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 H20 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 H20 and 0.3% NaCl solutions was 18 and 22 hours, respectively. However, when treated KNO3 priming (0 to 100 mM) in H20 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 H20 and 0.3% NaCl solutions. Regarding dry weight of plants after priming, an increasing tendency after the priming treatment in the H20 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.

MATERIALS AND METHODS
  Seed and other materials preparation
  Measurement of seed water uptake and EC value
  Germination tests to NaCl and KNO3
  Measurement of growth degree of shoot and rootto salt
  Germination performance measurements
  Statistics
 RESULTS AND DISCUSSION
  Response of kenaf to NaCl
  Effect of various immersion times on seed wateruptake
  Effect of various KNO3 and immersion times on ionleachate
  Effect of KNO3 on surging the germination percentage
  Effect of KNO3 on surging both T50 and MDG
  Effect of KNO3 on the dry weight
 ACKNOWLEDGEMENTS
 REFERENCES

• In-Sok Lee(Division of Agro-food Development, Jeollabuk-do Agricultural Research & Extention Services) Corresponding Author
• Chan-Ho Kang(Division of Agro-food Development, Jeollabuk-do Agricultural Research & Extention Services)
• Ki-Kwon Lee(Division of Agro-food Development, Jeollabuk-do Agricultural Research & Extention Services)