玉米粗缩病发生与播种期的关系

玉米粗缩病是晋南玉米生产上发生为害最严重的病害之一。试验表明，播种期与病害的发生关系密切，4月15日春播（早播）或6月15日复播（晚播）发病轻，减产少；5月25日套种发病重，减产多。据此，提出适当调整播种期、改变种植方式的防治措施。

Occurrence of MRD in Relation to Sowing-date

MRD is one of the most harmful diseases occurring in the production of maize in Southern Shanxi. The experiment on sowing-date showed that the disease was closely related to sowing-date.Whether spring sowing on 15th April (early sowing )or summer sowing on 15th June (late sowing), the incidence of disease was low. While intercropping on 25th may, the incidence of disease is high and the reduction of output was serious. The author suggested a control measure of adjusting sowing-period and changing planting pattern.