Co-inoculation of Bradyrhizobium lupini and Azospirillum brasilense Enhances the Agronomic Performance of Lupinus mutabilis Sweet in Two Agroecological Zones of Southern Peru

García-Blásquez-Morote J.S.; Alarcón-Romaní S.M.; Rojas-Cordero T.A.; Quispe-Tenorio J.A.; García-Blásquez-Morote C. · Plant Protection (2026) · DOI: 10.33804/10.33804/pp.010.02.6008

Resumen

Lupinus mutabilis Sweet (tarwi) is a high-protein Andean legume adapted to marginal environments; however, its productivity is often limited by frost and poor agricultural management practices in high-altitude regions. Plant growth-promoting rhizobacteria (PGPR) offer a promising approach to enhance growth, nitrogen fixation, and yield under stressful conditions. The present study evaluated the effect of co-inoculation with Bradyrhizobium lupini and Azospirillum brasilense on growth, root development, yield components, and grain quality of two tarwi ecotypes, Yunguyo (270-day cycle) and Andenes (180-day cycle), cultivated under field conditions. Results showed that co-inoculation significantly improved shoot growth parameters, including plant height, biomass accumulation, and stem diameter, compared with uninoculated controls. Root development was also markedly enhanced, with increases in root length, nodule number, and root and nodule dry weight, indicating improved biological nitrogen fixation and nutrient uptake. Reproductive traits such as pod length, pod number, stem number, and pod weight with seeds were significantly higher in inoculated plants. Grain yield components also improved substantially, with increases in seed weight, grains per pod, and overall yield. Yield gains reached up to 167.5 kg/ha in the Yunguyo ecotype and exceeded 1000 kg/ha in the Andenes ecotype, which benefited from its shorter phenological cycle and reduced exposure to frost. Co-inoculation also promoted a positive trend in protein content, reflecting enhanced nitrogen assimilation. In conclusion, co-inoculation with B. lupini and A. brasilense is an effective strategy to enhance growth, yield, and nutritional quality of tarwi under high-altitude conditions, supporting its sustainable production.

Instituciones: Universidad Nacional de San Cristóbal de Huamanga