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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 honey taste of the fruit, they may have to face a lot of trouble. For example, the leaves on a pear turn black, because this can occur due to many different reasons, each of which requires an individual approach. And if some are easy to deal with, others can lead to the complete death of the affected tree.
Why do pear leaves turn black
In fact, the appearance of black dots and spots on the leaves, fruits, and even pear bark is a fairly common symptom. And it can be both evidence of an innocent lack of some nutrient, and a sign of a formidable disease that is practically untreatable.
Diseases in which the leaves and fruits of the pear turn black, the bark
Blackening of pear leaves can occur with diseases of both fungal and bacterial origin.
Bacterial burn
If not only the leaves turn black, but the entire top of the pear, and the leaf blades, along with the color change, also curl, then there are all signs of a serious bacterial disease.
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 peduncles and ovaries of the pear are the first to blacken. At this stage, you can try spraying with biological antibiotics: Gamair, Fitolavin.
The next to suffer are the youngest leaves, they are covered at the edges with brown-dark spots. Soon the spots turn black and spread over the entire leaf surface, and the leaves themselves fold into tubules. Then the tips of young shoots turn black at the pear. In a fairly short period, all young branches can be attacked by the ubiquitous bacteria and look like they have been burned by a 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 various physiological processes in young trees against the background of still insufficiently developed immunity. Pears in the southern regions most often suffer from this disease. This may be due either to insufficient resistance of southern pears to bacteria, or due to the specifics of a hot climate in which the disease spreads too quickly.
Bacteria can be carried by wind, insects and even birds. Infection also often occurs when using a non-sterile tool when pruning branches.
destroyed
Because of this most common fungal disease, not only leaves turn black, but also shoots, flowers, and fruits on both the pear and 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 the 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 brown-yellow hue are formed, over time they grow and darken, then blacken. Pear leaves are almost completely 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 ripen. 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 pear fruits that have time to form are distinguished by hard cork-like pulp, a large number of dark dots 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, Smuglyanka.
fruit rot
The scientific name of this fungal disease is moniliosis, and with it, first of all, the fruits are affected and turn black. The first signs appear during the period of pear fruit pouring and are small spots of dark brown color. Then they begin to spread 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 begin to gradually dry out.
Sooty fungus
This fungal disease can affect a pear either during flowering or during fruit ripening. 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;
- work of insect pests.
As a result, a dark coating 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 soot 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 nutrition of sucking insect pests. As a result of their activity, they secrete a sugary liquid, which becomes the basis for the development of soot fungus.
Black pear crayfish
This disease of fungal origin is sometimes also called cytosporosis. As a result of its impact, first of all, the bark of a pear and a branch turns black. True, with a strong defeat, both the leaves and even the fruits begin to suffer, becoming covered with spots of a reddish hue. On the trunk, small black spots are first formed, flowing with gum. Soon, extensive wounds of a brownish hue appear in place of the spots, and soon the entire trunk on the pear may turn black. It is believed that the disease is not cured, and a heavily 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.
vermin
Among the main pests of the pear, whose activity leads to the fact that the leaves of the pear turn black, one can name the sucker, aphids and leafworms.
The sucker 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 the flowers and ovaries fall off, 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 sooty fungus. As a result, the leaves on pear seedlings turn black and fall off.
Aphids that have multiplied in large numbers are no less dangerous for the leaves of pear trees. As in the case of a leafworm 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 individual sections 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 a lack of humidity in the air, when a large number of dust particles accumulate in it.
What to do if the leaves on the pear turn black
The easiest way to deal with the problem is if black spots on pear leaves 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 bacterial burn. In general, the official effective treatment of a bacterial burn has not yet been invented. But you can try to save the tree with conventional antibiotics.
To begin with, with the help of secateurs and a container of medical alcohol, you need to cut off each branch on which even the slightest damage is found. After each pruning, the secateurs must be disinfected in an alcohol solution. All cut pear branches are placed in a metal basin and burned as soon as possible. All sections are also disinfected by wiping them with a rag soaked 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 carefully sprayed with each branch and each leaf from all sides. The first treatment is carried out in the budding phase – the beginning of pear flowering. Then repeat the operation at least three times, every five days.
If the procedures done do not help, you will have to part with the pear, 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 not easy to cope with the situation when the trunk of a young pear has turned black. It must be realized that black cancer is most often the result of frost holes received after winter, when an infection enters the weakened wood. But if the disease was captured in 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 tissues. All wounds must be treated with a solution of copper sulfate and covered with oil paint.
For washing the remaining parts of the tree, the following components may also be effective:
- pharmacy green tea;
- copper-containing preparations;
- a solution of clay and mullein in equal parts;
- a strong solution of potassium permanganate;
- saturated salt solution with a few drops of iodine;
- diluted alcohol or vodka;
- “Vitaros”;
- “Kresoxim-methyl”.
Agrotechnical events
To cope with the many reasons that cause the appearance of black leaves on a pear, it is sometimes enough to carry out a set of agronomic and mechanical measures in a timely manner. They include the following:
- In early spring, immediately after the snow melts, the ground under the pear is cleared of all plant debris.
- After that, they dig up the soil 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.
- During the appearance of buds, they are sprayed with Agat biofungicide.
- After flowering, pears make potash-phosphorus fertilizer.
- After 18-20 days, repeat the treatment with a biofungicide.
- In the middle of summer, the pear is fed for the last time, using ash and humus.
- In autumn, in order to prepare for winter, they make sanitary pruning of the tree, remove and burn all plant residues.
- The kidneys are treated with a 5% urea solution. And to disinfect the soil around the tree, a solution with a 7% concentration is used.
- The trunk and 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 that 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.
To do 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 sugar from insect secretions, 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 found: Bordeaux liquid, copper sulphate and others. Spraying with these products is especially effective in the spring and autumn periods. After bud break, it is better to use fungicides – Fitosporin, Folicur, 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 bud break);
- 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.
Folk methods
As for insect pests, the easiest way to get rid of them is to wash them off the trees with a good water pressure.
For spraying, you can also use a solution of ordinary dishwashing detergent in water. The procedure is repeated every other day for two weeks.
You can also dilute 1 ml of 400% alcohol and 70 tbsp in 1 liter of water. l. liquid soap and spray the trees in the morning until the sun has risen.
Good against insects and infusions of all kinds of herbs: garlic, tansy, onion peel, yarrow and tobacco. To obtain an infusion, 400 g of any herb is poured into 3 liters of water and infused for about 3-4 days. Add a few handfuls of wood ash. Filter, bring to a volume of 10 liters and spray the trees.
preventive measures
The 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, you should not forget:
- regularly trim trees, especially sanitary;
- after trimming, do not forget to disinfect the tools;
- ensure the correct irrigation regime;
- to make all the necessary nutrients;
- prevent waterlogging of the root neck of the tree;
- provide reliable protection against frost in the winter.
In addition, it is important to choose a healthy and high-quality material for planting.
Conclusion
If the leaves turn black on a pear, then this can be a sign of both the most dangerous and completely harmless diseases. But in both cases, it is necessary, first of all, to make a correct diagnosis. 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 means of protection will help to cope with any problem.
