How to prevent and treat anthracnose in pears, the causes and treatment of anthracnose in pear trees

Hello! Pear anthracnose, which is a fungal disease, has latent infection characteristics, and most of them occur when they are mature. The high temperature and high humidity of the disease are conducive to the epidemic of the disease, and the tree is weak, the branches and leaves are dense, the nitrogen fertilizer is applied partially, the drainage is poor, and the excessive fruiting occurs seriously.

Generally, July and August are the peak period, and if there is high temperature and high humidity during the storage period, it is easy to get sick and cause fruit rot.

Prevention and control measures: 1. Strengthen cultivation management and enhance tree potential.

2. Completely remove the source of bacteria. Before germination, spray the whole garden with 5 Baumé stone sulfur mixture.

3. Pharmaceutical prevention and control. Spray fungicide once 7 days after flowering, and then once every half month, 3 or 4 times in a row (can be combined with other disease control). The fungicides with high virulence to pear anthracnose, pear ring pattern fungus, and pear black spot fungus are:

50% prochloraz wettable powder, 25% prochloraz emulsifiable concentrate, 40% flusilazole emulsifiable concentrate, 25% azoxystrobin suspension, Shengshi 10% difenoconazole water dispersible granules, Shigao 10% difenoconazole water dispersible granules, 50% iprodione suspension. After June 20, spray the protective agent Bordeaux liquid, 1 part of copper sulfate: 2 parts of quicklime 3 parts:

200 240 parts of water, 3 4 times in a row, 20 days apart, pay attention to the choice of sunny day spray Bordeaux liquid.

4. Fruit bagging protection, spray fungicide once before bagging.

Pear anthracnose, also known as bitter rot, occurs in most pear producing areas in China. After the onset of the disease, it causes fruit rot and early fall, which has a great impact on the yield. In addition to harming the fruit, it is also harmful to the branches.

1) Cleaning and disinfection in winter, combined with pruning to remove dry branches and dead fruits, and eradicate the source of disease. Spray 3 5 Baumé stone sulfur mixture before the pear tree sprouts.

2) Pesticide prevention and control In areas with severe disease in the north, from late May or early June, spray every 15 days until 20 days before harvest, spray 4 5 times in a row. In years with a lot of rain, increase the number of sprays appropriately. The agent can be 1 2 240 times Bordeaux solution, 70% or 80% mancozeb wettable powder 600 800 times solution, 70% thiophanate-methyl 800 times solution.

3) Fruit bagging After bagging can reduce the damage, but spray fungicides before bagging.

When the pear tree grows, it will also cause the occurrence of anthracnose because of the low-lying terrain, poor drainage, and poor ventilation environment, when the temperature is relatively high, the probability of onset will be relatively large, and the condition will be more serious when the environment is too hot, so when anthracnose occurs, it is necessary to use the drug in time.

Causes of anthracnose in pear trees.

When the pear tree is growing, it will also cause the occurrence of anthrax due to the low-lying terrain, poor drainage, and poor ventilation environment, and the probability of onset will be greater when the temperature is relatively high, and the disease will be more serious when the environment is too hot.

Symptoms of anthracnose in pear trees.

After the occurrence of anthracnose in the pear tree, the most harmful is the leaves and fruits, in the early stage of the disease there will be brown lesions on the leaves, and in the later stage there will be black spots, the fruit will also have lesions, in the more serious time will cause a large number of leaves to fall off, and the fruit will also rot.

Pear tree anthracnose**.

After the outbreak of anthracnose, if the drug is used in time**, then it can recover gradually, but it is generally more difficult to recover in the later stage.

When anthracnose occurs in pear trees, it is necessary to use drugs in a timely manner**, generally using tebuconazole carbendazim suspension or etherstrobin suspension, **The effect is relatively good, but it needs to be sprayed continuously 4-5 times, once every 15 days.

Pear tree anthrax medication.

After the occurrence of anthracnose, pear trees can also use some special drugs, such as Liangguoan 300 times liquid, combined with garlic oil 1000 times liquid.

Methods for the prevention and control of anthracnose in pear trees.

After the occurrence of anthracnose, pear trees need to be pruned in time to remove some diseased leaves and branches, so as to prevent re-infection, and to have a good ventilation environment during the usual maintenance, which can reduce the occurrence of pests and diseases, and use chemicals in time when anthracnose occurs.

The main damage to the fruit is also the branches. The fruit is more likely to develop in the middle and late stages of growth. At the beginning of the disease, small round spots with light brown water-stained spots appear on the fruit surface, and later the lesions gradually expand, the color deepens, and the soft rot sags.

The surface of the lesion is staggered with distinct concentric wheel patterns. Under the epidermis of the lesion, numerous small spots are formed, slightly raised, brown at first, and then black. Sometimes they are arranged in concentric wheel patterns.

In warm and humid conditions, they break through the epidermis and emerge with a layer of pink goo. With the gradual expansion of the lesion, the diseased part rots into the flesh until the heart of the fruit, making the flesh brown and bitter.

Anthrax is infected in the early stage of fruit growth, the initial fruit surface appears black concave round spots, accompanied by a blue-brown halo, in the middle stage, the fruit surface appears light brown water-soaked small round spots, and then the color of the lesions becomes darker, and gradually expands, soft rot is concave, and the surface of the lesions appears obvious concentric wheel patterns, and the color is alternate. In later stages, small raised spots form under the epidermis of the diseased area, which are brown at first and then turn black. In warm and humid conditions, the spore disc breaks through the epidermis and emerges with pink slimes, also known as clumps of conidia of the fungus.

The lesions expand and rot into the flesh or reach the center of the fruit, showing a conical shape, and the fruit turns brown with a bitter taste, causing the whole fruit to rot or shrink into a stiff fruit.

The pear tree pest control is as follows:

1. Pear aphid

This is one of the most common parasitic pests of pear trees, mainly like parasitic interception of nutrients on the leaves, which can seriously affect the fruit yield of pear trees. "The symptom is that the leaves of the pear tree attach to the larvae of the pear aphid, and over time, the leaves begin to shrink into a cylindrical shape, eventually leading to shedding. It is generally accepted that these leaves should be removed and incinerated in time to avoid infection in more places.

In the initial stage, manual removal can solve serious problems, and 50% parathion EC can be sprayed 3000 times to prevent and **.

2. Pear scab

That is, the so-called pear scab, which often has initial results, leads to abnormal fruit growth, often due to pathological changes caused by excessive humidity. The disease showed that the surface of the pear began to appear speckles, and then slowly blackened, eventually causing the whole fruit to wilt, plus pear scab is a group disease, which should be dealt with in time after discovery. Guoshiling, terrazole and black star powder are commonly used drugs for this disease, and 40% nova emulsion can also be sprayed 800 1000 times in advance.

3. Pear tree rust

This disease is particularly harmful to the leaves, but also to the young pear fruits, mainly concentrated in the temperature alternating time with high humidity. rust spots appear on the leaves, followed by slow drying; The fruit is dry and necrotic to the apical growth. It is important to note that cypress trees and cypress trees can seriously increase the incidence of disease.

Spray 20% EC 1500 to 2000 times for prophylaxis twice a month for two months during the prone season. At the onset of the disease, use 20% Pink Ning 600 times solution**.

4. Pear heartworm

This is one of the most terrible parasitic pests of pears. Once discovered, the pears become hopeless and rotten. Therefore, early prevention and post-disease prevention must be timely and emphasized.

Most of the parasites enter the early stages of the fruit, and as the worm grows, the fruit becomes more and more visible. For fruits that are directly removed and brought out of orchard damage, the surrounding trees should be sprayed immediately, and both treatments are more common.

Diseases of the pear tree:

1. Rot disease: This disease mainly harms the bark of the main branches and side branches of the pear tree, causing rot. There are two symptoms: ulcer type and branch wilt type, and in severe cases, a large number of dead branches will occur, and even death.

The prevention and control methods are to strengthen management, control the amount of fruit set, improve the disease resistance of the tree, select and breed disease-resistant varieties, scrape off the disease scars on the pear tree, cut and burn the diseased branches in time, and reduce the source of infection.

2. Black spot disease: the disease mainly causes harm to fruits, leaves and new shoots, produces leaf spots, causes fruit drop, etc. The specific control methods are to strengthen management, increase the application of organic fertilizer, and pay attention to avoid partial application of nitrogen fertilizer, which can be combined with winter pruning, remove dead branches, fallen leaves and diseased fruits and bury them deeply.

3. Pear netting: When the pear tree suffers from the pear net, the adults and nymphs will suck the branch sap on the back of the leaves, and the front of the leaves is pale spots after being damaged, and there are dark feces and secretions on the back of the leaves, which can be sprayed on the ground from late March to early April every year, and can be sprayed once in late April and early May and early June respectively, 50% dichlorvos emulsifiable concentrate 1000 times and 50% pine moth emulsifiable concentrate 1000 1500 times for prevention and control.

4. Ring disease: pear ring disease is an important disease of pear trees, mainly for the damage to branches and fruits, to remove the source of the disease, combined with winter pruning and spring garden cleaning to sweep away fallen leaves and diseased fruits, cut off diseased shoots, dead branches, concentrated burning or deep burial. Before and after germination to the spring shoots are vigorous, scrape off the tumors and dead skin on the large branches, and apply 43 tebuconazole 30-50 times.