Effect of Peroxyacetic Acid (PAA) On Controlling Maize Late Wilt Disease Caused by Magnaporthiopses maydis

Abstract

Late-wilt disease of maize caused by Magnaporthiopsis maydis is the most serious disease of duet corn in many parts of the world. A strong oxidizing compound, peroxyacetic acid (PAA) as mixed of acetic acid (AA) and hydrogen peroxide (H2O2), gave a promising control approach against late wilt disease. All treatments of acetic acid (AA), H2O2 and peroxyacetic acid (PAA) at different concentrations reduced the linear growth of M. maydis fungus compared with control in vitro. 0.1 AA + 4.0 H2O2 m/L and 0.2 AA + 4.0 H2O2 m/L were the most effective treatments in reducing M. maydis linear growth which showed the highest growth reduction, while 0.1 AA m/L was the lowest effective treatment. All maize grain coated with AA, H2O2 and PAA alone or in combinations reduced the disease infection of maize late wilt compared with infected control in vivo. Treated by 0.2 AA+4.0 H2O2 m/L and 0.1 AA+4.0 H2O2 m/L were the most efficient treatments in reducing disease incidence, while 0.1 AA m/L and 2.0 H2O2 m/L were the lowest effective treatment in this respect. In field trails, treated grains with all PAA combinations, some growth and yield parameters increased (plant length, stem diameter, weight of the ear, length of ear and weight of 100 grains) and late wilt disease was significantly decreased, of maize plant compared with control under field condition during 2021/2022 and 2022/2023 growing seasons. 0.1 AA+4.0 H2O2 m/L and 0.2 AA+4.0 H2O2 m/L were the most effective treatments for decreasing late wilt disease incidence and increasing disease reduction, growth parameters and yield component during the two-growing season. On the other hand, 0.1 AA+1.0 H2O2 m/L was the least
effective treatment against late wilt disease incidence and growth parameters in both seasons. The effect of peroxyacetic acid on the oxidative enzymes in leaves of maize plants was evaluated. All PAA combinations resulted an increase in peroxidase and polyphenol oxidase activity. The highest increase in peroxidase and polyphenol oxidase activity was recorded due to treated grain maize by 0.2AA+4.0 H2O2 m/L and 0.1AA+4.0 H2O2 m/L compared to uninfected and infected control. Meanwhile, 0.1 AA + 1.0 H2O2 m/L was the lowest treatment in peroxidase and polyphenol oxidase activity.