Symptoms are mainly tuber damage. A white filamentous mycelium was densely covered on the tuber, and a brown saccharomycetous sclerotia was observed. The subcutaneous tissue of the diseased potato was browned. The pathogen, Sclerotium rolfsii Sacc., is known as S. sclerotiorum and belongs to the fungus Subgenie Fungi. The sexual state is Atheliarolfsii (Cursi) Tu. & Kimbrough. It is called Rhizoctonia and belongs to Basidiomycotina fungus. The mycelium is colorless and has a septum; sclerotia is composed of hyphae, the outer layer is cortex, and the interior is composed of pseudo-thin-wall tissue and loose tissue at the central part. The early white color is closely attached to the host and is yellow-brown Or oval small sclerotia, diameter 0.5-3mm. Under high temperature and high humidity conditions, the burden and basidiospores are produced. The burden is colorless, unit cell, stick-like, size 166.6 (μm), and the colorless basidiospores are formed on the tips of small stalks. In addition, it has been reported that Corticium rolfsii (Sacc.) Curzi is a bacterium that causes the disease. Prevention and control methods (1) The land masses with severe disease should be rotated with grass crops, and the conditional conditions can be better for paddy-soil rotation. (2) Deeply turning the land and turning the bacteria to the lower layers of the soil can reduce the incidence of the disease. (3) Before the formation of sclerotia, remove the diseased plants and disinfect the lime by disinfecting the diseased points. (4) The application of adequately cooked organic fertilizer, followed by application of ammonium sulfate, calcium nitrate, less incidence. (5) Adjust the pH of the soil, combined with soil preparation, applying 100-150kg of slaked lime per 667m2, making the soil neutral to slightly alkaline. (6) In the ward area, 40% pentachloronitrobenzene (1kg) plus fine dry soil (40kg) can be mixed and then removed from the base soil of the stem or sprayed with 50% seed dressing double wettable powder 500 times, 50% mixed sulfur or 36% % Thiophanate Suspension 500 times, 20% Triadimefon EC 2000 times, every 7-10 days. In addition, it is also possible to use 20% of Rickettsia (methyl tococipum) EC 1000 times in the initial stage of the disease to burr or apply 1-2 times, every 15-20 days. Healthy Cat Treats,Homemade Cat Treats,Best Cat Treats,Cat Dental Treats Jiangxi Welton Pet Products Co., Ltd. , https://www.weltonpetcare.com
Transmission routes and disease conditions are caused by sclerotia or mycelium left over in the soil or on the sick and overwintering. The sclerotium has strong resistance to stress, low temperature resistance, and can survive after being passed through the digestive tract at -10°C. It still has germination power under natural conditions for 5-6 years. After germination, sclerotia produced hyphae, which invaded from the base of the roots or near surface stems to form a central diseased plant. White mycelia mycelia and small round sclerotia were then generated on the surface of the diseased part and spread to the surrounding area. The mycelium is not dry, and the optimum temperature for development is 32-33°C, the highest temperature is 40°C, the lowest is 8°C, and the pH range is 1.9-8.4, and the optimum pH is 5.9. In the field, germs mainly spread through rainwater, irrigation water, fertilizers, and agricultural operations. The south is hot and humid in June and July. The humidity in the potato is too high or the plant is dense. The ventilation and light transmission between the rows is poor. The application of organic fertilizer that is not fully matured and the incidence of continuous cropping are heavy.