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Many summer residents and gardeners, planting young pears in their area, do not even suspect that before enjoying the juicy and honeyed taste of the fruit, they may have to face a lot of troubles. For example, the leaves on the pear turn black, because this can happen due to a variety of reasons, each of which requires an individual approach. And if some are easy to cope with, others can lead to the complete death of the affected tree.
Why do the leaves turn black on the pear
In fact, the appearance of blackheads and spots on the leaves, fruits and even the bark of a pear is a fairly common symptom. And it can be both evidence of an innocent lack of any nutrient, or a sign of a formidable disease that is practically impossible to cure.
Diseases in which the leaves and fruits of the pear turn black, the bark
Blackening of pear leaves can occur in diseases of both fungal and bacterial origin.
Bacterial burn
If not only the leaves have turned black, but the entire top of the pear, and the leaf blades, along with the color change, also curl, then all the signs of a serious bacterial disease are evident.
Bacterial burn, and this is the name of this insidious disease, is especially activated in hot weather with high humidity at the same time, when it rains constantly. The very first to turn black are the peduncles and ovaries of the pear. At this stage, you can try to apply spraying with biological antibiotics: Gamair, Fitolavin.
The youngest leaves suffer next, they are covered with brown-dark spots along the edges. Soon the spots turn black and spread over the entire leaf surface, and the leaves themselves roll up into tubes. Then the tips of young shoots turn black at the pear. In a fairly short period of time, all young branches can be infected with the ubiquitous bacteria and look as if they have been burned by fire. Therefore, this disease is called a burn.
The most susceptible to the insidious disease are young pear trees aged 2 to 10 years. Apparently, this is due to the greater activity of the course of various physiological processes in young trees against the background of still insufficiently developed immunity. Pears most often suffer from this disease in the southern regions. This can happen either due to insufficient resistance of southern pears to bacteria, or due to the specifics of a hot climate in which the disease spreads too quickly.
The bacteria can be carried by wind, insects and even birds. Infection also often occurs when using non-sterile tools when pruning branches.
Scab
Because of this most common fungal disease, not only the leaves turn black, but also the shoots, and flowers, and fruits both on the pear and on the apple tree. The disease develops intensively with the simultaneous development of factors such as high humidity and heat.If you do not stop it in time, but allow it to progress, then over time, all pears and apple trees in the garden may die, especially where they grow with thickening of the crown.
The first manifestations of the disease can be seen on pear leaves shortly after they bloom. Small spots of a brownish-yellow hue are formed, over time they grow and darken, then turn black. Pear leaves are almost entirely covered with black spots. The causative agent of the disease - the fungus Dothideales - usually hibernates in fallen leaves. Barely noticeable dark tubercles appear on them, in which spores mature. With the appearance of buds and flowers on pear trees, scab spores are thrown out and actively spread over the surface of the leaves.
Those pears that have time to form are distinguished by a tough cork-like pulp, a large number of dark spots on the peel and low taste. There are varieties of pears that are relatively resistant to this disease. Among them are Gurzufskaya, Dessertnaya, Clapp's favorite, Strawberry, Victoria, Exhibition, Darkie.
Fruit rot
The scientific name of this fungal disease is moniliosis, and with it, first of all, the fruits are affected and blackened. The first signs appear during the pouring of pear fruits and are small specks of dark brown color. Then they begin to creep over the fruit, and the pear becomes loose and tasteless. With the intensive development of the disease, not only the fruits are affected, but also the branches, which gradually begin to dry out.
Sooty fungus
This fungal disease can affect the pear either during the flowering period or during the ripening period. The following factors contribute to the spread of the disease:
- lack of light;
- thickened crown, into which air and light do not pass well;
- planting a tree in a lowland with stagnant water;
- the work of insect pests.
As a result, a dark bloom appears on the leaves and fruits, and the taste of pears decreases. Interestingly, these black spots are quite easily removed from the affected parts of the leaf. On this basis, the sooty fungus is easily diagnosed, it is difficult to confuse it with some other disease.
Most often, the fungus on pears appears as a result of the feeding of sucking pests. As a result of their activity, they secrete a sugary liquid, which becomes the basis for the development of a sooty fungus.
Black Pear Cancer
This disease of fungal origin is also sometimes called cytosporosis. As a result of its influence, first of all, the bark of the pear and branches turns black. True, with a strong defeat, both leaves and even fruits begin to suffer, becoming covered with spots of a reddish tint. On the trunk, at first, small black specks are formed, flowing out with gum. Soon, in place of the specks, extensive wounds of a brownish tint appear, and soon the entire trunk on the pear may turn black. It is believed that the disease cannot be cured, and the badly damaged tree must be destroyed. But gardeners have invented many ways, if not guaranteeing a cure, then able to stop the course of the disease.
Pests
Among the main pests of pears, the activity of which leads to the fact that the leaves of the pear turn black, are the honeydew, aphids and the leafworm.
Copperhead is a small winged insect that can jump and fly from tree to tree. Pests suck the juice from the shoots and leaves, as a result of which flowers and ovaries fall, the size of the leaves decreases. In the process of its life, the leaves are covered with sticky sweetish dew, which serves as an excellent breeding ground for the sooty fungus. As a result, the leaves on the pear seedlings turn black and fall off.
Aphids, which have multiplied in large numbers, are no less dangerous for the leaves of pear trees.As in the case of a leaf roll attack, the leaves begin to curl up, turn black and gradually fall off.
Improper care
The lack of some macro- and microelements in the nutrition of the pear tree can also cause blackening of certain areas of the leaves.
Most often, on acidic soils, there may be a lack of calcium, which is expressed in the appearance of dark yellow areas on the leaves. Over time, they turn black and dry, and the tree looks weakened.
Pear leaves turn black even with a lack of boron, but in this case they also curl, and the tips of the shoots are deformed and also begin to dry out.
The leaves on the pear also turn black from the lack of moisture in the air, when a large amount of dust particles accumulates in it.
What to do if the leaves on the pear turn black
The easiest way to deal with the problem is if the black spots on the leaves of the pear appear due to a lack of certain nutrients.
For example, the introduction of calcium nitrate or other complex calcium-containing fertilizer easily saves from a lack of calcium.
And in order to increase the humidity of the air, it is enough just to regularly spray the trees with ordinary water until the problem ceases to be relevant.
The hardest thing to deal with is a fire blight. In general, no official effective treatment for fire blight has yet been invented. But you can try to save the tree with common antibiotics.
To begin with, using a pruner and a container with rubbing alcohol, you need to cut off every branch on which even the slightest damage is found. After each pruning, the pruning shears must be disinfected in an alcohol solution. All cut pear branches are placed in a metal bowl and burned as soon as possible. All sections are also disinfected by wiping them with a rag dipped in alcohol.
Then you need to find one of the following antibiotics:
- Ofloxacin;
- Penicillin;
- Agrimycin;
- Thiomycin.
The drug is diluted in a small amount of boiled water and thoroughly sprayed on each branch and each leaf from all sides. The first treatment is carried out in the budding-beginning of pear flowering. Then the operation is repeated at least three times, every five days.
If the procedures done do not help, you will have to part with the pear by cutting it down at the root. The root must also be burned, and the place where the tree grew must be treated with strong bactericidal preparations.
It is also difficult to cope with the situation when the trunk of a young pear turns black. It is necessary to realize that black cancer is most often the result of frostbites obtained after winter, when an infection enters the weakened wood. But if the disease was captured at the initial stage, then you can try to cope with it.
Treatment of black cancer on a pear must begin with careful cutting and even scraping of all affected parts of the wood, down to healthy tissue. All wounds must be treated with a solution of copper sulfate and covered with oil paint.
The following components can also be effective in washing the remaining parts of the wood:
- pharmacy brilliant green;
- copper preparations;
- a solution of clay and mullein in equal parts;
- strong solution of potassium permanganate;
- a saturated solution of sodium chloride with a few drops of iodine;
- diluted alcohol or vodka;
- "Vitaros";
- "Kresoxim-methyl".
Agrotechnical measures
To cope with many of the reasons causing the appearance of black leaves on a pear, it is sometimes sufficient to carry out a complex of agronomic and mechanical measures in a timely manner. They include the following actions:
- In early spring, immediately after the snow melts, the ground under the pear is cleared of all plant residues.
- After that, the soil is dug up along a circle covering the crown of the tree, while simultaneously introducing organic or mineral fertilizers into it.
- Before bud break, the pear is treated with hot water at a temperature of + 60 ° C.
- In the period when the buds appear, they are sprayed with Agat biofungicide.
- After the flowering of the pear, potassium-phosphorus fertilizer is applied.
- After 18-20 days, repeat the treatment with biofungicide.
- In the middle of summer, they feed the pear for the last time, using ash and humus.
- In the autumn, to prepare for winter, they make sanitary pruning of the tree, remove and burn all plant residues.
- The kidneys are treated with 5% urea solution. And to disinfect the soil around the tree, a solution with a 7% concentration is used.
- The trunk and the main skeletal branches are coated with a solution of lime with the addition of copper sulfate.
Biological agents
Recently, quite effective biological agents have appeared, consisting of beneficial bacteria, which can quite successfully fight some diseases. Even with a bacterial burn on pears in the early stages of the development of the disease, you can try to cope with the help of biological products.
For this you can use Fitolavin and Gamair. The first drug has a really strong effect and can be used at the beginning of the growing season, before the fruit ripens. 20 ml of Fitolavin is diluted in 10 liters of water and the resulting solution is watered and sprayed on the tree.
It is advisable to use Gamair during the period of fruit ripening, since it is completely safe for human health. 2 tablets of Gamair are diluted in 1 liter of water and sprayed with pear branches.
Also, biological products will be effective against soot fungus. After all, the microorganisms used in them eat the sugar from the secretions of insects, thereby leaving the fungus without food. You can use Shining, VostokEM1 and Baikal.
Chemicals
All fungal diseases, as a result of which the leaves and branches on the pear turn black, must be treated with copper-containing preparations at the first signs of detection: Bordeaux liquid, copper sulfate and others. Spraying with these agents is especially effective in the spring and autumn periods. After bud break, it is better to use fungicides - Fitosporin, Folikur, Topsin.
You can also use solutions prepared according to the following recipes:
- 300 g of copper sulfate + 350 g of lime + 10 liters of water (before bud break);
- 100 g of copper sulfate + 100 g of lime + 10 liters of water (after budding);
- 30 g of azophos + 2 ml of SCOR (fungicide) + 6 g of Bayleton + 40 g of copper chloride + 10 l of water.
And against insect pests, it is necessary to use insecticides such as Fitoverm, Alatar, Biotlin and Fufanon. All damaged leaves and fruits must be removed from the pear and burned.
Traditional methods
With regard to insect pests, the easiest method to get rid of them is to wash them off the trees with a good pressure of water.
For spraying, you can also use a solution of a common dishwashing detergent in water. The procedure is repeated every other day for two weeks.
You can also dilute 400 ml of 70% alcohol and 1 tbsp in 1 liter of water. l. liquid soap and spray the trees in the morning until the sun rises.
Good against insects and infusions of all kinds of herbs: garlic, tansy, onion husks, yarrow and tobacco. To obtain an infusion, 400 g of any herb is poured into 3 liters of water and insisted for about 3-4 days. Add a few handfuls of wood ash. Strain, bring to a volume of 10 liters and spray the trees.
Preventive measures
Timely implementation of all agrotechnical measures will already serve as an excellent prevention of many pear diseases and will help prevent blackening of the leaves.
Therefore, in addition to the above measures, one should not forget:
- regularly prune trees, especially sanitary;
- after trimming, do not forget to disinfect the tools;
- ensure the correct irrigation regime;
- add all the necessary nutrients;
- avoid waterlogging of the root collar of the tree;
- provide reliable protection against frost in the winter.
It is also important to choose healthy and quality planting material.
Conclusion
If the leaves on the pear turn black, then this may be a sign of both the most dangerous and completely harmless diseases. But in both cases, it is necessary, first of all, to correctly diagnose. After all, the success of solving the problem will depend on this. And the abundance of modern agricultural practices, as well as chemical and biological remedies will help to cope with any problem.
