Performance and Character Association in Maize (Zea mays L.) under Normal and Low Nitrogen cCnditions in Different Environments

Abstract

A set of one-hundred and twenty genotypes including eight parents, their F_1’s, F_2’s and backcross generation of maize differing in their reaction to low-N conditions were used for estimating relative yield reduction and inter-character correlations between different morphological traits, planted at Pantnagar, Gorakhpur and Dholi. Analysis of variance showed that the genotypes differ significantly for all of the trait except plant height under low-N conditions. Among inbred lines Tarun 83 had the lower per cent yield reduction across all the three environments. This indicates that it is tolerant inbred line for low N condition. This inbred line could be incorporated in the future breeding program of maize for low N tolerance. In both F₁ and F₂ generations, crosses between tolerant and susceptible and tolerant with tolerant were found to be susceptible for low N tolerance, indicating thereby dominance of susceptibility over tolerance. Estimates of genotypic correlation coefficient were generally higher than phenotypic correlations coefficients in all environments. The result revealed those days to 50% tasseling was significantly and negatively correlated with yield under both high and Low-N conditions. It was also found that plant height; ear height and cob diameters were significantly and positively correlated with yield under both high and Low-N conditions. Thus, these three characters can be considered for selection.

Keywords: Maize, grain yield, correlation among yield components, low-N