Grape Leaf Disease Treatment
Diseases of grape leaves disrupt its vital activity and lead to a decrease or lack of yield.
Grape Leaf Disease Treatment
Description of the disease
Grapes are sick with viral and fungal diseases.
Anthracnose is a fungal disease that affects mainly young grapes. This occurs in spring and summer. Its causative agent is Gloeosporium ampelophagum Sacc. It is common in Europe, Asia, America, Australia. It reaches the greatest distribution in a warm humid climate in Central Asia, Transcaucasia, the subtropical climate of the Caucasus, Ukraine, and Moldova. The main reason for the development of the disease is soil acidity, lack of potassium, phosphorus.
The causative agent is able to tolerate frost in grape leaves spoiled by it. It remains inactive for up to 5 years in the form of a mycelium with spores. Under favorable conditions, produces 5 spore cycles per season.
Signs of the disease from mild to severe:
- the formation of brown, red spots of irregular shape on leaves with a light border on the edges;
- the death of tissues inside the spots, the formation of holes on the parts of the bush that turned red;
- the appearance of depressed points on the petioles of the leaves, which are covered with brown, pink, gray bloom, rust;
- petioles cracking;
- leaf curl;
- staining in a dark brown shade of most of the plant;
- loss of up to 70% of leaves.
Downy mildew, or mildew, does the most harm to plants. It is caused by the causative agent Plasmopara viticola Berl. et Toni. The disease was brought to Europe from America. Distributed in eastern Europe. The disease loves young grapes, humid weather of a temperate climate, cool summers with frequent rains and mild winters. It actively develops at a temperature of 20 ° C-25. " During the season, the disease displays 16 generations of spores.
The first sign of the disease is the appearance of an oily spot on young leaves. Then underneath it forms a powdery coating of a pinkish-white hue, which provokes curl of the leaves. As a result, the leaves turn red, twist, and the vine leaves dry. In severe cases, they appear curly.
Powdery mildew is spread by the fungus Uncinula necator Burril, which came to Europe from North America.
The main symptom of the disease is considered a lag in leaf growth. They darken, dry out, curl, become covered with a white-gray coating on the outside and inside, and become full of holes. Spores from spores appear on and around the holes.
After infection, the fungus adapts to a new environment in 1-2 weeks, spores and mycelium appear. The causative agent is characterized by the ability to reproduce at low humidity and a temperature of 5 ° C. The fungus quickly infects plants with poor ventilation, dense arrangement of foliage culture.
The causative agent of gray rot botritis settles on young leaves. It forms a gray dusty coating of spores at the edges. Prefers thick plantings in the cold rainy spring.
At the first stage, the leaves are twisted with a tube in grapes. The neglected stage is characterized by wrinkling of greens, tissue death. In dry weather, sick twisted leaves wither, the berries dry, become covered with pimples.
The disease can go to the berries.
The causative agent of black spotting is the highest mushroom of the Deuteromycetes. At the first stage, with an air humidity of 85% or more, pests penetrate the wounds with mechanical damage on the leaves, where they form round or oval black grains - pycnids. They exit at a temperature of 8 ° C. In wet weather, they are spread by drops of water, and during drought they are carried by insects, by the wind.
The bodies of the fungus are formed by a rotten brown area, in which the berries are also involved. Later they dry out, increase. On sites the food stops. Necrosis is surrounded by a light brown rim in the hole.
Among the viral diseases, the most dangerous are: yellow mosaic, or infectious chlorosis, short striae, bordering the veins. The cause of the disease is short-node viruses, which appears in the spring, as yellowing, twisting, rust of grape leaves. The shoots dry, curl up, the berries fall off, the flowers fade, grape leaves slow down growth, because the vascular system is affected. Pests are activated in humid, cool weather. With the onset of sustained high temperature, the disease is halted.
With fungal diseases in early spring, the plant begins to be treated when the length of their shoots is not more than 10 cm. The grapes are processed from top to bottom in the evening. The reason for this is the protection of the plant from sunburn. Leaves should not be wet. If it started to rain immediately after treatment with fungicides, they are reused.
Grapes are sprayed with a spray with small holes. Such drops are delayed, do not roll, getting on the inside of the sheet. The tank is filled with a chemical preparation.
When treating fungal diseases, it is taken into account that repeated use of one fungicide increases the resistance of fungi to it by 3-5 times.
Safety measures when working with fungicides:
- Wear gloves, a respirator;
- bred substances in the open air;
- avoid contact with eyes, skin;
- do not eat, do not smoke during the process;
- washed hands after work.
In contact with skin, mucous membranes, rinse thoroughly with running water. When swallowed, drink 2-3 tbsp. water with activated carbon, cause vomiting, consult a doctor.
Fundazole is a systemic, contact agent in the form of a white powder. Its active substance is benomyl. Its concentration in the drug reaches 50%. It is insoluble in water, other liquids. It has a faint odor, but irritates the human mucosa. The drug is highly toxic, has a 2 hazard class. It causes dermatitis when exposed to exposed skin. The solution is contactually absorbed into the leaf by spraying without passing into other green parts. A systemic effect is manifested when applied to the soil, watering. The substance moves upward from the roots through the vascular system.
The number of treatments depends on the stage of the disease.
Efficiency is due to a violation of the division of fungal cells. The medicine is used before flowering as follows: a powder is diluted with water in a proportion of 1:10, sprayed onto the leaves, and introduced into the soil.
The first 3 days, the drug treats the plant. The next week - protects against re-infection. The substance does not inhibit the growth of the culture when applied in the amount recommended on the package. It is not used simultaneously with acidic, alkaline agents. The number of treatments depends on the disease:
- black spotting - 4;
- powdery mildew - 3;
- gray rot - 2.
Previkur is a liquid systemic fungicide with active ingredients: propamocarb 530 g / l, fosethyl 310 g / l. The toxicity class for humans is 3, moderately toxic.
The treatment is based on the blocking of cell membranes, which leads to a halt in the growth of mycelium, spores within 24 hours. Then, for 1-2 weeks, the fungicide performs a protective function.
The substance moves through the roots of the plant, has an indirect effect on the immunity of the culture, which prevents bacterial infection. It helps with downy mildew, gray rot. The substance is bred in a plastic, and not in a metal container, because it causes corrosion of the metal. This solution in a concentration of 5 ml per 1 liter of water for 1.5-2 weeks moisten the green parts of the plant. The soil is watered at the rate of 3 ml / 2 l of water.
The tool is recommended to be mixed with contact fungicides. Complex action increases effectiveness.
The drug has contact, systemic, local activity. It is compatible with fungicides other than alkaline. The composition of the powder, which is moderately hazardous to humans (Grade 3), includes: copper chloride - 690 g / kg, cymoxanil - 42 g / kg. Compounds inhibit the growth and reproduction of fungal cells.
25 g of powder is stirred in a small amount of water until dissolved. Then the liquid is poured into 8-10 liters of water, mixed. For the treatment of anthracnose, downy mildew during the growing season, this agent performs 3 treatments per season with an interval of 14 days. The mixture is sprayed, the leaves are rubbed with it, introduced into the soil.
Chemical 60% preparation in the form of a light brown powder. Arceride is a quick-acting fungicide (1-3 hours), it contains metalaxyl and polycarbacin. Systemically, through contact through stems and leaves, it acts on pathogens, inhibits growth, and breaks intercellular connections.
The consumption rate in the treatment of anthracnose, black spotting, powdery mildew, powdery mildew is 35-40 g / 10 l of water 4 times with an interval of 20-25 days. During this period, the substance protects the culture from new infection.
Among the advantages are water resistance, preventive properties, protection during storage. It accumulates weakly in the body, at the recommended doses it is not able to cause human poisoning (hazard class 3).
Soda will help in the fight against powdery mildew
Folk remedies are effective in the early stages of the development of diseases, when the bushes are not yet completely covered with spores of the pathogen.
Fungal diseases do not tolerate the alkaline environment, so the treatment is based on alkali. Methods with soda are effective against powdery mildew and downy mildew. 25 g of soda ash are mixed with 5 l of hot water. The solution is cooled. With this tool, the plant and the topsoil are washed once a week. Spend 3 procedures.
4 liters of water are mixed with 0.5 tbsp. l liquid soap and 1 tbsp. l baking soda. The solution is used every week for a month.
To treat mildew, a potassium permanganate preparation is prepared. 2.5 g of the substance are mixed with a bucket of water. The plant is sprayed 2 times a week for 2 months.
Black spotting is removed with serum. The concentration of the product with water is 1:10. Irrigation of the plant prevents the contact of mycelium, spores with air. The fungus dies, and the grapes heal: the leaves no longer spin, are saturated with nutrients. The tool is used 3 times after 3 days.
Gray rot dies from a decoction of horsetail. Stages of cooking:
- grass is poured with 1 liter of cool water;
- every other day, boil;
- the resulting strong broth is filtered, cooled;
- the concentrate is diluted with water 1: 4.
Effective 4-time treatment for 4-5 days. Each time a new substance is prepared.
Rot can be treated with ash and soap. 1 kg of substance is poured into a bucket of warm water, insist 5-7 days. Then the liquid is filtered, add 1 tbsp. l liquid soap. The solution is poured under the root, they spray the inside of the leaves every day for a week.
Liquid from potassium iodide helps get rid of external local manifestations of rot. It is diluted with water in a ratio of 1: 5, after which it is applied pointwise to the lesions.
Treatment with copper sulfate is successfully used for any fungal lesions. 5 g of copper is diluted with 300 g of hot water. A solution of vitriol is slowly poured into a 5-liter container full of water with 50 ml of liquid soap. The fluid is thoroughly mixed. Spraying is carried out 3-4 times with a break of 10 days.
Against anthracnose helps rotted manure mixed with water in a 1: 3 ratio, infused for 2 days in a cool, dry place. The tool is suitable for dilution with water 1: 1.
A solution of garlic against fungal diseases is prepared as follows: 25 g of the product is mixed with 1 liter of boiling water, left for 1 day. After the time, the tool is filtered. It is used for any fungal plaque on the leaves.
An effective prophylactic method of combating fungal diseases is the cultivation of resistant varieties. Golden steady and Pineapple grapes are not affected by mildew. Dniester pink resists powdery mildew, black spotting. Buffalo is resistant to gray rot, mildew.
Immunity from fungi does not mean lack of care. To reduce the likelihood of a disease, the plant is sprayed with copper chloride, cuproxate, oxychoma.
The infection is transmitted through inventory, water. Pests contribute to its spread. Tools must be disinfected after use. Regular inspection for pests, timely disposal of them improves the stability of the grapes. The soil for culture is disinfected, calcined.
Preventive agricultural measures:
- improving air circulation by thinning out the stands;
- regular digging of the soil;
- proper pruning, debris;
- timely tying;
- weed removal;
- spraying with 1% Bordeaux liquid before flowering;
- wiping with potassium permanganate the green part of the stands.
Fungal diseases of grapes are difficult to remove. Fighting viral diseases of grapes should be the only effective method: sanitary selection. It is designed to create seedlings without viral strains. The diseased bush is destroyed in order to avoid infection of other plantings.