WATER STRESS AFFECTS GROWTH, RELATIVE WATER CONTENT, GAS EXCHANGE AND NITROGEN POOLS OF LOQUAT

Water stress in loquat (Eriobotrya japonica Lindl.) reduced both total and shoot dry matter (DW), but increased root DW, compared to the control. Plant height and stem diameter were reduced by 50 and 46%, respectively. Leaf and shoot RWC decreased significantly to 75.1 and 73.6% under water stress (20% full water holding capacity of soil. Water stress significantly increased concentrations of NH₃-NH₄⁺, arginine and proline, resulting in negative correlations between leaf RWC and concentrations of NH₃-NH₄⁺, arginine and proline in leaves. Under 20% PC treatment, Pn was only 3.98 µmol/m².s, which was 63.08% lower than the control.