The effects of plant growth promoting rhizobacteria and arbuscular mycorrhizal fungi on N, P and K uptake and yield of Thymus daenensis Clak

In order to study the effects of interactions between the arbuscular mycorrhizal fungi and plant growth promoting rhizobacteria (PGPR) on some elements content، dry matter yield and root colonisation in organic cultivation of Thymus daenensis Celak، an experiment was conducted at semnan natural resource research field at shahmirzad، in 2011-2012. Treatments included: A: the fungus of Glomus moseae (1-inoculated (AM) and 2- no inoculated) and B: PGPR inoculums (1- Bacillus subtilis 2- Pseudomonas fluorescens 3- control). A factorial experiment design was applied in a randomized complete blocks design with six treatments and three replications. Results showed that foliar K contents and root colonisation increased significantly with the G. moseae inoculation and the foliar P contents increased significantly with the B. subtilis inoculation alone. There was negative interactions between G. moseae and P. fluorescens on dry matter yield and nutrient uptake. The most effective treatment was observed in the co- inoculation with G. moseae and B. subtilis، which synergistically increased dry matter yield and nutrient uptake campared with singly inoculated or non- inoculated plants.