Effect of sunshine on the evolution of morphological and physicochemical parameters of preharvest mangoes (Mangifera indica L.)

To reduce post-harvest losses due to an uncontrolled harvest date, the effects of sunshine on the ripening of mangoes on trees were studied in the Kent variety intended for export from Côte d’Ivoire. On trees, some mangoes exposed to direct daily sunlight (DDS) and others shaded by the leaves, therefore subject to indirect daily sunlight (IDS) were monitored. Mangoes growth and development were accessed through morphological (weight, length, circumference and volume) and physicochemical (firmness, pulp color, total sugars, reducing sugars, flavonoids and tannins) parameters. Furthermore, temperature induced by daily sunlight was recorded until harvest. The obtained results showed that, except for pulp firmness and coloration, indirect sun exposure (IDS) increased more rapidly morphological parameters than direct sun exposure (DDS). For example, 78 days after fruit set; IDS increased faster (0.46 kg/week) mangoes weight than DDS (0.37 kg/week). However, mangoes physicochemical parameters changed faster under DDS than under IDS. Investigation of daily temperature effect on mango parameters evolution revealed that low temperatures (28.72; 30.22; 30.53°C) promoted morphological growth while high temperatures (31.55; 31.56; 32.55°C) rapidly evolved mango internal physicochemical parameters. Consequently, sun direct exposition (DDS) reduce mangoes harvest time than indirect exposition i.e. shadiness under leaves (IDS). Sunshine can now be harnessed by dropping branches in orchards after the mango trees have fruited. This is so that the maximum number of mangoes are exposed to the sun on the tree. Thus, quality of the harvested mangoes is improved and mangoes will be competitive in the international market.