Why doesn't the vine bear fruit?

Grapevines require regular and careful carebased on knowledge of the plant's requirements. If the vine grows well and produces a lot of leaves, buthas very little or no fruit , it's a sign that we've made a mistake somewhere. In this article, we discuss the most common causes of a lack of vine fruit. Seewhy the vine does not bear fruitand what to do to make the bush have a lot of grapes again!

Why does the vine not bear fruit?
Fig. pixabay.com

The grapevine does not bear fruit due to bad fertilization

Poor fruiting of the grapevine , or even a complete lack of fruit, may be caused by improper fertilization. There is a misconception that organic fertilizers can be used without restrictions. Meanwhile, over-fertilization with manure reduces the resistance of vines to diseases. It also increases susceptibility to frost damage, which results in reduced yields. Correctwe use manure for the grapevines once every two years

If we have access to cattle manure coming straight from farms, remember thatdirectly under the grapevine bushes, only well-composted manure should be usedSprinkle it under the bushes in autumn or early in spring, 5 kg / m².
Granular manure, commonly available in gardening stores, can also be successfully used. In this case, the dosage must be in accordance with the recommendations of the manufacturer of the selected granular manure. For example, the granular cattle manure available in the store of our guide is used in the amount of 200 g for each vine bush, and granulated chicken manure in the amount of 100-150 g per 1 m².

In the second year after manure, it is recommended to turn on nitrogen fertilization. For this purpose, 2-3 grams of ammonium nitrate are used under the plant. However, we must remember that too abundant nitrogen fertilization increases the green mass at the expense of flowers and fruit. Bushes over-fertilized with nitrogen branch strongly and thicken excessively, which increases their susceptibility to fungal diseases.

The grapevine is particularly sensitive to potassium deficiency(yellow discoloration is then visible on the leaves between the veins and on the edges, which turn brown and dry over time), magnesium (yellow or red discoloration on the leaves between the veins) and phosphorus (the leaf becomes deep red, the leaf becomes stiff and brittle). The deficiency of these compounds contributes to the death of grapes, especially in the initial stage of their development.To avoid the risk of shortage of nutrients, it is worth choosing a mineral fertilizer enriched with all the necessary macro- and microelements for the fertilization of vines.An example of such a fertilizer is the micronutrient vine fertilizer available in the store of our guide. The manufacturer of this fertilizer recommends using it in the period from April to August in the amount of 100 g per bush, administered every 3 weeks.

The grapevine does not bear fruit because it is poorly watered

Thanks to a strong root system, the vine is resistant to short-term droughts. However, when there is no rainfall for a long time, and in some phases of plant development, it is necessary to water the bushes.Irrigation of the grapevine is extremely important, especially in early springin the phase of bud bursting, as well as in the period of intensive growth of the shoots. Water deficiency negatively affects the formation of fruiting shoots.Vines should not be watered before or during the flowering period, because it causes flowers to fall and, as a result, prevents fruit setting.

The grapevine does not bear fruit due to cutting errors

Lack of pruning or improper pruning of the vine is one of the main reasonsthe reasons for the lack of fruiting of the vinesShrubs require strong and regular pruning to produce lush clusters.
For the first 2 the years of viticulture, we focus on obtaining strong, woody shoots, and in the third year we give the plant the desired shape. Then we cultivate and trim the shoots to get the best possible yield. We must remember thatgrapevines yields on the branches , i.e. young green shoots that grow from the main shoot, called the bed. This year's shoot bears fruit and in autumn it becomes woody, becoming a bed.
During the early spring cutting of the vine, which is best done in late February or early March, the last year's shoots are cut over the second or third bud, counting from the branching point . Thanks to this,the plant will generate a lot of new shoots that will be able to bear fruit.In the summer, we can make an additional shining cut, thanks to which we will reduce the risk of fungal diseases.We also polish the tops of the branches in order to improve their flowering.
People who have a lot of problems with pruning vinesI recommend the book Cutting School 2. How to prune fruit trees and shrubs? In this extremely well-written book on pruning fruit plants, 13 pages are devoted to pruning and grapevine cultivation. Detailed descriptions and drawing instructions allow you to thoroughly delve into the secrets of cutting the vine. All this is explained in a simple and understandable way.

Grapevine does not bear fruit due to pollination problems

Anotherthe reason for the lack of vine fruitmay be a problem with pollination of flowers. First of all, we must remember that apart from the self-pollinating grape varieties, such as Dakona, Bagrowyj, Agria, Anastazja, there are also non-pollinated grapevines that require another variety to be pollinated in the vicinity. The popular foreign pollination varieties include, for example,Alina Zaporoska, ARV-6-2pk, Kesza 1 or Łora.
Alsoweather conditions have an influence on pollination of flowersHigh temperatures and improper air humidity mean that the pollen does not stick to sternum, or saturated with moisture, loses its ability to move. In such a situation, manual pollination can be carried out by brushing.

The grapevine does not bear fruit due to frost damage

Poor fruiting of vines may be caused bylow temperatures and spring frosts. If the first fruiting shoots freeze and die, the second, the so-called substitutes, they grow back, but hardly bear fruit. After breaking, the frozen shoots are dark inside, brown or black. It is similar with frozen buds - the middle buds, the most fertile, freeze first. The remaining buds are more frost-resistant, but of little use - their fruiting capacity is very low. If we want to check whether the buds on the shoot are frozen, we tear off one - if the place from which it was detached is brown or black - it is a sign that the bud is frozen.

The grapevine does not bear fruit due to diseases and pests

Grapevines are susceptible to attack by pests and diseases that cause severe losses. The most common grapevine diseases are downy and powdery mildew and gray mold. The infection causes plants to wilt and die, poor flowering,lack of fruit buds or their droppingVine pests, such as aphids, scales or spider mites, which suck out plant juices, are equally troublesome. Caterpillars caterpillars damage inflorescences and young clusters, as well as swollen weevils and a horticulture.

MSc Eng. Anna Błaszczak