EVALUTION EFFICENCY OF LIQUID BRADRHIZOBIUM AND AZOTOBACTER CHROOCOCCUM DSM 2286 AS CO-INOCULATION AFFECTED BY SALINITY LEVEL OF IRRIGATION WATER ON PEANUT IN SANDY SOILS OF EGYPT

Peanut being a leguminous crop is capable of fixing atmospheric nitrogen. The present investigation had been carried out in order to study and evaluate the efficiency of both liquid and solid inoculum of Bradyrhizobium ssp (N2-fixing bacteria) and plant growth promoting rhizobacteria (PGPR); Azotobacter chroococcum DSM 2286, as co-inoculation to decrease the negative impact of salinity levels of irrigation water on peanut plants grown in cultivated sandy soils, as well as to comparatively evaluate the responses of two peanut cultivars to the studied treatments. A pot experiment peanut seeds were inoculated with solid or liquid inoculum of Bradyrhizobium and Azotobacter chroococcum DSM 2286 (PGPR) as co-inoculation, and planted in the sandy soils. Dry weights of the growing plants yield components and oil of two peanut cultivars were determined. It was clear that the rhizospheric soil of Gregory peanut cultivar plants achieved higher values of dehydrogenase activity compared with the Giza 6 peanut cultivar plants, with the assigned experimental treatments. The inoculation treatments with Azotobacter chroococcum, as Co-inoculation, with liquid Bradyrhizobium spp of Gregory cultivar peanut plants attained a higher seed protein and oil content (%), as compared to the other inoculation treatments.