套袋红富士苹果果面斑点的发生及其与果实钙含量的关系

为明确苹果果面斑点病的发生与果实钙含量之间的关系，采用田间调查与仪器分析方法相结合，对套袋果实果面斑点病发生情况，包括发病果实在树估上的部位、病斑在果实上的部位、发生时间以及与果实钙含量的关系进行了研究，结果发现：3种类型斑点即黑点、红点、黑斑分别在6月下旬、7月中旬和8月上旬开始出现，其中黑点的发生率最高，为8.6%；斑点主要发生在树冠下层和果实的胴部；墨斑果实钙含量低于正常套袋果实钙含量10.4％，差异显著。

The occurring of Fuji fruit-bagged spot and the relationship with calcium content

The occurring of fruit spot disease was studied, including the location of diseased fruit on the tree crown, the location of the narcotizing spot on the fruit, the time and the relationship with calcium content. The results are as the followes:the spot disease is divided into three types: black spot, black dot and red dot. Among which,the percentage of black spot is the highest (8.6%). Most diseased fruits are found at the down space of tree crown. Spot disease located chiefly at the fruit trunk. The black dot begins to occur in the last ten-day period of June, the red dot is found in the middle ten days of July, and the other begins in the first ten-day period of August. And the calcium content of black spot fruit is 10.4% lower than the normal fruit .