All physiological processes in the tree require carbohydrates, and the role of starch reserves in supplementing the photosynthate production is of vital importance. During flower bud development stage in May/June, carbohydrates are gradually stored in the wood and roots of mango trees. Flower and fruit set are strenuous on carbohydrate reserves and during this period the starch reserved readily decline until early fruit development stage at the end of September to the beginning of October. Tree pruning, that should have been done by now, has assured that enough light will penetrate the mango orchard to facilitate optimal photosynthesis. Not only does pruning improve light penetration, but increase the flower shoots, as branch removal enhance leaf ethylene which plays are role in converting a vegetative shoot to a flowering one.

Fruit set is dependent on successful pollination (which depends on the availability of high quality pollen, the presence of a high number of suitable pollinators, and optimal weather conditions), and must be optimised to limit fruit drop, which is extremely high in mango trees. Both male and female flowers open early in the morning and female flower stigmas area receptive at flower anthesis for at least 6 hours, although receptivity may last for several days. The cultivars Sensation, Tommy Atkins and Keitt may pollinate itself, although the first mentioned is more prone to do so than the latter two. Temperatures above 20°C are required for anther dehiscence and pollen shed, while temperatures above 25°C are required for pollen tube growth. Placement of beehives in mango orchards is of utmost importance to ensure sufficient pollination. One beehive per ha may be adequate, but farmers do sometimes place two hives between two blocks within the windbreak row with the intention not to limit bees from one hive to a specific block, but to encourage crosspollination between blocks. Although bee activity is of utmost importance, especially during flowering, so is the spray of chemicals to control bacterial and fungal infections as well as harmful insects. Although most of these chemicals do not kill the bees, they do hinder bee activity, and the most effective way to combat this is to implement a integrated pest management program.

The whole process of flowering and fruit set starts with flower induction, usually around April-May, when night temperatures drop below 15°C. Inflorescence development depends on climatic conditions and takes about two to three months. Once a year inflorescence primordials are initiated in the apical domes of terminal buds. Inflorescences are therefore terminal and the shoot apical meristem of the branches on which they are produced becomes wholly transformed into a flowering axis after a period of vegetative growth. The inflorescence has a compound structure and has first, second and third order lateral branches, which produce between 300 and 6000 flowers. Each inflorescence bears both hermaphrodite and staminate flowers. Male and hermaphrodite flowers are evenly spaced on the inflorescence, but in certain cultivars hermaphrodite flowers tend to occur only on the apical end of the inflorescence. Male flowers are therefore always present in more than double the number of hermaphrodite flower in a single inflorescence. Only small percentage hermaphrodite flowers contain functional pistils, which, after successful pollination and fertilization, can develop into mature fruit.

However, it is important to note that cultivars such as Keitt and Kent flowers in the lateral positions are also functionally female, translating that the changes of successful fruit set is much higher. Cultivars that have inflorescences where only a small portion of the flowers on any position of the inflorescence is functionally female, including Heidi, leads to poor fruit set and low yields.

To ensure healthy flowers and optimal pollination, a foliar application of elements are of the utmost importance. During flowering and fruit set a foliar application of boron, zinc and potassium is required.  Boron application, in the form of a leaf spray, at the onset of flowering favours pollen tube growth.

Plaaskem propose the following spray program: