Why do grape berries crack during ripening and how to treat the disease?

The question of why grape berries may crack during ripening is of interest to many novice winegrowers. Growing grapes is a complex but fascinating process, the harvest is awaited with great impatience, so it is very disappointing when the berries, filling with juice, begin to crack. The bunches lose their presentation, they can no longer be stored for a long time, this can ruin your mood for a long time.

Grape varieties prone to cracking

Global warming and the work of breeders have made it possible to grow grapes in regions where such a thing had never been dreamed of before. At the same time, gardeners are faced with a problem - the abundance of rain and some other reasons lead to cracking of the berries. That is why a novice winegrower needs to carefully select the varieties that are supposed to be planted on his plot. Some of them are prone to cracking berries even with proper care and compliance with all agrotechnical conditions.

The following problem was noticed:

• Laura;
• Highlights;
• Beauties;
• Viking;
• Rhizomata;
• Bullfinch and some other varieties.

It has been noted that grape varieties with a high sugar content and thin skin crack more often.

Why do berries crack during ripening?

They can crack not only from excess moisture, this problem can arise when grapes are affected by diseases (oidium, powdery mildew), or when there is an excess of nitrogen fertilizers in the soil.

Today there is no clear opinion as to why grapes burst, so we should consider the most common possible causes.

Excess moisture

Grapes need a lot of moisture in the period preceding flowering. A flowering vine needs significantly less water, and during the formation of the ovary and the development of the grape bunch, the need for watering increases again.

If the bushes suffer from a lack of moisture, and this period coincides with the onset of rainy weather, the berries begin to intensively absorb water.

In this case, their skin does not have time to stretch and bursts.

Insufficient Nutrient Content

Lack of nutrients is the second reason for grape cracking.The more fertile the soil, the less the grapes burst when ripe. The plant needs fertilizing with nitrogen, phosphate and potassium fertilizers.

Defeat by diseases

The berries burst when the bush is infected with oidium. Timely spraying helps prevent the spread of downy mildew and protects bushes from diseases and berries from cracking. There are varieties that are most susceptible to oidium (for example, Kishmish); in this case, the vines are treated every 3 weeks, before the grapes begin to be filled.

Varietal features

Winegrowers have long noticed that varieties with large green berries in the bunch crack more often. Small berries and dark grape varieties, with slightly less sugar content and thicker skins, are much less susceptible to cracking.

Prevention and elimination of disease

Bursting berries mean a loss of harvest, and the leaking juice attracts insect pests and provokes the development of various diseases. That is why the problem must be dealt with.

How to irrigate

Grapes do not like cold water, so the plants are watered from a barrel where the water has settled and been heated by the sun. Water depending on weather conditions. On average, it is enough to water the grape bushes once a month. Abundant watering is carried out after flowering, when berries the size of a pea appear.

Important: the amount of watering depends on the region in which it grows; When watering, it is better to focus on weather conditions.

The next time the grapes are watered is at the end of July. In August, only late varieties are watered, which are harvested at the end of September or beginning of October. Earlier varieties do not need to be watered.

The right fertilizer

Nitrogen is very important for grapes; the condition of the vine, the size of the bunches and berries, and the amount of harvest depend on it.However, an excess of this element in the soil leads to cracking. Grapes need mineral and organic fertilizers. The best organic fertilizer is rotted manure or compost. For fertilizing with mineral fertilizers, Kemira, Novofort, and superphosphate are used.

The first feeding of adult bushes is carried out in the spring, shortly after the opening of the vine. The bushes are fertilized with a mixture of superphosphate, ammonium nitrate and potassium salt. 20x10x5 grams are dissolved in 10 liters of water. This solution is prepared for each bush. The second such fertilizing is applied a week before flowering.

The third feeding contains no nitrogen fertilizers. It is added during the ripening period of berries, because excess nitrogen is harmful to the ripening crop. In addition, during the period of flowering, after flowering and during the ripening period of grapes, foliar feeding with complex preparations is used, which are easy to purchase in specialized stores. They must be used in accordance with the manufacturer's recommendations.

Reducing the negative impact of nitrogen fertilizers

Bird droppings are considered an excellent fertilizer for grapes, but it should be borne in mind that it contains a large amount of nitrogen, so it is not used during the ripening period.

Increasing the positive effects of potassium and phosphorus

It is potassium and phosphorus that are additionally added when the berries begin to ripen. Phosphorus and potassium fertilizers are used once every 3-4 years, in cases where the vineyard is located on fertile soils. When growing on sandstones, they must be applied once every 2 years.

Handling bushes with burst berries

If there are a lot of burst berries in a bunch, you should get rid of them. Such clusters are carefully trimmed.If the quantity is small, cracked berries are cut from the bunch with blunt-tipped scissors.

It is imperative to remove damaged fruits - they attract wasps, birds, insect pests, and contribute to the development of fungal diseases. Of course, it will not be possible to completely eliminate cracking of grape berries, but these simple tips will significantly reduce the associated yield losses.