90% of "rotten roots of fruit trees" are caused by these causes!

Author:Farmer Group Master Time:2024-06-28 15:24:11

Root rot of fruit trees directly affects the normal growth of fruit trees, resulting in a decrease in orchard yield. However, the root rot of fruit trees is largely caused by unreasonable fertilizer and water management, and the source should be identified and carefully prevented.

The damage of root rot of fruit trees is very serious, most of the root rot phenomenon is not easy to detect in the early stage, and wait until the aboveground part has symptoms, and then take top dressing and spraying prevention and control measures, and the control effect is not good. It can lead to the weakening of the tree, the decline of yield and quality, and the death of the plant.

Symptoms of root rot of fruit trees The aboveground part is mainly manifested as slow growth, weak tree, late germination but early leaf fall, small and yellow leaves (some have been yellow from spring leaf development to leaf fall), or leaf margins are scorched, yellowing and falling off, new shoots are stunted, it is difficult to flower and bear fruit, the fruit becomes smaller, the quality is reduced, and the whole tree dies in severe cases.

Digging up the topsoil to expose the roots, you will find that most of the fibrous roots are brown and dead, the diseased parts of the thick roots are uneven, some of the lesions are dark brown, the cortex is swollen and ulcerative, and the hands can overflow thick brown juice and accompany the odor.

Analysis of the causes of root rot in fruit trees

1. Long-term chemical fertilizer is in charge, and the root system of fruit trees is the first to suffer. Long-term application of chemical fertilizers such as diammonium, urea, potassium sulfate, compound fertilizer, compound fertilizer, etc., has damaged the soil and caused many catastrophic problems to fruit trees; First, the long-term use of chemical fertilizers, the organic matter in the soil is seriously lacking, and the organic matter in many orchards has dropped to less than 0.6%, and the beneficial organisms and bacteria have lost their living environment, and the harmful bacteria have multiplied, and the root system has been invaded by fungi, resulting in rotten roots and dead trees. Second, due to the serious lack of organic matter in the soil, the soil is compacted and the aeration is poor, which affects the healthy growth of the root system. Third, long-term chemical fertilizer is in charge, resulting in serious soil acidification, especially in the sandy mountain area, manganese poisoning is becoming more and more serious. Fourth, long-term excessive nitrogen fertilizer causes branches to grow, large and small years of serious fruiting, the tree is weak and vigorous but not strong, and the rot disease is serious. Fifth, long-term attention to a large number of elements, ignoring the application of medium and micro nutrients, the soil in the medium and trace elements are seriously depleted, physiological diseases are serious, and the quality of fruits is reduced.

2. A large amount of unfermented and rotted farmhouse manure is applied, resulting in rotten roots and dead trees. A large number of unfermented and rotted human, animal and poultry manure is directly applied to the orchard soil, and a large number of germs, pests, salt, etc. 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 and labor, the use of hole application, ditch application, digging ditches (holes) are few and small, and the fertilizer is filled with holes and ditches to cover the soil, resulting in burning dead roots. The root system of apples is mainly distributed 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 effort, fruit farmers dig ditches and apply fertilizer more and more shallowly, and even sprinkle fertilizer on the ground to water or wait for rain. The roots follow the fertilizer, and the root system of the fruit tree is led to the surface year after year, which is neither drought resistant, nor waterlogging, and is not conducive to the absorption and utilization of fertilizer. The serious consequence of the root system moving to the surface is that the stress resistance of fruit trees becomes poor, and it is easy to cause dead branches and dead trees in case of drought, waterlogging and freezing.

3. Long-term abandonment of soil management has exacerbated soil compaction. The orchard is not plowed for a long time, and the spring and summer weeds are all relied on herbicides, only weeds are eliminated, and the aeration of the soil cannot be dredged, resulting in the active soil layer being in a serious compaction state for a long time; Moreover, the root system of the fruit tree is led to the surface layer, which is neither drought resistant nor waterlogging, and causes poor soil aeration after rain, and the root system suffocates and loses a large number of leaves.

4. The serious shortage of nutrients stored in the tree is the main cause of rot disease. Orchard households, which normally strengthen management, spray pesticides to protect leaves, top dressing in summer, and apply basal fertilizer in autumn, all management is in place, and the tree body is stored with sufficient nutrients, and there are few rot diseases in winter and spring.

5. Excessive use of herbicides.

1. The use of glyphosate for weeding many times within a year, if the operation is improper, it will infiltrate into the soil and cause damage to the underground root system of the fruit tree, resulting in malnutrition in the aboveground part, the phenomenon of yellow leaves, and the weakening of the tree, which will affect the germination, flowering and fruit setting of the fruit tree in the following year.

Second, the use of glyphosate in orchards is also easy to cause soil zinc deficiency. Glyphosate ionizes anions in aqueous solution, and reacts with zinc in the soil after entering the soil, hindering the absorption of zinc by the roots, so that the fruit tree exhibits lobular disease. Zinc deficiency caused by glyphosate abuse occurs in apple trees and peach trees, and in severe cases, it has endangered the life of the tree. Therefore, many experts appeal: autumn basal fertilizer is "gold", winter basal fertilizer is "silver", spring basal fertilizer is "broken copper and iron".

Countermeasures to address rotten roots and dead trees

1. Change the awareness of fertilization and get out of the misunderstanding of chemical fertilizer. Promote the application of farm fertilizers, especially high-quality commercial organic fertilizers, to improve soil aeration.

2. Improve fertilization methods and strengthen soil management. The application of fermented and rotten farmhouse fertilizer should be pounded and sprinkled evenly, and the use of a planer and shovel to dig into the soil to prevent digging ditches and fertilizing too much to burn the root system, so that the fertilizer is widely in contact with the absorption roots of fruit trees, and the fertilizer is fully mixed with the soil to prevent the fertilizer from burning the root system in piles. For soil management, it is necessary to carry out a whole orchard after fruit picking every autumn, which not only keeps the living soil layer well aerated but also prevents the root system from being directed to the surface layer. In case of continuous heavy rain, it is necessary to hoe and aerlate in time after the rain to prevent a large number of fallen leaves caused by suffocation of the root system.

3. Apply sufficient basal fertilizer in autumn to increase stored nutrients. Fruit trees that are harvested early, such as large cherries, apricots, peaches, plums, walnuts, grapes, early and medium-ripening pears, apples, etc., should complete the task of applying base fertilizer in autumn in September. Hawthorn, chestnut and late-maturing varieties of apples, pears, peaches and other fruit trees, after harvesting in October, must rush to apply sufficient base fertilizer.

4. Dredging the drainage system to prevent water accumulation in the orchard. In the orchard, the orchard is planed, and the main trunk is raised by 15-20 cm to form a back shape to prevent water accumulation under the trees after heavy rains. The rows of fruit trees are arranged in a groove shape 15-20 cm below the canopy, which can be watered smoothly in dry days and drained smoothly after heavy rains.

5. Strengthen soil improvement and scientifically replant young trees. If the lower part of the fruit tree is clay and heavy, 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, sandy soil, weeds, straw and other organic matter to create a loose living soil layer. All the fruit trees with rotten roots and dead roots, there are many harmful bacteria left in the ground, and replanting small fruit trees is not easy to survive, and even if they survive, they are not prosperous.

6. Rational use of glyphosate. The use of glyphosate should be applied when the weeds are unearthed and have a certain leaf area (the leaves are best covered with mulch) and can adhere to a sufficient amount of medicine. Glyphosate weeding is carried from the stem to the root through the leaf surface, causing the roots to rot, so as to completely eradicate weeds. If the leaf area is small and the amount of medicine absorbed is insufficient, you can only do half the work.

In addition, combined with the weather forecast, spray in rainless weather to avoid the liquid medicine entering the soil. If it is a fruit that has rotted roots, it is necessary to find out the cause in time and open a ditch to prevent the diseased roots from coming into contact with the healthy roots of the surrounding fruit trees, resulting in the spread of the disease. At the same time, the roots are cleaned and disinfected, and the roots are replaced according to the actual situation.

After these tasks are completed, you can use biostimulants to drench the roots or add biological fertilizers to help improve the soil environment and promote root growth!