What is the disease of spots on the leaves of pears

Yes**Please send it over.

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, it's pear rust.

1. Removal of transgenic hosts: Removing transgenic hosts such as juniper and cypress around the pear orchard is the most thorough and effective measure to prevent and control pear rust. When building a new pear orchard, it should be considered whether there are any transshipment hosts such as juniper cypress and dragon cypress nearby, and if there is one, all should be removed, if the number is large and cannot be removed, it is not suitable for pear orchard.

2. Eradicate overwintering pathogens: If the pear orchard is near the scenic area or green area, and the main host such as juniper cypress cannot be removed, fungicidal pesticides should be sprayed on the juniper cypress tree to eradicate the overwintering pathogen and reduce the source of infection. That is, in the first to mid-March (before the germination of pear trees), the transplanted host such as juniper is first cut off to remove the diseased gall, and then sprayed with 4-5 Baumé stone sulfur mixture.

3. Pear tree spraying control: spraying on pear trees should be mastered within 25 days after the germination period of pear trees, that is, the peak period of basidiosporous transmission and infection. Generally, after the pear tree spreads its leaves, if there is rainfall, and it is found that the cypress tree produces winter spore horns, spray 1500-2000 times of 20% powder rust Ning emulsifiable concentrate, and spray it once every 10-15 days, which can basically control the occurrence of rust.

If it can't be controlled, it is necessary to add 800 times of 20% flusilazole chloraz, if the prevention and control is not timely, when the lesion (sex sporophyll) appears on the front of the leaf after the onset of the disease, spray 20% powder rust Ning emulsifiable concentrate 1000 times and Gaoke 20% flusilazole chloraz 800 times, which can control the harm and play a very good effect.

4. From the beginning of pear leaf development to the end of May, 1:2 200-240 times Bordeaux liquid can be sprayed; or 70% Dasheng M-45 800 times solution for protection. If the disease has been diseased, you can spray 20% powdery rust 600 times, enazole 3000 times, 10% flusilazole 1200-1500 times for prevention and control, pay attention to the flowering period can not be sprayed, so as not to cause pesticide damage.

Pear rust. 1. Orchard management.

Soil management: From the second year of the new orchard, the basal fertilizer in autumn and winter will be applied every year to carry out deep ploughing and hole expansion. Turn deep to a depth of about 40 cm, and backfill organic matter or organic fertilizer at the bottom to increase the permeability and root fertility of the deep layer.

In spring and summer, the trees are covered with green manure, weeds, crop straw, etc., with a thickness of 15-20 cm, and green manure is interplanted between the rows and pressed to increase the content of organic matter in the soil.

Fertilizer and water management: apply basal fertilizer 1 time per year, top dressing 2-3 times. The basal fertilizer is mainly organic matter, which is applied in mid to late October, and 15-50 kg of organic fertilizer is applied to each tree in the first fruiting tree; Fruit trees are fertilized with yield, and 1 kg of human base fertilizer is applied for every 1 kg of fruit produced.

The first top dressing was carried out 10 days before germination, and about kilograms of compound fertilizer were applied to each tree of the first fruit tree, and about kilogram of compound fertilizer was applied to each fruit tree; The second topdressing was carried out one week after flowering, and the water-soluble fertilizer of vine leaves was preferred, and the amount of application was the same as that of germination; For the third time, potassium fertilizer was mainly used in combination with phosphorus fertilizer and nitrogen fertilizer, and root application and foliar fertilization were used.

The water management of pear orchard is mainly done in the three key periods of pre-flowering, post-flowering and fruit expansion period, which can be combined with top dressing.

2. Pest control.

Pear rust: Damages leaves, shoots and young fruits.

Control method: keep the orchard away from cypress; In early and mid-March, the cypress trees around the pear orchard were sprayed with a 3-degree stone sulfur mixture of Baumé to kill the overwintering spores; Spray protection. Spray once when the buds sprout and spread the leaves, and then spray once every 10 days or so for 3 consecutive times.

Use 1:2:200 Bordeaux solution, or 80% zebsen 600-800 times, or 70% methyl tobuzine 800 times.

It's rust. <>

Can be sprayed with nathalox.

Metholafin, an organic compound, is a white crystal.

It is a fungicide that inhibits fungal protein synthesis.

Scope of application. It is effective for downy mildew of a variety of crops caused by downy mildew, Phytophthora and rot fungus, and phytophthora of melons, fruits and vegetables, and millet white disease.

How to use: 1. Generally, 25% WP750 times liquid is used to prevent and control cucumber downy mildew and blight, cotton blight of eggplant, tomato and pepper, vegetable white rust, etc., spray once every 10 to 14 days, and the number of drugs shall not exceed 3 times per season.

2. Prevention and control of millet white disease per 100 kg of seeds with 200 to 300 grams of 35% seed dressing agent, first moisten the seeds with 1% water or rice soup, and then mix with medicinal powder.

3. Prevention and control of tobacco black stem disease The seedbed is 2 to 3 days after sowing, 133 grams of 25% wettable powder per mu are used for soil treatment, and Honda is used on the 7th day after transplanting, and 58% wettable powder is sprayed with water 500 times per mu.

4. Prevention and control of potato late blight When leaf spots are first seen, spray with 500 times of 25% wettable powder per mu, spray once every 10 to 14 days, and not more than 3 times.

Precautions. With a single long-term use of the drug, the bacteria are prone to become resistant.

Packaging, storage and transportation. The original medicine is packed in galvanized iron drums, with a net weight of 50kg per barrel; All kinds of preparations are packed in 40 (inner diameter) 54cm hardfiber board drums, each barrel contains 200 bags (double-layer plastic bags), each package is 100g, and the net weight of each barrel is 20kg. Storage and transportation should be strictly protected from moisture and sun exposure, keep well ventilated, and do not mix with food and feed, and the storage temperature should not exceed 35.

Store in a ventilated, cool, dry place.

There are many small yellow spots on the leaves of the pear tree, which may be rust on the pear tree, which is one of the common diseases of the pear tree.

After being infected with this disease, it mainly harms the leaf part, dense lesions appear on the front of the leaves, and the light yellow mucus will overflow in wet weather, and the mucus will become black after drying, when the spots become black, the lesions are thick, the back is raised, and gray-brown hairs grow on the bulge, and after the hairs are broken, some rust spores will be released, that is, brown powder, and when the lesions increase, it will cause the leaves to fall. In the later stage, it will not only harm the leaves, but also the new shoots, leaf diseases, fruit stalks, young fruits and other parts.

Summary. Hello, there are usually several reasons why yellow spots appear on pear tree leaves, including:1

Diseases: Pear trees may be infected with diseases such as scab, anthracnose, leaf blight, etc., causing yellow spots on the leaves. 2.

Pests: Pear trees may be affected by pests, such as pear heartworms, pear moths, pear psyllids, etc., which will gnaw on the leaves, resulting in yellow spots. 3.

Malnutrition: Pear trees may have yellow spots on their leaves due to poor soil quality and a lack of nutrients such as potassium and zinc. 4.

Lack of moisture: Pear trees may have yellow spots on their leaves due to dry weather, lack of water, etc. If you find that the leaves of the pear tree have yellow spots, you should take measures in time, such as spraying pesticides ** diseases or insect pests, fertilizing to increase nutrients, watering in time, etc., so as to ensure the healthy growth of the pear tree.

Hello, there are usually several reasons why yellow spots appear on pear tree leaves, including:1Diseases:

Pear trees may be infected with diseases such as scab, anthracnose, leaf blight, etc., which cause yellow spots on the leaves. 2.Pest infestation:

Pear trees may be infested with pests, such as pear heartworms, pear moths, pear psyllids, etc., which will send food to eat on the leaves, resulting in the appearance of yellow spots. 3.Malnutrition:

Pear trees may have yellow spots on their leaves due to poor soil quality and lack of nutrients such as potassium and zinc. 4.Insufficient hydration:

Pear trees may have yellow spots on their leaves due to dry weather and lack of water. If you find that the leaves of the pear tree have yellow spots, you should take measures in time, such as spraying pesticides ** diseases or insect pests, fertilizing to increase nutrients, watering in time, etc., so as to ensure the healthy growth of the pear tree.

What medicine to use. Hello, if it is a pest or disease, you need to decide on the agent according to the specific situation.

The appearance of yellow spots on the leaves of the pear tree is caused by a disease, and the following agents can be used:1Carbendazim:

It is effective against a variety of pear tree diseases, such as scab, leaf blight, etc. 2.Virulence:

It has special effects on pear tree diseases such as anthrax and powdery mildew. 3.Dicofol:

It has a good effect on pear psyllids, pear heartworms and other pests. 4.Oxidized pot glycosides:

It is used to prevent and control anthrax and bacterial diseases. When using pesticides, please pay attention to the dosage, concentration, frequency and safety interval specified in the pat and pickle instructions.

Thank you for your patience, the following is the information compiled for your reference, please consider it according to the actual specific situation, so as not to affect you Pear tree lesions may be caused by pathogenic bacterial infection, and corresponding measures need to be taken. The specific **method** depends on the specific ** and the degree of the disease, Xiaoyuan Here are some common **methods:1

Pruning the infected area: Cut off the branches or leaves infected with the lesions in time, and burn or dispose of the cut parts to prevent the spread of the germs. 2.

Spraying fungicides: Effective fungicides can be used to spray onto the lesions of pear trees to kill pathogenic bacteria. However, it should be noted that when using fungicides, follow the instructions on the instructions to avoid excessive or improper use.

3.Adjust the tree environment: Maintaining the health of the pear tree and adjusting its environment, such as increasing sunlight exposure and strengthening ventilation, is conducive to reducing the possibility of germ breeding.

4.Disease control: Regular disease control of pear trees, such as pest control and lack of treatment, can effectively prevent the occurrence of disease spots.

It should be noted that different diseases require different methods, please confirm the lesions first, and then take corresponding measures. At the same time, regular maintenance and management of pear trees to maintain their healthy growth state are also important measures to prevent the occurrence of diseases.

Summary. Hello, glad to answer for you. When the leaves of the pear tree have yellow spots, it may be suffering from pear rust, in the spring rainy time is the high incidence of pear rust, you need to do a good job of drainage measures for the pear tree, if the leaves of the pear tree show yellow spots, first of all, you need to cut off all the branches of the disease, and then spray it with Mido stone sulfur mixture, powder rust Ning emulsifiable concentrate and other pests and diseases, so that the pear tree gradually recovers its vitality.

Yellow spots on pear leaves are pear rust.

In the process of pear tree growth, it is easy to appear yellow spots on its leaves, many people do not know, in fact, the yellow spots on the leaves are pear rust, in the spring rainy time is the high incidence of pear rust, will reduce the yield of the fruit, if it is serious, it will also make the pear tree die.

If the pear tree suffers from pear rust, causing its leaves to gradually appear yellow spots, it is necessary to first take drainage measures and cut off all the diseased branches to avoid rapid transmission of pests and diseases to other branches and leaves, affecting the normal growth of the pear tree in the soil.

The weeds around the pear tree can be cleaned up, and it needs to be sprayed with Baumé stone sulfur mixture, powder rust Ning emulsifiable concentrate and other pests and diseases, you can spray it once every other week, and spray it continuously for a month, so that the leaves of the pear tree can restore green vitality.

Usually during the spring growth period, it needs to be drained, and it needs to be placed in ventilation and sunlight for breeding, and it needs to be applied fertilizer in time, so as to avoid yellow spots on the leaves of the pear tree, so that the pear tree can grow well.

What should I do if I have yellow spots on the leaves of a pear tree?

Hello, glad to answer for you. When the leaves of the pear tree have yellow spots, it may be suffering from pear rust, in the spring rainy time is the high incidence of pear rust, you need to do a good job of drainage measures for the pear tree, if the leaves of the pear tree show yellow spots, first of all, you need to cut off all the branches of the disease, and then spray it with Mido stone sulfur mixture, powder rust Ning emulsifiable concentrate and other pests and diseases, so that the pear tree gradually recovers its vitality. Yellow spots on the leaves of the pear tree are pear rust pear trees in the process of growth, yellow spots are easy to appear on its leaves, many people do not know, in fact, the yellow spots on the leaves are pear rust, in the spring rainy time is the high incidence of pear rust, will reduce the yield of the fruit, if it is serious, it will also make the pear tree die.

If the pear tree suffers from pear rust, causing its leaves to gradually appear yellow spots, it is necessary to first take drainage measures and cut off all the diseased branches to avoid rapid transmission of pests and diseases to other branches and leaves, affecting the normal growth of the pear tree in the soil. The weeds around the pear tree can be cleaned up, and it needs to be sprayed with Baumé stone sulfur mixture, powder rust Ning emulsifiable concentrate and other pests and diseases, you can spray it once every other week, and spray it continuously for a month, so that the leaves of the pear tree can restore green vitality. Usually during the spring growth period, it needs to be drained, and it needs to be placed in ventilation and sunlight for breeding, and it needs to be applied fertilizer in time, so as to avoid yellow spots on the leaves of the pear tree, so that the pear tree can grow well.

If my answer is helpful to you, please give a thumbs up (in the lower left corner), I look forward to your like, your efforts are very important to me, and your support is also the motivation for my progress. Finally, I wish you good health and a good mood!