Combined effect of humic acids and Serendipita indica on photosynthesis and yield of bean plants

Abstract

Agriculture increasingly uses sustainable technologies to obtain higher yields and reduce environmental impact. In this context, the use of humic substances and growth-promoting fungi, such as Serendipita indica, has emerged as an alternative for increasing the yield of crops such as beans. This study aimed to assess the effects of using humic acid (HA) isolated from vermicompost on its own or combined with the fungus S. indica on the growth, photosynthesis, and yield of common beans (Phaseolus vulgaris L.). Initially, a dose-response trial was carried out with six treatments (0, 10, 50, 100, 200, and 400 mg L⁻¹ de HA) to identify the best concentration of HA in the initial growth of the bean plant. From the optimal concentration obtained, 200 mg L⁻¹ of HA, a new experiment was developed to investigate the influence of HA and the S. Indica fungus in photosynthesis and plant yield. The treatments were: T1 – control (no humic acid and no fungus); T2 – 200 mg L⁻¹ of HA; T3 – S. indica fungus; T4 – 200 mg L⁻¹ of HA and S. indica fungus. The joint application of HA at a concentration of 200 mg L⁻¹ with the fungus S. indica increased the photosynthetic efficiency and bean grain yield per plot. The associated use of biostimulants can change the production trend of common beans, making them more profitable and attractive for producers.