The basal cortex of some tomato stems in greenhouse is light brown or dark brown, which surrounds the basal part of the stems, some of them have lost water and shrunk, the leaves turn yellow and wilted, and the xylem in the stems turns brown after being broken, which is diagnosed as stem base rot, and the disease continues to spread. Medication scheme: Before taking the medicine, clean the seriously ill plants, then use 500 times of chlorothalonil solution to flood the seriously ill area and the area around the diseased plants for 1 time, and the rest will be irrigated with 400ml of liquid for each plant, and then fully irrigated once every three days to achieve the purpose of thorough irrigation. Effect of medication: Before medication: when the stem base of the diseased plant breaks, the vascular bundle becomes black, and the diseased plant increases day by day; After application: After the original slightly diseased plants were treated with Chinese medicine bactericide (Orlik-Qingkulik), the brown filamentous lesions in xylem no longer spread upward, and the original brown lesions were lighter than May 1 1, and the disease was effectively controlled. Analysis of prevention and control methods of tree death disease: For tree diseases such as stem rot and bacterial wilt, prevention should be given priority, and the prevention period is generally about one week after planting, that is, irrigation with 500 times chlorothalonil at the slow seedling stage, with 7 7- 10/day 1 time for 2-3 times. When the drug is used for treatment, 300-500 times of chlorothalonil solution can be used for small-area flood irrigation of severely ill plants and areas within 2-3 meters around the diseased plants, and the rest can be used for point irrigation prevention and control.