Effect of storage temperature and duration on Pouteria adolfi-friederici (Engl.) Baehni seed longevity and influence of soil mixture on seedlings growth performance

Abstract

Pouteria adolfi-friederici (Engl.) Baehni (Kerero) is an indigenous tree that is overexploited for high-quality timber production. However,  there is little/no documented information on its seed longevity and seedling quality for successful field establishment. Therefore, the  present study aimed to investigate seed longevity and evaluate the effect of soil mixtures on seedlings’ growth performance. Seeds were  collected from 20 selected mother trees in Gera District. Seeds were stored in cold room at +5 and 21/220c and tested their germination  ability at 5, 180 and 360 days after storage. The growth performance of seedlings in Greenhouse was further evaluated with three  different soil mixtures (2 part forest soil & 1 part sand, i.e., 2:1 Ratio (SM1); 1 part forest soil & 2 part sand, i.e., 1:2 Ratio (SM2) and 2 parts  forest soil alone (SM3)). From 1 kg (360 seeds) pure seeds of 95% purity, 257 seedlings were estimated to be raised at the Laboratory.  Seeds stored at 21/220c for 5 days had 75% germination potential. The highest seedlings survival rate (100%) was counted in soil  mixtures with 2:1 ratios (2 parts forest soil: 1 part sand). The highest mean value of height and root length was measured in 2 parts forest  soil alone. The largest root collar diameter (RCD) and root dry weight were recorded in 2:1 Ratio. Number of leaves and root fresh  weight had the highest record in 1:2 ratios (1 part forest soil and 2 parts sand). But, no significant variation (p<0.05) was observed among  the three soil mixtures. Unlike root-to-shoot ratio, height and RCD had a significant correlation (p<0.01) with other morphological variables. The quality index confirmed that 2:1 ratios were the best soil mixture for raising P. adolfi-friederici seedlings at greenhouse.  The best seed source provenance and vegetative propagation selection should be further considered for successful field establishment  and plantation development.