沈阳地区葡萄霜霉病流行时间动态及其气象影响因子分析

 通过2012-2014年田间小区试验,对沈阳地区葡萄霜霉病自然发病情况进行了系统调查和对比分析,并对影响葡萄霜霉病流行动态的气象因素进行了相关性分析。结果表明,沈阳地区葡萄霜霉病的季节流行曲线是典型的单峰S形曲线。应用SPSS19.0软件分析,明确了Logistic模型能够反映沈阳地区葡萄霜霉病流行时间动态情况。同时,推导了病害流行阶段:指数增长期为7月上旬至7月下旬,该时期为最佳药剂防治时期;逻辑斯蒂增长期为7月下旬至8月下旬;衰退期为8月下旬至葡萄生育末期。不同生长季病害发生日期、流行阶段天数和最大病情指数虽各不相同,但与Logistic模型推导趋势基本一致。各个流行阶段病害的表观侵染速率表现为:始发期＞盛发期＞衰退期。始发期和盛发期的是决定整个生长季葡萄霜霉病流行程度的关键时期。气象因素对葡萄霜霉病的流行有明显影响,其中表观侵染速率与7 d平均相对湿度、7 d累计降雨量和7 d叶面湿润时数成显著正相关,而与7 d平均气温呈显著负相关,以上4个气象因素是影响沈阳地区葡萄霜霉病流行的主导因子。

Epidemic temporal dynamic of grape downy mildew and its meteorological influencing factors in Shenyang,Liaoning

The epidemic processes of grape downy mildew were investigated and analyzed systematically in the field plots, Shenyang, 2012-2014. The correlation between epidemic dynamic of the disease and meteorological factors were analyzed in different years. The results were shown that the seasonal epidemic curve of grape downy mildew in Shenyang was a typical single peak S curve. The logistic model could reflect the temporal dynamic of grape downy mildew well by using SPSS19.0, and the epidemic periods were derived. The exponential phase was from early-July to late-July, which was the most effective period for chemical control. The logistic phase was from late-July to late-August, and the degenerating phase was from late-August to the end of grape growing season. Days of the disease occurrence, every epidemic phase’s days and the maximum disease index in different growing seasons were different significantly, but the trend was basically consistent with the logistic model. The apparent infection rate of the disease in each epidemic stage was shown: exponential phase＞logistic phase＞degenerating phase, exponential phase and logistic phase were the key periods of epidemic decision of grape downy mildew in the different growing seasons. Meteorological factors had significant effect on the epidemic degree of grape downy mildew. The apparent infection rate was a significant positive correlation with relative humidity, rainfall and leaf wetness duration before 7 days respectively, but was a significant negative correlation with temperature before 7 days. It was shown that the four meteorological factors were the key factors affecting grape downy mildew in Shenyang.