of the soybean planting areas,the alternate and continuous planting areas are increased year by year,the incidence of soybean sclerotinia stem rot are present the trend of enlarge,spread and aggravated harm,make greater threat to the soybean production.The soybean sclerotinia stem rot is a kind of disease that primary infection source mainly consist with sclerotia,the secondary infection in the field has little effect,control the initial amount of inoculum is the effective method to contrl the soybean sclerotinia stem rot. So the comprehensive control measures such as the selection of resistant variety,the agricultural control and the chemical control and so on were studied in this paper ,1. The most economic and effective method to control the soybean sclerotinia stem rot is plan- ting resistance cultivars. By comparing four different methods of artificial inoculation in this study,the method of broadcast-sclerotia was selected as the main identified method to identificati- on the resistance of a large number of varieties.Collection the main popularized soybean varieties that now used in current production and the reserved soybean varieties that will pushed out soon,by the method of artifical inoculation,identification their resistance to the soybean sclerotinia stem rot,screened out thirteen soybean varietie(slines)that showed the resistance of above R level to the soybean sclerotinia stem rot,which can provide scientific basis for the reasonable layout it in production and the resistance breeding.2. By the method of point survey and general survey in the field,we studied the effect of the soybean cultivation model to the occurrence law of the soybean sclerotinia stem rot,also about the ecological environment situation such as growth period,soil type,crops for rotation,varieties fertility,landform and so on,Clearly the influence of culture mode to disease incidence of soybean scleraotinia stem rot and the incidence in the mode of single ridge under Sparse cultivation is minimum,which can provide guidance to the control of the soybean sclerotinia stem rot.3. Use of chemical fungicides to control soybean sclerotinia stem rot has the characteristics of action rapid,obvious effect and simple using method.By the method of inhibitory test of mycxelium growth in lab,screened out five kinds of effective control,low toxicity,low residual chemical fungicides and biological agent that inhibited the proliferation of the soybean sclerotinia stem rot and well compatible with the environment:dimetachlone,5% Methoxy-acrylate Ec,Iprodione,carbendazim and Sumilex,and the inhibitory rate to S. sclerotiorum is 60.91%,60.07%,51.09%,49.56 and 47.25% respectively.Make the above research methods organic combination of scientifically and rational,prliminary developed the new way and new technology that can control the disease.