Grain yield, anthesis-silking interval and drought tolerance indices of tropical maize hybrids

Abstract Water deficit stress is the abiotic factor with the highest impact on crop yield. The objective of this study was to evaluate grain yield (GY), the anthesis-silking interval (ASI) and drought tolerance indices in maize hybrids. We evaluated GY and the ASI of 86 hybrids under two moisture levels (normal irrigation and water stress) for three consecutive years. The stress susceptibility index, water stress tolerance, drought resistance coefficient, drought resistance index, stress tolerance index and harmonic mean were evaluated. There were significant hybrid x environment interactions for GY and the ASI. Differences in the ASI among environments ranged from 0 to 5 days. The hybrids P3862, 1I873, 1I923, 1I862 and 1J1211 showed high GY, associated with the highest drought tolerance indices. The stress tolerance index and harmonic mean indices can be used to identify higher-yielding maize hybrids in environments with and without water restriction.