Midsummer is a time of “change of fate” for grapes. Its irrigation limits and deprives nitrogen fertilizers, replacing them with potash and phosphorus. For about a month, the winegrower looks to see if he managed to reorient the bush so that berries and shoots ripen on it. If not, and the tops of the shoots straightened up, indicating a slowdown in growth, in August he plans a responsible operation called “chasing grapes”. Actually, if we are talking about the middle zone of Russia, it is held in the third or fourth week of August, and if it is about the Russian south - in early September.
When chasing the upper part of the green shoots of grapes, on which 5-8 underdeveloped leaves grow, is removed. At this point, the tip from an integral part of the plant turns into a real parasite, because it consumes more nutrients than it produces. After minting, they are redirected by the plant to grapes and internodes - and the berries ripen better, and the shoots grow healthy. Moreover, it is precisely the grape tops in August that are often densely affected by mildew, so minting the green shoots of grapes is also a health-improving operation: fewer diseased leaves, worse conditions for the development of the disease.
It should be noted that although in some cases grapes can bear fruit well without minting, it must be carried out in irrigated vineyards in order to achieve greater sugar content of berries and better ripening of annual shoots. Their resistance to cold and productivity also increase, since the development of fruit buds is completely completed, and the bush as a whole has the necessary supply of nutrients.
Chasing should be differentiated depending on the
grape varieties and their regionalization. It is advisable for each variety to determine which leaf surface is best left after minting. Although this is not always and not everywhere. For example, in Bulgaria, famous for its vineyards, this operation is practiced on all varieties and in almost all viticulture regions.
Chasing grapes involves removing only the "inhibitory" top of the shoot. At the same time, less than 10-12 leaves should not remain over the bunch, otherwise it risks remaining without sugar. For the same reason, minting of low- and medium-sized varieties should be discarded in order to avoid a depressing effect on plants.
And certainly you should not mint a bush in the midst of its growth in the hope of leaving all your energy to the ripening of clusters early. Instead, powerful young stepsons are driven up, as if on the street it’s not July, but blissful May days. The owner will remain with sour meat instead of the crop and may generally lose the vine during wintering. Not much better is the late chasing of grape shoots, when a crop has already been harvested from two-meter vines. It seems to be no harm, but there is also no benefit.
But if the variety is overgrown, it is worth trying a method such as repeated chasing of grapes. The first time it is carried out before flowering, and on each shoot after it should not be less than 13 leaves. As the stepchildren of the two upper buds grow by 5-6 cm, a new chasing is carried out, but this time it should be 3-4 cm higher than the previous one. Thus, 3-4 chasing is gained during the growing season. Their result should be the same as with a single, and the yield at the same time increases by 25-30%.
Chasing grapes produces a waste that is a juicy green mass. This is a very valuable livestock feed that can be used for silage. One hectare of vineyards can produce several tons of green mass.