Apple rusty fruit and fruit embroidery should distinguish how to prevent and cure apple rust fruit disease.

Apple rust fruit disease, also known as mosaic disease, is a viral disease and one of the main diseases of Jiaodong apple in recent years. According to the survey, 50% of the orchards have diseased plants, and the rate of diseased plants in individual apple orchards is as high as 40%, and the serious disease rate is 20%. Many fruit farmers regard apple rust as the prevention and treatment of fruit rust, which not only aggravates the disease, but also causes losses.

Apple rust fruit disease

I. harmful symptoms

The symptoms of rust disease are mainly on apple fruits and leaves of fruit seedlings. There are three types of apple fruit:

1. Rust fruit type: the diseased fruit first appeared a slightly thicker water-stained discoloration at the top of the fruit, and gradually expanded into 5 regular vertical lines. Then the water-stained discoloration part gradually corked into rust spots, with the apple growth, along the fruit surface expansion, serious, can reach the fruit shoulder, and more vertical and horizontal cracking, fruit development hindered, fruit small, less juice, but sweet taste. This symptom is most common in apple varieties such as Guoguang, green banana, India, Yanqing, Jonagin and so on.

2. Flower face: the apple has no obvious change before coloring, but after coloring, yellow-green patches appear on the fruit surface, which turns the fruit face into a red and green flower face. This symptom is more common in Zhuguang, Danding, Beidou, Red Fuji and other apple varieties. When the bagged apple is unbagged, there are some white near-round patches on the fruit surface. In the later stage, these patches are not colored, and the fruit face is red and yellow.

3. Rust fruit flower face mixed type: that is, there are both rust spot and flower face symptoms on the same diseased fruit, and there are more mid-ripe apple varieties such as red banana, Xinhongxing, Chiyang and so on.

4. Rust fruit disease also showed symptoms in the seedling stage of some apple varieties: when Guoguang seedlings grew to 30~50cm high, the middle and upper leaves of apple seedlings rolled back from the base to the back, wrinkled near the midvein, the sides were curved, even circular, and the leaves of red Fuji seedlings, young trees and fruit trees had no obvious symptoms, so it was difficult to find them in the early stage.

Second, the law of the disease.

Rust is a viral disease. The whole plant of the diseased tree is poisonous, and the virus grows and propagates with the growth of the apple tree. therefore, once the apple tree gets sick, the disease will be aggravated year by year. It can be transmitted by grafting; healthy trees can also be transmitted when they come into contact with diseased trees; when pruning, they can be transmitted through scissors and saws; insect mouthparts can also spread.

III. Prevention and control methods

1. When raising seedlings, use seeds to sow and propagate, avoid using root-tillering seedlings, strictly prohibit taking scions from infected apple trees, avoid raising seedlings near old apple orchards, establish disease-free nurseries, and take scions from virus-free apple trees to prevent rust.

2. Strengthen the prevention and control of diseases and insect pests and reduce the ways of transmission.

3. The symptoms of orchards with good fertilizer and water management are mild, some people think that more fertilization and more watering can cure the disease, high temperature can also inactivate the virus, and the symptoms are mild, so many fruit growers are reluctant to plane diseased trees and aggravate the disease. Find the diseased tree.-dig it up and burn it in time.

4. Avoid mixed planting of apple trees and pear trees.