We are accustomed to the fact that only metals rust. Unfortunately, plants are also susceptible to “corrosion”. What is apple tree rust?
What is "rust"?
General definition
The disease known as apple rust is caused by the fungus Gumnosporandium tremelloides of the genus Phragmidium. It is especially dangerous if you have common juniper growing in your garden. This is where the pathogen appears, which is then transferred to the tree. In winter, spores accumulate, are “preserved” and live in juniper needles or branches until spring. This way they can be stored for several years. With the onset of warmth, spores develop, moving to the leaves of the apple tree. Thus, infection occurs. The disease is very widespread. More often it affects plants in the southwestern, southeastern regions of Ukraine, as well as Crimea.
First signs of illness
Symptoms can be detected for the first time in the summer, when the plant’s foliage is well developed. Convex round spots, orange or brown, appear on the upper leaf plate. Instead, there may be rust-colored stripes. The spots have black inclusions (spermogonia). Below them are places where spores accumulate—aecidia. They look like cone-shaped outgrowths. Later, the aecidia opens up like a “star,” throwing out a mass of tiny spores.
At the same time, the lower part of the leaf is affected yellow spots. With severe damage, the foliage dries out and then falls off. This process is facilitated high humidity air, windy weather. Then the spores spread faster. The wind can carry them up to 50 kilometers.
All the listed symptoms are clearly conveyed by the photo.
Where else does rust develop?
Much less often, the disease affects the branches, trunk, and even the fruits of the tree. Young shoots are the most vulnerable. They will no longer produce healthy growth. The sickest die off. Others are developing. But after 2-3 years, the wood cracks in the affected parts. The bark of the trunk is cracking. The fruits become deformed, stop growing, and fall off.
Why is apple tree rust dangerous?
In sick trees, photosynthesis and metabolism are impaired. Since spores draw moisture from the plant, the water balance suffers. This explains the falling of diseased leaves, fruits, and shoots. The plant lacks nutrients. As a result, the quantity of the harvest decreases and its quality deteriorates.
Control measures
What needs to be done to destroy plant rust and its consequences?
- If juniper grows in your garden along with fruit trees, then you need to get rid of it! This is a place to dig deep. You can fence the apple tree with other green spaces. They will delay pathogenic spores. However, infection can hardly be avoided.
- If the plants are already infected, then immediately remove all diseased parts (leaves, shoots, branches, fruits). To trim branches, take 5-10 centimeters below the damage site. Then spray with one of the chemicals: Bordeaux mixture 1%, Topaz, cuproxate, zineb solution 0.4%, Vectra. Repeat twice more every 10-14 days.
Methods for preventing apple tree rust
- Eliminate the practice of planting fruit trees and conifers in the same area. This way you will save yourself from unnecessary problems.
- In the spring, before the buds appear, it is necessary to clean out the old affected areas until healthy wood appears. Then disinfect them with copper sulfate 5%. Afterwards, coat with garden putty.
- Treat trees with antimicrobial agents (fungicides). As soon as the leaves bloom, spray. Repeat after two weeks.
Now you can provide proper care your fruit trees, and prevent such a dangerous phenomenon as apple tree rust.
The dream of many summer residents. Everyone wants to taste their own fruit straight from the branch. But while you are growing apple trees, you are faced with big amount problems that appear in the fruits and leaves of apple trees. Rust is one of the most common diseases of favorite fruits. Let's look at why it occurs and how to deal with it.
brief information
Rust is a fungal disease that manifests itself on leaves, branches and on the apples themselves. Don't ignore the problem. After all, if treatment is not organized in time, the tree will gradually wither. By conducting an external examination, you can easily determine whether your apple trees have such a disease or not. If the result is positive, do not despair. The rust that appears on the leaves of apple trees will pass, but you should immediately take active action.
Symptoms
Typically, the disease manifests itself in spring period. The spots may be bright orange or red. Juniper, which may be in close proximity to apple trees, will become a favorable place for the development and further wintering of a fungal disease. Therefore, when planting young trees, you should carefully select your neighbors. Such a disease can spread through the air over many distances without losing its activity. If the leaves of an apple tree are covered with rust, then this could happen due to two carriers:
- wind;
- insects.
Today, there are several dozen varieties of rust. She doesn't spare anyone cereal crops, neither decorative nor vegetable. If you find a fungal infection in your garden, you should immediately begin treating your fruit trees.
Struggle
- We dig up juniper. If your priority is an orchard, then completely rid it of the presence of this shrub. Otherwise, sooner or later the infection will begin to develop. The place needs to be dug to a greater depth and treated with boiling water.
- Fence your apple orchard with safer plants that will protect against diseases.
- It is recommended to remove infected leaves, fruits, branches and young shoots from apple trees. Pruning is carried out at a distance of at least 10 - 15 cm from the infected area.
- Be sure to spray the tree. For this, a wide range of products is offered, for example: Bordeaux mixture with a concentration of no more than 1%, zineb solution or Topaz. Spraying must be done two more times every two weeks.
The given algorithm of actions will help you if rust appears on the leaves of apple trees. Experienced gardeners It is not recommended to wait for the disease to develop. They advise carrying out preventative measures that will definitely protect your fruit.
Precautionary measures
Those considered and the fight against them should give you the idea that it is better to be a prudent summer resident and try to get ahead of the disease. You can do this as follows:
- Set your priorities. What is most important to you: a healthy apple orchard or beauty? coniferous trees which are carriers of fungal infections? They cannot exist together in the same area.
- Start each new season by treating apple trees. It is done in the spring. Remove all bad branches and bark. Treat these areas with a solution copper sulfate and seal all the cuts garden varnish.
- Spray with antimicrobial agents. This should be done before and after the first young leaves appear. Repeat the procedure three times until the fruit appears.
The above methods will help you not to wait for infection, but to prevent it in the early stages of development. Now you know that diseases of apple trees and spots on them do not entail anything good. And all the time you spent growing orchard, may be wasted.
Finally
Now you know that not only metal can rust, but also, oddly enough, our apple trees. Trees are subject to such “corrosion” more and more often, and it’s all to blame for our inattention and untimely treatment. We told you what to do if rust appears on the leaves of apple trees. You know how to properly treat trees. Now you are familiar with many apple tree diseases, and the fight against them will be easy and fruitful.
Have you noticed orange-yellow spots on the leaves of your apple tree? A healthy tree's leaves do not change color or shape. Lesions are a symptom of a plant disease or attack by pests. Rust stains may indicate a fungal infection fruit tree, especially since apple and pear trees are the most vulnerable types of garden plants. How dangerous is the disease, what consequences can it lead to? Why does it affect apple trees and is there a risk of affecting others? garden crops
? Let's figure it out.
Rust on the leaves indicates the appearance of a disease
Rust on apple leaves
Apple tree rust is an infectious disease caused by the fungus Gumnosporandium tremelloides. Typically, the first symptoms of the disease appear in mid-summer: small protrusions appear on the leaves and quickly grow over the entire surface. Soon stripes or round spots of brown color appear on the outer part of the leaves.
Black spots are visible on the spots - they appear in places under which there is an accumulation of spores. Periodically, this nursery opens up and releases a new batch of pests onto the plant. Multiple yellow- brown spots
occupy 2/3 of the leaf surface, the tree quickly sheds the affected leaves and already in August - September its branches become bare.
Rust most often affects the leaves, but the fungus can spread to the branches, bark and fruits of the plant. Young shoots are at risk - some of them die, and those that develop will not produce healthy growth and fruit in the future. The development of shoots can last up to 3 years, but then the bark in the affected areas and on the trunk begins to crack. Apples do not ripen - at some stage (for each plant individually) they slow down their growth and fall off.
Rust weakens the tree, resulting in a poor-quality harvest.
A sick apple tree does not receive the nutrition necessary for normal growth, as a result of which photosynthesis and metabolic processes slow down and the plant does not have enough moisture. As a result, gardeners receive a poor-quality harvest - the fruits are small, they lack the usual juiciness, and the core is often rotten.
Causes of the disease
The most vulnerable is an apple tree that grows in the same area as a juniper, because this plant is the causative agent of rust. During the cold season, fungal spores accumulate and overwinter in juniper needles - they can remain in a preserved state for several years. With the onset of warmth, the active development phase of the spores begins - they settle on the leaves of apple trees and infect the plants.
Rust is a common disease in southern and coastal regions. In humid climates, spores develop faster, and strong winds carry them over a distance of 40-50 km, affecting fruit trees within this perimeter.
How to fight rust?
Yellow-brown spots must be treated so as not to harm the tree:
To remove rust, you need to remove juniper from the garden.
- If the cause of the damage is juniper, it is advisable to remove it from the garden and dig deep into the soil in the place where it grew.
- Branches and leaves with stains will have to be removed. They need to be cut 10 centimeters below the affected area.
- After removing diseased areas, the plant is treated with Bordeaux mixture (1%) or other meadows-containing solutions. The apple tree is sprayed three times, every two weeks.
- A common mistake gardeners make is that they begin to treat the tree at the end of summer, when the apple tree has already dropped its leaves. Such measures will not have any effect.
Rust treatment in early spring has the greatest efficiency
The best time for treatment is early spring, before the buds bloom. First you need to clean the wounds on the shoots (cut as described above) and disinfect the sections with a solution of copper sulfate. After this, you can spray the tree:
- spraying - in the “green cone” phase;
- spraying - in the “bud” phase;
- spraying - after flowering of the tree.
How not to cause harm?
It is impossible to treat spots and other lesions on leaves with Bordeaux mixture in the heat. At high temperature In the air, the toxic chemical begins to actively evaporate, its concentration on the leaves of the fruit tree increases several times. The apple tree can get burned, and the gardener can get poisoned by toxic fumes. Breeders recommend spraying plants in the morning or evening, when it is cool outside.
Treating plants in wet weather will not give a positive result, because the solution will drain from the foliage along with dew drops.
Spraying is carried out when the apple tree is dry. At least 6 hours must pass after the rain. There will be no positive effect from treating a fruit tree at temperatures below +5 degrees, and the apple tree may get burned.
The same thing will happen if you spray the plant in the heat or immediately after rain. In such climatic conditions, copper sulfate, which is part of the Bordeaux mixture and similar preparations, is released in excess. It causes burns of leaves, shoots, and trunk.
Don't want any extra problems? Then do not plant coniferous trees in the same area as fruit trees. And if you take a risk, choose varieties of apple trees with strong immunity to scab and fungal infections, surround the plants with other varieties of fruit trees and properly care for the garden.
It is known that garden trees get sick, and the apple tree is no exception. And people also know that they only corrode hardware. But no, apple trees are also susceptible to rusting.
What kind of disease is “apple tree rust”? and how to cure it?
After all, if you do not take measures to combat rust as a disease, then a little time will pass and the diseased apple tree will die.
Leaves are predominantly affected by rust, but in some casesfungusspreads to the branches, fruits, and bark of the apple tree.
At risk the young-of-the-year branches remain, because some of them die when the disease develops strongly, and those that still grow by autumn will not bear fruit in the future large number fruits
Because the bark in places of severe infection begins to crack and over time peels off in large strips, exposing the branches.
The apples themselves do not ripen if there is an excessive dominance of rust and the entire formed crop slows down in development (everything happens individually for each tree), and then small apples may crumble.
What is the reason why an apple tree has rusty spots on its leaves?
Every gardener knows that The “correct” foliage of apple trees is uniformly grassy green. And various spots and specks of other colors and shades are not characteristic of leaves - this is a signal to the owner.
Healthy apple tree foliage. Something wrong is happening to the crown, since rusty or orange-yellowish spots are found on the leaves.
Such color changes are an important sign and gardeners are beginning to figure out why the leaves on the apple tree are rusting.
And most often it is rust or rust, but there may be other reasons.
For example, if after 15 days they are not noticeable on the leaves sporanglia or outgrowths, then the tree could have been exposed to poisons or released from an industrial enterprise.
Sporanglia are outgrowths on yellow spots. Because similar spots are possible from exposure to:
- Mercury,
- Arsenic,
- Cadmium.
Or from a sharp increase in soil salt solution: 
- Lead,
- Sulfur compounds.
But such the spots don't have a "rainbow", and also have clearly visible boundaries. And then they dry out so that the edges of the leaves curl to the bottom along the midrib.
Attention! Rust occurs on all pome fruits.
Pomaceous rust- the most common disease in the southern steppe and humid Black Sea regions.
This dangerous disease of apple trees generated by “rust fungi”, which are the reason why the apple tree has rusty leaves.
And in warm and damp climates, their spores quickly form mycelium, so such gardens require close attention from the gardener.
Is it true that apple tree rust is a disease of the fungus Gymnosporangium tremelloides Hartig.?
Gumnosporandium tremelloides genus Phragmidium widespread in our country.
This is one of the dangerous diseases of pome crops in the Russian Federation.
ADVICE! You should not plant juniper where apple trees grow!
Symptoms and first signs of the disease
The main symptoms of the disease and the first signs of apple tree rust will be described below.
IN initial stage formation of a disease that becomes noticeable in early June, orange-brown spots are found on the leaves of the apple tree ovoid, which are slowly growing.
If during this period the disease is not fought, then closer to mid-July growths will appear on the lower surface of diseased leaves.
Rounded spots of a green-canary hue are also found, which gradually grow, becoming rusty carmine or orange. Rusty canary specks sprinkle fiery dots on the outer edge of the apple tree leaves.
Important! When apple trees become infected with rust, they experience massive leaf fall at the end of July. It significantly weakens the trees.
Rust hyphae. Rust hyphae They feed on mineral juices intended for leaves, as a result of which the water-salt balance in apple trees is first disturbed, then the assimilation of sugars through photosynthesis and the interchange of substances in the entire tree deteriorates.
Subsequently, the yield decreases sharply, and the quality of the collected fruit remains low.
Disease carriers
The apple tree will get sick when it gets hit spores released from the wintering horns of sporangia. And these rust spores are carried away by the wind, carried by insects and optional.
The dispersal of formed spores by the wind can excite "mass infection" on large tracts of apple trees. Birds and contaminated gardener’s clothes and shoes can also be carriers.
So a person who has come into contact with diseased juniper bushes drags fungal spores over a distance of 15 km, and Birds can infect apple trees in an area of 45 km!
That is why this disease is often found near forested plantations of coniferous trees, where juniper is grown as a picturesque shrub.
Is juniper a bad neighbor for apple trees?
Yes, junipers are considered the main cause of rust fungus.
Since fungal spores from juniper plantings can be spread by the wind over such a distance.
Rust development in summer
Once on the apple tree as an intermediate host, the spores of this species of dioecious rust fly in mid-June or early July make their way into the middle of the leaf blade and begin to form their mycelium there.
The rust plant spreads hyphae inside the leaf tissues, which penetrate into the conducting vascular bundles. What provides the mycelium with stable mineral nutrition.
Following this, all leaf cells located directly above the cluster of hyphae die.
This is how they appear on the leaves of apple trees. rusty spots with a yellow border (or “rainbow”).
And due to the intensive development of mycelium the leaf tissue begins to deform and swell.
Attention! Without treatment of this disease, by the end of July, all infected leaves cease to assimilate and their mass fall occurs, which greatly weakens the tree.
On apples sometimes show spots, they are larger than on the leaves, up to 3-3.4 cm in diameter, often located near the former flower calyx.
Sick fruits, apples, are underdeveloped and lopsided.
On shoots and twigs of this year's growth, the spots are initially greenish-lemon, then they become orange-red or even rusty-crimson.
After 20-29 days from the moment the hyphae grow, growths appear on the lower edge of the infected leaves, similar to bundles of thin tubes of a light yellowish hue.
Useful videos
Watch the video why the leaves on an apple tree turn yellow:
See what leaf rust is on fruit trees, video from experts:
Watch the video for advice from gardeners on treating fruit trees:
Not allowing rust spots on apple tree leaves, the summer resident guarantees himself a large collection of tasty and sweet fruits.
In contact with
The appearance of any spots on the leaves of an apple tree should alert the gardener. This is a signal that the tree is affected by a fungal infection. Unfortunately, there are many of them and they all lead to significant yield loss. Apple leaf rust is one of many fungal pathogens that have become a frequent visitor to orchards.
To successfully fight an infection, you need to know the signs of the disease, what preventive work should be carried out in orchard and how to get rid of the emerging infection.
Description of the disease
Disease prevention
Fighting the disease
Conclusion
Description of the disease
The appearance of orange dots on the apple tree is a sure sign of the development of a fungal infection. It does not immediately cause damage, but always has a strong effect on yield. Often gardeners do not immediately take action emergency measures, citing employment.
The appearance of rust can be observed in the last month of spring; it appears after rains. Signs of rust damage appear after flowering in late April or early May:
- yellowish spots on the leaves;
- spots of the same color on shoots and fruit branches.
The infection inevitably develops and by the end of summer the rusty speck grows and affects the leaves so badly that it hurts to look at them. By the end of the season, apple tree rust has completely affected all parts of the tree:
- large yellow-orange spots with small black dots on the upper side of the leaf;
- thread-like or cone-shaped formations on the back of the leaf (ethidia), spores ripen in them;
- infected leaves dry out and fly off much earlier than expected;
- large spots appear on the fruit, often near the calyx;
- apples grow small, deformed, lose their taste, and are often affected by rot;
- diseased shoots do not grow and remain short stumps;
- Severely damaged branches die, bark and wood crack on slightly damaged branches.
This disease, with its symptoms, resembles damage to an apple tree by black cancer.
Important! The sensitivity of apple trees to rust is directly dependent on the amount atmospheric precipitation. The wetter the summer, the more cases of rust infestation.
The reasons why apple tree leaves rust are quite simple. Rust on plants is caused by rust fungi.
Rust fungi can have one host plant or several. The fungus Gumnosporandium treme lloides, which causes rust on apple trees, has many hosts. Such fungi are the most dangerous and difficult to eradicate.
The cedar-apple rust fungus begins its development cycle on common juniper and ends on apple trees. Spores from the apple tree again infect the juniper and the two-year cycle of fungal development is repeated again and again until both plants die. Infection can occur if there is no more than 2 km between the juniper and the apple tree.
The fungus overwinters on juniper branches. In spring, orange growths appear on its branches; after wetting in the rain, they swell and become enveloped in mucus. Basidiospores that look like plaque germinate in it. orange color, which are carried over a considerable distance.
Growing fashion coniferous plants caused an outbreak of rust on the site.
Some gardeners are unaware of the connection between the infection and juniper. They don’t know that they need to be treated at the same time.
The development of rust and the dispersal of spores begins at the end of the season. Kidney-shaped brown galls - growths - grow on the underside of the apple tree leaf. When the leaf is exposed to rain, the galls grow jelly-like tendrils or horns in the moist environment. The microscopic spores produced by these horns are carried by wind and insects. The spores infect only juniper.
Important! Rust does not cause significant damage to juniper and develops on it unnoticed for a long time.
Disease prevention
Rust on apple tree leaves can only appear from one source - infected common juniper. However, the difficulty is that juniper can grow in a neighboring plot to which there is no access. And although disease prevention involves caring not only for the apple tree, but also for the juniper, in reality this is not always possible.
However, if common juniper grows on the site, it should be treated with protective and preventive drugs in the same way as an apple tree. By the way, Caucasian juniper is an intermediate host of the rust fungus for pears.
TO preventive measures The following works include:
- treatment of apple trees with copper-containing preparations in early spring and late autumn;
- cleaning and burning fallen leaves in the autumn;
- autumn digging of soil under a tree;
- pruning heavily affected branches;
- sealing all wounds in the bark;
- spraying with fungicides.
In early spring, collect and burn all fallen leaves; it is even better to do this in the fall after the leaves fall. Before winter, they dig up or loosen the soil in tree trunk circle. After this, the soil is treated with a 7% urea solution or a 10% ammonium nitrate solution.
At the end of February or at the beginning of March, all diseased and twisted branches are pruned. At the same time, they capture 5 cm of healthy wood on small branches and 10 cm on large branches.
At the same time, the trunk and branches are carefully inspected, cracks, wounds, and hollows are cleaned of dust and rot. Such places are the gateway for any infection. Cleaned wounds are disinfected with a 5% solution of copper sulfate, after drying they are covered with garden pitch or oil paint on natural drying oil.
In early spring, remove juniper shoots affected by the fungus if it grows in an accessible place. Apple tree varieties that are resistant to rust are treated with a fungicide once every 3 years, moderately and weakly resistant - 2 times a year:
- 5% urea solution in the fall after picking fruits;
- 1% solution of Bordeaux mixture, 0.3% solution of copper sulfate, 0.5% lime-sulfur decoction in the spring on a “green cone”.
Important! When spraying an apple tree, urea behaves like a fertilizer applied to the leaf. As a result of such treatment, the tree grows foliage, fattens, and reduces the yield.
Bordeaux mixture and copper sulfate are toxic agents; they accumulate in the tissues of the plant and inhibit it.
If you have to fight rust fungus for more than one year, you should try using new products in the garden instead of the usual ones. For example, the drug Zineb. This fungicide not only treats the plant, it is able to block infection from entering the apple tree, increases productivity, increases fruit weight and vitamin C content, does not cause leaf burn, and is slightly toxic.
For the purpose of prevention, you can use very effective drug organic origin Poliram DF. The drug Cumulus is created on the basis of colloidal sulfur, which very quickly copes with rust fungi.
A good tip is to plant rust-resistant apple trees in your gardens:
- Mac;
- Sparta;
- Priscilla;
- Liberty;
- Autumn striped (Strifel).
Fighting the disease
The most in a reliable way get rid of rust damage to apple trees - eliminate the juniper on the site. However, it can grow with neighbors who are unlikely to comply with such a desire.
Juniper, which can grow within a radius of several kilometers, is unlikely to be detected at all. Therefore, you will have to strengthen the health of the apple tree. Measures to combat rust are quite traditional; fungicide treatment is used for any fungal infections.
In autumn or early spring, the apple tree is sprayed with a 3% solution of Bordeaux mixture or a 3% solution of copper sulfate, spraying it before the leaves appear, so as not to burn them. This spraying destroys overwintered spores, as well as overwintering larvae and eggs of pests.
It is necessary to fight rust on an apple tree during the period of active growth of the fungus:
- before flowering, before spores begin to disperse;
- immediately after flowering;
- 2 weeks after the last treatment;
- after harvesting fruit.
It is at this time that the spores of the fungus rust, scab, rot, and powdery mildew most actively scatter and germinate. Treatments will help prevent infections from occurring on trees.
Important! If the trees were sprayed with preparations for other fungal diseases, this also stops the spread of rust.
- The first treatment is carried out in early May, before flowering. The apple tree is sprayed with a 1% solution of Bordeaux mixture or with the following preparations: Zineba, Poliram DF, Culumus.
- The next spraying is carried out at the time of greatest dispersion of the infection - immediately after flowering.
- The third treatment is 14 days after the second.
In the fight against infection, systematic and constant treatment of plants is necessary. Only in the right time Spraying will give positive results.
Treatment of apple tree rust, as well as the destruction of powdery mildew, scab, and rot, lasts 2-3 seasons. Disease prevention – annual compulsory work every competent gardener.
Conclusion
Rusty spots that appear on the leaves of an apple tree should not go unnoticed. Active actions by the gardener will help get rid of this unpleasant disease and save the long-awaited harvest. And prevention and proper care will prevent uninvited guests from entering the garden.
