Common diseases and insect pests of chestnut and their control

Chinese chestnut is a famous dried fruit tree in China, which provides a lot of economy for farmers in mountain areas and is one of the pillar fruit trees. Although the economic benefit is relatively high, it will be threatened by a lot of diseases and insect pests in the planting process, which will seriously affect the growth of Chinese chestnut. In serious cases, it may even die trees and destroy the garden, causing inestimable losses to the economic interests of farmers in mountainous areas. What kind of diseases and insect pests will happen to Chinese chestnut? How to prevent and cure it? Let's take a look at it.

1. Chestnut carcass blight

Symptoms: carcass blight, also known as chestnut blight, mainly harms the trunk and branches of chestnut trees. After the chestnut tree is infected with carcass blight, the branches will gradually fade green, appear yellowish-brown patches on the bark, and will continue to extend until it surrounds the whole trunk, generally expanding up and down, causing the bark to crack, and the leaves will gradually turn brown and die.

Prevention and control methods: seed selection should be in strict accordance with the quarantine system, do not select seedlings from disease areas. Strengthen the soil fertilizer and water management, enhance the tree potential of Chinese chestnut, timely pest prevention and heat preservation, and improve the disease resistance of Chinese chestnut. Timely treatment of all kinds of wounds on the tree, especially the gap in the graft, should be smeared with Bordeaux liquid and other agents. Diseased plants and diseased branches should be dealt with in time and burned centrally.

2. Chestnut anthracnose

Symptoms: anthrax can harm any part of the chestnut tree. The diseased buds will have brown decay, and the leaves will appear irregular brown patches with reddish-brown edges. The top branches will form irregular dark brown sunken patches and eventually die. After the disease, the branches begin to be relatively smooth and appear round black patches, which are easy to be broken by the wind. The injured fruit will produce gray-white hyphae from the tip, appear dark-brown disease spots, and finally wither and fall.

Prevention and control methods: first, after the winter harvest, carry out winter cutting, cut off all the diseased branches, then burn them centrally, clean up the orchard, and disinfect in all aspects, and can spray polysulfide suspension to disinfect. Spray an appropriate amount of medicine before germination to prevent it. It is not suitable to harvest prematurely when harvesting. And in the period of harvest and storage, we should pay attention to prevent the fruit from being injured and reduce the conditions of pathogen invasion. Do a good job in cultivation management and timely control of diseases and insect pests.

3. Peach borer

Harmful symptoms: peach borer is a common pest of Chinese chestnut, which occurs three times a year. The most harmful time to Chinese chestnut is from August to September, and a large number of larvae will be attached to the chestnut bud when harvested. These larvae will eat back and forth between the involucre and the young fruit and hollow the fruit, which means that the chestnut loses its edible value and should not be stacked for too long. The peak period of larval damage is when it is stacked for more than half a month.

Control methods: when adults hatch the third generation larvae in chestnut trees, fenitrothion and deltamethrin are sprayed to kill them, and sunflowers can also be planted in the garden for trapping and killing. Then clean up the empty chestnut buds, sunflowers and other things stacked together before winter, burn them centrally, disinfect the orchards, clean up the overwintering places, and eliminate the overwintering larvae.

The above three kinds are the diseases and insect pests that often occur in Chinese chestnut. When using pesticides for control, we should also carry out reasonable prevention and control according to the actual situation of the planting area. The diseases and insect pests which pose the greatest threat to the yield of Chinese chestnut are taken as the main control target. It is also necessary to carry out prevention, check potential diseases and insect pests, as the goal of dual treatment, check specific diseases, prescribe the right medicine to the case, and not use drugs blindly, otherwise it will be counterproductive.