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Studies were conducted to determine the effect of plant population on seed physiological attributes of African Yam
Bean (Sphenostylis stenocarpa) at the Federal University of Agriculture, Abeokuta, Ogun State, Nigeria in 2013 and
2014. In the experiment , the effect of three plant populations (55,555, 24,975 and 10,000 plants ha-1) were conducted
in a factorial arrangement using completely randomized design in three replicates with genotype and plant
population as factors in 2013 and 2014 in the laboratory. In this experiment, clean seeds obtained under each plant
population and years were evaluated for four seed physiological attributes. Data collected from the experiment were
subjected to analysis of variance. Mean separation was carried out by Tukey's HSD test. Pearson correlation
coefficient (r) was used to determine the relationship among attributes. In the experiment, TSs83, TSs86 and TSs9
were superior in seed germination and seedling vigour under the 10,000 plants ha-1 across cropping years. All the 18
genotypes of AYB studied indicated genetic variability and similarity. The statistical analysis of mean values of all the
genotypes confirmed variations in all the seed quality characters. The laboratory germination percentages ranged
from 83.78 to 97.33 % (p<0.01) under the 2013 cropping year. However, the standard germination ranged from 83.11
to 96.67 % (p<0.01) under the 2014 cropping year. The effect of plant population on seedling dry weight showed that
seed performance was influenced by population density. Among the seed quality traits, standard germination and
seedling vigour index indicated significant responses to the three plant population densities in the two cropping years.
Across the plant density and cropping years, TSs86, TSs83, TSs209, TSs42, TSs48, TSs331 and TSs311 were among
the excellent performance genotypes with a consistent high standard germination and seedling vigour index. The
highest standard germination was recorded in both years under the highest plant population density of 55,555 plants
ha-1. TSs9 had highest seedling vigour index of 23.48, seedling fresh weight of 1.13 g and dry weight of 0.55 g,
respectively. Standard germination had positive and highly significant correlations with seedling vigour index (r =
0.236) and seedling dry weight (r = 0.149).
Key words: Planting density, Seed quality and Seedling vigour.