Nodulation, contribution of biological N2 fixation, and productivity of the common bean (Phaseolus vulgaris L.) inoculated with rhizobia isolates

Abstract

The common bean has a great economic, social, and nutritional importance and requires high levels of nitrogen for its cultivation. The plant in symbiosis with rhizobia bacteria can benefit from biological nitrogen fixation (BNF). To assess the agronomic efficacy of rhizobia isolates on the nodulation, contribution of BNF and productivity of the common bean, two experiments were conducted in separate locations. Seventeen Rhizobium tropici isolates were selected and compared with three commercial Rhizobium spp. strains: CIAT 899 and H12 (R. tropici) and PRF 81 (R. freirei). The variables analyzed were: number of nodules (NN), nodules dry weight (NDW), root dry weight (RDW), leaf area (LA), shoot dry weight (SDA), total nitrogen in shoots (Total-N), number of pods (NP), number of grains (NG), grain yield (GY), percentage of nitrogen derived from BNF (Ndfa%), and total nitrogen derived from BNF in the shoots (NdBNF). Inoculation with R. tropici isolates promoted significant gains in nodulation, growth, and productivity of the common bean. About 50% of the isolates promoted GY rates equal to or superior to the nitrogen treatment (NT) and to the standard strains CIAT 899, PRF 81, and H12. Among the best isolates, the Ndfa% ranged from 64.2% to 75.8%, with NdBNF ranging from 802.91 to 1037.56 mg plant -1 . The isolate JPrG10A6 of Rhizobium tropici provided high values of NdBNF and GY, showing great potential to be used commercially as inoculant of the common bean crop.

Productivity and Economics of Inoculated Common Bean as Affected by Nitrogen Application at Different Phenological Phases

“…Considering the average of the two cropping year (2017 and 2018), the GY of the inoculated treatment was about 10.2% higher than the N-fertilized ones. Although the literature still reports that inoculation alone is not able to reach the same levels of productivity of N-fertilization (Bertoldo et al 2015), our results corroborate to authors which found GY values of inoculated common bean higher than those of Nfertilization (Mercante et al 2017;Moreira et al 2017;Samago et al 2017).…”

Response of the common bean to liquid fertilizer and Rhizobium tropici inoculation

“…Similarly, GY was also affected by this interaction, where higher GY was found under the inoculation with R. tropici and application of N-P formulation at 6 cm depth (Table 4). These results corroborate Moreira, Oliveira and Ferreira (2017), who reported that inoculation with R. tropici provides an improvement in yield components, such as NG, reflecting in GY increasing. Additionally, as seen in table 3, the GY of common bean inoculated with R. tropici was about 13% higher than that not inoculated, which represents an increase in GY by 214 kg ha -1 .…”

Biological nitrogen fixation by irrigated dry bean (Phaseolus vulgaris L.) genotypes

“…Both of these results were also observed in the greenhouse experiment (Akter et al 2014). Differences in compatibility between Rhizobium strains and dry bean genotypes are well known, and they are the basis for screening both symbiotic partners for BNF potential to find effective combinations (Dwivedi et al 2015;Armenta-Bojorquez et al 2016;Ouma et al 2016, Moreira et al 2017. The suppressive effect of high soil nitrogen content on legume nodule formation and function has also been established before (Gentili and Huss-Danell 2003;Clayton et al 2004;Nanjareddy et al 2014).…”