The Effect of Hot Water, Sulphuric Acid, Nitric Acid, Gibberellic Acid and Ethephon on the Germination of Corchorus (Corchorus tridens) Seed

摘要

Laboratory trials were carried out to evaluate the effects of concentrated sulphuric acid (98%), concentrated nitric acid (65%), simmering hot water 98.5°C, gibberellic acid (GA_3) and ethephon on the germination capacity of one-and-two-year old Corchorus tridens seeds. The results showed that treating one-year-old Corchorus tridens seeds with concentrated sulphuric acid (98%) for 10, 20, and 30 min significantly broke the seed dormancy and promoted the germination of the seeds compared to control seeds (treated with distilled water), hot water treatment, nitric acid (65%) (seeds treated for 10, 20 and 30 min), gibberellic acid and ethephon. Treating Corchorus seeds with concentrated sulphuric acid for more than 10 min significantly decreased germination capacity. Concentrated nitric acid, gibberellic acid and ethephon had no effect on the germination capacity of corchorus seed. Simmering hot water also broke seed dormancy of Corchorus tridens seed but was not as effective as concentrated sulphuric acid. The results also showed that Corchorus tridens seed stored for two years lost their viability by up to 91.5%. It was concluded that Corchurus tridens seeds from Botswana have hard seed coat or impervious seed coat dormancy but not physiological dormancy as an adaptation to arid and desert conditions.