Effect of plant population and nitrogen fertilizer levels on seed yield and its components of some different cowpea genotypes.

摘要

This work was carried out at Sakha Agricultural Research Station, during the summer seasons of 2011 and 2012 on cowpea. The main objective of this research was to evaluate two cultivars (Kaha-1 and Kafr El-Sheikh-1) and four lines (L-118, L-167, L-311 and L-315) of cowpea under three nitrogen fertilizer levels (10, 20 and 30 kg N fed.-1) and two plant populations (44.000 and 64.000 plant fed.-1). A split-split plot in a randomized complete blocks design with four replicates was used. Results are summarized as follow: Lien L-167 surpassed the other genotypes in plant height, followed by Kafr El-Sheikh-1 cv., while Kafr El-Sheikh-1 cv. produced the highest values of number of branches plant-1, followed by Kaha-1 cv. and line L-167. However lines L-311 and L-315 produced the lowest values of plant height and number of branches plant-1, respectively. Kaha-1 cv. and line L-167 produced the lowest values of number of days to flowering in both seasons. Moreover, seed yield and its components, i.e., seed yield plant-1, seed yield fed-1, number of pods plant-1, number of seeds per pod and weight of 100-seeds, line L-167 surpassed the other genotypes followed by Kafr El-Sheikh-1 cv. However, line L-315 produced the lowest seed yield and weight of 100-seeds in both seasons. In addition, the line L-167 surpassed the other genotypes in seeds protein content. Less plant density improved vegetative growth characters, as well as yield components and increased seeds protein content. While, seed yield was increased as a consequence of increasing plant population in both seasons. The results, also, indicated that increasing applied N rate up to 30 kg N fed.-1 was accompanied with significant increases in vegetative growth characters. And reflected positively and significantly on increasing, seed yield and its components, and seed's protein content positively and significantly affected.