Prevention and treatment of grape black pox disease in rainy days

Grape black pox, also known as scab, commonly known as bird's eye disease, is one of the main diseases of growing grapes, harming green and tender parts of grapes, such as fruit, fruit stalks, leaves, petioles, new shoots and tendrils, etc.

Grape black pox

The occurrence of grape black pox is closely related to rainfall, atmospheric humidity and the tender condition of grape plants, especially Rain Water. Rainy and humid is beneficial to the formation, spread and germination of conidia, and the young tissue invading grape grows rapidly and the disease occurs seriously.

In order to control grape black pox, we should reduce the source of bacteria, select disease-resistant grape varieties, strengthen field management and cooperate with chemical control.

Disinfect the seedlings. As the non-distance transmission of black pox is mainly through grape seedlings or cuttings with pathogens, disease-free seedlings should be selected or disinfected in advance when planting in vineyards.

Clear the garden thoroughly. The primary infection of black pox mainly comes from the mycelium overwintering on the remains of grape disease. therefore, in winter, do a good job in clearing the garden and reduce the number of bacteria infected at the beginning of the second year, which is helpful to slow down the disease. When pruning in winter, cut off the diseased branches and residual diseased fruit of the grape, scrape off the diseased and old bark, and thoroughly remove the dead branches, fallen leaves and rotten fruit in the vineyard.

Using disease-resistant grape varieties. There are obvious differences in the resistance of different grape varieties to black pox. Before planting in the vineyard, the local production conditions and technical level should be considered, and the grape varieties with high commodity value and good disease resistance should be selected according to local conditions.

Strengthen management. In addition to improving sanitation and reducing the source of bacteria, we should pay close attention to various field management measures, especially fertilizer and water management. Before and after harvest, the vineyard should be ditched and fully applied with organic fertilizer to maintain a strong grapevine potential. Topdressing should use full fertilizer containing nitrogen, phosphorus, potassium and trace elements to avoid separate or excessive application of nitrogen fertilizer. Vineyards replanted from flat land or paddy fields should be drained in time after rain to prevent stagnant water. Timely weeding between rows, picking tips and binding vines, so that the vineyard has good ventilation and light transmission, and reduce the field temperature. These measures are beneficial to strengthen the resistance of grape plants, and are not conducive to bacterial infection, growth and reproduction.

Chemical control. In addition to the prevention and control of overwintering in the clear garden, spraying Bordeaux solution of 0.7 and 250 Bordeaux once before and after flowering in the growing season plays a key role in controlling grape black pox. From June to July, 25% pyrimethrin 1000 times solution and 40% fluorosilazole 8000 times solution can be sprayed once every 10-15 days for 2-3 times.