symptom
It mainly damages the seed plants. At the beginning, fusiform or irregular gray spots of different sizes are formed on the stems, with dark brown edges and large differences in size. The lesion surrounds the stem for a week, the leaves above the diseased part are withered, and the root cortex of the diseased plant is mostly rotten, and severely withered.
pathogen
Phoma spinaciae Bub.et Kreig., called spinach Phoma, belongs to the fungus kingdom Ascomycota Phoma.
Transmission routes and disease conditions
The fungus overwinters with mycelium or pycnidium in the soil with the diseased residue or on the seeds with mycelium and conidia. When the conditions are suitable, conidia are produced for initial infection and re-infection. Warm and high humidity are prone to disease, and the disease of seed-collecting plants is severe.
Prevention method
①Clear the diseased residues in time after harvesting to reduce the source of bacteria.
②It is necessary to strengthen the management of the harvesting field, and drain water in time after the rain to prevent moisture retention.
③ Spray 500 times liquid of 20% Thiobacterium copper suspension concentrate or 600 times liquid of 78% Bomancozeb WP and 700 times liquid of 40% biguanide trioctylbenzenesulfonate WP at the initial stage of the disease.
