When a person, sparing no energy, cultivates an apple orchard, he expects to get a rich harvest. And there is nothing nicer than seeing the result of your labors. But often it also happens that the gardener does not have time to collect the fruits - they rot right on the branches and fall off. At the same time, apples and pears look quite healthy in appearance, but the insidious enemy of all stone fruit and pome crops - fruit rot - has lurked inside. Despite the fact that this dangerous adversary is well studied and can be defeated, amateur gardeners often do not notice signs of infection in the early stages of the disease.
Pathogen, habitat
The official name for the fruit rot of trees is moniliosis. It is also called a monilial burn. This is a dangerous disease that causes a fungal pathogen of three main types:
- Monilia cinerea - “gray necklace”, a fungus that affects stone fruit trees, is particularly aggressive rapid growth.
- Monilia fructigena - the pathogen is mainly distributed on pome crops, for example on an apple tree or pear, causes minimal damage.
- Monilia Cydonia - “quince necklace”, fungus infects quince.
These pathogens are mainly distributed in the temperate zone of Russia, in regions with cold springs with high humidity. Most often, trees in the north-west of the country, in the central regions, in the Southern Urals, at agricultural enterprises of the Urals and Siberia, in the Far East, in the west of the North Caucasus suffer from fruit rot.
Stages of the disease
- For moniliosis, two stages of the disease are characteristic: Conidial stage. Throughout the entire period of the disease, it can develop repeatedly, its biological function is to promote mass reproduction and resettlement of the fungal pathogen. In the conidial stage, the fungus behaves like a parasite. Externally, this stage of the development of the disease is manifested by the formation of spores in the affected areas of horticultural crops in the form of medium-sized gray pads. These formations consist of unicellular mitospores (conidia). In spring, when the culture begins to bloom profusely, the pathogen infects the flower, and, spreading further along the branches and shoots, causes a monilial burn.
- Sclerotic stage of fruit rot. The stage of rest of the pathogen that occurs under adverse conditions. At this stage, sclerotia can be found on trees - dense formations inside which fungal hyphae are preserved for several years, while maintaining the ability to begin to grow at any time. Sclerotia is usually small, from a few millimeters to fractions of a millimeter.
Two forms of the disease
Also, specialists who have been developing measures to combat fruit rot for a long time identify two forms of the course of moniliosis:
- Rot. Primary signs appear on the fruits, which leads to their instant spoilage and loss of yield up to 100%. The disease progresses during the entire period of fruit growth and ripening. Pears and apples with signs of infection are not suitable for food.
- Monilial burn. It is also called a leaf burn. At the initial stage, buds, ovaries, shoots and leaves become infected. Infection leads to a change in color (they become brown), in the future - to wither. If they do not fall for a long time, then they look burnt.
How does infection happen?
During flowering, mitospores penetrate the pistil of each flower. Then comes the stage of rapid growth of the mycelium. Pedicels and young shoots are the next to suffer. Soon, the gardener, instead of a ripening crop, observes a picture of the widespread drying of shoots and wilting.
During the ripening period, the disease has the character of an epidemic - the fruits are affected en masse. The first to suffer are fruits and berries that have some kind of damage - wounds, cracks, traces of insects, other deformations caused by concomitant diseases (scab, cytosporosis, black cancer). The presence of pests exacerbates the situation.
Incubation period
The incubation period lasts 1.5 weeks. After that, during the flowering period, the ovaries and buds begin to wither, during the fruiting period, characteristic brown spots appear on the fruits and berries, which gradually grow over the entire surface of the fruit. Inside, the fruits and berries become soft, have a typical smell of fermentation. After some time, the fruits and berries are covered with yellow pads-growths and begin to fall. In padanza, the fungal pathogen can easily survive the winter, and with the onset of heat, the cycle will repeat.
Climatic conditions
Fruit rot most often appears during prolonged cold springs with high humidity of 75 - 90%. Warming is not a deterrent - the main catalyst is high humidity. But it alone is not the cause of moniliosis. The disease appears from other sources.
Reasons for the appearance
Where does the causative agent of fruit rot of apple, pear, cherry, quince and other fruit crops come from? There are not so few sources. Here are the main ones:
- Damage to the bark of trees through which the fungus can penetrate.
- Physical contact of already infected fruits with healthy parts of the plant.
- Violation of the integrity of the skin of the fetus (mechanical) and caused by pests (goose and codling moth). Fruits with intact skin can become infected with gray rot only in the event of close physical contact with infected objects.
- The presence of other diseases that weakened garden crops.
- High susceptibility of a particular type of plant or variety to a particular type of fungal pathogen.
- The presence of uncleaned, mummified fruits in which the fungus is preserved.
Factors that increase the risk of contracting moniliosis:
- flowering time;
- hail and cold thunderstorms;
- fogs;
- snowy winters;
- windy weather (spores travel long distances);
- humidity above 75%;
- raw, dirty containers for collecting and storing fruits;
- dirty, unprocessed tools used to trim branches;
- cold and long winters.
Signs of infection
Before taking any measures to combat the fruit rot of apple trees, pears and other garden crops, you need to make sure that this is moniliosis, and not another disease. Gray rot has the following characteristic features:
- Leaves, ovaries, inflorescences and young shoots turn brown and fade.
- Infected leaves do not fall and turn black.
- Fruits begin to rot with the appearance of a small brown spot on the skin.
- The pulp of the fruit becomes soft, brown in color with a characteristic alcoholic aroma.
- The stain grows in size until it captures the entire surface of the fruit. The fruit turns black or brown.
- Yellowish-gray pads form on rotting fruits. Against the background of the color of the brown fruit, they may look white.
- These pads - mitospores (conidia) - p00 are located on the fruit in concentric circles.
- In the future, infection occurs located near the fruits and parts of the plant through physical contact or by air.
- With the spread of the fungal pathogen, the number of affected fruits and berries increases.
- If the fruit is not picked for a long time, then the fungus will spread along the peduncle, then it will move to the branch, etc.
How to fight
How to deal with fruit rot? Moniliosis is a dangerous fungal disease that can seize 100% of the trees in the garden within one season. Therefore, at the first signs of gray rot, it is necessary to begin sequential treatment. It consists of two stages:
- Collection and destruction of affected berries and fruits. Collection of mummified Padadans. Trimming branches, removing damaged parts of trees.
- Treatment of foci of the spread of moniliosis with fungicidal preparations.
The implementation of these two stages gives good results, but, unfortunately, the crop will be partially or completely lost. Experienced gardeners argue that fruit rot is one of those types of disease that is easier to prevent than fight it. Therefore, it is necessary to carry out certain preventive measures.
Prevention
The fight against fruit rot should begin with the implementation of various measures aimed at minimizing the risks of infection. In order to reduce the likelihood of gray rot on fruit crops, it is necessary:
- Regularly trim the excess shoots on the tree so as to form a “breathing” transparent crown. In the shady foliage, the fungus feels excellent, while ventilation and sunlight make it wait for better times.
- Conducting regular feeding. Healthy plants, provided with good nutrition, are more resistant to various diseases.
- The destruction of pests, especially the moths, goose sawfly. It violates the integrity of the fruit and actually opens the door for the fungal pathogen.
- Regular treatment of the garden with copper-containing preparations. They destroy not only moniliosis, but also other diseases, for example, scab and black cancer.
- Plan the placement of trees at the planting stage so that the garden is well lit and ventilated.
- At the stage of buying seedlings, preference should be given to special varieties that cope well with this disease.
- Regular rejuvenation of plants by removing old branches in which there may be fungal spores.
- Collect and burn the paddans.
- Remove weeds.
Moniliasis drugs
Treatment of fruit rot is carried out with various drugs. Most often recommend “Medyan”, “Topsin” and “Skor”.
At the beginning of the flowering of cherries and cherries, Medyan Extra can be used for spraying at the rate of 5 g per liter of water. It is recommended at this stage due to the relatively low harmfulness to fruit crops in particular and the environment in general. But if it does not help, then it is worth trying a more effective "Skor".
Plums, peaches and apricots, as well as other stone fruits, will be well protected by Topsin-M at a dosage of 3 ml per liter of water. It works well even at low temperatures (less than 12 ⁰), while Skor at these indicators has less efficiency. If the trees already have signs of the disease, then Topsin-M is used twice, with an interval of a week. Also often during flowering I use Fitosporin-M - 20 ml of the drug per 10 liters of water.
To treat infected areas of the plant, a 3% solution of Bordeaux fluid is used, the trunks are covered with a layer of lime with copper sulfate. For preventive purposes, gardens are treated with a 1% solution of copper sulfate twice a year - in early spring and autumn, after harvesting. If there was a protracted cold spring, then this treatment is required. In rainy summer, copper-containing preparations are used 3 times.