Fusarium wilt of pomegranate is a destructive disease in pomegranate production. In recent years, with the increase of pomegranate planting area, there is a tendency of gradually aggravating. Pomegranate wilt is harmful to both small and large trees. Pomegranate trees suffer from frostbite, and the tree is weak and prone to disease. Repeated use of garbage fertilizer is also prone to disease.
Symptom
It mainly damages the leaves, and the lesion is round to nearly round, brown to dark brown, with a diameter of 8-10mm. In the later stage, small black dots appear on the lesion, which is the conidia disc of the pathogenic bacteria.
Pathogen
Monochaetia pachyspora, also known as Monochaetia pachyspora, belongs to the asexual ascomycetes of the fungal kingdom. Conidia are spindle-shaped, with colorless cells at both ends, yellowish-brown cells in the middle, and 1 to 2 appendage filaments at the top.
Transmission routes and disease conditions
The fungus overwinters in the diseased tissue as a conidia disc or mycelium, and produces conidia in the next year, which are spread by wind and rain, and carry out initial infection and multiple re-infections. Rainy summer and autumn or moisture retention in the pomegranate garden are prone to disease.
Prevention method
(1) Carefully maintain, ensure sufficient fertilizer and water, adjust the ground temperature to promote root and tree growth, fertilize the soil, loosen the soil, suppress weeds, and avoid farming. Advocate the use of grass-covering cultivation method and dense planting single-stem method, that is, 110 trees are planted in 667m2, and only one trunk is left for each tree, so that the ventilation and light transmission are good, the canopy is compact and easy to control, and the tree vigor is stable and strong, which can be vigorously promoted.
(2) In the early stage of the disease, you can spray 1 : 1 : 200 times Bordeaux mixture or 50% iprodione wettable powder, 47% Chunlei · Wang copper wettable powder, 30% basic copper sulfate suspension concentrate, 20% thiazolin copper Or 20% thiesin copper suspending agent, once every 10 days or so, control 3 to 4 times.
