Control of crown rot in `Santa Catarina Prata' and `Williams' banana with hot water treatments

Abstract

Abstract Immersion of banana ( Musa spp., cultivars `Santa Catarina Prata' and `Williams') in hot water was evaluated as a potential control procedure for crown rot. Fruit in clusters were subjected to 45, 50 and 55°C for up to 40 min followed by a 20-min shower in ambient temperature water. Exposure of fruit to water at 55°C for 10 min and longer caused severe skin scald and a failure to soften. Scald generally only occurred on fruit treated for 30 min and longer at 50°C. Scald development on fruit treated at 45°C for 40 min varied with harvest date. There were seasonal differences in the severity of fruit to injury. Inoculating the cut crown surface with Chalara paradoxa spore suspension at different times up to 20 min after dehanding or trimming gave similar disease severity. A 45°C hot water treatment for 20 min given 15–20 min after dehanding reduced crown rot from 100% to less than 15%. When fruit were exposed to hot water at 50°C for 20 min, irrespective of the time after dehanding, crown rot was reduced to less than 3%. Hot water treatment has the potential to replace chemical fungicides to control crown rot of banana.