Productivity of cowpea as affected by salt stress in presence of endomycorrhizae and Pseudomonas fluorescens

This study was executed to evaluate the impact of endomycorrhizae and Pseudomonas fluorescens on growth parameters, yield and some biochemical constituents as well as spontaneous nodulation of Rhizobium-uninoculated cowpea (Vigna unguiculata L.) under salt stress. Results revealed that mycorrhizal infection percentage decreased with increasing the water salinity. Cowpea plants irrigated with tap water and inoculated with endomycorrhizae and P. fluorescens gave the highest significant increment in fresh and dry weights of the 4th leaf, pod length, number of seeds per pod and total protein being 3.560, 0.543 g, 13 cm, 9 seed/pod and 31.8 mg/g f.wt., respectively. The highest significant increment in the weight of 100 seed was recorded with plants irrigated with 6000 ppm NaCl solution and inoculated with P. fluorescence being 19.71 g. The highest significant increment in carotenoides was recorded with plants irrigated with 6000 ppm NaCl solution and inoculated with endomycorrhizae + P. fluorescens being 0.449 mg/g f.wt. The highest significant activity of Superoxide dismutase (SOD) was recorded with uninoculated plants irrigated with 3000 ppm NaCl solution, being 7.25 unit/mg protein. The highest significant concentrations of proline and total soluble sugars were recorded in plants irrigated with 6000 ppm NaCl solution and inoculated with endomycorrhizae being 1001.62 μg/g f.wt. and 2.5684 mg/g f.wt. respectively.