The Effect of Combined Application of Plant Growth Promoting Rhizobacteria and Different Levels of Vermicompost on Quantitative and Qualitative Performance of Rapeseed (Brassica napus L.)

Integrated plant nutrition management is a good method to increase the ‎productivity of crops and improve the environment. To evaluate the ‎effects of using ‎growth promoting bacteria and different levels of vermicompost on quantitative ‎and qualitative yield of rapeseed (Brassica napus L.), a field experiment was ‎conducted in 2014-2015. The treatments consisted of inoculation and non-‎inoculation of canola seeds with growth promoting bacteria and application of ‎different levels of vermicompost (0, 4, 8 and 12 t.ha-1). The results showed that ‎simple effects and interaction of vermicompost and growth ‎promoting bacteria ‎on quantitative and qualitative traits of canola were significant. That is to say ‎with ‎increasing the application of vermicompost from 4 to 12 tons per hectare, a ‎‎significant increase was observed in the traits under study as compared to the control.‎ ‎Inoculation of seeds with growth promoting bacteria also increased the ‎‎amount of measured traits as compared to the control. The application of 12 tons of ‎‎vermicompost per hectare, along with growth promoting bacteria, resulted in an ‎increase in ‎the number of pods per plant, 1000-seed weight, biological yield, ‎grain yield, harvest ‎index and oil yield, (28.63, 4.68 g, 10785.2 kg‎, 3484.2 kg, ‎‎38.02% and 1795.93 kg.ha-1, respectively, as compared with control). Application of ‎‎12 t.ha-1 of vermicompost per hectare along with growth promoting ‎bacteria resulted in grain ‎yield, harvest index and oil yield increase by 83%, 45% and 43%, ‎respectively, ‎as compared with control. Therefore, in soils ‎with low organic matter content, ‎simultaneous application of vermicompost and growth ‎promoters bacteria can ‎improve the quality and quantity of rapeseed yield ‏.‏‎