CHLOROPHYLL FLUORESCENCE AS AN INDICATOR OF WHEN TO HARVEST MANGO 'COGSHALL' FRUIT ACCORDING TO THE MARKET (EXPORT OR DOMESTIC)

Abstract

A non-destructive technique to predict harvest date of mango according to the market (domestic or export), combined with the traditional criterion was presented. Changes in chlorophyll fluorescence of mango and in indicators of maturation were evaluate at different maturity stages. Maximal (Fm), minimal (Fo), variable (Fv), variable to maximal ratio (Fv/Fm) chlorophyll fluorescence, fruit size, density, total sugar content in flesh, and respiration rate were evaluated at three harvest dates (i.e. 106, 120 and 132 days after full bloom, the latest corresponding to the traditional date of harvest, according to change in fruit appearance). No difference in Fv/Fm value was found, regardless of the harvest date, while the three maturity stages were differentiated using Fm, Fo, and Fv values. These chlorophyll fluorescence parameters declined with the maturation process. The respiration rate increased with harvest date, especially for fruit from the latest harvest in which the climacteric crisis has begun. Total sugar content and fruit density increased as chlorophyll fluorescence parameters decreased. Chlorophyll fluorescence appeared to be a helpful, non-destructive technique to predict harvest date before visible changes in fruit appearance, especially for export market. Whereas, the traditional criteria could be kept as an indicator to harvest 'Cogshall' mango for domestic market, in which it is not necessary to store fruit. (Resume d'auteur)