GROWTH AND BIOCHEMICAL CONSTITUENTS OF OLIVES AS INFLUENCED BY IRRIGATION WITH TREATED INDUSTRIAL WASTEWATER

Abstract

The suitability of treated industrial wastewater for irrigation of ‘Improved Nabali’, ‘Nabali’, and ‘Manzanillo’ olives was investigated. Irrigation with six electrical conductivity (EC = 0.78, 1.0, 2.0, 3.0, 4.0 and 5.0 dS m-1, respectively T₀, T₁, T₂, T₃, T₄, T₅) were compared in the greenhouse experiment. The olive trees in the field experiment were trickle-irrigated with potable water and treated wastewater. Regardless of the cultivar, length and number of new shoots, diameter of the main trunk, leaf area and dry weight of the plants were significantly enhanced under the influence of different treatments. ‘Improved Nabali’ was the most positively affected cultivar. The leaf biochemical contents from proline and total chlorophyll contents showed no variations among the treatments and cultivars. Proline content was enhanced by irrigation with wastewater only under the field condition. Olive oil acidity and peroxide value were not affected by treatments. These results indicate that this kind of wastewater is suitable for application to olive orchards under irrigation with continuous monitoring of mineral levels.

Keywords:

• wastewater
• olive
• growth
• proline
• chlorophyll
• oil acidity
• peroxide value

ACKNOWLEDGMENT

This study was supported by grants from the Deanship of Scientific Research, University of Mu'tah.