Rusty leaves on an apple tree: what to do, how to treat it, causes

Rust on apple trees is common in the southern regions, although it can also occur in the middle zone. The disease is very easy to recognize by the characteristic spots on the foliage of an orange-brown, “rusty” color. It develops over a period of one and a half years, and the fight against the pest has to be carried out for more than one season. To do this, use chemical, biological fungicides and folk remedies.

What does rust look like on an apple tree?

Rust is an infectious disease of apple trees and other fruit crops (quince, hawthorn, rowan), caused by pathogenic fungi of the genus Gymnosporangium tremelloides Hartig.

Symptoms of apple tree rust damage are clearly visible. The main signs are:

1. The spots on the leaves are round in shape with sharply limited edges.
2. Color orange-yellow, light brown.
3. There may be black or brown dots on top of the spots.
4. The shape is convex at the top, and there may be outgrowths at the bottom.
5. Rarely does rust lead to the formation of warts.
6. Spotting on fruits.

The disease is widespread, but is more common in the southern regions, including the Krasnodar Territory, the North Caucasus and other neighboring regions.

The development cycle of the fungus is complex - four main stages can be distinguished:

1. In August or September, spores fall on the branches of the apple tree and begin to parasitize. They germinate and form a mycelium. The process is gradual.
2. Every year in March–April, myceliums form teliospores, which begin to germinate, especially in wet weather.
3. At the end of May - beginning of June, when it finally gets warmer, the rust spores become dry, after which they break off and are carried with the wind to neighboring apple trees.
4. At the end of summer, aecidia form on the lower surface of the leaves, in which spores also ripen. They open and disperse, again infecting the apple trees.

Damage to an apple tree is easy to recognize by the characteristic spotting of the foliage.

Why do the leaves on an apple tree rust?

Rust fungus spores are spread by the wind, and it is impossible to completely eliminate this process. There are several reasons that provoke the development of pathology:

• warm weather;
• excess watering, too humid air;
• quite strong wind in spring and summer;
• infected plantings nearby, for example, juniper, rowan, quince.

Scheme for treating apple trees against rust

Treating apple trees against rust should be carried out according to a certain scheme.The pest is quite dangerous, its development cycle is long and complex. Therefore, one or even two treatments with fungicides or folk remedies will clearly not be enough. For effective treatment it is necessary to follow this scheme.

*counting starts from the moment signs of rust are detected on the apple tree

Treatment takes place in several stages

How to deal with rust on apple tree leaves

You can get rid of rust on an apple tree in different ways. The most effective are chemicals. Folk remedies will also help for processing. They can also be used for prevention. It is important to understand that it will not be possible to cope with the disease within one season. The work must be comprehensive. Treatments are carried out for at least two years.In the future, it is necessary to follow basic preventive measures.

Fungicides

If the apple tree is covered with rust, the main treatment method is fungicides:

1. "Chorus" is a systemic drug with an active component from the aminopyrimidine class. Used to treat rust, as well as scab and other fungal diseases. Consumption rate – 2 g per 10 l.
   
2. "Skor" is a systemic fungicide, the active substance of which belongs to the class of triazoles. Use in an amount of 2 ml per 10 l. It is resistant to rain and is not washed off from the surface of leaves and shoots.
   
3. "Raek" is a universal fungicide containing the active component diphenokenazole. Used in the form of a solution. Dosage – 2 ml per 10 l.

Preparations with copper for rust on apple trees

Among the effective copper-containing preparations for treating apple trees against rust are the following:

1. Copper sulfate is used at the “green cone” stage. One of the best broad-spectrum fungicides. It is produced in the form of a powder, highly soluble in water - the standard dosage is 300 g per 10 l.
   
2. "Abiga-Peak" is used at the stage of bud formation. Consumption rate – 50 g per 10 l. The drug can be used in tank mixtures with insecticides.
   
3. "HOM" is a preparation based on copper oxychloride. They are produced in powder form, usually packaged in 40 g units. This amount is diluted in 10 liters of water and several sprayings are carried out at intervals of 10-15 days.
   

This is the minimum time that should elapse between the last application and harvest. Therefore, spraying apple trees must be planned in advance.

Preparations with sulfur

If the leaves of an apple tree rust, sulfur-containing fungicides can also be used for treatment:

1. Colloidal sulfur is a universal drug against fungal infections and insects. It is safe for plants and soil. Used as an antiseptic against rust, scab, gray rot, powdery mildew. The dosage of the solution is 80 g per 10 l. Treatment should be carried out only in warm weather (from 20 degrees).
   
2. "Tiovit Jet" is another sulfur-containing drug. They are produced in the form of granules, which need to be dissolved in warm water, based on a ratio of 100 g per 3 liters. Treating apple trees against rust should also be done in warm weather.
   
3. "Cumulus" is a contact fungicide, produced in the form of granules, soluble in water. Dosage – 5-8 g per 10 l.
   

Biological drugs

You can also treat rusty spots on apple tree leaves with biological fungicides. The most effective drugs are:

• "Fitosporin";
• “Respect 25%”;
• "Trichodermin";
• "Fitolavin" and others.

Treatment of rust on an apple tree with folk remedies

Treatment of rust on apple tree leaves can also be done using folk remedies. They are quite effective for prevention and in the early stages of damage. The following recipes are especially helpful:

1. Wood ash solution - fill the bucket 2/3 full and fill it with water, then place it in the sun and leave until a yellowish tint appears on the surface. It is drained and diluted with water in a 1:1 ratio, after which processing begins.
2. Horsetail decoction - 500 g of raw material is poured with water, boiled for 20-30 minutes and left for 24 hours. Then filter, bring to a total volume of 10 liters and begin processing.
3. Soda ash - 5 tablespoons per 10 liters.Add 50 g of crushed laundry soap there, mix thoroughly and start spraying.
4. Pharmaceutical alcohol solution of iodine – 10 ml per 10 l. The apple tree is treated with this anti-rust product several times at intervals of 3-4 days.
5. Infusion of wormwood - fresh herbs are crushed, filled with half a bucket and filled with water. Then it is left in partial shade for several days to allow the mixture to ferment. When foam appears on the surface, filter the infusion and add water (the volume is five times larger), after which they begin to spray the trees.

Prevention

Rust is a rather dangerous disease of the apple tree, which leads to a decrease in yield, weakening of the tree and a slowdown in the rate of development. It is not always possible to cope with it - in some cases it is necessary to cut down the affected trees to prevent further spread of the infection. Therefore, experienced gardeners recommend preventing the disease using the following prevention methods:

1. Carry out sanitary pruning regularly.
2. In the fall, dig up the tree trunk circle and water it with a solution of any fungicide.
3. Remove leaves and branches in the fall and burn them completely.
4. Maintain adequate watering, especially in rainy summers.
5. Do not forget about phosphorus-potassium fertilizing, especially during flowering and ovary formation.
6. Thin out the crown.
7. When planting, maintain a minimum distance between trees (4 meters).
8. Several times a season, foliar spray the leaves with a solution of potassium monophosphate (30 g per 10 l).
9. Remove root growth.

Conclusion

Apple tree rust is a dangerous infectious disease that can affect several trees at once. Therefore, it is recommended to carry out regular pruning and preventive treatments. And when the first signs of the disease appear, begin treatment immediately.

Recommended Posts

When to prune apple trees in the fall: in what month

How to transplant an apple tree to a new location in the fall

Apple tree variety Ligol: photo and description of the variety

Orlik apple tree: variety description, planting and care

Decorative Niedzwiecki apple tree

Grafting a wild apple tree

Summer varieties of apples with photos and descriptions

Chinese apple tree (Long): description, photo, cultivation, reviews

Apple tree Autumn joy: description, care, photos and reviews