Two pot experiments were carried out during growth seasons of 2016 and 2017 at the experimental station of faculty of
agriculture, Benha University. The investigation target was to find out the effect of using plant growth promoting rhizobacteria
either PGPR-group (A) containing 7×109 cell suspension of each (Azo. lipoferium D178, B. megaterium ATCC14581 and B.
circulans ATCC4513) or PGPR-group (B) containing 7×109 cell suspension of each (A. chroococcum EMCCN1458, B.
megaterium ATCC14581 and B. circulans ATCC4513) individually or in combination with mineral fertilization rates (25, 50, 75
and100%) NPK on the vegetative growth characteristics and chemical constituents of Moringa oleifera plant at 75 and 150 DAS.
The combination of plant growth promoting rhizobacteria PGPR group (A) and inorganic fertilizers treatments gave the highest
values of dehydrogenase (DHA), alkaline phosphatase (ALP) and nitrogenase (N2-ase) activities as compared with each one
individually. In all treatments, enzymes activities were increased to reach the maximum values after 90 DAS. The highest values
of enzymes activity recorded for treatment which inoculated with PGPR group (A) and amended with ¾ of mineral fertilizers
followed by treatment which inoculated with PGPR group (B) amended with ¾ mineral fertilizers. Vegetative growth
measurements, photosynthetic pigments, promoting endogenous phytohormones, total phenolics, flavonoids and ascorbic acid
contents as well as the highest values of antioxidants activity were recorded for treatment that inoculated with PGPR group (A)
amended with ¾ of mineral fertilizers followed by treatment that inoculated with PGPR group (B) amended with ¾ mineral
fertilizers, respectively compared to mineral fertilization. Abscisic acid was reduced with different applied treatments as
compared to the control, but the reduction was more obviously clear for treatment of PGPR group (B) amended with ½ mineral
fertilizers. While, salicylic acid was increased with the different tested treatments compared with the control and reached its
maximum values with PGPR group (B) amended with ¾ mineral fertilizers and PGPR group (A) with ¾ mineral fertilizers
treatments, respectively. |
