Seed characteristics and dormancy of four important indigenous and exotic tree species in Sudan

Abstract

This study focused on generating knowledge on the characteristics of the seeds of some important indigenous and exotic tree species of economic and environmental importance. The studied seeds are namely Diospyros mespiliformis (goghan), Oxytenanthera abyssinica (gana), Moringa oliefera (Rawaq), and Conocarpus errectus (Damas Saudi). The goal of this work was to study the phenomenon of dormancy in the seeds of the above mentioned species and to find the best method to break it. The aim is to provide the right information and the suitable techniques for foresters in charge of afforestation programs and for tree planters in general for the success of tree planting processes in the Sudan. A second objective was to know the effect of cool storage (12±1Cº) on seeds characteristics e.g. longevity and to determine the suitable period for storing the seeds, so as to save the resources of the Tree Seed Center and to determine the amount of stock of quality seeds to meet the demand. Also to reduce the cost of annual collection of the seeds of the same species. In this work the seed physical and physiological characteristics were explored through the determination of purity percentage, seed soundness, seed moisture content, number of seed /kilogram, seed viability and germination. Also the kind of dormancy found in the four species was identified and the longevity of Diospyros mespilifomis in the cool store was estimated. Seeds of D. mespiliformis, O. abyssinica, and M. oliefera were found not to have any type of dormancy. C. errectus seeds identified as dormant. The study suggests further studies to understand the causes of this dormancy and to find a suitable method to break it.