Control of Fusarium sp. on pineapple by megasonic cleaning with electrolysed oxidising water

Abstract

The effects of megasonication (MS) with electroly sed oxidising (EO) water (MS/EO treatment) on Fusarium sp. which causes postharvest decay of pineapple cv. Phu Lae were investigated. Spore suspensions containing 105conidia mL -1 and 1 cm mycelium discs of Fusarium sp. were subjected to MS (1 MHz) in EO water with available free chlorine at 100 ppm for 10 min., and compared with non-treated control samples. The MS/EO treatment completely inhibited spore germination and mycelial growth for 3 days and reduced fruit decay. Development of Fusarium sp. on de-crowned pineapple fruit was also investigated by scan ning electron microscopy. The fungal growth was restricted on de-crowned pineapple fruit for 72 hr, following MS/EO treatment. The MS/EO treatment also enhanced the activity of two enzymes: phenylalanine ammonia lyase (PAL) and peroxidase (POD), which play important roles in plant defense responses.

Keywords

• megasonication
• electrolysed oxidising water
• pineapple
• Fusarium sp.
• fruit decay
• crown rot