Rationing the number of brushes on grapes

Rationing brushes on grapes makes it possible to adjust the quantitative and qualitative characteristics of the future crop.

Rationing the number of brushes on grapes

Rationing goal

The main purpose of rationing is the removal of the load from the vine, which it is not able to bear. When berries are overloaded, much more is formed on the plant than it is able to provide good nutrition for growth and development.

Table crop large-fruited varietal varieties are prone to excessive crop formation.

As a result, the crop does not reach the size of the berries and their taste provided for the varietal variety. Redirection to the ripening of excessive fruit leads to depletion of the plant and poor ripening of the vine and does not provide an opportunity to prepare the garden culture for wintering to the proper extent.

Rationing time

The number of berries in the vine is normalized to the beginning of the flowering stage, visually assessing the size and number of inflorescences on individual processes. The best option for an adult fruiting vine is early normalization in the presence of fully or partially formed inflorescences. At the same time, all the food will begin to flow into the left clusters, and this has a positive effect on the dimensional characteristics, preventing the outflow of nutrients on the berries, which still have to be removed.

When determining the time of normalization, they are guided by the rule: varieties with stable pollination are normalized at the stage of inflorescence formation, in young bushes with poor pollination quality in past seasons, the load on the grape bush is regulated at the end of flowering.

For those who have no experience in winegrowing, it is possible to effectively determine the excess inflorescences during visual inspection immediately after the end of the flowering and pollination stage, when qualitatively formed ovaries are visible.

The calculation of the number of bunches

When calculating the load on the grape bush, the following features are taken into account:

  • maturity,
  • average weight of bunches
  • the size of the resulting berries,
  • winter hardiness
  • the length of the autumn pruning of the vine.

These parameters together help to determine the optimal normalization to the grape bush.

Mathematical approach

Some winegrowers use the Magarach formula: M C * N, where M is the optimal number of eyes of the grape bush, N is the number of overgrown shoots, and C is a correction factor taken as 2.5.

This formula is applicable when calculating the rate per bush not by future productivity, but by the number of eyes. In this case, the correction factor takes into account losses. Among the minuses is the need to adjust the normalization indicators after trimming the shoots.

Varietal Approach

The rate of brushes depends on the variety

Most wine growers determine the rate per vine bush by varietal characteristics:

  • for large-fruited table species of early ripeness with a cluster weight of 0.8 kg and large berries of 3.5 * 2.5 cm - at the rate of 1 per 1 shoot, with a large number of crops, such varieties ripen much longer,
  • for table species with a cluster weight of up to 0.5 kg - based on no more than 2 per 1 shoot,
  • for technical species and table varieties with a cluster weight of up to 0.2 kg - 3 or more per 1 shoot.

Varieties that have brushes of 1.5 kg or more are left infertile on every third process. Small brushes swirling varieties do not require normalization.

The older the vine, the more it can withstand the volume of the crop, however, the number of brushes on the shoots is increased gradually, usually with a plus of half an additional brush for each subsequent year.

Some varietal varieties are able to form brushes with an increased density of berries, as a result, the fruits found inside do not ripen. Such clusters are normalized by thinning, removing up to 30% of the fruits.

Normalization Features

In the process of calculating the normalization of the poor grape harvest, several factors should be taken into account, the presence of which requires a decrease in the weight per vine shoot.

The soil

When growing large-fruited varieties in the process of calculating grape rationing, grapes take into account the saturation of soil with phosphorus and potassium, which are able to provide good nutrition to the number of brushes selected during rationing. If the bioactivity of soil is at the stage of formation, it is recommended to leave no more than 1 brush on 1 shoot on cultivated table large-fruited varietal varieties.

Frost resistance varieties

For the subsequent successful wintering of the plant, the frost resistance of the varietal variety at -21 ° C is necessary. In the absence of such a characteristic, in order to provide the required number of elements for the winter, the load on the grape bush is reduced in relation to the indicators calculated empirically and leaves less brushes than it should be.


Rationing the load on the grape bush ensures the timeliness of the ripening of berries and the complete ripening of the vine before the onset of cold weather. It is used, depending on the regional climate, soil fertility and cultivated varieties.


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