Effect of chemical and hormonal treatments on breaking the dormancy of edy mayal (Malus baccata) seeds at Jumla, Nepal

Abstract

The experiments were led to study the effect of pretreatments (concentrated sulphuric acid and gibberellic acid) on germination behavior of Malus baccata by analyzing three parameters i.e. GP: germination percentage, MGT: mean germination time (days) and GRI: germination rate index for various time interval in petridishes. Pre-sowing treatment included immersion in sulphuric acid (98%) for 10, 20 and 30 minutes and immersion in gibberellic acid of 1000, 1250 and 1500 ppm for 24 hrs. The sowing in distilled water (Control) had no positive effect on the germination induction. Generally, the seed pretreatments with sulphuric acid (98%) were very useful to improve germination. Time of immersion significantly (P < 0.001) affected GP, MGT and GRI. Treating Malus baccata seeds with sulphuric acid (98%) for 10, 20 and 30 minutes significantly broke the seed dormancy and promoted the germination of the seeds compared to control seeds (treated with distilled water) and gibberellic acid. However, increasing duration had a negative effect on seed germination, reducing the final germination percentage from 93.33% at 10 minutes of immersion to 85.33% at 30 minutes. Priming with gibberellins enhanced the germination but did not completely overcome the dormancy of intact Malus baccata seeds.