Abstract :
A set of laboratory and field experiments were conducted during 2005 to investigated the influence of seed age, size and moisture content on seed quality attributes of sorghum cultivar Tabat. Simple correlation coefficients were conducted to determine the degree of association between the different vigor tests and seedling emergence under field conditions. Parameters measured included germination percentage, speed of germination, seedlingʹs shoot length, root length, and shoot to root length ratio, seedlingʹs fresh and dry weight. Results showed that all vigor attributes measured in this study were significantly affected by seed treatment particularly under laboratory condition. In this respect, the new, large seeds (>3.15mm) and seeds with medium moisture content (7.5%) consistently resulted in a better vigor attributes compared to the old, small (<3.15 mm) and seed with either high (10%) or low moisture content (5%).The results also showed that field emergence was positively correlated with the speed of germination (r = 0.91), seedling length (r = 0.67) and seedling dry weight (r = 0.59) suggesting that these vigor attributes could be used to estimate field emergence of sorghum seeds. Therefore, further vigor tests were required to enable ranking of seed lots in a manner that would reflect their stand establishment capabilities under varied field conditions.
