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Often grape growers of similar diseases caused by different fungi are called rot, without going into details. There is gray, white, black, acidic, root rot.
From different diseases of grapes, to combat them on video (at the end of the article) treatment from a knapsack sprayer is shown. The author processes a tank mixture of several drugs, which is economically advantageous and saves labor. During the season, several treatments are carried out - depending on the weather, the condition of the plantations, the presence of diseases or pests.
Gray rot on grapes
Mushroom Botrytis cinerea Pers, except grapes affects other woody and herbaceous plants. It hibernates on any parts of the plant - in the bark and fallen leaves, berries, often - crests. In spring it activates, affects all parts of the plant. Easier to penetrate any mechanical damage to plant tissues and unstable tissues, for example, due to unilateral feeding of nitrogen. The possibility of infection directly depends on the thickness of the skin of the host, varietal characteristics. Slowly germinates even at a slight positive temperature.
Gray rot on the leaves of the grapes is manifested in the form of brown spots, covered with a gray coating of conidiophores.
In the heat, the affected part dies. On the woody parts of the plant the spots are white or light yellow, the berries are brown. When the crests of the bunches are damaged, they become greenish-brown, increase and decay. Leads to the falling of bunches. On all the spots over time, there is a gray bloom that dusts when touched: the fungus multiplies.
Danger of gray rot of grapes when breeding shrubs, as Botrytis easily settles in places of vaccination and does not give rise to callus.
The defeat of white varieties in hot, dry days during late stages of berry ripening can improve the sugar content and quality of the wine obtained. Additional harm on red varieties is the destruction of the pigment by the fungus.
Gray rot on grapes, how to fight? You should know that copper-containing drugs are not effective enough. Preparations from the benzimidazole group (benomyl, cercobin, and derozal) are good, but there are strains that are resistant to them. One processing can not be destroyed. Treatment,% solution of rinilan and, 75% of the run helps. The first treatment is more advantageous to carry out those preparations against mildew, which simultaneously affect Botrytis. It is better to treat with different preparations, this prevents the development of pest resistance and gives the best effect.
Not bad helps the folk method - treatment with iodine solution. On the bucket - 30-50 drops, until the appearance of a light yellow tint and a weak iodine odor. Process once a decade or after a rain.
Of great importance is proper agrotechnics, prevention of thickening of the bush, timely implementation of green operations, proper top dressing. In dry, hot weather, disease is always less affected.
White rot of grapes
Called the fungus Coniothyrium diplodiella Sacc. Plants are affected in hot weather, often at the end of the ripening of berries. Berries bloom, dry up, get a boiled look, color purple, concentric. The leaves dry out, become dirty-green, do not fall off. On shoots gray-white long spots, often ringing shoots. Everywhere the hillocks of pycnidia are noticeable, at the end the color of the affected berries becomes dirty white. The ripening pycnidia lift the skin of the berries, between it and the flesh penetrates the air. The berries therefore appear white, the peel is easily removed by a pouch.
Outbreaks of the disease are observed after hail, on burned berries, with thickened bushes. The need for treatment separately from white rot is rare. Is that right after hail, using copper-containing drugs or others.
The treatment of vineyards against mildew or oidium also affects the causative agent of white rot of grapes.
Black rot of grapes, black mouth
The causative agent Guignardia bidwellii requires for infection the moistening of the plants for a while, otherwise the fungus does not penetrate into the host cells. Most often affected are plantings near reservoirs, after mechanical damage, especially in the evening - dropping dew at night contributes to infection.
On the berries appears a brown spot with a white dot in the center. It grows, it grabs the whole berry. Later, the fruits turn black, dry up. In rainy weather, wet rot develops, in the dry - the berries hang wrinkled, mummified, dark violet or blue-black. They hold on to the bunches for a while, fall in autumn. They serve, like dead leaves, as a source of infection in the future.
On leaves, the disease manifests itself in the form of cream stains with a dark green fringe. The fabric inside the stains is dry, dead. On shoots stains in the form of black strokes. Later ulcers are formed, the cortex is cracked. It looks like mildew, but with the advent of black pectids it is impossible to confuse.
The trouble with this disease, like some others, is that the infection of the berry is unnoticeable for a long time. And then the disease develops very quickly, and it is too late to treat... Therefore, prevention is important, treatment begins before the appearance of signs of the disease.
It is important to prevent disease, remove leaves and fruits, shoots, raskorchevyvanie abandoned vineyards.
Root rot of grapes
This is a group of diseases grouped according to external signs. The causative agents are fungi from different orders: imperfect, basidial, marsupial. This includes the defeat of psatireloy, dropsy, rosaline.
It is always easier to damage roots, damaged by weather, mechanically, pests - phylloxera, nematodes, mites, etc. Initially, fungi develop on dead roots, but gradually infect and healthy.
The disease occurs in heavy, humus-rich, floating soils. On sandy loam, poor in organic soils, the disease does not develop. Initially, the fungi develop as saprophytes on dead wood, then pass to the developing roots of the grapes and behave like parasites.
Chemicals are ineffective, mainly reduced to the prevention of disease and the removal of affected bushes.
- The native grape varieties of European grapes should not be planted in heavy, poorly aerated soil or infected with mushrooms.
- Use of mineral fertilizers instead of organic.
- Remove vegetable residues from the field.
- To root out and remove dead or injured bushes.
- Adhere to the correct agricultural techniques. Loosen the soil on the floating soils.
Sour rot of grapes
The name is not associated with color (as in many other rot), but with a smell: the affected berries have an acetic odor. The smell arises from the vital activity of microorganisms, processing sugar berries in vinegar. Near the Drosophila, small fruit flies, their larvae - tiny white worms - are inside the berries. Drosophila reproduce very quickly, which in its time so pleased geneticists. Alas, here they bring significant damage, affecting the berries of grapes and causing the development of many diseases. In damaged berries flies are easier to penetrate, on the other hand, they also carry yeast and fungi from berries to berries.
When the disease develops, we process, and the mixture of fungicide and insecticide - from flies. If you are not sure that the preparations can be mixed (there are special tables, but they are not always at hand), then prepare the solutions separately, merge before use.