Use of Plant-Growth Promoting Rhizobacteria and Mycorrhizal Fungi Consortium as a Strategy to Improve Chickpea (Cicer arietinum L.) Productivity under Different Irrigation Regimes

Abstract

Climate change prediction indicates an increased likelihood of precipitation variability and droughts in the Mediterranean region. Previous studies demonstrated that microbial symbionts combined with supplementary irrigation could mitigate climate change effects and boost chickpea production in low-fertility soils. The aim of the study was to assess the effects of inoculation with a consortium of plant growth-promoting rhizobacteria (PGPR) (Pseudomonas sp., Burkholderia sp. and Mesorhizobium sp.) and arbuscular mycorrhizal fungi (AMF) (Rhizophagus irregularis, Funneliformis geosporum and Claroideoglomus claroideum) on growth, grain yield and crude protein content of chickpeas under the following irrigation regimes: I1-no water stress, I2-moderate water stress, I3-strong water-stress, I4-no water stress in critical growth stages of plant cycle development and I5-severe water stress). Plants irrigated only during the critical growth stages of flowering and pod filling showed higher grain yields compared to plants from other water deficit irrigation treatments. Additionally, chickpeas co-inoculated with PGPR and AMF, and irrigated only during critical growth stages, presented higher grain yield than non-inoculated plants without water stress (1.45- and 1.33-fold increase in 2018 and 2019, respectively). Inoculation with beneficial microorganisms and supplemental irrigation at critical stages benefits chickpea growth and should be considered for increasing crop productivity and promoting agricultural sustainability.