Estimation of Genetic Improvement of Maize in Ghana under Three Levels of Nitrogen Fertilizer Application

2016

English

Recent release and promotion of hybrid maize production in Ghana necessitated a study to estimate the genetic improvement of maize (Zea mays L.) in Ghana under three levels of nitrogen fertilizer application. The experiment was conducted in 2002 major and minor seasons at Fumesua and Kwadaso representing four planting environments. Three local accessions, seven improved open pollinated varieties and two quality protein maize hybrids released from 1972 to 1997 were evaluated in a two factor, randomized complete block design in a split-plot, with four replications in each environment. Nitrogen levels (0, 45, 90 kg N ha-1) were randomized in the main plots and the 12 varieties were randomized in the sub-plots. Analyses of variance showed highly significant (P<0.01) Genotype x nitrogen interactions for grain yield, shelling percentage and blight disease but significant (P<0.05) for cob diameter and rotten ears. Significant (P<0.01) linear regression analysis indicated that yield gains attributed to genetic improvement were 12.5, 35.1 and 33.1 kg/ha/yr at 0, 45 and 90 kg N ha-1 respectively implying an annual contribution to farm income of US$2.4M, US$4M and US$4.4M respectively. The study showed that progress has been made in genetic improvement of maize in Ghana since the mid-1950s.

Ewool, M.; Sallah, P. Y. K.; Akromah, R.