Combined application of microbial and non-microbial biostimulants to improve growth of peanut plants exposed to abiotic stresses

Abstract

Peanut is a widespread legume, with an important agricultural and economic significance. It symbiotically interacts with rhizobia, increasing atmospheric nitrogen assimilation by the biological nitrogen fixation process, therefore improving yield. The presence of the environmental pollutant arsenic and the occurrence of water deficit episodes constitute severe abiotic stresses affecting this symbiosis, being biostimulants a sustainable alternative to increase crop yields. Thus, the objective of this work was to determine the effects of the joint application of a commercial seed non-microbial plant biostimulant (Nutrifer® 202) and a microbial plant biostimulant on growth, nodulation and oxidative stress indicator-levels, on peanut plants exposed to arsenic or drought. Biostimulant addition reduced As translocation to leaves and improved plant growth and nodulation in the drought stress condition, in association with proline accumulation, with a protective function on the cellular redox balance. Therefore the application of the biostimulant combination Nutrifer® 202 and Bradyrhizobium sp. C-145 is promising for peanut crops growing in regions susceptible to water deficit or arsenic exposure.