The most dangerous disease for wood is rust. You need to know right away what to do if there are yellow spots on the pear leaves. Previously, the disease was practically unknown, but now this phenomenon occurs on almost every tree. If measures are taken in time, there is a significant chance of recovery. You should also pay attention to nearby plants that may be a source of infection.
What it is?
On the affected plant, the leaves are covered with red-orange spots with a yellow rim. Gradually the color becomes darker. Then the orange spots become deformed and swell. They begin to resemble a tumor. Because of this, the affected plate falls off.
Causes of the disease
The culprit of the disease is a fungus. It attacks the plant in the summer and deprives it of half its harvest. The carrier of the disease is juniper. This is where the infection overwinters. In humid, windy, and most importantly warm weather, the opened spores break off and are transported over long distances. At this moment, the fruit crop becomes infected. After some time, changes gradually appear on the foliage.
Red spots are especially noticeable in July. They then transform into “horns” and cause the leaves to fall off. In winter, the infection moves back to the juniper.
How does the disease develop?
If after flowering the leaves become covered with orange spots, it means the crop is sick. In summer, the infection spreads to the petioles. Then brown or red spots, as well as individual dots, form on the outside.
The peak is in autumn. Growths appear that are visible on the inside of the leaves. They fill with fungal spores, which then disperse.
Varieties with the lowest immunity
If the leaves are covered with yellow spots, it means that a plant that is not resistant to rust grows in the area. The varieties have the lowest immunity:
- Boudet Ardanpont;
- Clapp's favorite;
- Dikanka winter;
- Curé.
When purchasing, you should not opt for these varieties.
Why is rust dangerous?
A diseased plant's leaves fall off early. The petioles turn dark, and spots appear on the shoots.As a result, the number of ovaries decreases, which causes low yields. The fruits begin to fall off before reaching technical maturity.
What else is dangerous?
- The culture's natural immunity becomes weak. Therefore, after being damaged by rust, the plant becomes very vulnerable to other diseases and is attacked by pests.
- Reduced immunity subsequently reduces the winter hardiness of the plant. Shoots affected by the disease will not withstand frost. As a result, frost holes and cracks of various sizes will appear on the surface. In their place, hollows are formed, which contribute to the destruction of the tree, since due to damage to the bark the crop will become unstable to bad weather conditions.
- Rust will reduce the plant's photosynthesis process. This will not allow the tree to develop properly and will lead to its weakening. If treatment is not started immediately, the plant will not be able to survive the frost.
- In a diseased pear, the fruits become small. Therefore, if there is rust, there will definitely not be a large harvest. Very often, a tree that has recovered from the disease does not bear fruit the next year.
Methods to combat corrosion on a pear
It is possible to cure a plant disease in different ways. The main thing is to start fighting in time.
Mechanical fight
Starting from the beginning of spring, the plantings are constantly inspected. Set of events:
- To save the plant, pruning is carried out on time at the beginning of the season. Before the buds bloom, infected branches are cut off and necessarily burned. The cut is made at a distance of 13 centimeters from the damaged areas.
- The wound caused by rust on the trunk is cut back to healthy wood. Then the area is treated with iron sulfate.
- Cut back nearby juniper stands.Since the formed spores in the pustules of the leaves, by the onset of winter, for further development, they tend to fly to the juniper, on which they will germinate again and overwinter in gelatinous growths. In the spring they will fly away again to settle on the pear tree.
- It is better to plant rust-resistant varieties.
- Remove fallen leaves, broken and cut branches from under the trunk. You can't throw them away. The only right decision is to burn it. All shoots that appear under the crop are cut out to avoid the spread of the disease.
- The soil is constantly loosened and weeds that can be sources of fungal spread are removed.
Important rule! The tools used to clean the plant must be disinfected. Otherwise, during the next treatment, the disease will quickly spread to healthy plantings.
If the rust spots are not pronounced, then the crop can be treated with drugs.
Chemicals
Fungicides are used for treatment. It is recommended to spray with colloidal sulfur. The solution should be 0.4%. The affected plant is treated 5 times:
- Before flowering.
- After flowering.
- When the leaves appear.
- When the fruits begin to grow.
- When the leaves fall.
If you treat the plant at the time of flowering, the fruits will also become infected with rust.
Treatment is also carried out with the drug:
- "Cumulus DF";
- "Polyram DF".
When fighting yellow-orange spots and dark spots, it is recommended to alternate fungicides, otherwise the fungus will develop immunity.
If the leaves are affected by orange spots and dark spots, it is recommended to treat them with Iskra. Its advantages include:
- non-toxic to birds and beneficial insects;
- safe for all plants;
- has a beneficial effect on plantings;
- helps increase productivity.
But the drug also has a drawback. It is prohibited for use in fishery areas.
“Strobi” also helps in the fight against the disease. This is a new generation drug. Advantages:
- does not pose a danger to warm-blooded and beneficial insects;
- compatible with many drugs;
- is not addictive;
- does not have phytotoxicity;
- precipitation does not wash away the drug;
- allowed to be used at the time of flowering.
A broad-spectrum drug—Green Belt. It helps fight not only rust, but also spotting and scab. The advantages include:
- compatibility with pesticides;
- safety for birds, insects;
- does not harm plants.
The drug is not compatible with most fungicides.
It is worth paying attention to the drug "Raek". It is a systemic fungicide. Advantages:
- non-phytotoxic;
- precipitation does not wash away the product;
- compatible with other drugs;
- does not pose a threat to beneficial insects.
Folk remedies
Experienced summer residents fight with the help of infusion:
- Ashes. An infusion of 500 grams of ash and a bucket of water (10 l) will help get rid of the disease. The mixture is stirred and left for 2 days.
- Soap and soda. Linen soda (65 g) is combined with soap shavings (50 g). Fill with water (10 l). Stir and leave for half an hour.
- Mullein. An infusion of two parts water and one part slurry helps with rust stains. Leave it for a couple of weeks. Then pour into the mixture twice as much water as the volume of infusion, and water the plant. One bucket will be enough for a mature tree.
- Marigold. To do this, collect half a bucket of flowers, which must be fresh. And fill it with the same volume of water. An important point is that the water needs to be warm. Cover with a lid.They put it in the basement for two days. Then pour 50 g of laundry soap shavings into the strained infusion and mix.
Also, for a pronounced disease, use a decoction of horsetail or a fertilizing shower made from a urea solution. A urea solution is very easy to prepare. This is a universal remedy that will help fertilize, get rid of pests and defeat diseases. To do this, take 7 liters of ordinary water per 350 g of product. Stir and process before frost.
It is recommended to spray not only the plant, but also fallen leaves.
Preventative treatment
If the disease was defeated, all nearby juniper plantings were cut out and there is no forest nearby, then there is still no guarantee that the rust will not return again. The disease is difficult to eradicate, so you should constantly monitor the condition of the plants for several years after treatment and take preventive measures. Which include:
- trim on time;
- cover up newly formed cracks and frost holes;
- feed on time, a healthy plant has a much better chance of resisting illnesses;
- Flavor the soil, this will help strengthen the immune system and protect against illnesses.
For prevention, treat several times a season with one of the following drugs:
- Bordeaux mixture, you will need a 3% solution;
- “Chorus”, 10 liters of water are mixed with 2 grams of the drug;
- “Gamair”, you will need 10 g per bucket;
- “Alirin” or “Raek” are diluted like the previous remedy.
Tips to follow for tree health:
- The pear is grown far from the juniper.
- Set up windproof plantings around the garden. This allows you to protect plantings from wind-borne fungal spores. Any plants are suitable as protection, the main thing is that their height is at least half a meter greater than the pear.
- If decorative juniper grows nearby, constantly inspect it for the presence of spores. This plant is also treated preventively, like a pear.
If you identify the disease at the initial stage and immediately apply the necessary measures, then you can get rid of the disease within a year. There is no need to be afraid that other fruit trees growing nearby will become infected with spores. The disease is transmitted only to juniper.
