Genetic studies of extra-early provitamin-A maize inbred lines and their hybrids in multiple environments.

Vitamin A deficiency, drought, low soil nitrogen (low-N), and parasitism of maize ( L.) cause malnutrition and food insecurity in sub-Saharan Africa. The objectives of this study were to determine combining abilities of extra-early provitamin A (PVA) lines, classify them into heterotic groups (HGs), identify testers, and determine yield stability of hybrids under contrasting environments in two trials.