EFFECT OF SALICYLIC ACID AND KAOLIN ON YIELD, PHYSIOLOGICAL TRAITS, AND FATTY ACID COMPOSITION IN OLIVE CULTIVARS UNDER REGULATED DEFICIT IRRIGATION

In this study, effect of salicylic acid (SA) and kaolin (KL) separately and simultaneously on yield, physiological traits and fatty acids composition of two olive cultivars (i.e. ‘Zard’ and ‘Roghani’) was investigated under three irrigation regimes. Results showed that deficit irrigation, especially 50% crop evapotranspiration (ETc), increased accumulation of MDA, proline and activity of antioxidant enzymes, but decreased chlorophyll content and yield in both the olive cultivars, as compared to full irrigation (100% ETc). Applying SA and KL alleviated the harmful effect of water deficit on plants through enhancing their chlorophyll content and antioxidant activity, and accordingly improved their yield, as compared to the controls. On the contrary, low irrigation mounted some fatty acids such as palmitoleic acid, stearic acid, arachidic acid, while reduced unsaturated/saturated fatty acids. Moreover, applying SA and KL simultaneously, as compared to the controls, increased unsaturated/saturated fatty acids and the quality of extracted olive oil. In general, the results showed that a simultaneous effect of SA and KL, in comparison to their separate application, had a better effect on yield and quality of olive under water deficit.