The Inhibitory Effect of Sodium Bicarbonate, Phylex and Seaweed Extract Against Penicillium digitatum Causing Green Rot Disease in Local Lemon Fruits

Abstract

This study was conducted in the College of Agricultural Engineering Sciences/University of Baghdad during the years 2021 and 2022. The study aimed to evaluate the biological activity of Sodium bicarbonate, Phylex and the Seaweed extract in controlling the green mold infection in the local lemon at refrigerated storage conditions (4°C). Two isolates of Penicillium digitatum were identified on Potato Dextrose Agar (PDA) and coded as L1 and L2. The results of this study confirmed the high pathogenicity of P. digitatum isolates to lemon fruits. The symptoms of green rot infection appeared on the fruits after 4 days of pathogen inoculation. The preservative and anti-fungal activity of Sodium bicarbonate, Phylex and Seaweed extract were assessed using local lemon fruits under refrigerated-storage conditions. The highest inhibitory effect was reported when 64 g/L Sodium bicarbonate, 4ml/L Phylex and 128 g/L Seaweed extract were used, preventing 100% of P. digitatum colonies growth after 6 days of treatment at 25±2°C. The data of the refrigerated-storage experiments showed that the Phylex treatment of artificial-wound fruits inoculated with the pathogen was more efficient than Sodium bicarbonate in protecting the lemon fruits from green mold infection. Phylex treatment protected the fruits from the fungal infection for 45 days storage, compared to the Sodium bicarbonate treatment, with which, the fruit infection appeared after 30 days of refrigerated-storage (at 4°C).