Performance of tropical and subtropical maize inbred lines under well-watered and drought-stressed environments

Drought is a major constraint for maize production in sub-Saharan Africa. Developing high-yielding drought-tolerant maize germplasm will safeguard maize yields in the ever-increasing fluctuating rainfall conditions. This study aimed to identify high-yielding inbred lines with stable performance for utilization in hybrid production. One hundred eighty-two (182) maize inbred lines were evaluated under well-watered and drought-stressed conditions at Ukulinga, Makhathini, and Cedara research stations in KwaZulu-Natal, South Africa. The experiments were carried out in a 13 × 14 alpha lattice design with two replications. The inbred lines exhibited significant differences (p ≤ 0.001) for grain yield and yield-related traits under well-watered and drought-stressed environments. The GGE biplot identified three mega-environments, clearly separating drought-stressed from well-watered environments. Inbred lines TZISTR1190, TZISTR1231, TZISTR1261 and CML540 were superior under well-watered conditions, while TZISTR1164 and CML390 performed well under drought condition. TZISTR1190 displayed both high average yield and stability across environments. Inbred lines combining stable high yielding performance in optimum and stress conditions such as TZISTR1190 and TZISTR1231, can be incorporated into local maize breeding pipelines to develop stable high yielding resilient hybrids.