Yield Stability of Four Population Types of Grain Sorghum,1Sorghum bicolor (L.) Moench, in Different Environments
- V. H. Reich and
- R. E. Atkins2
Eight parental lines, 16 F1 hybrids, 16 2-component blends of parental lines, and 16 2-component hybrid blends of grain sorghum (Sorghum bicolor L. Moench) were grown in 9 environments over 2 years in Iowa.Standard analyses of variance and analyses for estimating stability parameters were made for grain yield and yield component data. A stable entry or population was defined as one with a regression coefficient close to 1.0 and deviations from regression near zero. A high mean yield also was deemed an essential attribute for an entry or population.
The parameters for grain yield indicated that hybrid blends were the most productive and stable population type, although none of the populations were distinctly superior for all parameters. Hybrid blends had the highest mean yield over all environments and were second among the population types in terms of low deviations from regression and an average regression coefficient near 1.0. Data for the components of yield tended collectively to support the conclusion that hybrid blends were the most stable population type.
A hybrid was the highest yielding individual entry in each environment, except one, where a hybrid blend was the most productive. Also, a hybrid had the highest mean yield among individual entries over all environments. Across all environments, 22 of the 32 blended populations yielded more than the pure-stand mean of then: components. Yields for twelve of the 16 hybrid blends exceeded their mid-component value. Collectively, the heterogeneous populations yielded 102% of the mean of their homogeneous components. Six of the blends exceeded the mean pure stand yield of their more productive component.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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