ShareSaveAdd as preferred on GooglePriti GuptaTechnology Reporter, MumbaiIIHR BangaloreCustard fruit trees can survive months without wateringAshoka Shivareddy comes from a family of farmers, but it was hard to make a living in their drought-prone district of Kolar in southern India.
"The area receives rainfall of only 60 to 70 centimetres, and farmers dig borewells of up to 1,300 feet - most of their money goes into chasing water," he says.
Amid mounting losses the family gave up farming and in 2005 moved to the city - to Bengaluru - and started a vegetable shop.
Shivareddy became an AI software engineer, but he never lost the farming bug.
In 2018 he decided to revive the family farm, but with a more scientific approach.
"I was looking for a crop that could survive with very little water, grow with rainfall, and not depend heavily on pesticides," he explains.
Custard apple seemed to be a good fit. A knobbly fruit the size of a large avocado, its creamy, sweet flesh tastes a bit like custard - hence the name.
Custard apple trees grow wild in Shivareddy's area and locals would harvest the fruit and sell it at the market. That seemed promising to Shivareddy.
Looking to maximise his yield, he planted trees closer together than on typical farms.
Shivareddy also carefully selected three varieties, each with different benefits. The approach appears to be working.
"Last year I produced around 20 tonnes. This year, it's about 25 tonnes. There is huge demand for custard apple in India and abroad," he says.
While custard apples can survive in dry conditions, there are challenges to growing them.
The traditional variety Balangar has a very short shelf life, sometimes as little as a three or four days, which limits the farmer's selling options. It also has a lot of seeds, making it less attractive to the customer.
"Traditional varieties have excellent flavour, but they suffer from low pulp content, high seed count, and a very poor shelf life," says Dr Sakthivel T, principal scientist at Indian Institute of Horticulture Research (IIHR) in Bangalore.
His team developed a hybrid fruit, named Arka Sahan, which can survive for a week at room temperature and has fewer seeds and more pulp.
Over the past 20 years this variety has spread across southern India.
"The shift from 30% pulp recovery in wild varieties to 70% recovery in hybrids like Arka Sahan has effectively doubled the usable harvest for farmers without needing more land," Sakthivel says.
His team is now looking at better ways to process the fruit and extract the pulp, so it can be more widely used in processed foods like ice cream and milkshakes.
One problem they are currently trying to fix is that custard apple pulp turns brown very quickly after extraction. Researchers at IIHR are experimenting with new equipment and techniques that will help custard apple pulp maintain its milky colour for longer.
The central Indian state of Maharashtra is the leading producer of custard apples, accounting for almost a third of the national output.
It's where Navnath Malhari Kaspate has been farming the fruit for decades.
He travelled across India collecting seeds and brought them back to his farm where he cross-pollinated them.
"No one had really paid attention to custard apple or done research, so I decided to keep working on it. It takes 12 to 15 years to develop a new variety. This is not quick work - it's decades of experimentation," he says.
His work resulted in the NMK-01 (named after his initials) variety, known for being high yielding. It went on sale in 2014.
"We now grow custard apple on nearly 50 acres, with yields of about 10 tonnes per acre. This improved variety which does not get spoiled has created opportunity for exports. We started exporting to Gulf countries, and even sent it to Europe, something that hadn't been done before at this scale," he says.
Kaspate's development work continues, he's currently working on a variety with an improved appearance and greater resistance to disease.
Manoj Kumar Barai exports the NMK-01 variety to the US, UAE, Saudi Arabia and Europe.
"For exports we prefer the NMK-01 variety because it has better shelf life, thicker skin, more pulp, and a sweeter taste compared to others," he says.
Nevertheless, exporting such a delicate fruit requires an intricate process.
"We have to plan everything precisely - harvesting time, transport to pack houses, airport transfer, flights, customs clearance - every hour matters."
"Custard apple is highly sensitive to heat, and even short exposure can reduce its shelf life," he says.
Road journeys are often done overnight to avoid the worst of the heat.
"In regions like Maharashtra, temperatures can go up to 40 degrees, and even during transit it can reach 30–35 degrees, which is not ideal for this fruit."
The fruit is pre-cooled for five hours before being packed and transported in refrigerated vans and then stored in cold rooms before being air freighted.
Special corrugated boxes have been developed to protect the fruit and help keep them cool.
More fruit is being exported as pulp or in a powder form, which is a "revolution" for the export industry says Barai.
Pulp is used by overseas ice cream makers, bakeries and at "pulp-shot" cafes.
It's still not simple, as the pulp has to be stored and transported at -18C.
But it's still cheaper than air freight and allows large volumes to be transported over weeks without any fruit going to waste.
Back in Kolar, Shivareddy wants to expand his business by selling pulp as well as whole apples.
He plans to set up a pulp processing unit that would use the portion of his crop that he can't sell.
But extracting the pulp and chilling it to -20C involves significant investment in equipment which, he says, will involve a change in mindset for many farmers.
"Custard apple sits in a strange gap. Demand is rising, but the farming hasn't gone high-tech as the crop is naturally hardy. It grows in poor soil, needs very little water, and survives on rainfall. Farmers don't need expensive irrigation, sensors, or controlled environments so tech adoption stays low," he says.
