A comparative performance of single cross, three way cross hybrids and open pollinated sorghum (sorghum bicolor L. mcench) culitivars

Abstract

The study was conducted to determine and characterize grain yield, grain yield stability, uniformity of three way cross(TWC), single cross (SC) hybrids and open pollinated (OP) varieties of sorghum and relate their grain yield to morphological and physiological attributes via leaf area index and duration.Twenty five entries comprised of 12 TWC, 11 SC and two OP of sorghum, Sorghum bicolor (L) Moench were planted in a 5x5 triple lattice design at Lusitu, Masstock, Liempe Farm, Golden Valley and Field Station. Plant aspect score, seedling vigour score, leaf area before flowering (LAI), leaf area.after flowering (LA2), plant height, within plot standard deviation of plant height, grain yield, grain yield stability, 100 grain weight, disease score, days to 25%, 50%, and 75% heading were recorded. Leaf area index before flowering (LAI-1), leaf area index after flowering (LAI-2) and leaf area duration (LAD) were determined. SC were superior to TWC and OP with regard to plant aspect score. On the other hand, TWC plant aspect score were similar for OP. The OP had higher 100 grain weight and better disease ratings than hybrids which were themselves simi1ar.Leaf area parameters were similar among TWC, SC and OP. Correlations between grain yield and leaf area parameters were positive and significant for TWC and SC.SC gave better grain yields than both TWC and OP which were similar in grain yield, though in terms of grain yield stability, TWC and SC were marginally better than OP. Marginal advantages of TWC over OP in grain yield and grain yield stability should be considered in light of requirement of one more generation in seed production which is in itself a disadvantage. The uniformity of SC and OP was relatively better than that of TWC as depicted by plant height. Such differences were absent when days to maturity was used for uniformity.