Concurrent Enhancement of Provitamin A and Yield in Tropical Maize Hybrids

Abebe Menkir^1*Ibnou Dieng¹SILVESTRO MESEKA¹Bussie Maziya-Dixon¹Bunmi Bossey¹Muhyideen Oyekunle²Manfred Ewool³Mamadou Mory Coulibaly⁴Wende Mengesha¹Muhyideen Oyekunle²Mamadou Mory Coulibaly⁴

• ¹International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria
• ²Institute for Agricultural Research, Ahmadu Bello University, Zaria, Kaduna, Nigeria
• ³CSIR Crops Research Istitute, Kumasi, Ghana
• ⁴Institute of Rural Economy (IER), Bamako, Mali

Maize is a strategic food crop in sub-Saharan Africa, where vitamin A deficiency affects millions. Significant investments have thus focused on developing maize varieties that provide 50% of the daily vitamin A requirement for vulnerable populations. Despite the release of many provitamin A enriched maize varieties across Africa, estimates of genetic gains in provitamin A content and grain yield from long-term breeding programs are undocumented. This study analyzed data from 124 provitamin A-enriched hybrids and eight commercial checks over 12 years across diverse environments to estimate genetic gains. Results showed a significant annual increase of 2.05% in provitamin A and 3.54% in β-carotene, alongside a 1.09% reduction in β-cryptoxanthin. Additionally, a genetic gain of 1.88% for grain yield was noted, with a 0.09% decrease in silking days, a 0.31% increase in plant height, and a 0.35% decrease in plant aspect score. We identified 23 hybrids that accumulated 54% to 95% more provitamin A and produced 10% to 30% higher grain yields compared to the best commercial hybrid (COMYH129). These findings demonstrate concurrent genetic gains in provitamin A content and grain yield, indicating potential for further improvements in productivity and human health.