Emergence and early seedling growth of Tamarindus indica L. from geographically diverse populations in the Sudan

Information on genotypic variation and horticultural potential of Tamarindu s indica L., a multi-purpose evergreen tree found naturally in the Sudan, i s lacking. Tn this study, we examined seed emergence behaviour and early se edling growth in three geographically diverse populations from the Sudan. T he Central Sudan (CS) and the Eastern Sudan (ES) populations exhibited a ne arly threefold variation between the largest and smallest seeds, whereas th e Western Sudan (WS) population showed about twofold variation. Seed size w as largest for WS (0.55 +/- 0.09 g), intermediate for CS (0.48 +/- 0.08 g) and smallest for ES (0.43 +/- 0.11 g). Tamarind seeds are generally slow to germinate as indicated by the allowance of 15 to 42 days from planting bef ore the first and the last emergence count, respectively. Even though diffe rences were not significant, the highest total percent emergence (97%) was recorded for WS population, followed by CS (92%) and ES (90%) populations. Seeds of WS population achieved E-50 (days to 50% emergence) two and three days earlier than ES and CS, respectively. They also showed more uniform em ergence with a span of 19.7 days versus 24.7 and 25.3 days for ES and CS po pulations, respectively. Seedling vigour, evaluated in terms of seedling he ight, number of leaflets, total leaf area, total dry weight and leaf dry we ight, was superior in WS population, while there were no measurable differe nces between CS and ES. Leaf photosynthetic characteristics did not vary am ong the three populations. Mean values for CO2 assimilation rate (A(CO2)), transpiration rate (E) and stomatal conductance (g(s)) were low but well wi thin the range expected for evergreen woody species. In conclusion, for fas ter and uniform emergence and plant establishment in the nursery the WS pop ulation is the most suitable candidate.