Assessment and Multivariate Analysis of Maize Response to Basal Nitrogen Phosphorus Potassium (NPK) Application at Vegetative Phase

Maize is an economically important crop in sub-Saharan Africa. Its production is greatly affected by biotic and abiotic stresses. Among the abiotic stresses, low soil fertility and drought have been reported to cause economic yield losses. Therefore, this study aimed to: (i) investigate the nitrogen, phosphorus and potassium (NPK) (10:20:10) application rate that produced the most favourable root architecture; (ii) identify the parameters that best discriminated among the genotypes; and (iii) identify the maize genotype(s) that developed the most favourable root architecture during the vegetative phase across NPK (10:20:10) application rates. Two cropping trials were conducted, and daily mean temperatures were recorded. The experiment was arranged in a completely randomised design (CRD) as a 6 (maize genotypes) × 4 (NPK application rates) factorial with three replicates under potted screen-house conditions. The results showed that the optimal NPK rate was 219 kg/ha, which produced the highest mean root length, root biomass and shoot biomass of 48.9 cm, 22.8 g and 46.7 g, respectively, across genotypes (P < 0.001). Furthermore, root biomass, plant height, shoot biomass and plant biomass were identified as important parameters for discriminating genotypic performance. Genotype C657 exhibited strong vegetative performance, suggesting potential for drought resilience. It had mean root and shoot biomass values of 22.46 g and 39.8 g, respectively.