The effect of different water regimes with different quality on the growth and production of “Nabali” olive cultivars was studied. Three levels of fresh water (20, 25 and 30 CM) and three levels of treated gray waste water (20, 25, and 30 CM) were used. A control treatment without irrigation was also included. Thirty year old olive cv “Nabali” trees were irrigated from April to July with the different water treatments, each level was applied for a tree. Irrigation water was applied by drip laterals. The experiment was conducted as Beit Doko village close to Jerusalem. Gray waste water was treated through a gravel and filter plant. Both types of water significantly increased olive yield compared to that obtained in the control. A higher vegetative growth (shoot number and length) was obtained with higher water level (30 CM / tree) treated water. Higher olive fruit production was obtained with both olive 30 CM / tree of fresh and treated water. Non irrigated trees exhibited the lowest production and shoot growth.
Both higher levels (25 and 30 CM) of water treatment gave significantly higher oil percent, product or oil acidity and refractive index were not highly influenced by water treatments. These results influenced by the water treatments. These results indicated that this kind of treated wastewater is suitable for application to olive orchards.