Effectiveness of biochar and wood vinegar from guava trees in controlling Fusarium verticillioides and enhancing growth and anatomical traits of maize (Zea mays L.)

Maize (Zea mays L.) stalk and ear rots are the most serious diseases, affecting grain yield and quality in a number of regions of the world. The purpose of this study is to evaluate the efficacy of biochar and wood vinegar from guava trees (Psidium guajava L.) against Fusarium verticillioides, the pathogen that causes stalk and ear rot diseases, as well as the growth and anatomical traits of maize in laboratory and greenhouse experiments. In in vitro studies, biochar and wood vinegar at concentrations of 0.50, 1.00 and 2.00% (v/v) were tested on the mycelium growth of the pathogen. The results showed that wood vinegar had a high ability to inhibit the pathogen's growth at a concentration of 2% (78.32%). Treating corn cobs with these treatments at concentrations of 2% led to a decrease in the severity of ear rot. Soil drenching with biochar and wood vinegar reduced the disease severity of stalk rot disease in maize in greenhouse experiments, with wood vinegar being the most effective in reducing the disease severity compared to the control. Biochar and wood vinegar both clearly affected plant growth, as measured by changes in plant height, fresh weight and dry weight of maize plants. Furthermore, these treatments enhanced the anatomical characteristics of maize roots and leaves compared to the untreated control plants. Data also revealed that total phenol contents and enzyme activity of peroxidase (POD) increased in treated plants with these treatments, but the highest increase was obtained when biochar was applied. These results highlight the efficacy of biochar and wood vinegar as effective, safe and eco-friendly methods to control of stalk and ear rot disease of maize and improve the anatomical characteristics and growth of plants.