玉米灰斑病发生和流行规律及其发病条件的研究

Study on Incidence,Regularity of Epidemiology and Inducing Condition of Gray Leaf Spot in Maize

玉米灰斑病病原菌在干燥条件下 ,能够在地表的病残体上安全越冬。降雨量和空气相对湿度是影响玉米灰斑病发生和流行的重要环境因子。描述玉米灰斑病季节流行曲线(S型曲线) ,Gompertz模型比Logistic模型更切合实际。灰斑病的发病条件试验结果显示 ,此病害与玉米品种的抗性、土壤类型和种植形式等的关系密切 ,而与生育期、种植密度、地势和施肥的关系不密切。

The pathogens of maize gray leaf spot, Cercospora zeae-maydis, overwinteres in maize debris positioned on the soil surface under the arid condition and do not survive in leaf tissue buried below the surface. The key factors that affected the incidence and epidemic of this disease were precipitation and air relative humidity. The Gompertz models was fitted into the epidemic curve of gray leaf spot in the field than did the Logistic model, based on F tests and coefficients of determination (R2), and was therefore used to estimate rates of disease increase. The inducing conditions of maize gray leaf spot were studied in the different ecological locations in Liaoning Province, the results showed that this disease was concerned with the resistance, soil types planting patterns,and was not concerned with development stages of maize varieties, planting density, topographical condition, precipitation, applying fertilizer. Damage caused by gray leaf spot in maize was reduced effectively by application of the resistant variety, fall ploughing and spring farming, and inter-cropping.