How to identify and control jujube rust

(1) symptoms: jujube rust only harms leaves. At the initial stage, there are light green dots scattered on the back of the leaves, and then gradually protruding into a dark yellow, that is, a pile of germ summer spores. The shape of the summer spore pile is irregular and mostly occurs on both sides of the midrib, leaf tip and base. Yellow summer spores are scattered after the surface of the lesion is ruptured. There are small green dots on the front of the leaf corresponding to the summer spore pile, the edge is irregular, and the leaf surface is mosaic. Finally, the leaves withered and fell early, so as to weaken the tree potential and reduce the yield and quality. (2) incidence regularity: jujube rust is a disease caused by fungi. Generally, the disease began in the middle and late July, and a large number of summer spores appeared from late August to September, which invaded again, entered the peak period of the disease, and began to shed leaves. There is a lot of rainfall from August to September, which is beneficial to the occurrence of the disease, and the incidence is mild in the dry year. (3) Control measures: ① should strengthen cultivation management. Reasonable close planting, pruning over-dense branches, improving ventilation and light transmission conditions, strengthening fertilizer and water management, eliminating stagnant water, and preventing orchards from being too wet can reduce the occurrence of diseases. ② spray protection. The occurrence of jujube rust could be effectively controlled by spraying one time in July, one time in July, and one time in July, and then spraying one more time after one month.