One of the most unpleasant and dangerous diseases of fruit trees is scab. This fungal infection mainly affects apples and pears.
Scab is not able to destroy the tree, but significantly reduces the quality and quantity of the crop. In the article I will tell you what control measures should be used against apple and pear scab, as well as what preventive measures should be used to prevent the development of fungal disease.
The causative agent of the fungus is the pathogenic microorganism Venturi unequal. Scab mainly affects fruit seed trees - pears, as well as apple trees. Lemons, oranges, as well as plums, cherries, cherries and even beets suffer from fungal infections.
Cool weather and rainy are a favorable environment for the development of pathogenic fungus. The defeat of the trees begins in early spring, during frequent rains. Under the influence of high humidity, fungal spores attach to the surface of the kidneys and begin to parasitize on the plant.
Scab is classified as a disease that affects only one plant species. For example, if apples and pears grow in the garden, then when the apples are infected, the fungal infection cannot be transmitted to the pear.
The development of fungal disease occurs in stages. First, 2 weeks after the period of bud opening, on the outer surface of the leaves of the fruit tree spots of olive tinge form. Spots are the breeding ground and the development of fungal spores.
In the future, the disease affects the fruit, as well as branches of the tree. Dark-colored spots are formed on the branches, dark-colored areas of different sizes on the fruit, under which rotting of the pulp begins.
The final stage of development of scab begins in late autumn, when the plant drops all the leaves. At this point, the spores of the fungus penetrate into the bark, branches, fruits and fallen leaves. The fungi that overwintered in a safe place in the spring “awaken” and again begin to parasitize on fruit trees.
Scab does not adversely affect the photosynthesis of plants, which means that the affected tree continues to grow and develop. Fruits of apple and pear trees suffer from a fungal disease; on the affected tree, almost the entire crop spoils and rots.
Scab treatment with chemicals
Chemicals used to fight scab on apples and pears: Skor, Diskor, Horus, Strobe, Fitolavin, Gamair, Raek.
To effectively get rid of scab on plants, it is recommended to alternate chemicals, that is, to treat trees alternately with one or another means. In this case, the fungal infection does not form "immunity" to the active component, which is part of the chemical.
A full cure of the scab plant will occur if you carry out 3-4 treatments.
The first treatment with the above preparations is carried out at the phase of formation of leaf plates (first leaves), the second - at the time of bud formation, the third - the period of formation of the ovaries (after the flowering stage), the last - after collecting the entire crop and falling leaves from the tree.
When working with chemicals, it is important to follow the recommendations clearly stated in the instructions for use of the corresponding product. Chemical treatment of plants must be carried out in a protective suit, rubber gloves and goggles.
Treatment of scab folk remedies
The relevance of using folk remedies to combat various diseases is very high. Gardeners prefer to use safe and effective drugs. The following recipes are used to treat scab:
- Infusion of horsetail. To collect leaves of a horsetail, 1/3 of a 10-liter bucket is required. Add to the vegetable mixture 10 liters. cold water. Leave the mixture for 3 days, then mix thoroughly and spray the fruit trees. Pears and apples are treated with a decoction of horsetail in the period of leaf blooming.
- Saline solution. Thoroughly mix 1 kg. salt (preferably large) salt with 10 liters. water. Prepare the prepared solution of fruit trees. Treatment with saline is carried out in early spring, immediately after the completion of frosts.
- Mustard solution. 100 gr. mix mustard powder in 10 l. fluid. Processing apples and pears is made in the spring after rain.
- A solution of potassium permanganate. Prepare a light pink solution of potassium permanganate and process the plant immediately. Processing is carried out in the period of swelling of the kidneys and at the time of formation of ovaries.
Dealing with a fungal infection is much more difficult than preventing it. Preventive measures against scab are:
- Annually do pruning trees. It is important that the sun's rays reach the surface of the plant. The sun contributes to the drying up of moisture droplets on the surface of leaves, fruits and branches, which are provocateurs of the development of a fungal disease.
- Timely cleaning and destruction of fallen leaves. Spores of the fungus “hide” in the foliage; if the affected foliage remains on the soil, the fungus soon begins to parasitize. Foliage under the trees must be promptly removed and destroyed. We can not allow the accumulation of plant residues under fruit trees, as they can also "hide" fungal spores. Patients shoots and branches are required to immediately cut and destroy, especially pears.
- Before winter, clean the bark from apples and pears to “living tissue”.
- In late autumn, whitewash the trunks and thick branches of fruit trees.
- After harvesting and completely dropping the foliage, treat the trees and the soil around them with a copper-containing solution, for example, 5% solution of copper sulphate.
- Periodically it is recommended to carry out preventive treatment of trees. A good option is to spray the plants with a 7% urea solution. Preparation of the active solution: 700 gr. urea to 10 liters. fluid.
- Prior to budding (March), fruit trees should be treated with a 1% solution of Bordeaux mixture. Analogous to the drug are solutions Kuprozan, Cineba, Kaptan.
- During the period of bud break, prevention is the treatment of the fruit tree with the “Agat-25K” preparation. Preparation of active solution: 3 gr. drug on 10 liters. fluid.
- After flowering, spraying the trees is repeated. To do this, you can use a 1% solution of Bordeaux mixture. To fix the result, another spraying is carried out (2 weeks after the previous one).
- It is preferable to plant in the garden fruit trees that are resistant to the development of scab. The varieties of scab-resistant apple trees are Jonathan, Pepin Saffron, Lobo, Anise, Saffronca. Varieties of pears resistant to scab - In memory of Parshin, Muratovskaya, Memorable, Yanvarskaya, Rusakovskaya, Central Russian.
Features of the disease
Such popular seed crops, such as apples and pears, are not often affected by scab, while respecting agricultural practices and carrying out preventive treatment. However, in order to reduce the risk of disease and to choose the most effective control measures for the treatment of fruit trees, you must know some features of the disease:
- the causative agent of this common disease goes to wintering in the immature fetal body phase, or pseudothecia,
- pseudothecations are able to form on the fallen leaves, as well as the fruits of pome crops,
- disputes are scattered at the initial stage of growth of the branches and shoots of the fruit culture,
- the shell of the spores has a characteristic mucus, which contributes to the fastest and easy mounting of the pathogen on the leaves,
- spores germinate in the space between the cuticle and the epidermis in conditions of high humidity and insufficient temperature indices,
- after about two weeks, the infection passes to the conidial stage, and secondary foliage of the fruit culture occurs.
After the stage of active leaf fall, the fungal infection continues its active development in the form of saprotroph. In order to properly treat the affected plant, it is necessary to detect the appearance of the disease in a timely manner and assess the degree of harmfulness. It should be remembered that it is necessary to fight scab timely, otherwise even the strongest and most modern chemical agents will not be able to guarantee a favorable outcome.
Signs of defeat
Pear scab is different from apple tree scab by the type of pathogen of fungal infection, but the signs of the disease are almost the same. The first signs of scab damage are the appearance of small light-green, oily spots that have just appeared on the newly spreading leaves. After a while, a brownish-olive velvety plaque appears on the surface of such stains.
Symptoms of scab apple and pear
Scab - one of the most common fungal diseases in the garden. The development of the disease of the apple tree is favored by a wet and cool spring, abundant dew and warm rain.
External symptoms of the disease are very characteristic. Olive-green leaves appear on the leaves, later blackening spots, the fruits are bent, covered with cortical cracks and growths.
Scab affects fruits, leaves, leaf stalks, stems and flowers, shoots. A sick tree overwinter worse, its yield decreases, the type and quality of fruits deteriorates.
In years with rainy weather, the ovary is severely affected and falls off, so that the crop can not be seen at all.
The main anti-scab measures should be to prevent and contain the spread of the disease in the summer.
In gardens infected with scab, trees and soil are abundantly sprayed with nitrafen, vitriol, copper sulphate, oleculture. Spraying is carried out before bud break in early spring.
If necessary, bordeaux liquid (400 g per 10 l of water) can be used to control scab and apple trees by spraying in the green cone phase (at the beginning of bud break). If the first spraying is carried out in the budding phase, apply a 1% solution of Bordeaux mixture (100 g per 10 l of water).
The second spraying is carried out immediately after flowering with 1% Bordeaux liquid or zineb solutions, chlorine copper, captan, phthalan, cuprozan and other fungicides.
The third spraying is carried out simultaneously with the spraying against the codling moth (15 to 20 days after flowering). When using drugs oxychloride copper and Bordeaux liquid for the third spraying, you must first make sure that they do not cause burns of the leaves. To check select control branches and spray only them. Burns appear as necrotic spots on the leaves or nets on the fruits. apple disease scab photo
In the case of severe contamination of the garden with a scab, they spend 4-6 times treating trees per season.
You can spray trees with the drug Rajok in the green cone stage.
Spraying carried out in compliance with all rules.
Some gardeners recommend spraying with a solution of table salt (1 kg per 10 liters of water), while 10 liters of solution are used per adult tree, and 2 liters per young tree.
It is necessary to remove all fallen leaves under the garden trees and dig the soil in the circle of the tree.
Proper care of the garden reduces the risk of developing the disease. The main work on the prevention of apple diseases is carried out in the fall. After harvesting, trees should be thoroughly cleaned of mummified fruits, collected fallen leaves, cut dried branches, clean up the trunks to healthy tissue and whitewash. Then to eradicate spraying of apple crown with 3-5% solution of copper sulphate.
For the prevention of apple diseases in the early spring, before bud break, it is advisable to spray Fititosporin M or 1% Bordeaux liquid. Prior to the onset of scab infection, treatments with immunostimulating biologics, such as potassium humate, are useful, which reduces chemical treatments.
Choice of scab resistant varieties
Before buying, you need to carefully study the description of varieties and choose scab-resistant and other apple varieties.
- Strongly affected by scab: Chinese Belfleur, Borovinka, Kalvil snowy, Melba fruitful, Papirovka, Reninet Simirenko, Zhigulevskoe.
- Weakly affected by scab: Anise Scarlet, Antonovka Zolotaya, Lobo, Cinnamon Striped, Rennet Kursk, Mleyevskaya Beauty, Orlik, Stark, Welsey.
Resistant to scab: Grandma, Jonathan, Cinnamon New, Parmen winter gold, Pepin saffron, Suvorovets, Senap, Zorenka, Belarusian crimson.
Description, signs and stages of scab
Fungus venturia unequal - the causative agent of the disease called scab. It spreads from fusicladium (Fusicladium dendriticum) - asexual form of the fungus. The scab most often “attacks” fruit trees in early spring with raindrops. In a humid environment, spores of the fungus are attached to young leaflets by mucous membranes and germinate in them.
This fungal disease most often affects seed trees, such as an apple tree and a pear tree. Lemons, oranges, potatoes also suffer from it. Less commonly, scars suffer from cherries, cherries, plums, beets and bulbous flowers.
It is noteworthy that the fungus that develops on an apple tree will not switch to a pear. Although, according to the signs and methods of dealing with them, these disputes are very similar.
The development of scab occurs in 3 stages:
- 2 weeks after the buds have opened, olive-colored spots appear on the leaves of the infected tree. These are the breeding sites of fungal spores.
- At the next stage, scab infects young branches and the apples themselves. Damaged tissues appear on them - dark areas, under them the fruit pulp quickly deteriorates.
- The last stage of the season comes in the fall, when the tree sheds foliage. During this coprotrophic period, the fungus hides in the bark, fallen leaves and fruits, to overwinter. And in the spring of waking disputes will lead to a new infection.
Scab does not affect the photosynthesis of trees, so the apple trees continue to grow and develop even when infected. And this, in turn, contributes to the further development and maintenance of the fungal spores.
Although scab is a common disease, apples and pears can and should be protected from this fungus. Moreover, prevention is less time consuming and more simple than treatment. You need to do this in the fall and in the spring.
In the autumn, as soon as the harvest of apples or pears is gathered, it is necessary to remove all dried and spoiled fruits. Then you need to cut dry branches and clean the trunk of the old bark. Place pruning branches and peeled bark should be covered with whitewash. All “waste”: fruits, leaves, bark should be removed from the garden and, preferably, burned outside the backyard. After that, the bare crown of the apple should be sprayed with a 5% solution of copper sulphate.
Council If it is impossible to destroy the foliage for some reason, it should be treated with 7% urea solution, it will destroy the infection.
In the spring, apples and pears are prevented from being prevented until the buds have blossomed on the trees. That is, it must be March. This month, gardeners spray trees with 1% Bordeaux liquid. Also suitable solution of kuprozan, captan, zineb.
After flowering, if necessary, you can repeat the procedure. The third time the tree is treated again after 2 weeks. But you need to be very careful, as Bordeaux liquid can burn the leaves.
Treatment of scab without chemistry
Very often, scab is recommended to be treated with chemicals. But these funds can be absorbed into the apples and pears themselves. Consequently, with the fruits chemistry will enter the human body. Therefore, in the treatment of this fungal disease, it is first necessary to turn to the folk methods of struggle.
- Trees can be treated with regular saline. At 10 liters of water you need to take 1 kg of salt, which is sold in any store. You need to process trees in early spring, when apple or pear trees have not yet moved away from wintering. True, fruit trees treated in this way may linger in the growing season. But this should not frighten the gardener.
- Another effective natural solution for scab control is 1/3 of a horsetail bucket in 10 liters of water. Insist means for 3 days, and sprayed fruit trees during the foliage.
- The scab can also be cured with a solution of mustard. 10 l will need only 80-100 g of dry mustard powder. In this case, it must first be diluted slightly with warm water. Trees need to be treated immediately after the rain. Best of all, the solution will work until the beginning of summer, while the disease has not yet entered its full strength.
- Experienced gardeners recommend treating tree branches with fire. Of course, this is not very convenient and rather dangerous. Processing is carried out in the fall, when the foliage is completely fallen.
Attention! If the fruit trees of the neighbors are sick with scab, it is imperative to persuade them to also treat seedlings. Otherwise, fungal spores will constantly fly over to the site, and prevention and treatment will be wasted.
A scab is a fungal infection that can destroy a crop before the owners get there. Therefore, this common disease needs to be closely monitored, prevented and the scab treated at the first signs.
Manifestation of scab
- Для распознавания парши на ранней стадии нужно осмотреть листья пораженного дерева. Если на них имеются маслянистые желтоватые пятна, и они со временем покрываются бархатистым зеленовато-бурым налетом, значит, это парша. When the disease appears in the autumn, the spots are small - 2-3 mm, but in the spring they are larger - up to 1-1.3 cm in the most part.
- If you do not take urgent control measures, the disease affects the flowers, fruits, and on the pear and branches. A scab on a pear can appear as early as spring, because harmful fungi hibernate on fallen leaves and branches. On fruits, signs of disease are round, dark gray spots. The site of infection is dense. Due to corking, the growth of the fetus is delayed, therefore, infected pears and apples are formed by crooked.
- The appearance of scab promotes rainy cold weather. The process of the disease and its degree depends on the temperature and humidity. More influenced by moisture. Even in dry and hot summers, scab can appear if heavy dew falls on nights.
Apple and Pear Scab: Control Measures
- As a preventive measure, infected leaves are destroyed, which after autumn leaf fall can be burned, buried in the ground in the near-stem circle, removed into compost. If you did not have time to do this in the predawn, remove the foliage in the spring. In addition, the affected branches are also cut off at the pear.
- Pristvolny circles are exempted from weeds, are mulched by peat or humus.
- In wet weather, the crowns of trees should be purged and well lit. Therefore, the crown is cut annually, dry and diseased branches are removed, as well as those that thicken the tree.
Features of treatment
- One of the measures that help in the fight against scab is the treatment of soil in the spring of the pristvolnom circle with solutions of mineral fertilizers of high concentration, before budding on the trees.
- 165 g of urea or 250 g of ammonium nitrate, or 250 g of potassium chloride is dissolved in 2.5 l of water. This amount of solution will be enough for 10 m². The soil is treated only in pristvolnom circle. To prevent burns of the tree you need to make sure that the tool does not fall on him.
- To fight the scab of pears and apples, make spraying. The first is made before bud breaks or when buds are advanced. In a liter of water, 40 g of lime and 30 g of copper sulfate is diluted. If you do not have time to process within the specified period, before flowering, spray wood with a Bordeaux mixture - 20 g of lime and 20 g of copper sulphate are diluted with 2 liters of water. This amount is enough for a young tree, an adult and a fruit bearing will need 4-5l solution. The second treatment is carried out at the end of flowering. The following composition is used: 2 ml of the drug “Skor” or 40g of “Abig-Pick” is diluted in 10 l of water. Bordeaux mixture of a concentration of 1% or other drugs that have a similar effect can also be used. The third treatment is carried out 2-3 weeks after the second, and the same preparations are used as for the second spraying.
- Better than other fungicides, the Bordeaux mixture, which can protect a tree for up to a month, is held in the cultivated areas. During the period of fruit development, preparations containing copper can cause burns on the fruit, especially at high humidity.
- More recently, long-acting drugs have appeared that protect trees for up to 30 days. This, for example, is Chorus, which, among other things, is not washed off by rain. Especially effective at low temperatures - 3-10 ° C. Processing is done twice per season, when buds bloom and after flowering.
- The drug "Strobe" is valid for a total of more - up to 35 days. In addition to treating scab of apple and pear, it also helps with powdery mildew. During the growing season is carried out up to three treatments with an interval of two weeks. This tool can be used together with other similar fungicides.
Gives the best results. After harvest, before autumn leaf fall, trees are sprayed with ammonium nitrate or ammonium sulfate. These drugs are used in a concentration of 10%. For potassium chloride and potassium sulfate, the concentration should be 3-10%. Potash saltpeter and potash salt should have a concentration of 5-15%.
Processing is performed at air temperature not lower than 4 ° С. This measure contributes to the destruction of scab, and other dangerous fungi and various pests, increases productivity.
There are varieties of pears and applesresistant to scab. Know that early varieties of apple scab are more likely to hit.
Among the early varieties of apple trees include:
- Grushovka Moscow,
- Pink filling
These varieties are well resisted by scab:
- Cinnamon new
- Pepin saffron, etc.
More resistant to the disease varieties of pears:
With timely measures of prevention against scab on pears and apples, at the first signs of the disease, the disease will recede.
In rainy summer, a large amount of nutrients is washed away from the topsoil. In such conditions, trees are stronger affected by disease and less tolerate frost. Continuing fertilization will help prevent this.
Scab on pear - how to fight?
For the fight are offered drugs fungicidal action. Before use, you should read the instructions and follow the prescribed precautions.
The most popular drugs are based on copper. The fungus quickly dies under the action of this trace element. Despite the high efficiency drug, it has its drawbacks and features:
- The drug acts only in the place of contact with the tree. In areas not affected by spraying, the fungus continues to spread.
- After harvesting the leaves are burned, because the components of the funds can be toxic.
- After processing the trees, traces remain on their leaves and fruits.
- Copper from fungicides accumulates in the soil, and its concentration may exceed the permissible rate many times.
- The solution is prepared in plastic or glass containers. When diluting the concentrate, proper precautions should be observed.
The drugs are sold in specialized stores. It is necessary to process a pear three times:
- with the appearance of buds,
- after flowering,
- before the autumn harvest.
The last spraying is carried out at least two weeks before harvest.
The fungicide contains copper sulphate and lime. The drug is available in powder form, which is diluted with water and applied to the affected areas of the plant. Gardeners are advised to prepare an aqueous solution in such concentrations:
- 3% treatment solution in very advanced cases before flowering,
- 1 percent solution after flowering.
During the season, pear is processed no more than four times. If the agent does not protect well enough, the fungus is not afraid of copper and multiplies, up to seven chemical treatments are allowed.
The preparation includes the same active substances as in the Bordeaux mixture, but diluted with water. The tool is available in plastic bottles of 100 and 500 ml. Liquid is more expensive than powder.
An aqueous solution of scab eliminates no worse than a dry mixture. Also, it must be diluted with water to obtain the desired concentration. The instructions indicatedHow to treat a plant with varying degrees of damage, the exact dosage indicated.
There is no copper in the soluble granules of Horus. The main active ingredient in the composition is cyprodinil, also an effective fungicide. Protection against infection is achieved after two treatments: before and after flowering. It is necessary to spray a pear with an interval of 10 days, the effect after that lasts a month.
The fight against scab should be carried out at the first signs of the disease. Chemical treatment is the only method of pear from scab, when the fungus has already struck a tree, and brown spots have appeared on the leaves and fruits.
Subject to the rules of prevention and the choice of resistant varieties, do not have to worry about the fact that the tree is sick, and look for information about how to get rid of scab.
What the scab looks like
With scab damage on fruit trees, those parts that are above ground suffer. These are leaves and shoots, stems and flowers, and most importantly fruits. What negatively affects the quality and quantity of the crop.
When buds grow on the trees, and leaves appear, small, rounded spots of olive color can be seen on them. Gradually, the spots will begin to darken, acquiring a brown-olive color. Spots of apple trees appear on the top of the leaf, and on the bottom of the pear.
Simultaneously with the darkening of spots on the leaves, spots appear already on the flowers, on the ovaries, and on the peduncles.
Strongly affected leaves begin to dry out and fall off before time. From the leaves, the infection passes to the fruits, and they become covered with the same brown-olive spots.
On the affected areas of the fetus spots become hard, which further, with the growth of the fetus, leads to cracks. Also, the fruits are deformed and become irregular in shape, they can be one-sided. The ovaries affected by the fungus fall, stopping their growth. This is the worst thing in this disease, since the loss of the harvest is inevitable even before its appearance.
In winter, the fungus tolerates well on the shoots of trees and on the fallen leaves. In spring, during the flowering period, little black bumps begin to appear on last year’s infected leaves. In them, disputes just ripen, up to several hundred thousand can form on one leaf.
In wet weather, the scab disputes are released and intensely spread. They quickly fly to large areas with wind currents. When it hits the trees, penetrating into the tissues of plants, a mycelium develops.
Preventive measures against scab
For the garden you need to choose the right place. The garden needs a large amount of light, it must be well ventilated.
When planting alternate seedlings, do not plant them too tight, because after a while they will significantly increase in size. When buying is to give preference to seedlings that are resistant to scab.
The health of trees, you need to carefully monitor them. It is necessary to enrich the soil, maintaining the required acidity, put in time the supports and tie up the branches, whitewash the trunks of the trees. Canted green grass can be used as a fertilizer.
It is also necessary to periodically thin out crowns. Do not feel sorry for the old and just extra branches, they can be cut or sawed off. Cuts and, if any, the cracks must be treated with garden pitch. Fruits that fall need to immediately clean, do not leave them in the garden.
Regardless of whether there are trees scabbed in the garden, every autumn you need to remove fallen leaves (collect and burn). This is a must in the care of the garden.
Many gardeners say that leaves protect plants in the winter from hypothermia and do not need to remove the leaves until spring. But the leaves of fruit trees are no good, since it is not known when disputes will come out in the spring. To shelter the roots of plants, it is better to use birch, linden leaves or aspen.
Spray the soil. To do this, you can take solutions of either ammonium nitrate (10%) or urea. You can also handle tree trunks and branches.
How to deal with scab on apple and pear
In the fight against fungus, preventive measures alone are not enough, especially when defeat has already settled in the garden. It is necessary to apply treatment with pesticides. The main effective drugs in the fight against the disease are drugs containing copper:
- Bordeaux mixture or mixture
- Raik and Skor,
They are very popular due to their effectiveness, but there are some disadvantages:
- contact area of application (the fungus survived where the treatment did not get),
- stains remain on the application areas (this especially affects the fruit),
- can damage the leaves during processing,
- The copper content in the soil increases by 2-3 times.
The first time to process trees, copper-containing preparations, you need in early spring, until the leaves bloom. The second time immediately after the trees faded. The third time, in about 1.5-2 weeks. It is necessary to spray very carefully to treat the entire surface of fruit trees.
If you comply with preventive measures against the fungus (scab), and fight it at the first signs of the appearance of the disease, then the garden will be happy every year with a good harvest of pears and apples.
It should be remembered that low airflow through the garden, warm weather and high humidity of the air are the conditions for the favorable development of the fungus. Therefore, it is so important to know how to treat apple and pear scab, the control measures. It is especially important to observe the preventive measures described above. They will allow to get rid of defeat at an early stage of its formation.