Mango is among the 70 fruits grown commercially in Bangladesh. It occupies 40 per cent of the land under fruit, and the area keeps growing. Yields vary by region: in Chapainawabganj and Rajshahi they are higher than elsewhere.

It is the month of Magh. Blossom on the mango trees of Chapainawabganj is still about a month away; as soon as Magh ends, the warm winds of Falgun will bring blossom to almost every tree.

But mango farmers in Chapainawabganj have already started early care of their orchards.

Trees need extra care just before blossoming, so growers with large and small orchards are busy. They are clearing weeds, irrigating and applying fertiliser, and spraying pesticide against insects. This drives off pests and brings healthy blossom, which should lead to a good crop. The light rain a few days ago also helped the growers.

Fertiliser in mango orchards needs attention. How much each tree needs a year depends on the soil, and demand rises as the tree grows. The doses by year are:

• Cow dung: 20 kg one year after planting, 25 kg after two years, increasing by 5 kg a year, and 125 kg at 20 years and older.
• Urea: 250 g one year after planting, 375 g after two years, increasing by 125 g a year, and 2,750 g at 20 years and older.
• TSP: 100 g one year after planting, 200 g after two years, increasing by 100 g a year, and 2,150 g at 20 years and older.
• MoP: 100 g one year after planting, 200 g after two years, increasing by 100 g a year, and 2,100 g at 20 years and older.
• Gypsum: 100 g one year after planting, 175 g after two years, increasing by 75 g a year, and 1,600 g at 20 years and older.
• Zinc sulphate: 10 g one year after planting, 15 g after two years, increasing by 5 g a year, and 110 g at 20 years and older.
• Boric acid: 5 g one year after planting, 7 g after two years, increasing by 2 g a year, and 50 g at 20 years and older.

All fertiliser is best applied in two instalments: half before the monsoon and the rest in Ashwin, after the monsoon. If a grower misses the first instalment, the full requirement must be applied with the second. Many growers apply fertiliser after harvesting Fazli and Ashwina mangoes, which is not scientific at all.

For bearing trees, cut a circular trench 30 cm wide and 15–20 cm deep, 2–3 metres from the trunk, and mix the chemical and organic fertiliser well with the soil in it. Alternatively, scatter the fertiliser over the area shaded by the tree at midday and mix it in well by digging with a spade. Mango trees are usually weakened after fruiting and need food; if the monsoon begins after fertiliser is applied, the tree can take the nutrients it needs from the soil.

Orchards need regular irrigation, but not when the soil is moist. Research shows that a modified basin method uses less water and lets the tree take up most of it: keep one metre around the trunk slightly raised and make a plate-shaped basin over the area shaded at midday. The basin also keeps the base of the tree clean so weeds cannot grow.

Monjurul Huda, deputy director of the district Department of Agricultural Extension, said that if the weather stays good in the coming days there will again be a bumper mango crop. Growers are being given various instructions, and they are working accordingly in hope of higher yields.

Covering the area with water hyacinth after irrigation keeps the soil moist for up to a month. But it is better not to irrigate in the month before flowering: watering then brings out new leaves, reducing the number of blossoms and the yield.

If an orchard lacks organic matter, dhaincha should be grown. Adding organic matter and other nutrients this way raises the soil's productivity.

Two or three kinds of parasitic plant are seen on mango trees, attacking large trees more than small ones. Their seeds germinate on mango branches and grow by drawing water, sap and minerals from the branch. They have no roots, but form root-like haustoria to feed from the branch. The seeds spread most during the monsoon.

Source: Staff Correspondent. First published in Bengali on The Agro News.