Combination Between Citral and Chitosan for Controlling Sour rot Disease of Lime Fruits

Sour rot caused by Giotrichum candidum is the most important disease affecting lime fruits. Effect of citral and chitosan as single or in combination for controlling sour rot disease of lime fruits was studied. Complete inhibition of linear growth and spore germination of G. candidum was obtained with citral at concentrations of 5.0 ml / l and chitosan at 8.0 g / l. The promising concentrations of citral i.e 4.0 & 5.0 ml / l and chitosan at 6.0 & 8.0 g / l were applied as single or in combination against sour rot disease. Fresh lime fruits were artificially wounded using sterilized scalpel and inoculated with spore suspension (106 spores/ml) of G. candidum then treated with citral and /or chitosan.Results indicate that the most effective treatments are combined treatments between citral at 4.0 or 5.0 ml / l and chitosan at 6.0 or 8.0 g / l which reduced the disease incidence and rotted part tissue more than 89.5 and 93.5% respectively.While single treatments of each concentration of citral and chitosan reduced the sour rot incidence and rotted part tissue more than 81.5 and 84.5 %. respectively. It could be suggested that combination between citral and chitosan as fruit coating considered as one of applicable safely for controlling postharvest diseases of lime fruits.