Effects of pre-sowing treatments and harvesting period on the seed germination of Zanthoxylum armatum DC

Abstract

This study was carried out to determine the effects of different treatments and harvesting period on the germination behavior of seeds of Zanthoxylum armatum. Treatments including mechanical stratification, acid treatment, gibberellic acid (GA3) and sowing seeds harvested at different time period were evaluated. Several experiments including various treatments were conducted during 2018 and 2019 at the Laboratory of Dabur Nepal Private Limited Nursery, Banepa to study the germination behavior in the seeds of Z. armatum. It was found that the seeds of Z. armatum do not germinate easily. Chemical and hormonal treatments had relatively some effects on the germination, while the hot water, cold water and chilling treatment did not induce germination. Nitric acid had comparatively better germination than hydrochloric acid and sulfuric acid. Among the mechanical treatments, sand scarification was the most effective with germination of 35.33±2.90 %, which is comparatively higher than that of chemical treatments. Germination percentage increased with the increase in concentration of GA3 with the highest 54.67±8.11 % at 1500 ppm and decreased thereafter. Viability decreased with storage for long period. Among all the methods for inducing seed germination in Z. armatum, the most effective was sowing freshly harvested seeds at proper time. A maximum of 62.44±8.94% germination was obtained for the seeds collected during 16 September-15 October. Seeds germinated better during mid-phase of harvesting than early or late. Sowing seeds immediately after harvesting is a simple, safe, reliable, low-cost and efficient way to obtain higher germination percentage in Z. armatum.