What is pear rust and how to treat it
Pear rust is one of the most difficult diseases. From rust on the pear, the leaves lose their ability to photosynthesize and become stained. And with a strong infection, the disease passes to the fruits and by the time of harvest there may not be a single healthy fruit left.
Pear rust and its treatment
The cause of the disease
The disease received such an unusual name because of the color of the spots on the leaves and fruits. They are usually bright orange, yellow, and pale red.
Rust is caused by a pathogenic fungus called Gymnosporangium sabinae.
In most cases, the fungus infects those varieties that grow in home gardens, because for the disease to arise, two plants are needed - a pear and a juniper. But the source of the disease is juniper, namely those varieties that are used to decorate houses outside and areas near them.
On these plants, the fungus develops, lives and forms spores that infect the tree. But the pear is only a stage in the development of the fungus. Then he again switches to the juniper, infecting it, at this the cycle of life of the pest-fungus ends, but this can last up to 2 years. During this cycle, neither the pear nor the juniper can infect themselves.
Juniper has low frost and cold weather resistance. Indeed, in late autumn, winter, and early spring, when the temperature drops below 0, the bark and branches of the plant are damaged - this provokes the appearance of a fungus.
The life cycle of the pest begins in the spring. After the first rain has passed, the spores come to life and wind currents can carry them up to 40 km. So the juniper variety can become a source of rust on the leaves of fruit trees.
Symptoms
Rust on pear leaves often appears in the spring, when the disease is still in its early stages of development.
The first signs of a pear disease such as rust can be seen during flowering. On the leaves, near their beginning and on the first fruits, small dark orange spots begin to appear. Already in July, they become larger and acquire a pink color with black dots inside.
If the infection is massive, then rusty spots on the leaves of a garden pear spread to the entire tree, and sometimes to neighboring trees. After a strong effect of the disease, the leaves may fall off prematurely, and the first shoots do not grow and even dry out. After exposure to the disease, photosynthesis in the plant is disrupted, the tree does not receive sufficient nutrition, the fruits become smaller, and the yield decreases.
Resistant varieties
There are varieties that are resistant to rust on the pear:
- summer varieties: Chizhovskaya, Sakharnaya, Ilyinka, Skorospelka;
- autumn varieties: Bere Bosk, Red Borovinka, Autumn Decanka;
- winter varieties: Belorusskaya late, Bere Ligel, Nika, Yakovlevskaya.
Most often, these varieties are planted in large gardens where fruits for industrial use are grown.
Unstable varieties
Some varieties do not respond to treatment
There are unstable varieties for which even timely treatment does not always help:
- Bere Ardanpon;
- Dikanka is winter;
- Curé;
- Clapp's favorite.
But in addition to pears, apple, quince, hawthorn can also become infected with the disease, and instead of juniper, thuja can become a focus of the disease. After exposure to rust, crop losses can be very large, sometimes more than 50% of the total harvest.
Ways to fight
To save a tree from disease, you need to know how to treat and what to do. It is important that there is regular care: formation of crowns, timely harvesting, fertilization of the soil and, of course, protection from diseases and pests.
But if after all there are spots, you need to look for methods of treating trees. The most common and effective means of control are chemical mixtures and solutions with mineral additives, which can cure the plant or even save it from imminent death. Here is some of them:
- processing pears from rust with a solution of Bordeaux liquid (3%). It is better to do this in the spring, during the budding period, when the temperature has reached 5 °;
- spray the branches and trunk with an organic preparation with minerals even before flowering;
- having bought a drug to enhance resistance (fungicide "Topaz"), process the crown when the trees have already faded and ovaries begin to form.
Scab treatment of trees will be an additional means of combating rust. But when spots on the leaves are found, it is recommended to process fruit trees up to five to six times per season, with a break of three to four weeks. You can also spray it with a solution of colloidal sulfur or use a drug such as Topaz, which is widespread among gardeners and has good efficacy.
Prophylaxis
Rust control measures on the pear are used when the infection has already manifested itself. In order for the pear to be more resistant to disease, preventive measures must be followed. You need to think about this even in the fall, when the time of cold weather is approaching and the trees become vulnerable.
The most reliable prevention methods:
- do not grow juniper and thuja in garden plots, near fruit trees;
- arrangement of the site with special systems against the wind so that fungal spores from wild-growing infected plants do not fly into the garden;
- if coniferous plants are already growing on the territory near the house, it is necessary to examine them in early spring for the presence of fungus or the disease itself, and cut off the damaged areas;
- regular inspection of trees, pruning, fertilizing and processing protects against dangerous diseases: in spring and autumn, juniper and other conifers need to be treated with any preparation that contains copper;
- all infected leaves must be burned at the end of autumn;
- to rejuvenate and heal the plant, you need to cut off the leaves covered by the disease and branches up to 10 cm from the outbreak, and disinfect with a 5% solution of copper sulfate.
Conclusion
Now you know how to treat a young pear from rust. Keep an eye on all trees in the garden, check for signs of illness, so that the tree does not die.
Rust on a pear is very dangerous and infects plants at an enviable speed. It is necessary to choose varieties resistant to the disease and remember about preventive measures and the timeliness of treatment.