Response of yield and yield components of rice ( Oryza sativa L. cv. Shiroodi) to different phosphate solubilizing microorganisms and mineral phosphorous

摘要

Plant growth stimulating rhizosphere bacteria are a heterogeneous group of rhizosphere bacteria which improve plant growth indices throughout diverse mechanisms. The present study aimed to evaluate the efficiency of phosphate solubilizing microorganisms (P SM) in terms of improving growth and yield of the rice plants (cv. Shiroodi). Experiment was conducted at Neka, Mazandaran province, Iran as split plot arrangement based randomized complete block design with four replicates in 2012. Main plots were phospho rous at three levels (0, 83 and 165 kg ha - 1 from concentrated superphosphate triple source) and sub plots were phosphate solubilizing microorganisms (PSM) at four levels [control, inoculation with Pseudomonas fluorescens (PSF), P. putida (PSP), and coinoculation of PSF and PSP]. Results showed that there were a significant difference for mineral phosphorous and PSM in terms of number of stems, biological yield, straw yield, and paddy yield. Paddy yield varied from 457.8 gr m - 2 in the control treatmen t to 625.1 and 630.2 gr m - 2 in plots which received either 83 or 165 kg ha - 1 mineral phosphorous, respectively. Inoculated rice plants with PSM had higher yield attributes. Paddy yield ranged from 498.9 gr m - 2 in the control to 528.9, 561.5 and 561.6 gr m - 2 in the PSF, PSF+PSP and PSP inoculated plants, respectively. Consequently, the maximum paddy yield of 699.9 gr m - 2 (51.8% more than control) was recorded in plots which inoculated with PSP and received 83 kg ha - 1 P.