How to solve the black spot disease of pear

The pear is full of water, crisp and delicious, which is conducive to cool detoxification and relieve fatigue. However, in the process of planting pear trees, many friends often find that there are many black spots on the surface of pears, which will seriously affect the growth and development of pear trees and cause great economic losses to those who plant pear trees. What's with these black spots? How can it be well prevented? Let's take a look at it.

1. Symptoms

This kind of black spot is commonly known as black spot disease, which usually occurs on bagged pears. In the early stage of the disease, there will be black spots of various sizes on the surface of the pear, these black spots will gradually spread, and finally many spots will spread together to form patches. But this black spot harms the pericarp, has no effect on flesh, leaves, taste, and does not cause problems with dog meat. Although none of these has any effect, it destroys the appearance, affects the beauty, and makes it impossible to sell.

2. The regularity of the disease

If the young fruit is infected before bagging, it will not get sick. It usually starts before and after the Beginning of Summer, and the pear fruit expansion period begins in July, when the pear fruit needs a lot of breathing. The temperature and humidity in the bag will increase, and this environment is more conducive to the growth of black spot pathogen. If we encounter continuous overcast and rainy weather, the permeability in the bag decreases seriously, resulting in an increase in the incidence of black spot disease, and high temperature and humidity in paper bags will lead to an increase in the incidence of black spot disease.

3. The cause of the disease

There are many causes of the disease, such as yellow powder insects and other pests invade the pear pericarp in the paper bag, gnawing on the pericarp, resulting in the immune system failure of the pericarp, unable to absorb nutrients, and the pericarp blackens. In addition, Alternaria and other diseases will parasitize in the soil and the residual body, spread through Rain Water and wind and other media, affecting the pericarp development. The last reason is bagging, which may be due to poor bagging quality, poor permeability and high temperature leading to partial cell necrosis of the pericarp.

4. Prevention and control measures

When the pear tree is too tall and too large, it is necessary to prune the high branches reasonably and properly, strengthen the ventilation and light transmittance of the orchard, disinfect the soil and concentrate on cleaning up the diseased and diseased bodies. Properly reduce the temperature in the garden and choose high-quality fruit bags. Professional data show that the incidence of the highest incidence of plastic film, the incidence is as high as 55.7%, the lowest is double-layer non-wax newspaper, the incidence is only 7%. After bagging, set up several more vents in the fruit bag to ensure the temperature and humidity in the bag. Spraying pesticides before each stage of pear trees for pest control.

In fact, a large part of the black spot disease is caused by improper management after bagging, although the black spot disease will not have any effect on the flesh quality and taste of the pear fruit, but the appearance of the pear fruit will be affected by the black spot. The failure to sell seriously threatens the economic interests of growers. All aspects must be sorted out before and after bagging to avoid black spot disease.