Effects of canopy size and water stress over the crop coefficient of a Tempranillo vineyard in south-western Spain

This paper describes the assessment of the crop coefficient of an irrigated Tempranillo vineyard measured in a weighing lysimeter during 5 years in south-western Spain. During the first year of the study (2006), young vines displayed a different canopy growth compared to the subsequent years. From 2007 to 2010, vines experienced 2 years with no restriction in water supply, and two other years with short periods of crop water stress. Basal crop coefficient (K (cb)) started from 0.2 at bud-break until 1.0 at full development in every year, being this maximum management-dependent. K (cb) showed a good correlation with canopy size indices, which allows to interpolate these results to a wide range of commercial vine systems that are usually managed with lower vegetation size. Moreover, a simple linear model of crop evapotranspiration reduction with relative water content is presented, allowing the estimation of consumptive water use under deficit irrigation conditions.