Study On Biological Characteristics Of Alternaria Solani Causing Processing Tomato Early Blight And Disease Control In North Of Xinjiang

Through observing colony characteristics,it was found that Alternaria solani causing processing tomato early blight in xinjiang had two kinds of pigment,One was hoar with yellow,the other was without yellow.Visible light could accelerate hypha growth of alternaria solani more than Ulteraviolet.in contrast,this pathogen grew more slawer in the dark.summarizing various methods for production of spores,It was demonstrated that exposing the colony whose hypha was scraped away to Ultraviolet,the spores could be induced rapidly and largely.Observation of the conidium amount in field was carried out through the spores capturter. The results indicated that the quantity of spores captured in the daytime was more than that in the night, and it captured the most between 19:00 and 21:00.further more,the suitable height for setting the spores capturter was found to be 1 to 2 meters.the microscope slides horizontal placed could captured more spores than upright placed when the microscope slides was hunged to capture spores.Two models used in prophase and meta-anaphase for forecasting disease prevalenet were established acceording to the relation of results of the disease, the quantity of captured spores and weather factors.Based on the models,could be commence control disease when the initial spores captured by a individual microscope slide reached 10,and controlling in this period could effectively avoid disease prevalence. The disease will rapidly expand after spores rised 3-5days and the climate was far.So,by the numbers of the capturing-spores,we could predict the development of disease 3-5dats ahead and provided the reliable basis for disease control. Early blight disease of processing tomatoes mainly occured in the mid and late period of processing tomatoes,if there had a large quantity of rainfall in the mid-June to mid-July,could dramatically increased disease index,which usually was a main reason for early blight disease outbreak.Resistance identification of the leaves and the stems of 21 varieties of processing tomatoes to tomatoes early blight disease in Xinjiang showed that only Hong-fan was a leaf-endurant and stem resistant variety;while Liger 87-5,UC-82 were stem resistant and leaf-susceptive varieties.The remaining varieties were basically both stems-susceptive and leaves-susceptive or high susceptive. It was found that the disease occurence of stems notably lags behind the leaves,the disease were basically stable nine days after innoculation, if identification were carried out at this time,it could nicely reflect the resistance of the varieties.Results of the effect of the tested pesticides in plate and in field indicated that Amixida, Daisenmengxin,Gold mines could used to control the diseases in the early stage,continuous two times and used for 9-10days a time could effectively restrain the disease from expanding.