上海柑橘黑点病田间流行与降雨关系研究

自2009年起柑橘黑点病逐渐成为上海地区影响柑橘果实商品价值的最主要病害，严重制约上海市柑橘产业的效益。为了解该病的田间流行动态以及病害发生与降雨量的关系，2010年—2018年连续9年进行了病害发生动态调查和分析。结果表明，上海地区6月上旬至8月下旬是果实感病期，其中，6月中旬至7月中旬为发病高峰期；雨水是黑点病发生的必要条件，果实生长期不同阶段的降雨参数，尤其是6月下旬的降雨量与病情指数密切相关。本文以病情发展的3个时间节点(7月15日、8月15日和9月10日)的病情指数为因变量，以这3个时间点之前各旬的降雨量、降雨日为自变量筛选变量建立了多元线性回归方程，根据分析结果，采用6月下旬的降雨量等气象因子建立的多元线性回归方程，可以比较准确地预测7、8月中旬和9月10日即病害发展稳定期的田间病情。

Relationship between citrus melanose and precipitation in Shanghai

Since 2009, citrus melanose disease has gradually become the most important disease affecting the commercial value of fruits in Shanghai, and seriously restricted the benefit of citrus industry. In order to understand the epidemic dynamics of the disease in the citrus orchard and the relationship between the disease incidence and rainfall, the investigation and analysis of disease occurrence dynamics were carried out for nine consecutive years from 2010 to 2018. The results showed that the susceptible period of citrus fruit was from early June to late August , and the peak period of the disease incidence was from mid-June to mid-July. The rainfall was essential for the occurrence of the disease. The precipitation variables in different growth stages of fruits, especially the rainfall in late June, was closely related to the disease index. In this paper, The multiple linear regression equations were established according to disease index at three time points of disease development (July 15, August 15 and September 10) as the dependent variable, and the rainfall and rainfall days of each ten days before the three time points as independent variables to screen the parameters closely related to the change of disease index. The results showed that multiple linear regression equation established by meteorological factors such as rainfall in late June can accurately predict the disease development in the field in mid-July and Mid-August and September 10 when the disease development is stable.