Path analysis of cowpea early seedling growth under saline conditions

Our objective was to study the effects of salt on growth parameters of cowp ea using path-coefficient analysis which describes a priori cause-and-effec t relathionships. We used three salt levels with electrical conductivities of the irrigation treatments of 0, 7.8 and 15.6 dS/m. Net assimilation rate (NAR), crop growth rate (CGR), leaf area ratio (LAR), and relative growth rate (RGR) were measured according to Radford & Hunt. The results show that as salt levels increased, all growth parameters decreased quadratically by a reduction of the main components of growth: dry-matter and leaf area. Pa th-coefficient analysis revealed that NAR and LAR had positive direct effec ts on RGR at the 7.8 and 15.6 dS/m salt levels. These growth parameters are important in selecting for higher relative early growth rate of cowpea see dlings under saline conditions.