Plant Growth, Nutrient Concentration, and Leaf Anatomy of Olive Plants Irrigated with Diluted Seawater

Abstract

The effects of six seawater dilutions (0%, 4.3%, 8.5%, 12.8%, 17.1%, and 21.3% seawater) on shoot growth, leaf development, nutrient concentration and distribution, and leaf anatomy of young olive plants of three cultivars (“Chondrolia Chalkidikis,” “Manzanilla de Sevilla,” and “Kalamon”) were studied under greenhouse conditions. Olive plants showed a high tolerance up to 21.3% seawater. In general, the effects of seawater were: a reduction in growth, an increase in sodium (Na) and chloride (Cl) concentration, a decrease in potassium (K) and calcium (Ca) concentration, and a decrease in K/Na ratio of all plant parts. Furthermore, leaf boron (B) concentration was decreased. In contrast, magnesium (Mg) concentration increased in stems and roots. The plants retained Na and Cl ions in the basal part of stems and in roots, excluding them from leaves. Plants of “Chondrolia Chalkidikis” grown under 21.3% seawater developed leaves with a thicker palisade and spongy parenchyma, and with a hairier lower surface than the plants of the other two cultivars. “Kalamon” showed relatively high tolerance to salinity, followed by “Chondrolia Chalkidikis” and “Manzanilla de Sevilla.” At all seawater dilutions, Na and Cl concentration of all plant parts was significantly lower in “Kalamon” than in the other two cultivars.

Keywords:

• Olea europaea
• leaf development
• nutrient content
• nutrient distribution
• shoot growth

Notes

^*Average of all leaves newly developed on the main shoot during the 157 d of the experiment.

^*Significant differences at the 0.05% level.

⁽¹⁾Includes the lower lamina of palisade parenchyma.