How to treat the yellow leaves and fallen leaves of the pear tree? What should I do if I have yellow

The early defoliation of pear trees will not only cause insufficient nutrients stored in the autumn of that year, but also affect the process of flower bud differentiation, flowering and fruiting in the coming year, and eventually cause the fruit to appear deformed or fall off.

The reasons for the early yellow leaves and defoliation of pear trees are:

1.The structure of nutrients is unreasonable.

2.The structure of the tree is not reasonable.

3.Moisture regulation is not reasonable.

4.Improper use of chemical pesticides.

The main prevention and control measures are:

1.Improve the nutrition of the tree and enhance the tree strength.

First of all, pay attention to the application of organic fertilizer, especially for those orchards with less than 1% of organic matter content, or even below, more attention should be paid to the application of organic fertilizer. Specifically, after the fruit is harvested in autumn, the organic fertilizer can be applied through furrow application or hole application, and about 2-3 kg of crude fertilizer can be applied per kilogram of fruit, combined with an appropriate amount of nitrogen and phosphorus fertilizer and trace element fertilizer. Secondly, pay attention to the application of top dressing, such as pre-flowering top dressing, fruit expansion top dressing, pre-harvest fertilizer, etc.

Among them, sufficient potassium fertilizer can be applied during the fruit expansion period, and fertilizers such as urea and potassium dihydrogen phosphate can also be applied to properly supplement the nutrition of branches and leaves.

2.Strengthen pruning to create a ventilated tree shape.

For pear trees with too tall crowns and erect trees, they can be retracted and pruned in stages, and the tree shape can be reshaped, so as to finally achieve the purpose of reducing the fruiting part and increasing the fruiting area. For orchards with closed canopy and no ventilation, some side branches can be selectively cut off according to the characteristics of the tree, and the inner branches, peripheral cross branches, dead branches, and branches with diseases and insect pests can be thinned, so as to improve the ventilation and light transmission conditions inside and between the trees, improve the utilization rate of light energy, and reduce the phenomenon of early defoliation.

3.Reasonable water control and the pursuit of water balance.

In the process of watering pear orchards, the principle of "small water and long watering is not dry, and large flood irrigation should not be taken as much as possible" to meet the water demand of plants. At the same time, for areas where flooding often occurs, it is necessary to prune a reasonable drainage system in the orchard to avoid large-scale water accumulation in the orchard. For orchards that are often drought, the method of orchard grass can be adopted to increase soil water retention capacity and improve water use efficiency.

4.Regulate the structure of chemical pesticide use.

First of all, strictly control the number of use of organophosphorus pesticides and the concentration of use, can be replaced by other pesticides, it is best to replace with biological pesticides or pyrethroid pesticides, must be used, pay attention to the use of concentration, spraying time, avoid the noon high temperature period. Secondly, the use of fruit expansion period spray Bordeaux liquid to prevent and control diseases, so that the operation can not only prevent rain erosion, but also can supplement the leaves of the pear tree with copper and calcium, so that the pear tree grows vigorously, the leaves are thick green and black, and the early defoliation is reduced, but it should be noted that it can not be used when there is pear psyllid harm.

This could be a lack of water or an insect infestation. We can replenish water first, and if it is a pest, we need to spray pesticides in time.

It's pear rust. Occurrence rule: Pear rust fungus overwinters in the tissues of juniper cypress disease with perennial mycelium.

In March of the following year, the winter spore angle began to appear, and when the temperature was 14-15, it took about 10-20 days for the winter spores to mature. The germination period of winter spores was from late March to early May, mainly from late April to mid-April. Winter spores can only germinate after rainfall, producing basidiospores, which are spread by wind and rain.

From the germination and leaf development of pear trees to the young fruit stage, it is the susceptible period. When basidiospores scatter and fall on young leaves, shoots and young fruits, the spores germinate directly from the epidermal invaders and can also invade through the stomata. Plaque forms on the hand about 10 days after invasion.

Generally, the pear leaves with 1-9 days of leaf age are the most susceptible to the disease, and the infection is mild after 13-21 days, and after 25 days of leaf development, the incubation period is about 6-15 days, and then the sexual spore organ grows on the lesion, and the sexual spore organ is produced in the sexual spore organ, and the sexual spore organ overflows with the mucus through the orifice, and is carried to other sexual spore organs by insects and rainwater, and about 25 days after fertilization, the rust organ is formed on the back of the leaf. Rust spores are produced in rust apparatus, which spread to juniper cypress from late May to early July, invade cortical tissues, and overwinter in diseased areas with mycelium.

In the non-summer spore stage of pear rust fungus, no repeated infection occurred, and only a short period of time was infected by basidiospores in a year. The severity of the disease is related to whether there is a cypress planting around the pear orchard, the order of magnitude and the distance, especially whether there is a juniper within a kilometer from the pear orchard. Under the condition of the presence of juniper, whether the disease can occur seriously is mainly determined by climatic factors.

If it is warm and rainy during the period from leaf development to young fruits, and a large number of winter spores germinate, pear rust will occur severely. If the weather is dry and rainless, the winter spores cannot germinate, and the pathogen is inhibited.

Control methods: 1) Removal of the main host: Completely cutting down cypress trees within 5 kilometers from the pear orchard is an effective method to control pear rust fungus. When establishing a new pear orchard, it should also be considered whether there are juniper trees nearby, and if there are scattered juniper cypresses, they should be completely cut down.

2) Spraying the main host: If the juniper near the pear orchard is not suitable for cutting, the juniper can be sprayed to kill the spores. The spraying time is before the pear tree germination, the winter spores have matured, but the end of gelatinization is appropriate, which can basically control the disease of the pear tree, and the use of the medicine Baume 3-5 degrees of stone sulfur mixture or 40% Fumei arsenic 100 solution.

3) Spraying pear trees: spraying juniper cypress, when the disease cannot be completely prevented, pear trees must be sprayed to prevent the infection of basidiospores. The spraying time of pear trees should be carried out within 25 days after the pear tree germinates to the leaf exhibition, that is, during the peak period of basidiospore transmission and infection, and sprays once every 10 days, three times in a row.

The type of agent can be 1000-1500 times of 25% powder rust wettable powder or 500 times of 65% zebsen wettable powder, 200 times of 50% sulfur suspension, and 800-1000 times of 50% antibacterial special wettable powder.

Hello, the mesophyll of the young leaves at the top of some pear tree shoots is green and yellow, the leaf veins are still green, and the whole leaf is yellow and falls off, and the above symptoms are likely to be caused by iron deficiency in pear trees. Iron deficiency in pear trees generally starts from the young leaves at the top of the new shoots, the initial mesophyll loses green and turns yellow, the two sides of the leaf veins remain green, and the leaf veins are green reticulated, with the aggravation of the disease, the degree of yellowing is also aggravated, and finally the whole leaf is yellowish-white, the leaf edge is brown and scorched, and the whole leaf is scorched and falls off when it is severe, and the apical bud dies. Remedies for iron deficiency in pear trees:

Increase the application of organic fertilizer to improve the soil and increase the absorption rate of iron by plants. For pear orchards and plants with severe disease, ferrous sulfate should be sprayed after the pear trees germinate in the following year.

The pear tree suffers from yellow leaf disease, its leaves will gradually turn yellow, at this time you can spray it with yellow leaf spirit, you can also use an appropriate amount of ferrous citrate or ferrous sulfate, improve the acidity of the soil, so that the yellow leaf disease of the pear tree gradually improves, at this time it also needs to be placed in a sunny environment, and need to keep the environment ventilated, so that the pear tree grows better.

If the pear tree suffers from yellow leaf disease, it is generally caused by iron deficiency, and it may also be caused by soil discomfort, so what is the best medicine for pear tree yellow leaf disease, you can spray the pear tree with an appropriate amount of yellow leaf spirit, so that the leaves of the pear tree can be improved, and the situation can be avoided from becoming more serious.

In fact, you can also spray ferrous citrate or ferrous sulfate on the pear tree in an appropriate amount, which can improve the acidity of the soil and make the pear tree grow better in the soil, but it should not be used too much, otherwise it will affect the normal growth of the pear tree, and may even affect the fruit yield of the pear tree.

Pear trees suffer from yellow leaf disease, part of the reason is that the soil is not suitable, so it is necessary to give yellow leaf disease a better new soil in time, you can use garden soil, pine needles, organic fertilizer mixed soil, which can also add an appropriate amount of peat, so that it can grow better.

It is recommended that the yellow leaf disease of pear trees should be placed in a sunny environment as much as possible in the process, and it is necessary to keep the environment ventilated.

Generally, the soil is rich in pure iron, but in alkaline soil, a large amount of soluble ferric iron is converted into insoluble ferric salt and precipitated, which cannot be absorbed and utilized, so that pear trees show iron deficiency (yellow leaves). In addition, the application of a large amount of available nitrogen fertilizer leads to soil compaction and iron fixation. Sandy soil is imitation, with strong permeability, easy loss of iron, and serious disease; In spring, the branches and leaves grow vigorously, and the amount of iron required is large, which is easy to lead to iron deficiency; The terrain is low-lying, the soil is clay, poorly drained, and seriously ill.

Yellow leaf drop of pear trees is one of the common diseases of pear trees, mainly caused by malnutrition, pests and diseases, etc. The following measures can be taken:

1.Harvest Wine 20% Suspension: This is a calcium fungicide, 600 times liquid spray can effectively prevent and control a variety of diseases and improve the disease resistance of pear trees.

2.Methyl tobuzin: This is a broad-spectrum fungicide, 1% dilution sprays the canopy, which can prevent pear leaves from falling yellow. Dosage and usage methods should be operated according to the product manual.

3.Kabambital Forest: This is also a broad-spectrum fungicide to control the yellowing of pear leaves, spraying the canopy with 1% diluent and covering the foliage, with remarkable results.

4.Dimethoate Ammonium 40% Water Solution: This is a calcium-burning wild ammonium root fertilizer, which can supplement the calcium and nitrogen of pear trees, enhance tree vigor and improve disease resistance. It is generally sprayed at the flowering and fruiting stage, and the dosage is.

5.Copper sulfate: This is a fungicide, the diluent of which can be used to control diseases such as pear leaf spot. Spray pear trees at the beginning of the disease to prevent the disease from getting worse. The dosage should not be too much to avoid copper poisoning.

6.Dimethoate potassium phosphate: This is a high-bark fertilizer dedicated to fruit trees, providing two nutrients, potassium and phosphorus, which can improve tree strength and enhance disease resistance. Generally, it is applied once before flowering and once in summer and autumn, and the dosage is 2-3%.

7.Green plant protection oil: This is a plant-derived insecticide, which has a good control effect on common pests of pear trees such as aphids, codling moths, red spiders, etc., and is a biological pesticide with low toxicity and low residue, which is safe and environmentally friendly. Spray the canopy with 2% dilution to control pests and diseases.

The above recommendations are all more commonly used and safe pear tree leaf yellow drop medicines, I hope it will help you. Read the instructions carefully before using these medicines and follow the recommended dosage and usage methods.

The yellowing of pear trees is caused by iron deficiency, mainly due to insufficient ferric** in the soil. Leaf diseases mostly occur for a long time in the new shoots, and the symptoms begin to manifest from the young leaves at the top of the new shoots. In the early stage, the mesophyll loses green and turns yellow, and the leaf veins and both sides of the leaf veins remain green, making the leaves green and reticulated, and the diseased leaves become smaller.

With the aggravation of the disease, the degree of green of the jujube gradually increased, resulting in the yellowish-white color of the whole leaf. In the later stage, brown scorched spots began to appear on the edge of the leaves, and in severe cases, the whole leaves scorched and fell off, and the apical buds died. On specific new shoots, with the aggravation of damage, the leaves gradually scorched and fell off from the top down, and the young stems of the new shoots gradually turned brown and died from top to bottom.

When it is severe, you can see the yellowing of the upper leaves of the newly dismantled shoots in the whole garden from a distance, and you can see that there are many bare branches at the top of the trees up close. The degree of soil salinity is heavy, low-lying, high groundwater level, soil clay weight, and drainage.