Symptoms are mostly on the petioles near the ground. Brown necrotic spots develop at the site of initial infection, and then spread to the entire petiole, overflowing the dark brown juice. When the weather is dry, the disease department is limited to one spot and has brown depression spots. When the conditions are right, the leaf ball will be harmed, resulting in the entire leaf ball appearing wet rot. The diseased department often produces reticular mycelia or brown sclerotia. The onset of pathogenic bacteria in the soil in the winter, mycelium contact with the host after the lettuce leaves surface infiltration. The average daily temperature in the field is above 20°C, and the disease becomes heavy when the humidity is high or water is accumulated. Prevention methods 1 Agricultural measures: Choose high-dry plots to grow lettuce to prevent the surface humidity from being too high. Avoid planting too dense and keep the fields airy and transparent. Drain the water immediately after the rain. 2 Chemical control: It can be sprayed with streptomycin sulfate 4000 times, or 72% of agricultural streptomycin sulfate powder 3000~4000 times, or 20% methyl-rhodium phosphate emulsion 1200 times, or 10%. Aqueous suspension agent 300 times liquid, or 15% aphrodisiac agent 450 times, once every 7 days, even spray 2 or 3 times. Preservation tubes are swabs with disposable virus sampling tubes to collect DNA tests for disposable nasal flocking sterile medical transport. swabs with disposable virus sampling tubes , to collect DNA tests for disposable nasal flocking sterile medical transport. Jiangsu iiLO Biotechnology Co., Ltd. , https://www.iilogene.com
Diagnosis and treatment of stalk rot in lettuce