mint blight

Latin name: Sclerotium rolfsii Sacc. Harmful crops: symptoms of menthol damage: the upper leaves of the diseased plant were discolored at the beginning of the disease, and there were a large number of white mycelium and brown rapeseed sclerotia in the stem base and intersoil, which led to the weakening of plant growth, withering or death of the whole plant after the expansion of the disease. Morphological characteristics of the pathogen: on PDA medium, the mycelium was white, yellow, and radiating; the mycelium was 2-8 microns in diameter, the branches were not at right angles, with septum; the sclerotia was milky white at first, then became light yellow to tea brown or brown, globose to ovoid, 1-2mm in size, and the surface was smooth and shiny. The surface layer of sclerotia consists of three layers of cells, the outer layer is brown, the epidermis is pseudoparenchyma, and the middle is filamentous tissue. Taxonomic attribute: it is called Roxanthium, or Sclerotinia uniformis, which belongs to the distribution area of half-known subphylum fungi: Jiangsu, Anhui, Guangdong, Sichuan, Yunnan and other provinces: the pathogen overwintered in the soil with the disease residue through the hyphae or fungal cords, and when the conditions were suitable in the following year, the sclerotia or mycelium produced hyphae for primary infection. The silky filamentous hyphae produced by diseased plants extend to contact with adjacent plants or sclerotia are re-infected by water transmission, resulting in the spread of the disease. Continuous cropping or clay weight of soil and low-lying or high-temperature and humid years or seasons. Prevention and treatment: avoid continuous cropping in seriously ill areas. It is recommended to apply Japanese enzyme bacteria retting fertilizer or fully mature organic fertilizer. Check in time, remove and burn the diseased plant in time. The disease point and its adjacent plants were irrigated with 5% Jingangangmycin water agent 1000-1600 times, 50% tianan water agent 500,600 times, 20% methyl rifampicin EC 1000 times, 90% dimethophos wettable powder 1000 times, each plant was irrigated with 0.4-0.5L. Or mix it with 40% mixed seed Ling and fine sand to form a 200-fold medicinal soil mixed with diseased soil, 100-150 grams per hole, once every 10-15 days. With 0.4-0.45 kg of cultured Trichoderma harzianum and 30 kg of fine soil, mix well and sprinkle on the base of the diseased plant. Stop taking medicine 5 days before harvest. Commonly used agents: 5% Jingangmycin water agent 50% Tian'an water agent 20% methyl rifampicin EC 90% dimethophos wettable powder 40% mixed with seed ling.