Fruit rot: causes, first signs and symptoms of infection, methods of treatment and improvement of the garden

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

When a person, sparing no effort, cultivates an apple orchard, he expects to get a rich harvest. And there is nothing more pleasant than to see the result of your labors. But it often 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, in appearance, apples and pears look quite he althy, but from the inside, an insidious enemy of all stone fruit and pome crops lurks - fruit rot. 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 tree fruit rot is moniliosis. It is also called monilial burn. This is a dangerous disease that causes a fungal pathogen of three main types:

• Monilia cinerea - "gray necklace", a fungus that affectsstone fruit trees, characterized by particularly aggressive rapid growth.
• Monilia fructigena - the pathogen is predominantly distributed on pome crops, such as apple or pear, causes minimal damage.
• Monilia Cydonia - "quince necklace", fungus infects quince.

These pathogens are predominantly common in the temperate zone of Russia, in regions with cold springs with high humidity. Most often, fruit rot affects trees in the north-west of the country, in the central regions, in the Southern Urals, at agricultural enterprises in the Urals and Siberia, in the Far East, in the west of the North Caucasus.

Stages of the disease

• Moniliosis is characterized by two stages of the disease: Conidial stage. During the entire period of the disease, it can develop repeatedly, its biological function is to promote mass reproduction and settlement of the fungal pathogen. In the conidial stage, the fungus behaves like a parasite. Outwardly, 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.
• Sclerocial stage of fruit rot. The dormant stage of the pathogen that occurs under adverse conditions. At this stage, sclerotia can be found on the trees - dense formations,inside which fungal hyphae are stored for several years, retaining the ability to start growing at any time. Sclerotia are usually small, ranging from a few millimeters to fractions of a millimeter.

Two forms of the disease

Also, experts who have been developing measures to combat fruit rot for a long time distinguish two forms of the course of moniliosis:

• Rot. Primary signs appear on the fruits, which leads to their instant spoilage and yield loss 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 leaf scorch. At the initial stage, buds, ovaries, shoots and leaves are infected. Infection leads to a change in color (they become brown), in the future - to wilting. If they do not fall off for a long time, they look burned.

How infection occurs

During the flowering period, mitospores penetrate into the pistil of each flower. Then comes the stage of rapid growth of mycelium. Pedicels and young shoots suffer next. Soon, instead of a ripening crop, the gardener observes a picture of 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 any damage - wounds, cracks, traces of insects, other deformations caused by concomitant diseases (scab, cytosporosis, black cancer). The presence of pests exacerbatessituation.

Incubation period

The incubation period lasts 1.5 weeks. After, during the flowering period, the ovaries and buds begin to fade, during the fruiting period, characteristic brown spots appear on fruits and berries, which gradually grow over the entire surface of the fruit. Inside, fruits and berries become soft, have a typical smell of fermentation. After a while, fruits and berries become covered with yellow growth pads and begin to fall off. In padans, 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 in itself is not the cause of moniliosis. Illness comes from other sources.

Reasons for appearance

Where does the causative agent of fruit rot of apple, pear, cherry, quince and other fruit crops come from? There are not so many sources. Here are the main ones:

• Damages on the bark of trees through which fungus can penetrate.
• Physical contact of already infected fruits with he althy plant parts.
• Violation of the integrity of the skin of the fruit (mechanical) and caused by pests (goose and codling moth). Fruit with intact skins can only become infected with gray mold through close physical contact with infected objects.
• Presence of othersdiseases that have weakened horticultural crops.
• High susceptibility of a particular plant species or variety to a particular type of fungal pathogen.
• The presence of unharvested, mummified fruits in which the fungus has been preserved.

Factors that increase the risk of contracting moniliosis:

• flowering time;
• hail and cold thunderstorms;
• fogs;
• snowy winters;
• windy weather (spores travel long distances);
• air humidity above 75%;
• unprocessed, dirty containers for collecting and storing fruits;
• dirty, untreated tools used for cutting branches;
• cold and long winter.

Signs of infection

Before taking any measures to combat fruit rot of apple trees, pears and other horticultural crops, you need to make sure that this is moniliosis, and not another disease. Gray rot has the following characteristics:

1. Leaves, ovaries, inflorescences and young shoots turn brown and wither.
2. Infected leaves do not fall off and turn black.
3. Fruits begin to rot with a small brown spot on the skin.
4. Fruit pulp becomes soft, brown in color with a characteristic alcohol aroma.
5. The spot grows in size until it captures the entire surface of the fruit. The fruit becomes black or brown.
6. Yellowish gray pads form on rotting fruit. Against the background of the color of the brown fruit, they may look white.
7. These pads - mitospores (conidia) - are located on the fruit in concentric circles.
8. Further, infection occurs near the fruits and parts of the plant through physical contact or by air.
9. With the spread of the fungal pathogen, the number of affected fruits and berries is increasing.
10. If the fruit is not picked for a long time, then the fungus will spread along the stem, then move to the branch, etc.

How to fight

How to deal with fruit rot? Moniliosis is a dangerous fungal disease that can capture 100% of the trees in the garden within one season. Therefore, at the first signs of gray rot, it is necessary to proceed with consistent treatment. It consists of two steps:

1. Collection and destruction of affected berries and fruits. Collection of mummified padans. Pruning branches, removing damaged parts of trees.
2. Treatment of foci of moniliosis with fungicidal preparations.

The implementation of these two stages gives good results, but, unfortunately, the harvest 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 to fight it. Therefore, it is necessary to take certain preventive measures.

Prevention

The fight against fruit rot should begin with the implementation of various measures aimed at minimizing the risks of infection. Toreduce the likelihood of gray rot on fruit crops:

1. Regularly prune excess shoots on the tree so as to form a "breathing" transparent crown. In shady foliage, the fungus feels great, while airing and sunlight make it wait for better times.
2. Carrying out regular top dressing. He althy, nutritious plants are more resistant to various diseases.
3. Destruction of pests, especially codling moth, sawfly goose. It violates the integrity of the fruit and actually opens the door for the fungal pathogen.
4. Regular treatment of the garden with copper-containing preparations. They destroy not only moniliosis, but also other diseases, for example, scab and black cancer.
5. Plan the placement of trees at the planting stage so that the garden is well lit and ventilated.
6. At the stage of buying seedlings, preference should be given to special varieties that cope well with this disease.
7. Regular rejuvenation of plants by removing old branches that may contain fungal spores.
8. Collect and burn scum.
9. Remove weeds.

Moniliosis drugs

Treatment of fruit rot is made by various preparations. Most often they recommend Medyan, Topsin and Skor.

At the beginning of cherry and cherry blossoms, you can use the drug "Median Extra" for spraying at the rate of 5 g per liter of water. It is recommended at this stage due to its relatively low harmfulness.for fruit crops in particular and the environment in general. But if it does not help, then it is worth trying a more effective "Speed".

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 ⁰С), while "Skor" at these indicators has less efficiency. If there are already signs of disease on the trees, then Topsin-M is used twice, with an interval of a week. I also often use Fitosporin-M during the flowering period - 20 ml of the product per 10 liters of water.

To treat infected areas of the plant, a 3% solution of Bordeaux liquid 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 harvest harvest. If there was a prolonged cold spring, then this treatment is required. In rainy summers, copper-containing preparations are used 3 times.