Bengal and its neighbouring states locked in a potato dispute stemming from scarcity of stocks may take heart in a US project that could eventually make the staple that features in every Indian dish imaginable more accessible and less vulnerable to frequent price fluctuations.

Scientists have genetically engineered the potato to make it grow well even in searing hot weather, a key step towards enabling access to the world’s fourth most produced crop under global warming.

In field trials, the genetically modified potato equipped with two newly inserted genes showed up to a 30 per cent increase in tuber mass even under heat wave conditions, US researchers said in a study published on Wednesday.

“The 30 per cent increase in tuber mass shows promise to improve photosynthesis to enable climate-ready crops,” Katherine Meacham-Hensold, a scientist at the University of Illinois, Urbana-Champaign and lead researcher in the study, said in a media release.

The potato, grown on every continent, is the world’s most important non-grain crop and the fourth most produced crop after maize, rice and wheat. Potatoes grow best between 15°C and 20°C and higher temperatures can adversely impact growth. A 2015 study in Poland after two years of observations had found that heat and drought stress can reduce yields by up to 35 per cent.

Crop researchers say yield losses could lead to supply disruptions which might rapidly impact markets, as recent events in eastern India indicate. On Thursday, the Bengal government reaffirmed that the ban on the transport of potatoes to other states would continue, citing a limited stock of the produce.

While Odisha has accused Bengal of creating an artificial potato crisis, Jharkhand has got in touch with the Bengal administration and got an assurance that a committee would be formed to resolve the issue. The price of potato has gone up sharply in both states after Bengal stopped the inter-state transport of the crop citing stock constraints and a price surge.

Meacham-Hensold and her colleagues have tried to address the challenge from hot weather by tweaking the potato genome. They have added two genes for enzymes that can improve the efficiency of photosynthesis — the process through which plants make energy from sunlight. The altered genome helps remove a toxic byproduct that builds up in hot weather and reduces the yield.

In the trials in the US, the genetically modified potatoes grew 30 per cent more tuber mass during a heat wave marked by temperatures above 35°C for four consecutive days with peak temperatures above 38°C.

“These yield increases had no impact on the nutritional quality of the potato,” Don Ort, professor of plant biology and crop sciences at the university, said in the media release issued by the university.

The researchers say field trials would need to be conducted in multiple locations to validate the observations made in the US. The strategy may help “future-proof” potatoes and other root storage crops against extreme heat waves expected to occur more frequently under global warming, the scientists said, reporting the results of their field trials in the research journal Global Change Biology.

Scientists in multiple countries, including India, have been working on genetic engineering strategies to develop crops resistant to heat, among other stresses. But the commercial release of genetically modified edible crops in India has faced intense opposition from environmental activists.

India’s apex regulatory panel had approved a genetically modified version of brinjal in 2009 and a genetically modified version of mustard in 2022. But the government has not allowed their release for commercial cultivation.