A Complete Guide to Common Pests and Diseases of Chestnut and Their Control Methods
Chestnut is a fairly well-known nut tree species in China, providing substantial income for farmers in mountainous areas of the country, and is one of the pillar fruit trees. Although its economic benefits are relatively high, it faces threats from many pests and diseases during cultivation, which seriously affect the growth of chestnut. In severe cases, it can even kill trees and destroy orchards, causing incalculable losses to the economic interests of farmers in mountainous areas. So what pests and diseases can affect chestnut? How should they be controlled? Let's take a look below!
1. Chestnut blight
Symptoms: Chestnut blight, also known as chestnut canker, mainly damages the trunk and main branches of chestnut trees. After a chestnut tree is infected with chestnut blight, the branches gradually lose their green color, and yellow-brown patches appear on the bark, continuously extending and developing until they surround the entire trunk, generally spreading upward and downward, causing the bark to split, and the leaves also gradually turn brown and die.
Control methods: When selecting seeds, strictly follow the quarantine system and do not choose seedlings or seeds from diseased areas. Strengthen soil fertilizer and water management, enhance the tree vigor of chestnut, carry out timely pest control and insulation, and improve the disease resistance of chestnut. Promptly treat all kinds of wounds on the tree body, especially the gaps at graft unions, which should be coated with agents such as Bordeaux mixture. Diseased plants and diseased branches should be treated promptly and burned in a centralized manner.
2. Chestnut anthracnose
Symptoms: Anthracnose can harm any part of a chestnut tree. Diseased buds show brown rot, and leaves develop irregular brown patches with reddish-brown edges. Twigs form irregular dark brown sunken patches and eventually die. After branches and trunks are affected, they are initially relatively smooth and develop circular black patches, and are easily broken by wind. Affected fruits begin to produce grayish-white mycelium from the tip, develop dark brown lesions, and finally wither and fall off.
Control methods: First, after the winter harvest is completed, carry out winter pruning, cut off all diseased and dead branches, then burn them in a centralized manner, clean the orchard thoroughly, and disinfect it comprehensively; a polysulfide suspension concentrate can be sprayed for disinfection. Before germination, spray an appropriate amount of agent for prevention. Harvesting should also not be done too early. During harvesting and storage, care should be taken not to injure the fruits, reducing conditions for pathogen invasion. Carry out cultivation management well and control pests and diseases in a timely manner.
3. Peach fruit borer
Damage symptoms: The peach fruit borer is a relatively common pest of chestnut. It occurs three times a year, and the period when it is most harmful to chestnut is from August to September. At harvest time, a large number of larvae are attached to the chestnut burs. These larvae bore back and forth between the involucre and young fruits, hollowing out the fruits, making the chestnut lose its edible value, and it should not be stacked for too long; stacking for more than half a month is the peak period of larval damage.
Control methods: When adults hatch the third generation of larvae on chestnut trees, spray agents such as fenitrothion and deltamethrin to kill them, or plant sunflowers in the orchard for trapping and killing. Then, before winter begins, clean up all empty chestnut burs, sunflowers and other materials that have been piled together, burn them in a centralized manner, disinfect the orchard, clear the overwintering sites, and eliminate overwintering larvae.
The three types above are the pests and diseases that commonly occur on chestnut. When using pesticides for control, reasonable control should also be carried out according to the actual local planting conditions. Pests and diseases that pose the greatest threat to chestnut yield should be taken as the main control targets. Prevention should also be carried out, checking potential pests and diseases as secondary control targets, checking specific diseases, and applying the right remedy, and pesticides must not be used blindly, otherwise the result will be the opposite of what is desired.