SALINE IRRIGATION OF CV. MANZANILLO AND UOVO DI PICCIONE TREES
Growth, water consumption and mineral composition of one year old 'Manzanillo' seedlings in sand culture, irrigated with a nutrient solution and supplemented with 0, 15, 30 and 60 mM NaCl (percolation conductivity of 2.7, 5.2, 7.5 and 12.3 dS/m, respectively) was evaluated for 115 days. Dry weight accumulation of leaves, shoot and root and water consumption per plant was reduced progressively by higher salinity levels. Transpiration and leaf weight per seedling declined proportionally, indicating a uniform water use efficiency, regardless of salinization. Concentration of root Ca and root, shoot and leaf K and Mg was reduced by salinization. Concentration of shoot P and root, shoot and leaf Na and Cl was increased.
Olive trees, established during 18 months of growth in the Negev of Israel by drip irrigation with good quality water (Ca 1.2 dS/m) were subsequently irrigated for 18 months with saline water (5.5 – 6.5 dS/m) from local wells. Saline water irrigation decreased occasionally fruit size but increased significantly percent dry weight, percent oil and oil yield per unit fruit weight of both 'Manzanillo' and 'Uovo de Piccione' olives. Salinization had only a marginal effect on growth or foliage density and no visual symptoms until the occurrence of a sudden winter rains of Ca. 10 mm. Within 10 days following the rain, severe leaf yellowing, leaf drop and shoot dieback occurred. Leaf analysis of individual trees, correlated to severity of symptoms, revealed that the salinization damage was correlated to tissue Na rather than Cl concentration.