The Early Selection of Grapevine Rootstocks for Resistance to Drought Conditions

The resistance to severe drought conditions of 20 classical grapevine rootstocks and seven new rootstock genotypes was determined using an early selection test. One-year-old vines were grown under a restricted water regime (1/9 maximum evapotranspiration) in small containers inside a greenhouse. For each plant, the parameter F/rs (F = total active leaf area; 1/rs = stomatal conductance of active leaves) were determined. The results specify the pedoclimatic adaptation of the rootstocks and indicate that the water absorbing activity of the rootlets were the likely primary mechanisms of adaptation to drought.