Grape leaves turn yellow: what to do and how to deal with it, how to process

Grapes - perennial vines, refers to cultivated plants grown for the production of juices, drinks, raisins, extracts and homemade preparations. Growing a he althy bush is quite a challenge, especially for beginner gardeners. Often, yellowing leaves become the first signal of the presence of a disease or pest. What to do if the grape leaves turn yellow, what is the reason.

Why can grape leaves turn yellow?

To grow grapes, you need to follow the agricultural practices of cultivation and carry out preventive measures. Grape leaves may turn yellow for several reasons:

1. The soil is oversaturated with fertilizers.
2. Lack of nitrogen or potassium in the soil.
3. No watering during dry weather.
4. Lack or excess of sunlight.
5. Pests.
6. Infectious, non-infectious chlorosis.
7. Fungal diseases.

Beginner gardeners should pay special attention to the time and type of feeding the grapes. Incorrectly applied fertilizer or frequent top dressing affects the formation of the vine and the yield. Particularly dangerous is manure or bird droppings that are applied incorrectly, which release large amounts of carbon dioxide and increase chlorosis.

Nitrogen deficiency may be accompanied by other symptoms: reduced yields, burn spots, stunted growth, shredded new leaves.

Potassium deficiency manifests itself as yellowing of the leaves around the edge and spreading further.Thanks to nitrogen and potassium in the soil, the vine grows intensively, matures quickly and safely tolerates winter frosts, and also saturates the berries with taste and aroma. And also the lack of magnesium and iron contributes to yellowing.

On hot summer days, an adult, and especially a young seedling, needs intensive watering, its absence weakens the plant's immunity to many diseases. Water deficiency contributes to the withering and drying of the root system of grapes, after which the leaves begin to turn yellow, dry and fall off. And excessive watering during such a period can contribute to the development of fungal diseases.

It is especially important to choose the right planting site for grapes. Some varieties like a shaded place, others - a sunny one. An excess for some and a deficiency for others can affect the proper development of the plant and the yellowing of the green mass, weakening the vines.

Pests large and small can damage the root system or suck the juice from the leaves.Rodents, such as moles, mice, bears, eat up the root system, and can infect the disease, after which the leaves on the vines begin to turn yellow and fall off or wither. Onion fly larvae, grape mites or aphids also suck out their beneficial juices, the lack of which leads to yellowing and curling.

Chlorosis on grapes can be infectious and non-infectious due to the development of some factors:

1. With an excess of lime in the soil.
2. Unfavorable weather conditions - long periods of rain.
3. Soil exhaustion.
4. Infection with nematodes.

First of all, it is necessary to eliminate the factors of chlorosis, cut off damaged specimens and feed the grapes.

Important to know! If the bush begins to turn pale, then the upper leaves turn yellow, then chlorosis arose due to a lack of iron. If lower, then lack of nitrogen. Along the entire length of young and old vines, you need to loosen the soil and make drainage grooves to remove excess water.

Fungal diseases, as well as chlorosis, can occur due to improper care, weather changes, pests that carry fungi from other plants. The most common diseases that lead to yellowing of green mass:

1. Mildew is a dangerous disease that reduces the plant's defenses and reduces the yield. The leaves begin to turn yellow in the form of spots, then dry and fall off.
2. Oidium - spreads quickly throughout the vineyard, first a white coating appears on the plates, then on young vines, after which they turn yellow, turn brown and dry. An untimely treated plant runs the risk of not surviving the winter cold due to a decrease in frost resistance and weakening.
3. Verticillosis (wilt) manifests itself in the form of rapidly yellowing and drying leaves vine after vine, and subsequently the complete drying of the bush.
4. Fusariosis usually appears on the plant in early summer, often in June, yellow dry spots form on the leaves, which quickly spread throughout the plant.
5. Alternariosis occurs in mid - late spring, small yellow spots form on the leaves, after which they become gray, brown, black and dry.
6. Gray rot looks like a white coating that gradually grows throughout the bush, the leaves change color to pale green, then yellow and dry out.
7. Root rot is the first sign: yellowing of the leaves and weakening of young shoots, especially after heavy rains or lack of drainage.
8. Black spot - may appear due to high humidity or when the disease is carried by pests. On the grapes, the affected areas begin to rot, the leaves turn yellow, the color of the berries changes.

Yellowing can also cause anthracnose or bacterial cancer. Any change in the color of the leaves or change in their shape should alert the owner and force them to take preventive measures to eliminate diseases.

The leaves turn yellow in an adult plant

Adult grape bush most often suffers from a lack of nutrients or diseases that are carried with rain, wind, pests, and gives signals in the form of yellowing of the leaf plate. Also on the vines, by the end of summer, in August, premature aging of the leaves may begin, they begin to turn yellow from one edge, gradually covering the rest. Reasons for this yellowing may be:

1. Sudden temperature changes, during the day - heat, at night a decrease of 10 ° C or more.
2. Also affects aging if there were frequent frosts in the spring, the summer was hot and humid, and the end of summer and autumn were cold.

The leaves usually begin to turn yellow, located at the bottom of the bush or in the middle, where there is little access to the sun's rays.

Edaphic chlorosis can also occur, caused by climate change, changing soil composition, acid rain, transplanting a bush or grafting a rootstock.

Yellowing of leaves in young grapes

Rooted cuttings or young seedlings are the most susceptible to external influence, immediately react to improper handling. First of all, this is reflected in the leaves, which become pale green and begin to turn yellow: spots, all over the plate, except for the veins. It is highly likely that improper care contributed to the occurrence of non-infectious chlorosis:

1. Irrigation with cold water.
2. Lack of soil aeration.
3. Incorrectly selected fertilizer, which can cause yellowing of the entire vine or upper young leaves.

Therefore, in the first years of cultivation, any grapes require special attention and compliance with agricultural technology.

What to do if the leaves start to turn yellow?

Before you start processing chemicals or pouring fertilizer, you need to find out the reason why the leaves began to turn yellow:

1. Fully inspect the plant for pests and fungal spores.
2. Examine diseased leaves. Where it starts to turn yellow or after that. If the entire plate turns yellow, fades or twists, the bush lacks moisture or, conversely, dry soil. The presence of holes or tubercles in the soil around the bush may indicate rodents that have damaged the roots. If at the same time the plant stops growing, the vines wither or dry out, then the plant has overcome root rot. Rodents must be de alt with by setting up baits or making repellents.
3. If yellow or brown spots appear in the middle, which then darken and dry out, or the disease begins to spread through the vines and berries - black rot, oidium, mildew. In this case, a quick and effective treatment is necessary so as not to lose the bush.
4. If the whole leaf turns yellow, and the veins remain green, this is non-infectious chlorosis, which is treated by fertilizing with iron, nitrogen, potassium, manganese. Treat the leaves with iron chelate or sprinkle with iron vitriol.
5. If there are small insects on the inside of the leaf, and a yellow stain forms there, then they must be removed mechanically and sprayed with insecticide.

After finding out the cause, you need to choose the right drug or fertilizer complex, which is used in accordance with the instructions.

Preventive measures

Disease prevention should begin with the removal of leaves and weeds around the plant, which often cause infection. The second important point of preventive measures is treatment in the spring when new buds appear, then when the leaves bloom with such preparations:

1. Bordeaux blend;
2. "Aktofit";
3. Fitosporin;
4. "Trichodermin";
5. iron vitriol;
6. "Maxim";
7. colloidal sulfur;
8. urea;
9. Vitaros.

The second time in the spring they are sprayed preventively against awakened insects:

1. drug 30V;
2. Topsin-M;
3. Oxychom;
4. Envidor.

The next treatment with drugs is carried out after flowering and harvesting, as well as in the fall before preparing for winter.

It is also very important to loosen the soil around the bush, apply sand, peat, light mixtures so that the air permeability of the soil is better. When transplanting grapes, make a large layer of drainage so that the roots do not rot. If the bush cannot be transplanted, then make grooves around it to remove excess water.

Complex fertilizers should be applied in early spring, during flowering, in autumn. And it’s better to take the soil to the laboratory to find out what is missing in the soil, its acidity, and then add individual elements to improve the composition.

Most grape varieties require careful care and proper planting, new varieties are less demanding and have better immunity against disease. It will take a lot of effort to grow a he althy bush with a bountiful harvest.

Recommended