Coffee senna [Senna occidentalis (L.) Link] exhibits variable seed features, and these
may influence germination and growth habits. Senna seeds from the rainforest (Akure, RF) and
southern Guinea savanna (Ilorin, SGS1; Jebba, SGS2) zones, extracted immediately after harvesting
mature pods collected during the regular seed production season, were evaluated to ascertain the
influence of water imbibition on its germination characteristics. Seed sources differed significantly
(P= 0.05) in 7-d germination; SGS2 had distinctly better and faster germination than RF and SGS1.
Average percent germination and germination rates were 36.1, 0.94 seeds/day in SGS2, 16.9, 0.80
seeds/day in RF and 13.9, 0.74 seeds/day in SGS1. Seed imbibition water content was positively
correlated with seed germination (r= 0.999***) and germination rate (r= 0.999***), but not with
either plumule (r= -0.71) or radicle (r= 0.33) length in all seed sources. Plumule and radicle growth
were not significantly influenced by seed source. Observed differences in seed germination capacities
were primarily attributed to seed food reserve, environment, and post-harvest seed moisture content.
There is a need to prevent cross-contamination of farm implements, machinery, and harvested agricultural
produce by Senna seeds.
Keywords: Weed, ecotypes, water potential, plumule, radicle
