How do you modernise mango farming?

Even in good years, mangoes are considered one of the most difficult fruit crops to cultivate.

They depend on a delicate balance of climate, tree physiology, and farming techniques.

Getting that balance right is crucial for India, the world's biggest producer of mangoes, where 23 million tonnes of the fruit is harvested every year - almost a fifth of India's total fruit output.

But for many farmers mango cultivation has, in recent years, become more challenging.

"Mango farming has become unpredictable," says Upendra Singh, who farms 16 acres of land in Malihabad, in the northwestern state of Uttar Pradesh.

He is the fourth generation of mango farmers in his family, and started work on the farm when he was 12-years-old.

"Seasons no longer follow a pattern. Flowering, fruiting, and harvesting all shift every year because of climate change," says Singh, now 62.

"Input costs have gone up, pesticides, labour, irrigation. But yields have gone down. Farmers are spending more money but earning less from mango orchards," he adds.

Almost 700 varieties of mango are cultivated across India, with each region having its own dominant variety. So, in northern India the Dasheri is the most common, in Maharashta the Alphonso dominates, and in Bihar and West Bengal the Langra and Malda varieties are most frequently seen.

But few farmers escape the effects of climate change.

"With erratic weather patterns becoming the norm, mango farming is under pressure," says Dr Hari Shankar Singh, a scientist at the Central Institute for Subtropical Horticulture (ICAR).

"Mango is highly temperature-dependent," he explains.

"Last year, flowering happened early, strong winds affected fruit development, maturity came too fast, and much of the crop went waste.

"This year, prolonged low temperatures in north India delayed flowering altogether," Singh says.

To help make farmers more resilient, researchers are developing new varieties of mango which can tolerate wider temperature ranges and resist pests and disease.

But it's slow work. Mango trees take between five and ten years to flower after breeding.

In addition mango trees have another unhelpful biological quirk: they are heterozygous, meaning offspring rarely resemble their parents.

"Mango breeding is a multi-decade scientific commitment, not a quick innovation," says Hari Singh.

Genetic science is helping speed up that process. ICAR led a group of scientists who announced the sequencing of the mango genome in 2016.

Their work focused on the Alphonso mango.

"Mango genome sequencing allows researchers to identify genes linked to fruit colour, aroma, sweetness, flowering behaviour, climate resilience and disease tolerance," says Hari Singh.

That has "significantly" reduced the 10 to 20 years traditionally needed for mango breeding he says.

Farmers are ready to embrace innovation when it comes along.

On his farm, Upendra Singh has planted a new variety of mango, the coloured mango, in greater density than his old orchard.

"The biggest advantage of coloured varieties is they give fruit every year. Traditional varieties like Dasheri and Langda often have off years," Upendra Singh says.

Modern cultivation techniques also help.

"Scientific pruning, canopy management, and growth regulators are being used to control tree size, induce flowering, and manage early or uniform harvests," he says.

ICAR encourages farmers to use several techniques to improve their crops.

"Bagging" is a simple innovation, where each fruit is enclosed in a breathable protective cover in its early development.

"This method creates a controlled micro-environment around the fruit, reducing exposure to insect infestation, fungal pathogens, mechanical damage, and excessive solar radiation," says Dr T Damodaran, the Director of ICAR.

His organisation also recommends another technique, called "girdling". The involves making a narrow, controlled ring cut on selected branches. The resultant stress on the tree redirects the tree's energy towards flowering and fruit development.

Older orchards can also be rejuvenated, by cutting the trees down to between 14 and 18 feet in height.

"Once rejuvenated, flowering improves dramatically, fruit size increases, and most fruits become A-grade instead of B or C grade," says Hari Singh.

For Neeti Goel, mango farming started as a hobby. Ten years ago she planted a few trees out of curiosity.

Now she has more than 1,100 trees across 27 acres in Alibhaug, in the central state of Maharashtra.

"Instead of traditional trial-and-error farming, we use scientific mango cultivation," she says.

"We start every season with soil and leaf analysis. Without that, fertiliser application is guesswork, not farming. Micronutrients like boron and zinc play a decisive role in fruit, so ignoring them directly impacts yield."

Her next step could be to move the trees inside.

"We have stared building greenhouses so that the temperature can be controlled. If one does not adopt innovative methods we are doomed."

Saravanan Achari also believes that covering the trees is the way forward.

Achari is the founder of Berrydale Foods, which exports Indian mangoes to 13 countries.

Pests are one of is main concerns.

"Export markets demand zero tolerance on pests. Even if inspectors find a single fruit fly, the entire consignment is discarded, leading to huge losses," he says.

Climate change is making it more difficult to manage pests. Fruit flies appear after rainfall, but climate change is making that rainfall more unpredictable, so pests are appearing at different times of the year.

"Climate change has become the single biggest risk factor for mango exports today," says Achari.

So Achari is experimenting with greenhouses on Berrydale's farm.

"Countries like Japan and Israel are already using greenhouse and protected cultivation because they face similar climate challenges. Indian farmers will also have to move in this direction if we want consistent quality and reliable exports."