Direct and indirect effects of cob traits on yield in exotic maize germplasm under nitrogen deficient conditions

Abstract

Despite of adoption of hybrid maize cultivation to a considerable level, maize yields in Pakistan are lower than other countries in the region. With others, maize cultivation under low soil fertility and without supplemental nitrogenous inputs is an important reason for low yields. This derives national maize breeding programs to develop low-nitrogen responsive maize cultivars. In this context, exotic maize open-pollinated varieties were introduced from CIMMYT for adaptability testing and subsequent adaptation. The trial including these OPVs was planted under zero nitrogen application. Correlation and path coefficient analysis was used to establish association of grain yield with its components to ascertain specific selection criteria which will be used to enhance efficiency of the future maize breeding and yield improvement programs using this germplasm. The results complemented with heritability estimates revealed that 100-kernel weight and shelling percentage together with kernel rows per cob can be utilized effectively for yield enhancement under nitrogen deficient conditions.