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

Rust on an apple tree is common in the southern regions, although it can also be found in the middle lane. The disease is very easy to recognize by the characteristic spots on the foliage of an orange-brown, “rusty” color. It develops within a year and a half, and pest control 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, mountain ash) caused by pathogenic fungi of the genus Gymnosporangium tremelloides Hartig.

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

1. The spots on the leaves are rounded with sharply limited edges.
2. Color orange-yellow, light brown.
3. There may be black or brown dots over the spots.
4. From above, the shape is convex, and from below they may have outgrowths.
5. Rarely, rust leads to the formation of warts.
6. Spotting on fruits.

The disease is ubiquitous, 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, the spores fall on the branches of the apple tree and begin to parasitize. They germinate, form a mycelium. The process is gradual.
2. Mushroom picks annually in March-April form teliospores, which begin to germinate, especially in wet weather.
3. In late May – early June, when it finally gets warmer, rust spores become dry, after which they come off and, together with the wind, are transferred 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, re-infecting apple trees.

The defeat of the apple tree is easy to recognize by the characteristic spotting of the foliage.

Why do the leaves on the apple tree rust?

Rust fungus spores are spread by the wind, and it is impossible to completely eliminate this process. In this case, 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, mountain ash, quince.

The scheme of processing apple trees from rust

Rust treatment of apple trees 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 not be enough. For effective treatment, it is necessary to follow this scheme.

*the countdown is 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 leaves

There are many ways to get rid of rust on an apple tree. The most effective are chemicals. Also, folk remedies will 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. Processing is carried out for at least two years. In the future, basic preventive measures must be followed.

Fungitsidы

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

1. Horus is a systemic drug with an active ingredient from the aminopyrimidine class. Used to treat rust, as well as scab and other fungal diseases. Consumption rate – 2 g per 10 liters.

   

2. “Skor” is a systemic fungicide, the active substance of which belongs to the class of triazoles. Use in the amount of 2 ml per 10 liters. It is resistant to rain, is not washed off from the surface of leaves and shoots.

   

3. “Raek” – a fungicide of universal action, contains the active ingredient difenokenazole. Apply in the form of a solution. Dosage – 2 ml per 10 liters.

Preparations with copper from rust on an apple tree

Among the effective copper-containing preparations for treating apple trees from rust, the following can be distinguished:

1. Copper sulphate is used at the “green cone” stage. One of the best broad spectrum fungicides. Produced in the form of a powder, highly soluble in water – the standard dosage is 300 g per 10 liters.

   

2. “Abiga-Peak” is used at the stage of bud formation. Consumption rate – 50 g per 10 liters. The drug can be used in tank mixtures with insecticidal agents.

   

3. “HOM” – a preparation based on copper oxychloride. They are produced in the form of a powder, packaged mainly in 40 g. This amount is diluted in 10 liters of water and several sprays are carried out with an interval of 10-15 days.

   

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

Products with sulfur

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

1. Colloidal sulfur is a universal remedy for fungal infections and insects. Differs in safety for plants and the soil. Used as an antiseptic against rust, scab, gray rot, powdery mildew. The dosage of the solution is 80 g per 10 liters. Processing should be carried out only in warm weather (from 20 degrees).

   

2. “Thiovit Jet” is another sulfur-containing drug. They are produced in the form of granules, which must be dissolved in warm water, based on the ratio of 100 g per 3 liters. Rust treatment of apple trees should also be carried out in warm weather.

   

3. “Kumulus” – contact fungicide, produced in the form of granules, soluble in water. Dosage – 5-8 g per 10 liters.

   

Biological preparations

Rusty spots on apple leaves can also be treated with biological fungicides. The most effective drugs are:

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

Treatment of rust on an apple tree with folk remedies

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

1. Wood ash solution – fill the bucket 2/3 and fill it with water, then put it in the sun and insist until a yellowish tint appears on the surface. It is drained and diluted with water in a ratio of 1: 1, after which they begin processing.
2. A decoction of horsetail – 500 g of raw material is poured with water, boiled for 20-30 minutes and insisted for a day. Then filter, bring to a total volume of 10 liters and proceed to processing.
3. Soda ash – 5 tablespoons per 10 liters. There also add 50 g of crushed laundry soap, mix thoroughly and start spraying.
4. A solution of pharmaceutical alcohol iodine – 10 ml per 10 liters. With this remedy, the rust apple tree is treated several times with interruptions of 3-4 days.
5. Wormwood infusion – fresh grass is crushed, half a bucket is poured and poured with water. Then insist in partial shade for several days, so that the mixture is fermented. When foam appears on the surface, the infusion is filtered and water is added (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, a weakening of the tree and a slowdown in development. It is not always possible to cope with it – in some cases, it is necessary to cut down the affected trees in order to prevent further spread of the infection. Therefore, experienced gardeners recommend preventing the disease using the following methods of prevention:

1. Regularly sanitize.
2. In autumn, dig up the trunk circle and water it with a solution of any fungicide.
3. Carry away leaves and branches in autumn and burn them completely.
4. Observe the watering rate, especially in rainy summers.
5. Do not forget about phosphorus-potassium top dressing, especially during flowering and the formation of ovaries.
6. Thin out the crown.
7. When planting, observe the minimum distance between trees (4 meters).
8. Several times a season, carry out foliar spraying on the leaf with a solution of potassium monophosphate (30 g per 10 l).
9. Remove root growth.

Conclusion

Rust on an apple tree is a dangerous infectious disease that can affect several trees at once. Therefore, regular pruning and preventive treatments are recommended. And when the first signs of the disease appear, immediately begin treatment.