Effect of KNO₃ Priming on Various Properties of Kenaf Seed under Non-Saline and Saline Conditions

The main objective of this study was to increase the germination percentage of kenaf seeds with less number of times under non-saline and saline conditions. Therefore, the first goal was to assess the response of kenaf seeds to NaCl. The second goal was to evaluate the effects of KNO₃ on kenaf seed germination. The germination percentage exhibited a decreasing tendency in germination rate. Plant dry weight was approximately 0.2 g in all treatments at 5 days after germination. As time passed, the electrical conductivity (EC) value of hydro-priming (HP) consistently increased by 8.7 mS/cm at 24 hours of immersion. However, seeds primed with KNO₃ showed no difference in EC values even as times passed. Regarding the priming effect, priming in 100 mM KNO₃ concentration for 12 hours increased germination up to 85% in H₂O solution and in 0 mM KNO₃ concentration upto 73.8% under 0.3% NaCl solution, compared to that of Control. Germination synchronization, shoot length, and leaf unfolding of primed seeds were greater than those of the Control. In addition, main root and hair roots appeared more rapidly in the treated seeds and were more abundant compared to that of the Control. The T50 (times to reach 50% of the final germination percentage) of the Control in both H₂O and 0.3% NaCl solutions was 18 and 22 hours, respectively. However, when treated KNO₃ priming (0 to 100 mM) in H₂O and 0.3% NaCl solution, 9 hours was sufficient to reach T50. Primed (hydro-priming and KNO₃) seeds had a lower MDG (mean days untill germination; 0.6-0.62) compared to that of the Control (1.13-1.31) in H₂O and 0.3% NaCl solutions. Regarding dry weight of plants after priming, an increasing tendency after the priming treatment in the H₂O solution was observed. Furthermore, no significant difference in plant dry weight under 0.3% NaCl stress was observed between the Control and primed seeds. Taken together, the results suggest that 50-100 mM KNO₃ priming for 24 hours optimize seed germination rate in less number of times of exposure with great vigor. Therefore, it is recommended for kenaf seed invigoration before planting.