Drought Stress Indices In Some Silage Maize Cultivars

Several yield-based stress indices have been developed that may be more applicable to work on drought tolerance. In this study, we investigate possibility of using Stress susceptibility index (SSI), Tolerance index (TOL), Yield stability index (YSI), Yield index (YI), Stress Tolerance Index (STI), Geometric Mean Productivity (GMP), Harmonic Mean (HARM), Mean productivity (MP) to identify genotypic performance of some maize cultivars under normal and stressed condition. The results indicate that it was possible to identify superior genotypes for drought tolerance based on their stress indices and generally SSI indices which showed the lowest negative correlation with Dry matter yield can be used as the best index for maize breeding programs to introduce drought tolerant hybrids. It was found that SC 647 was as tolerant hybrid based on TOL and SSI. A higher STI, GMP, and HARM value is attained for ko6 and it may be able to be cultivated in moderate stressful environment of Iran