The symptoms are also called branch blight. It was the branch of the tree that was suffering from the disease. At the beginning of the disease, a brownish-brown to brownish-ovoid lesion develops near the base of the upper half-lignified branch of the tea plant. Afterwards, it expands into a ring and is slightly sunken. Black spots appear on the lesion at the later stage, that is, the pathogenic conidiospore. . Severe onset, moisture transmission is blocked, the evaporation of the aerial leaves is large, and the branches and leaves above the diseased part are dead.
Pathogen Macrophoma sp. Sphaeropsis is a fungus belonging to the fungus Aspergillus spp. Conidia are spherical to subglobose, with apical spores, conidiophores on the inner wall of conidiophores, and conidiophores. Unicellular cells are colorless, linear, with conidia, conidia, and long ovals. , Straight or slightly curved, unit cell, colorless, transparent, size 15.7?237.3?9.7(pm), with more than 1-2 oil balls.
Transmission routes and pathogenic conditions The pathogens in the diseased part of winter through the conidia or mycelium. In late spring, conidia are produced by wind and rain, and spores germinate from new shoots when conditions are appropriate. The disease was prevalent in May, and the branches and leaves died in July and August. Tea tree aging or low-lying tea gardens are prone to disease, poor ventilation or light transmission, and excessive application of nitrogen fertilizer.
Prevention methods (1) Strengthen tea garden management. Timely cultivator rake grass, timely drainage after rain, to prevent moisture retention, the aging of the tea tree to be pruned or Taiwan. The use of tea tree formula fertilization technology, rational use of N, P, K, so that tea grows robustly. (2) Apply 25% benomyl EC 800 times or 36% thiophanate-methylether suspension 600 times, 50% carbendazim WP 800 to 1000 times before the beginning of spring tea. Spray 0.6% of a 0.7% Lime half Bordeaux mixture or 30% of green detergent suspension 500 times, 12% of Green Milk Emulsion 600 times, and 47% of Garnett WP 700 to 800 times.
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