Why does grapes dry and how to deal with it?
Most grape varieties are not difficult to grow, but there is no need to completely eliminate the likelihood of problems. Among the most frequent troubles, one can single out the drying of leaves, shoots and even berries of a crop, and it is not always easy to determine the specific cause of such a phenomenon. So why grapes dry out and how to deal with it - read on.
Why does grapes dry: reasons and what to do?
The main causes of violations of the usual appearance of grapes, first of all, include miscalculations in the care of the plant: for example, excessive or insufficient liquid supply, improperly selected fertilizer or planting seedlings in a place highly lit by the sun, which causes burns on the vine leaves.
The problem can be solved only by eliminating all the adverse factors affecting the growth and development of grapes, and this primarily applies to the following points.
Water is the main component of any plant, which provides the processes of evaporation and transpiration, and also guarantees the competent distribution of nutrients in the body of the culture. Grapes were no exception in this matter, so properly organized watering can be considered almost the main part of the care.
- slowing down or complete cessation of shoot growth, tarnishing, withering and drying of their crowns;
- lignification of antennae, drying of their tips and falling of individual parts;
- massive yellowing of leaves, which starts from the edge of the lower leaf plates and often leads to their thickening and further decay;
- falling ovaries (during a period of severe drought, small berries of the lower part of the bunch dry first, and then all the rest).
If you limit watering in the pouring phase of grape fruits, then most of them will darken, and sometimes on a separate part of the berry it will be clearly visible as it turns brown. However, in this case, under a spoiled skin, there is often a healthy-looking fruit that differs only in taste from a normal, completely healthy grape.
Important! A lack of moisture is also possible in the winter, but in this case the plant root system suffers the most: small roots crack and no longer have the same vitality.
Mulching the soil and sheltering bushes for the winter will help prevent moisture deficiency in the soil with grapes, and in especially dry times it is recommended to perform fine loosening, which will prevent the formation of crust on the earth's surface and improve air exchange.
For high-quality and economical irrigation, it is possible to introduce liquid into tubes specially dug for this, which will be more preferable than just pouring water on the soil surface.
Direct sun exposure to grape fruits cannot but affect their appearance. On the hottest summer days, the clusters overheat, which makes them seem to be scalded with boiling water: they wrinkle and dry, up to the state of raisins.
Important! With a sunburn of grapes, all damage will be located only on that part of the plant, which is located on the sunny side. This will help to eliminate the likelihood of developing an ailment when the leaves and berry brushes dry on the entire vine.
To eliminate the problem, you will have to adjust the irrigation regime, supplementing it with timely mulching and loosening of the soil. In hot weather it will be useful to transfer young shoots from the sunny side to a more shaded place, covering the affected clusters with paper, newspapers or leaves of the plant itself.
Between rows of grapes you can leave grass, at least until the moment it gets cooler outside. This will help protect the root system of the culture from overheating.
Lack of nitrogen in the soil is also included in the list of common causes of limited growth and drying of cuttings and leaves of grapes. At the initial stages, the leaf blades only brighten a little, but over time they completely dry out and appear more brown (sometimes individual sections turn black much).
In order not to burn the root system of grapes, you can combine the application of fertilizer with conventional watering of the crop.
Did you know? According to approximate estimates of scientists, one adult should eat at least 8-9 kg of grapes per year, but most Ukrainians eat only about 1 kg during this time, thereby depriving their body of the proper amount of nutritional components.
Both overloading of shoots and an insufficient number of branches are dangerous for vine bushes, since the plant has to spend a lot of juice on a small amount of vines. In both cases, the growth of the hands is suspended, and the leaves turn yellow and fall off, sometimes together with the ovary of future fruits.
In addition, the limited or complete absence of pruning adversely affects the decorative properties of grapes, which in some cases plays no less role than the productive qualities of the plant.
Thus, it is possible to easily adjust the load on the fruit bush, although in the spring it is still desirable to tie the plants with wire to trellises. By the end of the third year of life, fruitful shoots are finally formed in the vineyard, which, after harvesting, are completely cut out (from the top to the knot).
It will also be useful for you to find out why white plaque appears on grapes and how to treat it.
If there were no inaccuracies in the care plan, and the leaves or entire branches continue to dry and lose their ovaries, then it's time to think about the possibility of developing fungal diseases.
- Mildew (or false powdery mildew) - is characterized by the appearance of elongated yellow spots on the leaves, which gradually acquire a brown hue and merge into one large spot. If the street is dry - the affected leaves and berries fall from the branches, and with high humidity quickly rot. To confirm the diagnosis, just look at the stem of the grape: with late infection, small, gray-blue spots form next to it, which later become wrinkled. In the fight against the active form of the disease (when the spores of the fungus germinate inside the plant), treatment with known contact fungicides is unlikely to bring the proper result. The only hope for a good harvest will be preventive measures based on regular watering, timely pruning (especially in the spring) and regular use of fungicides, which can prevent not only infection by the fungus, but also the spread of the disease through the vine.
- Anthracnosis is another disease caused by fungi. A favorable environment for their development will be waterlogged soil near the root system of grapes, from which mushrooms move to other parts of the plant and cause small brown spots to appear on the leaves, with a characteristic dark bordering. With the development of anthracnose, all of them gradually dry out and some parts of the leaf plates die, which is why holes appear on the leaves. With a severe defeat by the fungus, the entire leaf dies, and indented spots are formed on the shoots, resembling the image of a bird's eye. In the fight against grape anthracnose, it is effective to treat the plant with copper-containing preparations (for example, copper sulfate or Bordeaux mixture), and it must be carried out immediately after prolonged rains or hail, regardless of the time of the previous spraying.
- Powdery mildew (oidium). Characteristic signs of the disease are limiting the growth of vines, curls and falling leaves, the appearance of gray-white plaque on them. The berries also dry and fall, and this happens in a relatively short time: the first symptoms of the presence of the disease become noticeable within 1.5–2 weeks after the mushroom gets on the grapes. The optimal conditions for the development of oidium will be moderately warm and damp weather, although the spread of the disease is not excluded at low humidity. In the fight against powdery mildew, “Strobi”, “Tiovit”, “Topaz”, “Thanos” preparations are used, and as regards the agrotechnical methods of struggle, it is worth paying due attention to timely garter of a long vine, removal of weeds and maintaining the optimal level of humidity soil (do not allow overmoistening of the root system).
- Gray rot - characterized by the defeat of all the green parts of grapes and can be found in completely different regions of cultivation. The main signs of the presence of the pathogen is the appearance of a gray coating on young shoots and recently opened eyes. In some cases, when there is no proper ventilation between the plantings, all parts of the plant suffer from rotting and gray plaque is clearly visible not only on the leaves, but also on the grapes (when touched, it rises with dust). After the onset of steady heat, gray rot practically ceases to develop, but previously inflorescences or parts of them that are previously affected, still turn brown and fall off. As in the fight against powdery mildew, standard fungicides and compliance with the requirements for agricultural technology for growing grapes will help get rid of the problem.
So that the young grapes do not suddenly stop growing, and during the ripening period of the berries they do not dry out and fall off the brushes, it is important to observe a few simple recommendations for caring for the plant:
- make sure that all purchased seedlings are healthy, and when planting, select only well-lit places without the possibility of flooding with melt or rain water (avoid areas with cold gusts of wind);
- after planting the plant on the territory, provide it with timely and moderate watering, adding liquid only after the top soil layer has dried to a depth of at least 1-2 cm;
- to organize good air exchange, be sure to perform surface loosening of the substrate (preferably the day after watering);
- as nutritional compositions, you can use both ready-made complex mixtures and independently prepared solution from mullein or chicken droppings, but in this case only the use of infusion diluted in water is allowed;
- when grown in unfavorable zones, especially in places where cases of grape disease with fungal or infectious diseases have already been recorded, it is advisable to perform preventive spring treatments with one of the popular fungicidal preparations (for example, “Topaz”);
- regularly inspect plants for insects or signs of ailments, additionally removing excess branches and leaves from the bush (this will improve air exchange inside the plantations and prevent their decay).
Did you know? The first mention of the effectiveness of processing plants from pests dates back to 1000-800. BC e. and are associated with the name of Homer. This ancient Greek poet-narrator in his writings mentioned the benefits of fumigating plants with sulfur, and it is possible that in those days they were used in the fight against the above-mentioned powdery mildew and rust of cereals.
However, it is not necessary to take the situation to the extreme and it is better to immediately provide the cultivated crop with all the necessary conditions for active growth and the prevention of ailments.