Effect of Plant Growth Promoting Rhizobacteria (PGPR) on Coleus forskohlii

Plant growth-promoting rhizobacteria (PGPR) are beneficial bacteria that colonize plant roots and enhance plant growth by a wide variety of mechanisms. The use of PGPR is steadily increasing in agriculture and offers an attractive alternative to chemical fertilizers, pesticides, and supplements. The authors have isolated and characterized several PGPR strains from the rhizosphere soil of different medicinal plants from various locations in Andhra Pradesh. The present study pertains to the effect of three plant growth promoting rhizobacterial strains i.e., Pantoea sp. (Cf 7) and Pseudomonas sp. (Te 1, Av 30) in individual or in combinations treatments (T1 Cf7; T2 Te1; T3 Av30; T4 Cf7+Te1; T5 Te1+Av30; T6 Cf7+Av30; T7 Cf7+Te1+Av30; T8 Control) on Coleus forskohlii. The combinations of above mentioned PGPR strains significantly increased plant growth parameters (shoot length, number of branches, number of tubers, diameter of tuber and total biomass) of Coleus in field conditions in comparison to the control. The results of this study suggest that PGPR applied in combination have the potential to increase the plant growth of C. forskohlii. The present findings suggest that the PGPR isolates Cf7, Te1 and Av30 are beneficial for Coleus cultivation as they enhanced plant growth, total biomass; and as it provides an eco-friendly approach can be used as a biofertilizer.