How to prevent and cure licorice rust

Damage to crops: licorice damage symptoms: mainly damage to leaves. After the seedlings were unearthed in spring, there were round, gray-white blister spots on the back of the leaves, and the posterior surface broke into a yellowish-brown powder pile, which were germ summer spores and summer spores. In the later stage of the disease, the leaves of the whole plant were all covered with summer spores, resulting in the death of the aboveground part of the plant, the proliferation of phloem tissue at the junction of the stem base and the root or stem, the germination of latent buds, and the dwarfing of the plant. After the re-infection of summer spores, the leaves scattered black-brown winter spores on both sides, and scattered black-brown winter spore powder. The disease is the main disease of cultivated licorice, spread all over the main producing areas of licorice, and is the main factor affecting close planting. Classification attribute: basidiomycetes subphylum, unicellular rust fungi distribution area: the main licorice producing areas: the pathogen is a single main parasitic rust, overwintering with hyphae and winter spores on plant roots, rhizomes and aboveground withered branches, and produce summer spores in the next spring. Cultivated licorice has a high incidence of wild licorice. For example, if it was rainy last autumn and the temperature rebounded faster in the coming spring, it would be beneficial to its occurrence. In Yikezhao League, the peak occurrence of diseased plants of biennial cultivated licorice is in mid-May, the rate of diseased plants is about 10%, and the death rate of diseased plants is in late June, with a mortality rate of more than 90%. The peak period of occurrence of winter spore disease is in the middle of July. Control method: thoroughly remove the disease and residue in the field after harvest. Select the plants that are not infected with rust and grow healthily, and cut off the aboveground stems and leaves in winter and spring water and autumn in order to reduce the occurrence of the disease. In the early spring, 20% triadimefon was sprayed with 1500 times solution or 97% sodium triadimefon solution 2Mel 3 times. Commonly used potion: 20% trimethoprim