Abstract

Laboratory experiments were carried out during November 2010 to October 2011 at the seed testing Laboratory of the Institute of Agricultural Research and Training, Obafemi Awolowo University, Moor Plantation, Ibadan, to determine the effects of harvesting stages on seed viability and longevity of kenaf. Kenaf seeds of four genotypes were harvested at four stages of seed maturity namely; (1) four weeks after flowering (4 WAF), (2) five weeks after flowering (5 WAF), (3) six weeks after flowering (6 WAF) and (4) at full maturity (FM). All the seeds were packed inside envelop and wrapped with polyethylene bags and kept at 10°C and 60% RH for a period of 12 months. The highest germination percentage average seed moisture content, average dry seed weight and the lower ion leakage concentration were recorded in all the kenaf genotypes when harvested at 5 WAF. Upon storage, after harvesting, the germination percent declined, while the highest viability was recorded by genotype A-60-282b at 4 months after storage, followed by genotype Ex shika at 8 and 12 months storage periods, respectively. The seed deterioration during storage could be minimized by proper harvest timing. Seeds harvested 5 WAF and stored at 10°C showed the highest seed viability. Therefore, mature seeds are recommended for harvested 5 WAF for enhanced storability.

Key words: Kenaf seed, harvesting stage, seed longevity, viability.