What are the prevention and control methods for pear brown spot?

1) Agricultural control.

It is an extremely important measure to prevent and control brown spot disease by doing a good job in pear orchard hygiene, sweeping away fallen leaves in winter, burning them in a concentrated manner or burying them deeply, and reducing the source of infection. Strengthen the management of pear orchards, after the pear trees are harvested, fertilizers, especially organic fertilizers, should be increased, and reasonable pruning should be carried out to enhance the tree's strength and improve disease resistance. After the rain, pay attention to the drainage in the orchard, reduce the humidity of the orchard, create an environment that is not conducive to the development and spread of diseases, and achieve the purpose of controlling the development of diseases.

2) Pharmaceutical prevention and control.

In early spring, at the budding stage of pear trees, about mid to late March in the south, spray 1 protective fungicide, such as mancozeb, or mancozeb, or Bordeaux liquid; After the flowers fall, it is generally in the early stage of the disease, about mid to late April, spray the second liquid medicine. In rainy weather and years when the disease occurs heavily, spray the liquid medicine once again in early to mid-May, and the agent and concentration are the same as above. The key period of spraying for the prevention and control of brown spot disease is after the flowers have fallen.

Generally, spraying 2 or 3 times can achieve good control effects.

Prevention and control technology: 1. Remove the source of the disease, clean the diseased leaves in winter, burn them in a centralized manner or bury them deep on the spot, and eliminate the source of the disease.

2. Strengthen the cultivation and management of pear trees after entering the bumper yield period, increase the application of organic fertilizer to keep the tree strong and improve the disease resistance. When the orchard is waterlogged, pay attention to drainage, reduce the humidity in the orchard, and control the development and spread of diseases.

3. Before the germination of pear trees in early spring, spray 150 times lime multiplier Bordeaux solution (1 part of copper sulfate, 2 parts of quicklime, 150 parts of water) in combination with pear rust control. After the flowering, the initial stage of the disease, when there is a lot of rain and is conducive to the occurrence of the disease, spray 1 time, spray zinc sulfate, copper sulfate, quicklime water. 5 2 200 zinc-copper Bordeaux solution, can also be sprayed with 70% thiophanate-methyl wettable powder 800 1000 times liquid, 50% carbendazim wettable powder 600 800 times liquid or 65% zeb wettable powder 600 times liquid.

Among them, the focus is a spraying after flowering, and then combined with the prevention and control of other diseases for concurrent treatment.

It will cause a large number of leaves to fall, affecting the absorption of nutrients, which may seriously affect the quality of the fruit, and may also spread gradually. Pesticides must be sprayed in a timely manner, and the problematic parts must be removed in a timely manner, and ventilation should be properly strengthened.

It can affect the final yield, which can affect some diseases, which can lead to infection, and can also affect other crops, which can lead to a decrease in the yield of crops. This can be done with a number of medications** and should be applied to plants with this disease.

It can lead to poor growth, it can lead to the appearance of some diseases, it can lead to a decrease in yield, it will cause pears to be affected, and it will also lead to a decrease in the yield of pears. It can be carried out with some drugs**, so as to better prevent the occurrence of some diseases.

Prevention and control measures for pear black spot disease: (1) Before the fruit tree germinates, cut off the diseased branches, remove the fallen leaves and fruits, and burn them intensively. (2) Chemical control.

Before germination, spray 5 packets of Mido stone sulfur mixture, spray 1:2:200-240 times Bordeaux liquid or 600-800 times 50% carbendazim wettable powder, 1000 times 50% carbendazim wettable powder, 1000 times 70% mancozeb wettable powder or 1000 times 75% chlorothalonil wettable powder.

1) Do a good job of clearing the garden. Before the pear tree germinates, cut off the diseased branches and branches, remove the fallen leaves and fruits of the orchard, bury them deeply or burn them, and eliminate the source of overwintering bacteria. (2) Strengthen cultivation management, take measures such as intercropping green manure, increasing organic fertilizer, ditching and drainage, and strengthening pruning.

Strengthens the resistance of the tree and improves the light. (3) Fruit bagging can protect the fruit from pathogens. Bagging should be done by May 1 and mid-May.

Because the germ tube of Alternaria can penetrate the paper bag and harm the fruit, the effect of using old newspaper as a bag is not good. According to the experiments of the Shanghai Academy of Agricultural Sciences in recent years, ordinary paper bags are coated with tung oil, and then dried to form tung oil paper bags. The effect of preventing and treating pear black spot is very good.

4) Chemical control. Before the pear tree germinates, spray 5 Baumé stone sulfur mixture once to kill the overwintering bacteria on the branches. Generally, from the fall of the flowers to the end of the rainy season, that is, from late April to early July, spraying is required.

The spraying interval is about 10 days, and a total of 7 8 sprays are sprayed. The preparation can be 1 2 240 times Bordeaux liquid, 1000 1500 times 50% iprodione wettable powder, 1000 1500 times 10% polyantimycin wettable powder, 600 800 times 70% or 80% mancozeb. Polyantimycin should not be more than 3 times a year, so as not to develop resistance and reduce the control effect.

Control methods of pear tree black spot disease: pharmaceutical control.

The pear tree should be sprayed once before flowering and about 70% of the flowers have fallen to protect the inflorescences, shoots and new leaves. Later, according to the rainfall, spray once every 15 20 days, a total of 4 times. Generally, the first spraying is in mid-May (after the white pear sepals fall off, the diseased shoots are at the beginning of the stage), the second is in mid-June, the third is in late June to early July, and the fourth is in early August.

Generally, terprazole or enazole wettable powder 2000 2500 times and 40% Fuxing 8000 times liquid are used for pesticides, and the control effect is better.

When the seedlings become ill, yellow round dots are produced on the cotyledons, and the cotyledons rot after expansion, and the seedlings die. The newly exposed true leaves of slightly larger seedlings rot away, forming double-headed seedlings and multi-headed seedlings. All parts of the plant can be affected at the adult stage, but the wild melon strips are the most susceptible.

The leaf is affected, and the leaves are interspersed with small spots that are nearly circular and faded, and then expand into yellowish-white round spots with a diameter of 2 3 mm, and cracks are formed at the inner edge of the lesions in the later stage. The periphery of the lesion is star-shaped with yellowish-white circles.

Precautions for planting pear trees

1. Disinfection. It is best to disinfect the soil used for planting before using it, because some soils will not only contain germs, but also insect eggs. If you don't pay attention to disinfection, it will damage the seeds of the pear tree after planting.

2. Watering. Although it is said to create a moist environment for it to grow, the amount of watering should be well controlled, if you water a lot of water at the beginning of planting, it will not only brew the seeds, but also cause the seeds to rot.

3. Fertilization. Fertilizing pear trees is generally in July and August every year, and when the fruit begins to grow in July, phosphorus and potassium fertilizer should be applied at this time to promote fruit development. In August, when the fruit is about to ripen, you can apply potassium fertilizer again to make the pears grow bigger and fuller.

If you find that the pears are pecked by birds, you don't have to worry too much, you can use some protective tools appropriately, or install a device to repel birds, if it is a large number of pear trees, it is necessary to do this, but if you only plant a few trees in your yard, you don't need to spend too much effort to deal with it.

Prevention and control measures for pear brown spot disease: (1) Clean the countryside. After falling leaves, remove the fallen leaves and burn them intensively to reduce the source of disease.

2) Strengthen the management of pear orchards, enhance tree potential, and improve disease resistance.

3) Spraying prevention and control after flowering. Commonly used agents are 70% thiophanate-methyl wettable powder 800 times liquid, 50% carbendazim wettable powder 800 times liquid, 30% multi-well suspension 600 times liquid, 1:2:

200x Bordeaux liquid. Prevention and treatment 2 3 times, with an interval of 15 to 20 days.

(1) Do a good job of cleaning the garden Before the pear tree sprouts, cut off the diseased branches, remove the fallen leaves and fruits in the orchard, and bury or burn them in a concentrated way to eliminate the source of the winter fungus.

2) Strengthen cultivation management Adopt measures such as intercropping green manure, increasing organic fertilizer, ditching and drainage, and strengthening pruning to enhance tree resistance and improve light.

3) Fruit bagging Bagging protects the fruit from germs. Bagging should be done by early to mid-May. Because the germ tube of the black spot fungus can penetrate the paper bag and damage the fruit, the control effect of using old newspapers as a bag is not great.

According to the experiment of the Shanghai Academy of Agricultural Sciences in recent years, the ordinary paper bag is coated with a layer of tung oil, and after drying, it becomes a tung oil paper bag, which has a good effect on the prevention and control of pear black spot disease.

4) Pesticide control Before the pear tree germinates, spray 1 time 5 Baumé stone sulfur mixture mixture to kill the overwintering bacteria on the branches. Generally, after the flowers fall and before the end of the rainy season, that is, from late April to early July, it is necessary to spray for protection. The spraying interval is about 10 days, and a total of 7 8 sprays.

The agent can be 1 2 240 times Bordeaux solution, 50% iprodione (promehydrin) wettable powder 1000 1500 times liquid, 10% polyantimycin wettable powder 1000 1500 times liquid, 70% or 80% mancozeb 600 800 times liquid. Polyantimycin should not be used more than 3 times a year to avoid drug resistance and reduce the control effect.

Pharmaceutical prevention and control: 1Eradicate overwintering pathogens Before the germination of pear trees in spring, spray 100 150 times of 10% methionone (Guoyoubao) on the branches, or 3 5 Baumé stone sulfur mixture, to kill the overwintering germs on the tree.

2.During the spraying period, the disease was more severe in the orchards in the Yangtze River Basin, and after the pear trees fell to the end of the rainy season, the pesticides were sprayed once every 10 15 days, a total of 7 8 times. In Hebei, Shandong, Beijing, Japan and South Korea pear cultivation areas, combined with the prevention and control of other leaf fruit diseases, after the pear tree falls and before the pear fruit is bagged, fungicide was sprayed 2 3 times.

After that, in mid and late June and July and September, when there is more rainfall, spray 3 or 4 times again to control leaf diseases.

3.Commonly used agents 10% polyantimycin wettable powder, 50% iprodione wettable powder 1000 1500 times liquid, 80% mancozeb wettable powder 800 1000 times liquid, 65% zebzeb wettable powder 500 times liquid, 3% polyantimycin aqueous solution 400 500 times liquid, 50% pythium reliable wettable powder 1000 1200 times liquid.

Prevention and control of agriculture and industry:

1. Do a good job of clearing the garden before the pear tree sprouts, cut off the diseased branches on the tree, remove the fallen leaves and fruits in the orchard, bury or burn them in a concentrated manner, and eliminate the source of overwintering fungi.

2. Strengthen cultivation management, according to the specific situation, intercrop green manure in the orchard, or cover the grass in the tree tray. Increase the application of organic fertilizer to promote the health of the root system and the tree body, and enhance the disease resistance of the tree. Rational use of chemical fertilizers, nitrogen and compound fertilizer are mainly applied in the early stage of fruit tree growth, and the amount of nitrogen fertilizer is controlled in the middle and late stages, mainly phosphorus, potassium fertilizer and all-yuan compound fertilizer.

For low-lying orchards, ditching and drainage should be done. For orchards where pear black spot disease has occurred seriously over the years, proper thinning of branches should be done during winter pruning to enhance the ventilation and light transmission ability of the canopy, and to remove diseased branches, leaves and fruits in combination with summer pruning.

3. Fruit bagging can protect the fruit from pathogens, and the cracking can only reduce the disease rate of pear black spot. However, the bud tube of the pear black spot fungus can penetrate the general paper bag of the Xiangyuan cover, and the paper bag used should be mixed or soaked with paraffin wax and tung oil and then dried. 4. Cultivation of disease-resistant varieties In areas with serious disease, the cultivation of susceptible varieties such as the twentieth century should be avoided, and more disease-resistant varieties such as Fengshui, chrysanthemum, Xingshui, Huangguan, **, Huangmi, Late Sanji, this spring and autumn, and Tietou can be cultivated.

(1) Prevention: Spray 500 times dilution and spray with 500 times of liquid, and use the drug once every 7 days.

2)**: When the condition is mild, the quick net is diluted and sprayed according to 300 500 times of liquid, and the drug is used once every 5 7 days; When the condition is severe, the quick net is diluted and sprayed according to 300 times, and the drug is used once every 3 days, and the number of sprays depends on the condition.

3) Remove the overwintering source: remove the fallen leaves and fruits, and destroy the diseased branches.

4) Strengthen orchard management: apply organic fertilizer reasonably, enhance drainage facilities, and control pests.

5) Pesticide control: spray Baume 5 degrees stone sulfur mixture mixture solution before germination to eradicate overwintering bacteria on trees. Spraying during the growth period to prevent and protect leaves and fruits, generally from the first spray in early to mid-May, 15 20 days 1 time, 4 6 times in a row.