Designation (also Wassertrieb, water voyage or Geiltrieb) for side shoots on Rebstock arising from a "sleeping eye "Have formed. Normal shoots are formed by the axillary buds that were created last year pruning when winter eyes stopped on the one-year wood. On the other hand, water shoots are formed adventitious on perennial wood, which are not already laid out, but if necessary newly from reembryonalisierten cells of the cambium be formed. An old name is "brain drive" (brain stands for head). Because the buds often form on the head of the main trunk, where the vine is cut back in winter pruning to one or two rods or cones.
This radical reduction of shoots and Buds induces the formation of adventitious buds in the interior of the cambium of not too heavily woody stem areas. If the head is too heavily lignified, water shoots can also form on the trunk or at the root base below the earth's surface. Some grape varieties are particularly prone to the formation of water guns, others such as Trollinger ( Schiava Grossa ) drive very hard from the old wood. In general, the water guns do not bear fruit, because they were not created (which is a prerequisite) in the previous year.
The functional purpose of water shoots for a plant is rapid replacement in an emergency. This is the replacement for lost shoots and the quick guarantee of additional leaf mass for the photosynthesis which ensures the nutrition of the vine and the reconstruction of the crown structure. Therefore, they are very fast-growing and long-winded, but develop only a weak, brittle wood body and have poorly trained fruit plants. As they represent a water and nutrient depriving competition for the growth of fruit shoots, they are in principle still in the spring at the time of sprouting removed (broken out). There are also mechanical devices (see picture on the right a Rebstammputzer).
But you can also use them to rejuvenate over-aged vines. For example, if the main trunk is too old, split, rotten or infected by vermin and fungi, this is capped over the attachment point of the water shot and pulled the water shot for it. This then forms the new main trunk. The vine shown in the picture on the left was damaged by late frost. Therefore, low-priced Wasserschoße were left to rebuild the vine can. Not to be confused are water lapels with the suckers that develop from the summer buds in the leaf axils of annual fruit shoots. Therefore, water cannons and Geiztriebe are not the same (although they are often mistakenly called identical). See also complete listings below Weingarten Care (Activities) and grapevine (about the vine).