Control methods of apple rust

China is a big apple growing country, but the wider the planting area, the more diseases. Apple rust is a very common disease in apple orchards. It is also known as red spot disease, which is a typical alternate host disease. The outbreak of this disease will affect the growth and yield of apples and bring great losses to fruit growers. Let's take a look at its prevention and control methods.

1. Symptoms

Rust is mainly caused by the leaves of apple plants, but also harms the young parts of the plants, such as twigs, young fruits and fruit stalks. When the leaf is sick, there are small orange spots on the front of the leaf, which slowly expand until a round orange spot is formed and the edge is red. When the disease is serious, there are many or more than a dozen disease spots in the leaves, which are covered with yellow dots, and a mass of yellow villi will grow on the back of the leaves. When the young fruit is sick, there will be a round disease spot on the fruit surface, which begins to be orange and gradually turns yellowish brown, and finally there are tubular rust spores around the disease spot, resulting in the abnormal growth of the diseased fruit.

2. Morbidity condition

In the rainy, windy and suitable temperature environment, it is the external condition of apple rust, and its occurrence is proportional to precipitation. The greater the soil humidity and air humidity, the more conducive to the spread of the disease. Therefore, when planting, we should pay attention to the drainage and waterlogging prevention measures in the rainy season, but also strengthen ventilation and reduce air humidity.

3. The regularity of the disease

Apple rust is caused by Yamada gum rust, also known as oriental gum rust, which belongs to basidiomycete subphylum fungi and is a main parasitic fungus. The pathogen overwintered as mycelia on the branches and leaves of juniper. After the second year, microspores were formed on juniper and spread to apple plants by wind. The pathogen could spread as far as 50 kilometers.

4. Prevention and control methods

First of all, get rid of the main parasites and cut down all the juniper, cypress, cypress, and other trees within 5000 meters of the orchard. If they cannot be cut down in time, they should be sprayed to remove the source of overwintering bacteria. In order to build an apple orchard, we should pay attention to the planting density and do a good job of pruning, so as to make the plants well ventilated and transparent. Drainage measures should be taken in the rainy season to reduce air humidity, clear the garden in time in autumn and winter, burn or bury the residual branches and leaves, and reduce pathogens.

The above is the introduction of apple rust prevention and control methods, hope to help you, want to know more related knowledge, please pay attention to us.