Summer is the high incidence period of walnut branch blight How to prevent walnut branch blight

The conidium disk or mycelium overwinters in the diseased branches and trunks of walnut trees. When the conditions were suitable in the next spring, the conidia were infected by wind and rain and insects from walnut wounds or tender for the first time, resulting in branch blight, and spores were re-infected after the onset of walnut branch blight. The disease occurred from May to June, reached its peak from July to August, and stopped after September. Walnut branch blight is more serious in air humidity and rainy years, and young walnut trees with severe freezing and striping are susceptible to the disease. The bacteria belongs to weak parasitic bacteria, the branches of walnut trees with weak growth are easy to suffer from the disease, and the disease is serious in the year of spring drought or frost injury.

Walnut branch blight

Prevention and control methods:

1. Strengthen the management of walnut orchard, increase the application of fertilizer and water, enhance the tree potential and improve the ability of disease resistance.

2. Thoroughly remove the diseased plants and dead branches and burn them centrally. Pruning should be carried out after the walnut leaves are unfolded and before the fallen leaves. During dormancy, it is not appropriate to cut and saw branches, causing bleeding and causing dead branches and dead trees.

3. White the trunk of walnut trees in winter or early spring. Preparation of whitening agent: quicklime 12.5kg, salt 1.5kg, vegetable oil 0.25kg, sulfur powder 0.5kg, water 50kg.

4. Scrape off the disease spot. If disease spots are found on the main trunk of the walnut tree, scrape off with a knife, disinfect the wound with 1% copper sulfate, and apply the following agents: 50% thiram wettable powder 30 Mel 50 times solution; 3-5 Baomethol stone sulfur mixture; 0.15% Wuningmycin water agent 200 Mel 300 times solution; 5% bacteriological clear water agent 50 Mel 100 times solution, smear disinfection.

5. The following chemicals can be sprayed in walnut growing season: 70% methyl thiophanate wettable powder 800mur1000 times liquid; 45% carbendazim wettable powder 800mur1000 times liquid + 50% carbendazim wettable powder 500Mel 800 times liquid; 70% mancozeb wettable powder 800ml 1000 times liquid + 50% isobarbamide wettable powder 800ml 1000 times liquid, spray once every 1015 days, a total of 2ml 3 times, the above agents should be used alternately.