2018 ASHS Annual Conference

Punica granatum ‘Wonderful’ (pomegranate) is currently the industry standard cultivar that accounts for over 90% of all commercial trees planted. Little research based information is available on its salt tolerance. Plants were pruned uniformly prior to treatments: irrigation with nutrient solution at an electrical conductivity (EC) at 1.2 dS m^-1 (control), saline solutions at EC of 5.0 dS m^-1 (EC 5) or 10.0 dS m^-1 (EC 10). New growth, which was identifiable visually, was harvested eight weeks after treatment (first harvest). One week later, the same plants were received the same treatments for another eight weeks. The new shoot growth during the 2^nd eight-week treatment and roots were harvested (second harvest). Dry leaves, stems, and roots were ground, and samples were used for mineral nutrient analysis. At both harvest dates, all pomegranate plants had no or minimal foliar salt damage. At the first harvest, treatment EC 10 decreased the pomegranate shoot dry weight by 15%, but EC 5 did not. At the second harvest, treatment EC 5 and EC 10 reduced shoot dry weight by 13% and 31%, respectively. The sodium (Na) concentration in the leaf and stem tissue of ‘Wonderful’ pomegranate in all treatments was less than 1 mg g^-1 on a dry weight basis, while that in the root tissue was 0.8, 3.7, and 4.5 mg g^-1 in control, EC 5, and EC 10, respectively. The Cl content in leaf, stem, and root tissue increased by 36-90%, 101-156%, and 254-299%, respectively. These results indicate that ‘Wonderful’ pomegranate is very tolerant to the saline water irrgation in this study and has a strong capability to exclude Na and Cl accumulation in the leaf tissue to avoid salt damage.