A field experiment was conducted to evaluate newly developed heat tolerant maize hybrids canopy development and yield potential during rainy season relatively lower temperature. Four new hybrids tested in 60 and 45 cm row spacings and recommended and 25% graded fertilizers compared with local hybrids and existing recommendations. Results indicated that row spacing at 60 cm was found optimum to enhance growth and to achieve higher maize grain yield. Increased fertilizer rate at 25% higher than present recommendation was significant impact on grain yield of these hybrids. Among tested hybrids, RCRMH-2 was out yielded (19.4%) over local popular maize hybrid 900 M Gold. Light interception, leaf area index, aboveground biomass and yield attributes of maize hybrids was significantly influenced by row spacing and fertilizers rate.It indicated that heat tolerant maize hybrids are well performed during Kharif under well-watered condition.