Post Harvest Management of Horticultural Crops

Controlled ripening

Table : Conditions for controlled ripening of fruits at RH of 85-90%
Commodities	C2H4 (ppm)	Temperature (°C)	Treatment time (hr.)
Avocado	10-100	15-18	12-48
Banana	100-150	15-18	24
Honeydew melon	100-150	20-25	18-24
Kiwifruit	10-100	0-20	12-24
Mango	100-150	20-22	12-24
Stone fruits	10-100	13-25	12-72
Tomato	100-150	20-25	24-48

Sources of ethylene

Ethylene gas – pure C2H4 gas enclosed in the can/cylinder is sprayed /injected into chamber. Ethylene portable can which contain 3 g sufficient to ripe 2-6 ton of produce is available commercially
Ethephon – Used as spray/ dip, acidic in water releases C2H4
Ethylene mixture - C2H4 + inert gas like CO2. Inert gas because not enough O2 remains in the chambers to provide an explosive mixture. Eg, Ripegas contain 6% C2H4
Ethylene generators - Widely used method where in liquid spirit produces C2H4 when heated in the presence of catalyst platinised asbestos.
Use of ripe fruits – cheap and simple, where in ripe fruit with high C2H4 producers such as apple, banana, mango, sapota and tomato is used at home to ripe / degreen