一、品种选择 一般菜农因对某种品种的生长习性熟悉了,习惯多年种植同一个品种。一个品种在某一地方经多年推广种植,形成了一定的规模和面积后,它的致病菌就慢慢的积累增加,一旦环境适宜,易形成病害大流行。所以选择品种要有不断更新的观念,并做好品种的协调,如长筒形品种与包头形品种相搭配,老品种与新品种相搭配。 First, the choice of variety General vegetable growers familiar with the habit of growing a species, used to grow the same species for many years. After a variety of cultivars have been planted for some years in a certain area and have formed a certain scale and area, their pathogenic bacteria gradually accumulate and increase. Once the environment is suitable, it is easy to form a disease pandemic. Therefore, the selection of species should be constantly updated concept, and make the coordination of varieties, such as long-barrel varieties and Baotou-shaped varieties match, the old varieties match with the new varieties.