The Efficiency of Enterobacter cloacae Inocula on Growth Properties, Oil Yield and Type Fatty Acids of Rapeseed (Brassica napus L.)

Biofertilizers play major role in sustainable agriculture. Increasing the longevity and survival of the bacteria in the production of inoculants by using different materials, is notable to increase the effectiveness of biofertilizers. The aim of present study was to investigate the efficiency of liquid inocula of Enterobacter cloacae S16-3 on growth rate and percentage of rapeseed seed oil (Brassica napus L.) cultivar hayola 308.

The experiment was carried based on completely randomized design (CRD) with 12 treatments (including 9 liquid inoculants; F1-F9, one negative control treatment without adding any bacteria and NPK, and two positive controls e.g. 100NPK and 70NPK) and three replications, in the greenhouse of Agricultural Faculty of University of Tabriz in a sterilized sandy loam soil in 2018 . Nine liquid inoculants of S16-3 were prepared using different amounts of materials including glycerol, polyethylene glycol (PEG), trehalose, carboxymethylcellulose (CMC), Arabic gum (AG), polyvinyl pyrrolidone (PVP), glucose and starch, in different combinations.  

The results showed that in the presence of E. cloacaebacteria (in the form of nine inoculants), 100NPK and 70NPK treatments, the number of silique per plant, number of seed per plant, leaf chlorophyll index, plant height, stem diameter, root volume per plant, fresh and dry weight of shoot, root and seed, seed yield per plant, oil yield per plant, silique weight per plant, total fresh and dry weight, seed oil percentage and fatty acids content increased. The inoculation effect of E. cloacae liquid inocula on 1000 seed weight was not significant. The results percentage of seed oil and fatty acid analysis showed that the highest percentage of seed oil (47.02%) and the highest amount of oleic acid (53.1%) was obtained by F9 (glycerol, glucose, AG, PEG) treatment, and oil quality was affected by bacterial inoculation.  

According to the results of this experiment F5 (AG, starch, PEG) and F9 inoculants can be recommended to improve on growth properties, oil yield and type fatty acids of rapeseed.