There are years that we harvest plenty enough, but in most years, the harvest is low for various reasons. The first major threat is pest infestation, second is forest and/or grass fire, usually coming from the public forest land or in neighboring private farms. Third is strong typhoon or continued rains even in supposedly dry months. We clean the mango trees and their surrounding as much as possible, especially when the fruits are getting bigger. To reduce or prevent pest infestation, control grassfire, and so on.
Some nice photos of mango trees when they are bearing plenty of flowers, later the young mango fruits, below.
This year, we harvested practically nothing, due to pest infestation called "kurikong manga" or cecid fly.
From some literatures:
(a) Kurikong Infests Mango Farms in Central Luzon
... a pest called cecid fly or gall midge.
This fly, known as ‘saksak walis’ or `kurikong’ in Luzon, `buti,’ or `armalite,’ ‘Gloria-gloria,’ or ‘Nora-nora’ in the Visayas and Mindanao, infests mango farms across the country.
The adult mango cecid fly resembles a mosquito and commonly lays its eggs on young mango leaves. The larvae which develop from eggs, mine the leaves producing dark green circular galls or swelling of tissues along the leaf blade. When the adults emerge from these galls, the leaves develop circular spots or holes which are sometimes mistaken as fungal infection. Under heavy infestations, the leaves wrinkle and turn yellow.
The infestation, however, affects the fruits more. When hit early, young mango fruits fall off from the tree. Fruits that remain produce circular brown scab-like spots randomly distributed on the fruit’s surface. Infested fruits retain these scabby lesions up to harvest time, thus affecting the quality and commanding a lower market price....
(b) Preventing “Kurikong” Problem In Mango
The Cecid fly is a small mosquito-like insect that is active at night so spraying should be done at night or late in the afternoon. It lays its eggs on the developing fruits. If the mango tree is not in fruit, the Cecid fly lays its eggs on the leaves, causing circular protuberances on the surface.
The egg and larval stages are spent in the fruit while the pupal stage is spent in the ground, according to the BPI. The adult lives for only three to five days. Being small, the adults can be carried by wind. The pupa can be introduced in a new place when infested soil of planting materials is transported to that new place....
Bagging of mango fruits, ie, wrapping each and every fruit with paper, is a very labor intensive activity. There are huge costs involved, although the benefits are clear too, like the prevention of cecid fly attacks.
We should seriously consider this option next year.