Evaluation of Four Maize (Zea mays L.) Genotypes Using Drought Tolerance Indices

Drought tolerance is not often considered as an independent trait by breeders. The objective of this study was to evaluate and identify drought tolerant genotypes using eight drought tolerance indices namely the Stress Susceptibility Index (SSI), the YSI, the YR (Yr), yield index (YI), tolerance index (TOL), average productivity (MP), mean geometric productivity (GMP) and stress tolerance index (STI) of maize genotypes (Zea mays L.). A field trial was conducted to evaluate four genotypes during the hot dry season of 2016 and 2017 at the irrigated perimeter of Djirataoua. Drought tolerance indices were calculated on the basis of yield under optimal and stressed conditions. The comparison of the means of drought tolerance demonstrated the effects of drought on yield and showed significant differences between genotypes. The correlation coefficient and principal component analysis showed that the GMP, MP and STI indices were able to discriminate drought-sensitive and tolerant genotypes. Two genotypes CZH131001 and CZH142013 produced high grain yield under both optimal and stressed conditions. Overall, GMP, MP, and STI indices can be used as effectively drought tolerance screening indices and able to identify better genotypes, suitable for both optimal and stress conditions.