Causes of fruit tree rot and how to deal with it！

The rotten roots of fruit trees directly affect the normal growth of fruit trees, resulting in a reduction in orchard output. The rotten roots of fruit trees are largely caused by unreasonable fertilizer and water management, and the source should be identified and carefully prevented.

Root rot of fruit trees is very harmful. Most root rot phenomena are not easy to detect in the early stage. After symptoms appear in the aboveground parts, control measures such as topdressing and spraying are taken, and the control effect is not good. If it is mild, it will cause the tree to weaken, the yield and quality will decline, and if it is severe, it will cause the death of the plant.

Symptoms of root rot:

The aboveground part is mainly characterized by slow growth, weak tree vigor, late germination but early leaf fall, small and yellow leaves (some are always yellow from spring leaf opening to leaf fall), or leaf edges are scorched, yellow and fall off, and new shoots grow slowly. , It is difficult to form flowers and set fruit, the fruit becomes smaller, the quality is reduced, and the whole tree dies in severe cases.

Excavate the surface soil to expose the roots, and you will find that most of the fibrous roots are brown and dead, and the diseased part of the thick root is uneven.

Causes of fruit tree root rot:

1. Long-term application of chemical fertilizers, the root system of fruit trees is the first to suffer.

Long-term application of chemical fertilizers such as diammonium, urea, potassium sulfate, compound fertilizers, and compound fertilizers has destroyed the soil and caused many catastrophic problems for fruit trees;

(1) With the long-term use of chemical fertilizers, the organic matter in the soil is severely lacking. In many orchards, the organic matter has dropped below 0.6%. The beneficial biological bacteria have lost their living environment, and the harmful bacteria have multiplied.

(2) The serious lack of organic matter in the soil causes soil compaction and poor ventilation, which affects the healthy growth of the root system.

(3) Long-term use of chemical fertilizers has caused severe acidification of the soil, especially manganese poisoning in sandstone mountain areas is becoming more and more serious.

(4) Excessive nitrogen fertilizer for a long time will cause leggy branches, serious results in different years, weak tree vigor but not strong, and serious rot disease.

(5) Emphasis on macronutrients, ignoring the application of medium and micronutrients, severe depletion of medium and micronutrients in the soil, serious physiological diseases, and decline in fruit quality.

2. A large amount of unfermented and decomposed farmyard manure is used, resulting in rotten roots and dead trees.

A large amount of unfermented and decomposed human, livestock, and poultry manure is directly applied to the soil of the orchard, and a large number of germs, pests, and salt carried by it will cause serious damage to the root system, and in severe cases, it will cause rotten roots and dead trees; in order to save labor, To save labor, use hole application and furrow application, dig trenches (holes) that are few and small, fill the holes with fertilizer, cover the trenches with soil, and cause the roots to burn to death.

The root system of apple trees, the main distribution layer is in the range of 20-80 cm below the surface, and the concentrated distribution layer is about 40 cm below the surface. In order to save labor and labor, fruit farmers dig trenches and fertilize more and more shallowly, and even sprinkle chemical fertilizers on the ground to water or wait for rain. The roots follow the fertilizer and lead the root system of the fruit tree to the surface year after year. It is neither drought-resistant nor waterlogging-resistant, and it is not conducive to the absorption and utilization of fertilizer. The serious consequence of the root system going to the surface is that the stress resistance of the fruit tree becomes poor, and it is easy to cause dead branches and trees in case of drought, waterlogging, or freezing.

3. Long-term abandonment of soil management has aggravated soil compaction.

The orchard has not been plowed for a long time, and all weed control in spring and summer relies on herbicides, which only kill weeds, but cannot dredge the aeration of the soil, resulting in a long-term serious compaction of the live soil layer;

Moreover, the root system of the fruit tree is led to the surface layer, which is neither drought-resistant nor waterlogging-resistant. After the rain, the soil is poorly ventilated, the root system is suffocated, and a large number of leaves fall. the

4. The serious shortage of nutrients stored in the tree body is the main cause of the rot disease.

The orchard households who normally strengthen management, spraying pesticides to protect leaves, topdressing fertilizers in summer, and applying basal fertilizers in autumn, all management is in place, maintaining sufficient nutrition in the tree body, and few rot diseases in winter and spring.

5. Excessive use of herbicides.

(1) Glyphosate is used for weeding several times within a year. If the operation is improper, it will seep into the soil and cause damage to the underground root system of the fruit tree, resulting in malnutrition in the aboveground, yellow leaves, and weak tree vigor, which will affect the germination and flowering of the fruit tree in the next year. and fruit.

(2) The use of glyphosate in orchards can easily cause zinc deficiency in the soil. Glyphosate ionizes anions in aqueous solution, and reacts with zinc in the soil after entering the soil, hindering the absorption of zinc by the root system, so that the fruit trees show small leaf disease. Zinc deficiency symptoms caused by the abuse of glyphosate have occurred in apple trees and peach trees, and severe cases have endangered the life of the trees.

Countermeasures to deal with rotten roots and dead trees:

1. Change the awareness of fertilization and get out of the misunderstanding of chemical fertilizer application.

Advocate the application of farmyard manure, especially high-quality organic fertilizer, to improve soil aeration.

2. Improve fertilization methods and strengthen soil management.

When applying fermented and decomposed farmyard manure, it should be finely smashed and spread evenly, and dug into the soil with a planer shovel to prevent excessive concentration of fertilization during trenching and burning of the root system, so that the fertilizer can widely contact the absorption roots of fruit trees, and then sprinkle the fertilizer and mix it with the soil. Cover with soil to prevent piles of fertilizer from burning the roots. the

For soil management, it is necessary to insist on carrying out a whole planing of the orchard after fruit picking every autumn, which not only keeps the live soil layer well ventilated, but also prevents the root system from being led to the surface layer.

In case of continuous heavy rain, it is necessary to hoe and ventilate in time after the rain to prevent the root system from suffocating and causing a large number of fallen leaves. the

3. Apply enough base fertilizer in autumn to increase stored nutrients.

After the fruit tree is picked, it is necessary to apply enough base fertilizer in time. the

4. Dredge the drainage system to prevent water accumulation in the orchard.

In the orchard, the orchard is planed, and the surrounding trunk is raised by 15-20 cm to form a back shape to prevent water accumulation under the tree after heavy rain.

The rows of fruit trees are formed into a groove shape 15-20 cm below the canopy, which can be watered smoothly in dry weather and can be drained smoothly after heavy rain.

5. Strengthen soil improvement and replant saplings scientifically.

For fruit trees with rotten roots and dead roots, if the lower part belongs to heavy clay soil, it is necessary to dig a large hole (1-1.2 meters deep, 1-1.5 meters square), and fill the middle and lower parts with topsoil, sand, weeds, straw and other organic matter to create a loose soil. Live soil layer.

6. Rational use of glyphosate.

The use of glyphosate should be applied after the weeds have emerged, and there is a certain leaf area (the leaves are best covered with mulch), and when there is enough drug attached. Glyphosate weed control is transmitted from the stem to the roots through the leaves, causing the roots to rot, thereby completely eradicating weeds. If the leaf area is small and the amount of medicine absorbed is insufficient, it can only get twice the result with half the effort. In addition, combined with the weather forecast, spray in rainless weather to avoid the liquid entering the soil.

If it is a fruit with rotten roots, it is necessary to find out the cause of the disease in time, and open a ditch to block it to prevent the diseased root from contacting the healthy roots of the surrounding fruit trees, causing the disease to spread. At the same time, clean the root and disinfect it, and consider docking and root replacement according to the actual situation. After completing these tasks, the roots can be sprayed with biostimulants or biological fertilizers can be added to help improve the soil environment and promote root growth!

Ensuring the health of the roots of fruit trees is the top priority of fruit tree management. Only by ensuring the health of the roots can the high yield and harvest of fruit trees be ensured.