Explainer: What is grafting and how is it saving fruit trees?

Grafting is the process of fusing two or more plants together. It merges the rootstock of one plant with the scion (the young shoot or twig of a plant) of another, according to the University of Missouri. The plants usually need to be from the same genus. The procedure can fend off diseases, make a stronger plant and improve crop yield.

The ancient method of plant grafting inspired early skin grafting techniques for medical procedures.

"When [surgical grafts] were first written about outside of ancient India, they were referred to as the 'agriculture of the body' and 'the farming of men," cultural historian Paul Craddock told the BBC in a recent interview.

It’s a technique that’s been around for thousands of years, with grafting techniques likely having been used in China before 2000 BC, scientists say.

French wine growers used the process to stem a swathe of imported small insects called Phylloxera Vitifoliae infesting grapevines in the mid-1800s. They did this by merging local vines with bug-resistant North American roots, according to the Smithsonian.

The technique is being used to save various crops like the banana from disease. A recent upsurge in the prevalence of a fungal strain, Tropical Race 4, which has been dubbed by scientists as the “banana pandemic”, has threatened the world's most popular fruit.

“Bananas are undeniably among the most important fruits in the world and are a major staple food for millions of consumers,” Fernando García-Bastidas, a researcher in planthealth explained to the BBC. “We cannot underestimate the impact the current TR4 pandemic could have on food security.”

It had previously been believed that grafting didn’t work with monocot [single seed leaf] plants, but recent breakthroughs by scientists at the University of Cambridge have changed this viewpoint.

"At the moment, there's a disease that infects banana's roots and if we could graft disease-resistant roots onto bananas, that would be a potential solution," says Cambridge University’s Professor Julian Hibberd, head of his department's Molecular Physiology Group.

“We’ve achieved something that everyone said was impossible. Grafting embryonic tissue holds real potential across a range of grass-like species. We found that even distantly related species, separated by deep evolutionary time, are graft compatible,” he adds.

Grafting is also being used to resurrect endangered varieties of mango trees in India, the BBC report. Villagers in Kannapuram, in the Southern Indian state of Kerala, grew over 200 indigenous species of mangoes and used grafting to protect species that were in danger of dying out.

As a result, the village was named an “Indigenous Mango Heritage Area" by the Kerala State Biodiversity Board in 2020.

Elsewhere, Kaleem Ullah Khan, known informally as the ‘mango man’ succeeded in grafting 315 varieties of mango onto a single tree, according to the New York Times.

One university professor used grafting to create a single tree that can produce 40 different stone fruits, including peaches, apricots, plums, cherries and nectarines, according to CNN.

Many apple varieties we eat are cultivated hybrids, Insider explains. Braeburns, Galas, Pink Ladies, the Sweetangos, Honeycrisps, Fujis and other familiar edible apples are the result of grafted trees.