Yield and Yield Components Variability of Grain Sorghum Genotypes.

Understanding morphological and phonological aspects of grain crops may help improving their grain yield through cultivation management and breeding strategies. Correlation of phenology and morphology of ten sorghum varieties with their grain yield was studied in an experiment conducted in 2009-2010. No positive correlation was found between plant height and grain yield. In fact the shortest genotype produced the highest grain yield (9896 kg ha-1) whereas the lowest grain yield (6348 kg ha-1) obtained from the tallest genotype. We also found no distinctive correlation between biomass and final grain yield. In this study genotypes showed no differences in GDD requirement until the milk stage. Significant differences were found in GDD requirement for milk stage as well as dough stage. The most productive genotypes required greater GDD to reach these two important growth stages. For example the highest productive genotype, required 1359 GDD to reach milking stage whereas the least productive genotype, reached milk stage after collecting only 1171 GDD. Final grain yield determined primarily by grain number per plant followed by seed size. The top five high producing genotypes produced 12% more grains compared with the bottom five genotypes. The difference in seed size of high and low producing genotypes was only 4%.