Exogenous application of putrescine affects mango fruit quality and shelf life.
Malik A. U., Singh Z., Dhaliwal S. S.
Author Affiliation: Department of Horticulture/Viticulture, Muresk Institute of Agriculture, Division of Resources and Environment, Curtin University of Technology, GPO Box U1987, Perth 6845 WA, Australia.
: 121-127
Abstract : Short shelf life of mango fruit limits its export to distant markets. The effects of pre- and postharvest applications of putrescine on fruit ripening, quality and shelf life of 'Kensington Pride' mango, grown in Western Australia, were investigated. An aqueous solution of different concentrations of putrescine (0, 0.5, 1.0, or 2.0 mmol l-1) containing the surfactant 'Tween-20' (0.01%) was applied as preharvest spray onto trees 7 days prior to harvest and postharvest fruit dip treatments for 6 minutes. One lot of the treated and control fruits was allowed to ripen at room temperature (21±1°C) while the second batch was stored at 13°C (85% RH) for 20 days. Fruit ripening at ambient temperature revealed that putrescine treatments significantly reduced ethylene production and the response was more pronounced in the postharvest dip application than in the preharvest spray. Ethylene production decreased as the concentration of applied putrescine increased. Pre- and postharvest applications of putrescine increased fruit firmness and decreased sugars, compared with the control. Both pre- and postharvest applications also retarded fruit colour development. After 20 days of storage, preharvest-treated fruits exhibited higher firmness, total soluble solids and lower fruit rot whilst acidity, total and nonreducing sugars were reduced in fruits treated with both methods, compared with the control. In conclusion, preharvest putrescine spray was more effective than postharvest dip. Putrescine at 1 mmol l-1 was effective in delaying fruit ripening at ambient temperatures, whilst 2 mmol putrescine l-1 extended the shelf life and improved the fruit quality of 'Kensington Pride' mango.