Effects of floral and foliar application of plant growth promoting rhizobacteria (PGPR) on yield, growth and nutrition of sweet cherry

During 2003 and 2005, plant growth promoting effects of Pseudomonas BA-8 and Bacillus OSU-142 were tested alone or combinations on sweet cherry (Prunus avium L.) cv. 0900 Ziraat in terms of yield, growth, nutrient composition of leaves in the province of Konya, Turkey. The presence of Pseudomonas BA-8, Bacillus OSU-142 and BA-8 + OSU-142 stimulated plant growth and resulted in significant yield increase. Floral and foliar applications of BA-8, OSU-142 and BA-8 + OSU-142 in sweet cherry significantly increased yield per trunk cross-sectional area (16.3, 10.9 and 21.7%), fruit weight (4.15, 5.37 and 1.24%) and shoot length (11.3, 11.8 and 29.6%), respectively, compared with the control. In addition, N, P and K contents of sweet cherry leaves with BA-8, OSU-142 and BA-8 + OSU-142 treatments, Fe and Zn contents of leaves with BA-8 + OSU-142 treatment and Mn content of the leaves of sweet cherry with BA-8 and OSU-142 applications significantly increased. Nitrogen, P and K contents in leaves were determined to be increased from 2.00, 0.17 and 0.43% in the control to 2.19, 0.20 and 0.54% by BA-8 application, to 2.32, 0.24 and 0.54% by OSU-142 application and to 2.43, 0.22 and 0.51% by BA-8 + OSU-142 application, respectively. Co-inoculation of BA-8 + OSU-142 increased Fe and Zn contents of leaves up to 50.5 and 35.5% compared with the control, respectively. Manganese content of leaves significantly also increased by BA-8 (26.6%) and OSU-142 (27.0%) applications compared with the control. The results of the present study suggested that Pseudomonas BA-8 and Bacillus OSU-142 alone or in combination have a great potential to increase the yield, growth and nutrition of sweet cherry plant.