Plant-Vitamin-Bacteria Interaction Improves Gas Exchange and Initial Growth of Corn Plants

Abstract

The use of Azospirillum brasilense has been widely disseminated as a strategy to increase agricultural productivity, but its use in conjunction with other products is still not well studied. A promising compound for this purpose is nicotinamide, which positively influences the morphophysiological characteristics of plants and may result in biostimulant effects, in addition to enhancing the characteristics of inoculation with the bacteria. This study aimed to evaluate the effect of the foliar application of Azospirillum brasilense and nicotinamide as biostimulants on corn plants. The treatments consisted of T1: control, T2: foliar application of nicotinamide (200 mg L^–), T3: foliar application of Azospirillum brasilense (2 mL L^–), and T4: combined application of nicotinamide and A. brasilense. Gas exchange characteristics, vegetative growth, mass accumulation, and distribution were evaluated. It was found that applying these compounds increased the gas exchange capacity of the plants and improved growth and the accumulation of dry mass, mainly related to the root. There was also a correlation between root development and gas exchange capacity. The application of nicotinamide provides gains related to root development, positively impacting gas exchange characteristics. In addition, its combined use with Azospirillum brasilense results in a synergistic effect, producing more compact plants and increasing stem thickness and efficiency in terms of gas exchange.