Common Walnut Diseases and the Latest Control Methods
Walnut, almond, cashew and hazelnut are known as the world's four major dried fruits. It has a wide range of uses and is an economic crop that serves both as food and medicine, and it is grown over an extremely large area in China. But what affects its growth and yield is diseases and pests, causing huge losses for farmers. So what diseases and pests do walnuts have? Below, Qinnong Web brings you the common walnut diseases and their control methods.
1. Walnut powdery mildew
Powdery mildew mainly harms young buds and leaf tips, causing leaves to drop early, and in severe cases it can cause the plant to die. In the early stage, the leaves begin to fade and turn yellow, then slowly the leaves begin to distort, and white powder starts to appear. In the later stage, brown or black particles appear within the white powder.
Control methods: When the disease is found, promptly remove the diseased leaves and branches and burn them in a centralized way to prevent them from spreading to other parts, and use professional chemicals for spraying control.
2. Walnut anthracnose
Anthracnose mainly harms the fruit, and it occurs in the rainy season and in plants with weaker tree vigor. When the disease occurs, the pathogen enters through wounds, and brown or black disease spots appear at the affected site. In severe cases, the fruit rots and drops off, and the leaves wither and turn yellow.
Control methods: Likewise, remove the diseased leaves and branches and burn them in a centralized way, strengthen management, prune overly dense plants, improve ventilation, and reduce the growing environment for the pathogen. In the rainy season, promptly spray Bordeaux mixture to prevent the disease. When the disease is found, carbendazim or chlorothalonil can be sprayed to eliminate it.
3. Walnut rot disease
Rot disease mainly harms the branches and trunk. If it occurs on the trunk, it is not easy to notice. If the branches are infected, first they lose color, causing the branches to wither, and second there are obvious disease spots at the wound, gradually spreading along the branches. In the later stage of the disease, the branches and trunk lose water and rot.
Control methods: This disease is mainly spread by spores, so the soil and planting environment should be improved to increase the plant's disease resistance. If the disease is found in time, the disease spots can be scraped off and then sprayed with thiophanate-methyl. In winter, the trunk can be whitewashed, which can both prevent freezing and prevent the occurrence and spread of this disease.
4. Pests
Walnuts have many pests, but as long as it is not a large-scale pest outbreak, the harm to the plant is not great. The main pests include: scale insects, longhorn beetles, scarab beetles and various moths.
Control methods: In spring, collect and burn all fallen leaves or fallen branches, crush all the egg masses found, and when pests occur they can be caught by hand. If that is too troublesome, professional insecticides can be sprayed to kill them.
The above are the common walnut diseases and control methods brought to you by Qinnong Web. Walnut diseases and pests are unavoidable, so management should be strengthened and careful care should be given. They cannot be left to grow freely, otherwise relatively large losses will be caused.