I would like to know about the acceptability of ethephon for banana ripening. Is it commercially acceptable to use it for banana ripening and if so, are there are any specifications for its use? (M.A.)
Although ethephon is approved for preharvest application on processing tomatoes and table grapes with a maximum residue limit of 2 ppm, it is not approved for postharvest application (direct spray or dipping) on bananas and other fruits to enhance their ripening. However, it is possible to use ethylene gas liberated from ethephon to ripen fruits including bananas on a small scale if such a procedure is more economical than using ethylene gas from ethylene generators or gas cylinders with flow controls. In all cases, 100 ppm ethylene is the recommended concentration for stimulating faster and more uniform ripening of mature-green bananas. Also, optimal temperature (15-20 C) and relative humidity (90-95%) ranges must be provided regardless of the ethylene addition method.
To release ethylene from ethephon, calculate the quantity needed based on the fact that 200 ml of ethephon (active Ingredient) will release 27 liters of ethylene gas when 85 g of caustic soda (NaOH) pellets are added to neutralize the ethephon. CAUTION! CAUSTIC SODA AND ETHEPHON ARE CORROSIVE. WEAR SAFETY GLASSES AND RUBBER GLOVES.