What are the methods for controlling apple viral diseases?

Apple is a common fruit in our daily lives, and viral disease is a common disease during the planting process. If not controlled in time, it will lead to severe reduction in apple yield and cause huge losses to fruit growers. So how should apple viral diseases be controlled? Let's find out together.

1. Occurrence and harm

The apple viral diseases discovered so far include mosaic disease, rusty fruit disease, wrinkled fruit disease, small fruit disease, ringspot fruit disease, rough-skinned fruit disease, yellow leaf disease, etc. Once infected by a virus, the tree will remain diseased for life with persistent harm. The virus mainly spreads over long distances through grafting along with scions, rootstocks, and nursery stock. The more grafted plants are propagated, the faster it spreads, and it is difficult to prevent and control with chemical agents. After a fruit tree is infected by a virus, all parts of the whole plant will carry the virus, disrupting and infecting the normal growth of the plant, leading to problems such as weakened tree vigor, reduced yield, and deteriorated variety quality, and in severe cases, it can cause the death of the entire plant.

2. Disease symptoms

There are many varieties of viral diseases, and the symptoms of each disease are different. Mosaic disease mainly harms fruit trees and leaves. In the early stage, irregular bright yellow disease spots appear on the leaves, few at first, then gradually expand and turn white, and chlorotic spots also appear. Rusty fruit disease mainly harms the fruit and can be transmitted through grafting. The latent period is 3-27 months. Five radiating brown suberized rust spots appear in the stem cavity direction of the fruit. The epidermal cells at the rust spots become suberized and stop growing, causing the fruit surface to crack and the fruit to become deformed, seriously affecting fruit quality and the marketable rate.

3. Control methods

For propagation, virus-free nursery stock must be selected. This is the most fundamental measure for controlling apple viral diseases. Attention must be paid to the selection of virus-free seedlings before planting. Whether the rootstock or the scion carries the virus, after grafting, virus-carrying branches and plants will be formed, and they will carry the virus for life. First, the rootstock should be selected from seed-propagated seedlings. Second, the scion should be selected from virus-free material. Third, avoid collecting scions from orchards where apples and pear trees are mixed or from apple orchards near pear trees. Fourth, after planting and survival, regularly check whether there are virus-carrying plants, and if found, promptly pull them out and burn them.

The above is an introduction to the control methods for apple viral diseases. We hope it can help you. To learn more related knowledge, please stay tuned to us.