Early prevention of red star disease does not have furuncle in pear fruit.

Pear fruit furuncle disease, known as red star disease, also known as pear rust, pear red rust, or pear juniper rust. The disease was parasitized on juniper (including juniper and dragon juniper) trees in the form of mycelium in September before the defoliation of pear trees. As long as juniper trees are planted, red spot disease may occur in pear orchards every year. After the leaf is infected, there are orange oil droplet-like spots on the surface, which gradually develop into a near-circular spot with a diameter of 4-8 mm, and a small orange spot appears in the middle, and then the small spot gradually becomes black, and the spot is reddish brown around, the leaf is sunken on the front, and the back is swollen and raised. Longitudinal growth of gray-brown tubular objects (coarse looks like brown hair), generally about 10. When there are many diseased spots on diseased leaves, they often fall off early.

The susceptible symptoms of young fruits are the same as those of diseased leaves, while those who are not seriously affected will grow into malformed fruits, and some or several parts will be sunken because of disease spots, and this part of the flesh is like a hard furuncle that cannot be eaten. If the spring rain falls early, the disease will occur early; if there is more spring rain, the disease will also be serious. On the contrary, there was little or no disease in pear orchards due to drought and little rain in spring.

Prevention and control of pear red spot disease focuses on prevention. First of all, cut down all the cypress trees around your own pear orchard. In case juniper cannot be cut down, spraying juniper with 1-2 degree stone sulfur mixture 1-2 times before pear blossoms and leaves can also effectively control the spread of germs.

Secondly, spraying fungicides from flowering to young fruit stage of pear trees can effectively prevent the invasion and damage of bacteria. Bordeaux liquid is the most commonly used pesticide with a concentration of 1 part of copper sulfate, 2 parts of quicklime and 200 parts of water (i.e. 1 part of copper sulfate, 2 parts of quicklime and 200 parts of water). 40% thiophanate methyl (thiophanate methyl) wettable powder can also be purchased directly from the agricultural market into 500 times liquid, or 50% methyl thiophanate (methyl thiophanate) wettable powder into 800 times liquid, or 65% Dysen zinc (Schleite, zinc) wettable powder, mixed into 600 times liquid, to spray. No matter what kind of pesticide is used, once every 15 days, twice in a row can effectively prevent and cure bacterial infection, and the effect of 3 times is better.