新型栽培模式对玉米大斑病流行时间动态的影响

摘要

根据植物病害流行学原理,通过田间试验设计及人工接种技术,考察二比空栽培模式、大垄双行栽培模式和常规栽培模式下玉米大斑病的发生流行动态.采用温湿度记录仪24小时定点监测温度和湿度,结果表明:从接种开始到流行末期二比空栽培模式小区比常规栽培模式小区日平均温度低0.8℃,比大垄双行栽培模式小区日平均温度低1.5℃,日平均湿度分别低3.4%和8.2%.二比空栽培模式病情指数比常规栽培模式低11.4,比大垄双行栽培模式低16.0.整个病害流行过程中3种栽培模式温湿度依次为大垄双行栽培模式>常规栽培模式>比空栽培模式,且不同栽培模式的玉米大斑病的发生和流行差异显著.整个病害流行过程中病情严重程度依次为:大垄双行栽培模式>常规栽培模式>比空栽培模式.应用SPSS11.5软件对通过计算机所调查的3种栽培模式的病情指数进行曲线回归分析,拟合出最适Logistic模型,该模型最适用于描述二比空栽培栽培模式、大垄双行栽培模式和常规栽培模式下玉米大斑病流行时间动态.应用该模型推导病害指数增长期(始发期,该时期也是最佳药剂防治时间)可知大垄双行栽培模式的始发期出现较晚,而Logistic增长期(盛发期)常规模式长于二比空栽培模式和大垄双行栽培模式.%By using field experimental design and artificial inoculation technique, the epidemic dynamics of northern leaf blight was comparatively studied according to the principles of plant disease epidemiology among different planting patterns, two rows of plant with one row empty, broad row with two lines of plant and the conventional row spacing. The temperature and humidity were mornited with the recorders. From the inoculation to the end of epidemic, the daily average temperature of two rows of plant with one row empty was 0.8℃ lower than that of conventional row spacing, 1.5℃ lower than that of broad row with two lines of plant; the daily average humidity was lower by 3.4% and 8.2%, respectively. The disease index of two rows of plant with one row empty was 11.4 lower than that of conventional row spacing, 16.0 lower than that of broad row with two lines of plant. The temperature and humidity of three cultivation modes in the whole epidemic process was broad row with two line of plant > conventional row spacing > two rows of plant with one row empty, which caused significant difference in the happening and epidemic of the northern leaf blight. The disease index in the whole process was broad row with two line of plant >conventional row spacing > two rows of plant with one row empty. According to the regression analysis by SPSS 11.5, the optimal Logistic model was determined to describe the epidemic dynamics of northern leaf blight. It was shown that the exponential growth stage (beginning period, the best control time) of northern leaf blight appeared later under broad row with two line of plant, and the full incidence period was longer under conventional row spacing than uder other two modes.