Pay attention to the control of lettuce sclerotia
As the spring temperature gradually rises, lettuce sclerotia begins to occur, and farmers should pay attention to prevention and treatment. Sclerotinia sclerotiorum mostly occurs from the base of the stem, and begins to form a brownish-water immersed lesion. It gradually spreads upward to the stem and extends downward to the root, and the diseased tissue rots. Under wet conditions, the surface grew white flocculent mycelia, and long black murine schistosomiasis nucleus. The upper part of the diseased plants quickly wilted and died. Be sure to find early and treat early. The disease is a fungal disease. The bacterium sclerotia is mainly wintered in the soil. When the spring conditions are suitable, the sclerotia will germinate to produce sporangia and capsular spores, which will spread through the wind and rain and invade from the site of plant senescence. Reinfection in the field is mainly caused by contact with mycelium and spreads. The most suitable temperature in the field is about 20°C, and the relative humidity is more than 80%. Therefore, low temperature and humidity, excessive plant density, etc., are conducive to the occurrence of the disease. Control methods: 1. Agricultural control. The deep cultivator buried the sclerotia in soil below 10 cm. Rationally apply nitrogen fertilizer and increase phosphorus and potassium fertilizers. Covered cultivation, with soil colonization. Selection of disease-resistant varieties, such as red leaf lettuce, red round leaf and so on. When removing diseased leaves, diseased leaves should be brought out of the field to reduce the bacteria source and reduce the damage. 2. Chemical control. In the adult plant stage, 40% Sclerotium can be used as a 1000-fold wettable powder, or 70% thiophanate-methyl WP 800 times, or 50% acetaminophen WP 1000 times, or 50% ketamine. Wet powder 1500 times, or 50% nellikon wettable powder 1500 times, etc., spray 7 to 10 days, even spray 3 to 4 times. In order to prevent drug resistance, it should be used alternately. Hba1C Test,Hba1C Assay,Hba1C Analyzer,Handheld Hba1C Wuxi BioHermes Bio & Medical Technology Co., Ltd. , https://www.biohermesglobal.com