Many irrigation strategies  aimed at a certain wine making specification of grapes, have been tested in many areas and with different varieties of wine grapes . Each strategy determines a certain vegetation period and appropriate water deficit that may lead to the desired effect. Such strategies are usually named as RDI - “regulated deficit irrigation”. Mostly common RDI strategies for red wine grapes include application of water stress after flowering or after veraison or in both periods. Usually, RDI is expressed and controlled with the use of environmental factors, soil water content for instance. At the same time, more and more experts  agree that knowledge of external factors don't provide insufficient basis for drawing accurate conclusions about the degree of water deficit in plants. “Only the plant itself can show reliably when lack of water becomes a stress” (Larcher, 1995,p. 383), which actually affects metabolism and plant development. Many authors have noted a great importance of plant-related indications for accurate irrigation control of different crops and particularly grapevines. In fact, this approach is especially effective for irrigated wine grapes as the cultivar usually grown under controlled water deficit.
There are two plant-related indicators of water state usually used in irrigation practice. The first is stem water potential widely used now for many crops as well as for grapevines. The second technique is based on the analysis of stem micro variations implemented recently in experimental wine growing.