Each mango panicle carries from 1,000 up to 6,000 male and female flowers. Initially, depending on the variety, 1-30 fruitlets set on each cluster. Within 25-50 days of fruit set, only one or two fruitlets remain on each cluster; the rest fall for natural or internal reasons. Some panicles hold 4-5 mangoes, but in that case the fruit is small.

If the excess fruitlets do not drop, the mangoes stay small, which lowers their quality and the yield. A bumper crop comes when each panicle holds one fruitlet. To increase the number of mangoes per panicle, it helps to spray boric acid at 6 grams in 10 litres of water twice, 10-20 days after flowering. Spraying gibberellic acid at 50 milligrams per litre of water while all the flowers are in bloom also reduces fruitlet drop.

Fruitlets also drop when the soil lacks moisture. This shortage appears in March-April because of low rainfall, causing an abscission layer to form early in the stalk, and so the fruitlets fall. If fruitlets are dropping for lack of moisture, the area around the tree must be irrigated regularly. When the fruitlets are the size of a pea, irrigate the base of the tree once first. After the first irrigation, water every 15 days until the rains come.

Besides irrigation, fruitlet drop can be reduced by applying hormones. When the fruitlets are pea-sized, spraying them in mild sunlight with urea at 20 grams per litre of water, or with Planofix hormone at 2 millilitres per 4.5 litres of water, reduces fruitlet drop.

Hoppers can attack in the early stage after fruit set. The adult insects and their young suck sap from the fruitlets, which then dry up and fall. So when the fruitlets are pea-sized, an insecticide and a fungicide should be mixed together in water and sprayed on them.

When the fruitlets reach marble size, the fruit borer may attack. The adult lays eggs on the skin at the lower part of the mango. Within a few days the eggs hatch and the larvae bore into the mango through a hole as small as a dot. They eat first the flesh and then the stone. The affected spot later turns black, and sometimes the mango falls. If this problem appears, the orchard must be kept clean and tidy, and dead branches of the trees should be pruned.

Source: Jagonews24. First published in Bengali on The Agro News.