Effect of Irrigation Regimes on Productivity and Water Utilization Efficiency of Three Oil Olive Varieties Under Drip Irrigation System.

Abstract

A field experiment was conducted over a period of two successive growing seasons 2011and 2012 on 14 years old olive trees cultivated in sandy soil located at El-Bostan area in Ali Mubark experimental farm at south Tahrir region to investigate the effect of two different drip irrigation regimes (Traditional irrigation (TI) and deficit irrigation (DI)) on the productivity and water utilization efficiency of three oil olive cultivars (Olea europaea L.), Arbequina, Shamlali and Koroniki. The experimental design was split plot with three replicates (tree) where each tree has four emitters with discharge of 16 (TI) and 12 (DI) L/hr/emitter. Two applied irrigation water amounts (as mean value for two growing seasons) were used 28.61 and 21.46 m3/tree/year for TI and DI, respectively. The obtained data showed that fresh fruit weight, fruit and oil yield (as mean value for two growing seasons) were significantly decreased when olive trees subjected to deficit irrigation of the three olives varieties. With respect to olive varieties, the highest mean values of fruit weight were obtained from Arbequina variety (1.62 gm) followed by Koroniki (1.32 gm) while the lowest mean fruit weights were obtained with Shamlali (1.19 gm) variety. The percentage of reduction in fruit yield of trees under DI treatment (as mean value for two growing seasons ) were 15.3, 15.1 and 14.2 % as compared to TI regime for Shamlali, Arbequina and Koroniki olive varieties, respectively. The highest mean values of oil percentage (fresh weight basis) were obtained when olive trees subjected to deficit irrigation (DI) and Koroniki variety was the highest in oil percentage (19.52%). The highest values of water utilization efficiency (WUtE) were 2.73, 2.63 and 2.96 kg fresh weight fruit/m3 and were 0.50, 0.51 and 0.60 kg oil/m3 under deficit irrigation treatments (DI) (as a mean values of the two growing seasons) for Shamlali, Arbequina and Koroniki olive varieties, respectively.