Correlation analysis of maize (Zea mays L.) genotypes: A review

Abstract

In many regions of world, maize is one of the most significant crops grown for staple foods. To increase the effectiveness of breeding programs using the right selection indices, it is very important to be aware of the correlations between grain yield and its numerous causal (contributory) components. This article presents the results of many studies that were carried out to ascertain the nature of relationships between grain yield and its contributing factors and to pinpoint those factors with significant effects on yield with the goal of using them as selection criteria by using path coefficient analysis (PCA). The direct and indirect impacts of cause factors on effect variables are displayed through path analysis. This approach divides the components of the correlation coefficient between two traits into those that assess the direct and indirect effects. Plant height, number of kernels per row, ear per pant, ear height, leaf width, days to 50% silking, tasseling, ear diameter, ear length, thousand kernel weight, days to physiological maturity, tassel length, and ear weight may have significant (or non-significant) influence on grain yield, either positively or negatively. The present review of different studies might be useful to the breeders to select the potential parental materials for maize improvement program in Nepal as well as region with similar geographical topography.