Effect of Harvest Time, Delay in Destemming and Desapping Treatment on the Sap Volume and Visual Quality of ‘Carabao’ Mango Fruit

Abstract

The sap or latex injury in mango reduces fruit quality as it causes skin blemish during harvesting and postharvest handling. Sap volume and visual quality of ‘Carabao’ mango as affected by different harvest times during the day (every hour from 7:00 AM to 5:00 PM), delay in cutting (hourly up to 6 h) of the pedicel at either the pedicel base or at the abscission zone and different desapping agents applied 1 or 7 h from harvest were assessed. Sap injury was assessed by allowing the sap to flow on the fruit after re-cutting the pedicel at the abscission zone. Sap volume was measured during harvesting while sap injury, days to table ripe stage, visual quality, weight loss, degree of anthracnose and stem end rot were assessed during fruit storage. The experiments were laid out using the completely randomized design. Sap volume ranged from 0.06 to 0.25 mL fruit-1. The lowest sap volume was recorded in fruit harvested in the afternoon between 1:00 and 5:00 PM, while the highest volume was noted at 7:00 and 10:00 AM. The relative humidity of the air was highest at 7:00 AM. Better quality at table ripe stage was noted in mango fruit harvested at 1:00 - 2:00 and 4:00 - 5:00 PM. Sap injury at different harvest times did not vary. The delay in the destemming up to 6 h and the location of cut or pedicel length did not affect sap volume and fruit quality. However, the cutting of the pedicel at the abscission zone rather than at the pedicel base tended to result in better quality, which helped delay fruit ripening. All desapping treatments, such as 1.0 % alum, 1.0 % detergent, 0.5 % lime [Ca(OH)2], and water, could control sap injury. Untreated fruit showed longer shelf life due to a lower degree of anthracnose. Stem-end rot did vary among desapping agents. Among the desapping treatments, water is found to reduce sap damage better. Harvesting later in the day, cutting at the abscission zone, and washing mangoes with water can reduce sap or latex damage in ‘Carabao’ mango.