What causes white knots on the trunks of fruit trees?

It should be an insect infestation, a scale insect.

can be applied with relevant insecticides**.

How fruit trees are maintained.

1. Site selection: The growth of fruit trees is relatively easy to be affected by the environment, especially the soil water and fertilizer determine the state of the whole growth and development period of fruit trees. Therefore, it is best to choose varieties suitable for local growth, and if the topsoil is not suitable, it is necessary to dig deep to improve or change the soil to achieve suitable soil conditions.

2. Subsoil: Fruit trees have a large demand for water and fertilizer, and the suitable soil may not be able to meet the fertility demand. Although the effect of top dressing is obvious, base fertilizer is the basis of growth. Usually, the subsoil is mixed with well-rotted organic fertilizer and sterilized and disinfected.

3. Planting: The planting of fruit trees is relatively strict, although the survival rate of general planting is quite high, the initial growth is frustrated, and it is easy to fall into sequelae.

Even if it survives, it will affect flowering and fruiting in the later stage, and the quality is poor. Fruit trees are usually selected to take root and soak the roots or water, and take care of the roots before growing.

4. Water and fertilizer: fruit trees require a lot of water, and long-term waterlogging should be avoided when irrigation is sufficient. Similarly, top dressing should also be reasonably distributed in the appropriate period, the growth period is mainly based on the water-soluble fertilizer of the fertile leaf series, and the trace elements of phosphorus and potassium fertilizer are used in the flowering and fruiting stage.

Supplementally, don't be greedy for cheap single fertilization or over-fertilization and under-fertilization.

5. Pest prevention: pests and diseases are the natural enemies of fruit trees, prevention is the main thing in management, it is best to choose physical control methods, and try to avoid the use of pesticides. However, once the disease is found, the corresponding insecticidal and fungicidal drugs** should be used in time to avoid the spread of infection.

The white dots are scale insects. There are about 600 kinds of scale insects, such as red round scale, brown round scale, Kang pian scale, sagittal scale scale, blowing cotton scale, ash scale, Korean hairball scale, round shield scale, etc. Damage to leaves, shoots and fruits.

Males have wings and can fly, but once the females and larvae are feathered, they live on the branches and leaves or fruits for life, causing the leaves to turn yellow, the branches to wither, and the whole tree to die. Scale insects reproduce quickly, reproducing 2 to 7 generations in 1 year, and the insect body is wrapped in a thick waxy layer, so it is difficult for the liquid medicine to penetrate into the body. Therefore, ordinary contact killer drugs have limited effect.

Agents with superior systemic and penetrating effects should be chosen. You can try thiazinonechlorpyrifos or chlorpyrifos or spiroethyl pyrpropyl ether, as well as cocobizhi. Scale insects are mainly prevented.

In winter, it is necessary to do a good job of cleaning the garden, clean up the dead branches and leaves in time, and the pruned branches and fallen leaves should be cleaned up as soon as possible, not stacked. In winter, the trunk is whitened with lime and sprayed with stone sulfur mixture. In this way, it is possible to prevent the growth of scale insects in spring.

The appearance of white knots on the trunk of fruit trees should be caused by insect infestation and scale insects, and relevant insecticides can be used**.

Kiss Good evening The whitish leaves of the new shoots of the Chaizu fruit tree may be caused by different reasons, and some of the possible reasons are listed below:1Insufficient water and fertilizer or lack of anthocyanins:

If the fruit tree lacks sufficient water and fertilizer, or lacks the necessary trace elements such as anthocyanins, zinc, etc., it will lead to poor plant growth, atrophy of the growth point, and whitish leaves. 2.Pests and diseases:

The whitish leaves of fruit trees can also be caused by pests and diseases. For example, oil spots, powdery mildew, aphids, scale insects, etc., these pests and diseases will affect the normal nutrient absorption and photosynthesis of plants, and then cause plants to appear white. 3.

Weather and environmental problems: Large changes in the climate and environment can also cause the leaves of the new shoots of the fruit tree to turn white. For example, sunburn, too high or too low temperature may suppress the photosynthesis of plants, restrict the normal growth of plants, and form white leaves.

Appropriate governance measures should be taken according to the specific situation. If this persists, it is best to have a professional horticulturist visit the site to check the organic matter, pH and trace element content of the soil and take appropriate measures to correct the problem.

Recently, it has been found that the young leaves on some orchard trees are whitish, the white hair is bright and bright, the white is thorough, and there are black spots at the front end of the leaves, and the leaf veins have become white lead brigade color when they are serious, and the internodes become shortened and clustered. The reasons for this are all caused by the lack of "gas" underground. This phenomenon occurs from time to time in apricot orchards, apple orchards, pear orchards, vineyards, jujube orchards, peach, plum, plum, and cherry orchards.

For the general fruit tree, the air capacity (equivalent to the soil aeration porosity) required for normal growth should be more than 10%, below this standard plant can not grow normally, if it is less than 5%, the new young leaves at the top of the crown will stop growing, turn white, and appear black spots, which will have a great impact on the normal growth of the plant and the yield of the next year. If prevention and ** are not timely, there will be dead trees in severe cases. The preventive measures are (1) advocating the orchard grass system, planting white clover on the surface, or natural grass; (2) Apply more farmhouse fertilizer, apply more organic fertilizer, and advocate the use of amino acid liquid flushing fertilizer; (3) Increase the application of biological fertilizer to increase the content of beneficial bacteria in the soil; (4) When watering, only water the middle of the row spacing 1 2, and put an end to flooding with water.