Abstract:
Sorghum [Sorghum bicolor (L.) Moench] is an important cereal crop used for food, feed, and industrial
raw material. In Kenya, it’s a food and nutritional security crop in the semi-arid areas
which are prone to
maize crop failures. The study aimed at estimating the combining ability and heterosis for grain and
biomass yield among sorghum hybrids. Thirty- four F1 sorghum hybrids, their parents and a check were
evaluated at two KALRO research centers in Kenya during the 2014-2015 cropping seasons. Square
lattice trial design with three replications was used and fourteen agro-morphological traits studied at
each location. The combined analysis of variance showed highly significant differences (p<0.001) for
genotypes and locations for all traits, except for leaf length. Fresh biomass yield, panicle exertion, and
plant height had high heritability, genotypic coefficient of variation (GCV) and genetic advance (GA %)
showing the predominance of additive gene effect in their inheritance, hence these traits can be
improved through direct phenotypic selection. Hybrid parents ICSR 89058, ICSV 700 and ICSR 160 were
good general combiners for earliness, biomass and grain yield respectively. The highest grain and
biomass yielders were ATX 623 x Macia and ICSA 206 x IESV 91104DL respectively. High magnitudes of
SCA effect coupled with high heterobeltiosis, mean and standard heterosis for grain and biomass yield
were noted in hybrids ATX 623 x Macia and ICSA 11035 x Macia respectively. These hybrids can be
promoted for on-farm testing and possible release for food and fodder. Therefore, the improvement of
sorghum grain and forage yields in the semi-arid areas of Kenya can be done simultaneously through
the exploitation of heterosis by developing hybrids.
