Effect of the Deficit Watering in the Production and Quality of the Essential Oil, in the Cultivation of Salvia officinalis L.

Salvia officinalis L. is an aromatic and medicinal species suited to the climatic conditions of our region due to its xerophilous qualities. The crop was subjected to five different watering levels (100, 75, 50, 25 and 0% of ETo) through the summer of 2004, in the Vega del Guadalquivir (Alcala del Rio, Seville), under climatic conditions of extremely high temperature. The objective of this study was to describe the effects of water deficit on the crop's leaf and its essential oil production. It was observed that biomass production was directly related to the water rates during the studied interval in deficit irrigation. There were not significant differences among the monitored water rates with regard to the existing relation between the units of dry matter and the essential oil yields. If yields were directly related to the amount of grown dry matter alone, yield results per units of area were significantly affected by the tested water rates. In addition, water rates affected the composition of Salvia officinalis essential oil, as observed in autumn. These differences were significant in the concentration of alpha-pinene, camphene, cineole, alpha- and beta-thujone, bornyl acetate and alpha-humuleno. In autumn harvest, the high concentrations of alpha-thujone were outstanding as an index of low quality. These concentrations were lower in salvia with water deficit.