What are the causes of yellow leaves in fruit trees? How to distinguish prevention?

It could be due to insufficient light, rot, pests and diseases, or insufficient soil fertility. When encountering these problems, we must prescribe the right medicine, and then we should also spray some pesticides to remove insect pests in time to strengthen the management of water and fertilizer.

It can be due to nutrient deficiencies, malnutrition, glue overload, or lack of light. It can be distinguished by the symptoms and morphology of the plant.

Lack of water, lack of nutrients, weather reasons, land reasons, it is possible that it is sick, it can be determined by the time when the leaves are yellow, and can be determined by different colors.

The reason for the yellow leaves of fruit trees is the use of glyphosate herbicides, soil acidification, etc., and the best method of yellow leaves of fruit trees is to increase the application of organic fertilizer and supplement medium and trace elements.

1. The reason for the yellow leaves of fruit trees.

The use of glyphosate herbicides: due to the long residual time of glyphosate in the soil, one is the direct loss of the root system, and the other is that the phosphate antagonizes the medium and trace elements in the soil, so that the fruit trees produce iron, zinc, calcium and other elements, and produce nutrient-deficient yellow leaves.

Soil acidification: due to the large use of compound fertilizer caused by soil compaction and acidification, medium and trace elements in acidic soil produce macromolecules that cannot be absorbed by the roots of fruit trees, and fruit trees appear to be yellowing due to nutrient deficiency. Aluminum ions in acidic soil are easily absorbed, which harms roots and fruit trees, and causes toxic yellow leaves.

2. The yellow leaves of fruit trees.

Increase the application of organic fertilizer: apply organic fertilizer in autumn every year, and the areas where the organic fertilizer is difficult to handle can use ultra-concentrated deep organic fertilizer to ensure soil health, root health, improve organic matter, and fundamentally correct the physiological yellow leaves of fruit trees.

Supplement medium and micro lead lifting elements: slow release medium and trace elements can be added to the base fertilizer in autumn, medium and trace elements can be supplemented on the foliar surface at the beginning of flowering, and boron, calcium, iron, zinc, magnesium and other medium and trace elements can be supplemented according to the needs of fruit trees in different periods, such as zinc and boron supplementation before flowering, calcium and boron supplementation in Xie Hua, calcium and magnesium in the base cavity during the expansion period, etc.

How to prune the fruit locust sharp tree

1. Topping treatment.

When the fruit tree grows new shoots, it is necessary to carry out topping treatment, at this time, the top of the tender bud points and secondary shoots should be cut off to promote the germination of new branches, and lay a good foundation for the fruit tree to bloom and bear fruit in the later stage.

2. Branches are truncated.

After the fruit tree matures, it is mainly based on light pruning, cutting off the buds and shoots on the branches, and shortening the excessively long branches to concentrate the nutrients, which is conducive to better germination and growth of the branches and improves the fruiting rate of the fruit tree.

3. Thinning and pruning dense branches.

In the flowering and fruiting period of the fruit, the dense branches and long branches on the plant should be pruned to save space and nutrients for the differentiation of flower buds, and the withered yellow and weak branches should be cut off so as not to consume too much nutrients of the fruit tree.

The yellow leaves of fruit trees may be caused by too high or too low temperature, which can be controlled by irrigation to cool down or take measures to prevent cold and keep warm. The pesticide damage will cause the leaves to turn yellow when spraying the solution, and the pesticide damage can be diluted immediately to alleviate the pesticide damage. When the fruit tree is deficient in iron, it is easy to yellow the leaves, and the ferrous sulfate that can be sprayed can be sprayed once every 10 days, and sprayed 3 times in a row, and the control effect is obvious.

1. What is the reason for the yellow leaves of fruit trees?

1. If the temperature is too high or too low, the leaves of the fruit tree will turn yellow, when the temperature continues to be too high, the leaf stomata will become larger, and it will turn yellow due to water loss, and the temperature will continue to be too low, and the leaf stomata will be closed, and it will turn yellow due to shutdown.

2. When spraying fruit trees, if the concentration of the liquid is too high, it is easy to burn the leaves, resulting in yellowing of the leaves.

3. There are often pests and diseases in the root system of fruit trees, such as root-knot nematode disease, root rot, etc., which will cause the root system of fruit trees to rot, and the roots can not absorb nutrients and water, resulting in the inability of plant nutrients to deliver nutrients to leaves and fruits, resulting in the occurrence of yellow leaf disease.

4. When fruit trees are deficient in iron, the synthesis of chlorophyll in leaves will be affected, which is manifested as albinism, greening, yellow leaves, etc.

5. A large amount of heavy wet soil is adhered to the root system of fruit trees, which will be compacted for a long time, resulting in the inability of the roots to breathe, and the inability of oxygen to be absorbed by the roots, resulting in the occurrence of yellow leaf disease.

Second, prevention and control methods

1. When the temperature is too high or too low, it is necessary to pay attention to the prevention and control measures, if it is too high, it is necessary to irrigate and replenish water in time; If the temperature is too low, pay attention to water control and take measures to protect against cold and keep warm.

2. When spraying pesticides on fruit trees, it is necessary to choose low-toxicity and green pesticides, and use them in strict accordance with the instructions.

3. For the prevention and control of fruit tree root diseases and pests, a small amount of carbendazim can be added to the soil for disinfection, which can effectively prevent and control yellow leaf disease.

4. During the growth period of fruit trees, the ferrous sulfate or ferric citrate sprayed on the fruit trees should be sprayed once every 10 days, and sprayed 3-4 times continuously, which has a certain control effect on the yellow leaves caused by iron deficiency.

5. Do not irrigate fruit trees too often, if the soil is compacted due to poor drainage, it is necessary to loosen the soil near the root system of fruit trees in time to ensure that the roots can absorb sufficient oxygen.

1. Yellow leaves caused by viruses.

The diseased leaves are dark and light yellow, and the edges of envy are not clear; Others are bright yellow patches of varying sizes with well-defined edges; or striped spots, turning yellow and green along the veins, with wide bands or fine reticulations; There are also yellowing edges along the veins. To prevent and control viral yellow leaf disease, it is strictly forbidden to collect scion on diseased plants as propagation materials; The best way to destroy the diseased plants and promote non-toxic seedlings is to do so.

2. Yellow leaf disease caused by iron deficiency.

It is manifested that the new leaves in the upper part of the treetop are yellow-green or yellow-white except for the leaf veins that are still green, and the leaves are small and thin, and the leaf margins fall off in large quantities due to scorching in severe cases. Prevention and control methods: one is to increase the application of organic fertilizer, the other is to combine the deep application of 100 1 ferrous sulfate mixed fertilizer with livestock, and the third is to spray ferrous sulfate liquid at the beginning of germination.

3. Yellow leaf disease caused by nitrogen deficiency.

Due to the reuse of nitrogen in the leaves, the old leaves lose nitrogen and first turn yellow, and finally fall off. The control method can be more nitrogen fertilizer or sprayed urea solution.

1.The soil lacks medium and trace element fertilizers.

Nitrogen, phosphorus and potassium macro-element fertilizers were the main fertilization, and medium and trace element fertilizers were neglected, resulting in the lack of nutrients in the soil and yellow leaves.

Partial application of a large number of elemental fertilizers causes elemental antagonism, and it is difficult to absorb medium and micro fertilizers.

Soil acid-alkali imbalance, soil too acidic or too alkaline is easy to cause crop yellow leaves.

2.Weak or damaged root system.

If a strong root system is not cultivated in the early stage, or after harvesting a stubble, the intermediate fertilizer is not on the top of the plant, which is easy to cause the follow-up weakness of the plant, resulting in a lack of nutrients and yellow leaves. In the case of low ground temperature, large watering, long rooting time or excessive amount of fertilizer at one time, it will cause root damage and weaken root vitality, resulting in yellow leaves due to insufficient absorption capacity of the root system.

3.The fruit-to-leaf ratio is not suitable, there is a lot of malnutrition, and the removal of a large number of good functional leaves will also lead to malnutrition of the plant and the production of yellow leaves 4(1) Pests and diseases and virus infection cause yellowing of leaves.

2) Pesticide damage (herbicide drifting), air damage, incorrect selection of pesticides, large dosage or incorrect application methods, resulting in pesticide damage, accelerated aging of leaves, and yellow leaves.

Yellow leaves have appeared, what should I do?

We should determine the cause of yellow leaves according to the actual situation in the field, and then take targeted measures.

In the first category, the yellow leaves caused by the lack of medium and trace elements in the soil, we can spray foliar fertilizer containing medium and trace elements (Haifu calcium, magnesium, boron zinc) to quickly supplement, and then apply medium and trace element fertilizer + Haifu fish protein peptide at the root.

For the second type of yellow leaves caused by weak or damaged roots, first spray foliar fertilizer containing medium and trace elements (Haifu calcium, magnesium, boron zinc) to quickly alleviate the nutrient deficiency, and at the same time, each time per mu, 1kg of Haifu alginic acid + 5kg of Haifu fish protein peptide + Fuyou root, used 2-3 times, can effectively improve the root growth environment, activate the root system, generate new roots, strengthen the roots, and alleviate leaf yellowing.

In view of the yellow leaves caused by the uncoordinated fruit-to-leaf ratio of the fourth type, the excess fruits should be thinned firstly, the plant type should be arranged, the old leaves that lost photosynthesis in the lower part should be knocked out, the ineffective branches at the bottom should be removed, and all functional leaves and effective branches should be retained.

In view of the yellowing of vegetable leaves caused by pests and viruses in category 5, the types of pests and diseases are first judged, and pesticides are applied to control the pests and diseases, which can be sprayed with foliar fertilizer.

If it is a virus infection, it is also necessary to pay attention to the prevention and control of whiteflies and other transmission vectors, seriously infected plants, directly uprooted, and then spray amino-oligosaccharides (Fuyoukang) + brassinin + morpholinoguanidine hydrochloride + Fuyou leaves, spray 2-3 times in a row, with an interval of 7 days, while controlling pests and viruses, it can also quickly repair the damaged parts, so that the leaves can turn from yellow to green as soon as possible.