Agro-morphological Characterization of Maize (Zea mays L.) Hybrids Under Acid Soils in Two Contrasting Environments

Acidic soils cover 75 to 80% of the arable soils in the humid forest areas of Cameroon, causing maize yield losses of around 69%. Sixty-four accessions of maize hybrids were developped from “Line × Tester” crosses between twenty tropical inbred lines with three testers (Cam inbgp117, 88069 and 9450) and between testers themselves, and one acid tolerant open pollinated variety (ATP-SR-Y). Those inbred breeding lines were collected from CIMMYT, IITA and IRAD and the derived single hybrids were characterized using agro-morphological maize’s descriptors on a completely randomized block design in two contrasting environments (Nkoemvone and Nkolbisson). The data collected was subjected to multivariate analyses. The Principal Component Analysis showed the first two components being 73.60% and 78.99% of the total variation in Nkoemvone and Nkolbisson, respectively. Furthermore, grain yield showed a positive and highly significant correlation with the plant emergence rate in Nkoemvone (r = 0.61, P < 0.001) and Nkolbisson (r = 0.84, P < 0.001). Hierarchical Clustering Analysis indicated that these accessions forms four distinct groups, where each of the groups showed clear specific features for which the performance differs from that of the others in Nkoemvone and Nkolbisson. Characters such as plant emergence rate, prolificacy, ear appearance and grain yield have been found as important phenotypic markers for assessing agromorphological diversity of maize hybrids. These traits should necessarily be considered in maize breeding programs for varietal discrimination and formulation of cores collection of maize tolerant to aluminum and manganese toxicities in the soil.