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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。
Through field trials in 2012-2014, we systematically investigated and compared the natural occurrence of grape downy mildew in Shenyang, and analyzed the correlation between the weather factors influencing the epidemiology of grape downy mildew. The results showed that the seasonal epidemic curve of grape downy mildew in Shenyang was a typical unimodal S-shaped curve. Application of SPSS19.0 software analysis, made it clear that Logistic model can reflect the epidemic situation of grape downy mildew in Shenyang. At the same time, the epidemic stage of the disease was deduced: the period of exponential growth was from the first ten days of July to the second ten days of July, which was the best period for preventing and controlling pesticides; the logistic increase period was from the end of July to the end of August; Grape end of life. The incidence of disease in different growing season, the number of days of epidemic phase and the maximum disease index varies, but with the trend of the Logistic model is basically the same. The apparent infection rates of disease in various epidemic stages are as follows: onset period> vigorous period> decline period. The initial period and Sheng period is the decisive period of grape downy mildew throughout the growing season the critical period. The meteorological factors had a significant effect on the epidemic of grape downy mildew, and the apparent infection rate was positively correlated with the average relative humidity at 7 days, the accumulated rainfall at 7 days and the number of wet days at 7 days, but not with the average temperature at 7 days The above four meteorological factors are the main factors affecting the prevalence of downy mildew in Shenyang.