Improving yield and health of legume crops via co-inoculation with rhizobia and Trichoderma: A global meta-analysis

Trichoderma is a genus of fungi used for biocontrol and plant growth promotion; however, effects of co-inoculation with rhizobia in legumes still require detailed analysis. This study conducted a global meta-analysis of 59 published studies (1992–2021) on co-inoculation of legumes with rhizobia and Trichoderma spp. to assess factors affecting the efficiency of plant growth compared to inoculation exclusively with rhizobia. Co-inoculation favored plants by reducing disease incidence (−44%) and increasing root mass (+17%), nodule number (+32%), nodule mass (+37%), nodule nitrogenase activity (+35%), shoot nitrogen content (+8%), and grain yield (+14%). Co-inoculation of legumes can decrease root diseases caused by Fusarium spp., Rhizoctonia spp., Macrophomina phaseolina, Pythium debaryanum and Sclerotium rolfsii and also has potential as a plant growth promoter regardless of plant health. Positive effects of co-inoculation on grain yield and root mass were observed under the majority of the factors evaluated (e.g., legume species, microorganisms, co-inoculation methods, experimental conditions, plant health status, and edaphic factors). Co-inoculation with rhizobia and Trichoderma spp. may contribute to sustainable intensification of legume production systems due to multiple plant benefits under a wide range of conditions.