Effect of Nitrogen Fixing Bacteria and Nitrogen Rate on Yield and Growth of Common Bean

Abstract

To study the effects of nitrogen (N) rate and co-inoculation of nitrogen-fixing bacteria (Rhizobium phaseoli) on common bean, an experiment was performed in Rasht, Iran. Common bean genotype, Guilanian landrace, was planted in a factorial experiment based on a randomized complete block design with three replicates on April, 15th in 2014. The first and second factors were nitrogen rates (0, 30, 60, 90 and 120 kg.ha-1 as urea) and Rhizobium phaseoli (inoculation and un-inoculation), respectively. Nitrogen had significant effect on seed yield and plant height. The effect of Rhizobium phaseoli was significant on seed yield, plant height, pod length, pods per plant, seeds per pod and nitrogen content in leaf. Interaction effects of nitrogen and Rhizobium phaseoli were not significant on any of the traits. Application of 60 kg.ha-1 nitrogen significantly improved seed yield, plant height and number of pods per plant. Nitrogen supply beyond the 60 kg.ha-1 decreased plant height, pods per plant and seed yield. The greatest values of seed yield (1635 kg.ha-1), plant height (30.01 cm), pod length (13.19 cm), number of pods per plant (6.7), number of seeds per pod (4.34) and nitrogen content in leaf (4.12%) was observed in inoculation treatment. The results indicated the inoculation of common bean seeds by Rhizobium phaseoli improved the plant growth, productivity and quality. Therefore, the common bean inoculation with Rhizobium phaseoli is suitable to achieve the yield potential and reduce the adverse effects of environmental and may be recommended due to its advantages in terms of reduced application of nitrogen fertilizer.

Keywords

• Phaseolus vuigaris
• protected agriculture
• Rhizobium phaseoli
• mineral
• yield