Potential factors limiting viability of Milicia excelsa (Welw.) C.C. Berg. seeds in plantation establishement in West Africa.

Milicia excelsa (Odum-Iroko), one of the most important and high valued tropical timber tree species suffers a high level of exploitation. Efforts to establish M. excelsa plantations have proved futile as a result of low germination of M. excelsa seeds a few months after fruit harvesting, seed extraction and storage. To determine how viability of seeds is affected by seed extraction, two methods of seed extraction from mature fruits (not ripe) were used. A study was carried out to identify the microorganisms associated with fresh fruits and seeds as well as seeds stored over varying periods up to 24 months. Fusarium solani was the most prevalent fungus found on fresh fruits harvested from all three ecological zones of Ghana: Abofour, Amantia and Bonsa. Fusarium sp. and Lasiodiplodia theobromae were frequently isolated from seeds extracted immediately after fruit harvesting and from soaked fruits after 6 months storage. When seeds were subjected to germination tests, it was observed that those extracted from fruits without soaking were more viable (84–98.5 % germination) even after 1-year storage than those extracted from soaked fruits. Viability was sustained with storage in seeds extracted soon after harvesting, whereas it declined with storage for the seeds extracted from soaked fruits. Key words: Milicia excelsa; Odum; seed extraction; seed-borne pathogens