Abstract
This study investigated eco-friendly approach of utilizing plant growth promoting rhizobacteria (PGPR) and humic acid (HA) as bio-stimulants to improve the growth, yield and nutrition of canola (Brassica napus L.). In this study, we isolated 20 indigenous rhizobacterial strains that were subsequently screened and characterized for their plant growth promoting traits. After that one promising PGPR strain identified as Acinetobacter pittii by 16S rRNA gene sequencing was selected for field trial. The field experiment was conducted using RCB design with split-plot arrangement that was replicated four times. Three levels of humic acid (0, 10 and 20 kg ha(-1)) as main plot factor and two treatments of PGPR (with and without PGPR) as subplot factor were used. Data was recorded on plant height (cm), root dry matter plant, number of lateral root plant(-1), number of pods plant(-1), number of seeds pod(-1), 1000 seed weight (g), seed yield(kg ha(-1)), oil content (%), nitrogen (N), phosphorus (P) and potassium (K) contents and uptake. For most of the above mentioned parameters, significant enhancement was observed with the increment of humic acid, and also PGPR treatments were better than their respective control treatments. Maximum values of these parameters were recorded for the interaction of 20 kg HA ha(-1) with the PGPR strain. It can be concluded that integrated application of HA and PGPR is a better strategy to improve nutrition and yield of canola.