Effects of Some Plant Growth-Promoting Rhizobacteria (PGPR) on Growth and Nutrition of Apple Cv. “Braeburn” under High Lime Soil Condition

Abstract

ABSTRACT Calcareous soil may limit plant growth depending upon plant nutrient uptake. The change of apoplastic pH and deficiency of nutrients in high lime soils negatively affects plant growth with chlorophyll synthesis, root growth, enzyme synthesis. To overcome this abiotic stress, control (non-inoculated) and six bacterial strains; Alcaligenes 637Ca, Agrobacterium A18, Staphylococcus MFDCa1, Staphylococcus MFDCa2, Bacillus M3, and Pantoea FF1 were inoculated one-year-old apple saplings grafted on M9 and MM106. The M3, MFDCa1, FF1, and MFDCa2 strains were found to have the largest leaf area on M9 rootstock, while 637Ca had the smallest leaf area on MM106 rootstock. In the stem diameter, A18 and MFDCa1 were measured lower in M9 rootstock, while MFDCa1 and control were found lower in MM106 rootstock. The shortest shoot was determined in MFDCa2 on MM106 rootstock, while the FF1, M3, and control were found tallest shoot on M9 rootstock. For plant nutrition, all bacterial treatments were found higher than the control in both macronutrients and micronutrients. While the content of the N, P, Ca, and Cu was found highest in MM106 rootstock, K, Mg, Mn, Zn, and B were determined the highest on M9 rootstock. The FF1 and M3 bacteria strains were commonly determined to have the highest contents of the N, P, K, Mg, and Ca on M9 rootstock. As a result, bacterial strains used in the present study have an important potential to increase plant growth and to be used as a biofertilizer for Braeburn apple cultivar on M9 and MM106 under lime soil conditions.