Effect of TBZ, acetaldehyde, citral andThymus capitatusessential oil on 'Minneola' tangelo fruit decay

Thiabendazole (TBZ), citral, acetaldehyde (AA), andThymus capitatusessential oil-were tested for their ability to control decay on 'Minneola' tangelo fruit sprayed with a conidial suspension ofPenicillium digitatum, either alone, or in combination with a low dose (100 ppm) of TBZ. TBZ at 2000 ppm was used as the standard. Thyme oil, citral and AA, all at 100 ppm (v/v), were applied under reduced pressure (0.6 bar) and heated to complete vaporisation. Control treatments were performed at normal and reduced pressure. Viability of fungal spores was checked by plating the rinsing water of three fruit per experimental plot on potato-dextrose agar dishes. A colony count was performed daily. All treatments significantly reduced the viability of the pathogen, TBZ at 2000 ppm being the best. The volatile compounds provided better control of the patbogen than TBZ at 100 ppm. Thus,T. capitatusoil, citral and AA could be of great interest in controlling postharvest disease of citrus fruits.