A genetically modified variety of spud may have to be produced in Irish laboratories because of the growing threat from blight.

The fungal disease that wiped out the potato crop in the mid-19th century, causing more than 1m deaths, is posing a renewed menace after a more aggressive strain arrived, according to a leading scientist. This has prompted experts to intensify work, including using GM technology, to find a blight-resistant variety.

Dr Ewen Mullins, a research officer with Teagasc, the agriculture and food development authority, said the risk of blight has become more serious in the past two years.

He said: “It’s primarily our geographic location. We have humid, damp summers and the past two years have seen outbreaks of blight, probably the worst on record.

“That’s a significant challenge to the industry. Our research shows a new strain has come in. It migrated westward across Europe probably in the past 12 to 18 months. It was in the UK about two years ago and in the eastern counties of Ireland in 2008. It’s a highly aggressive strain.”

Currently, potato farmers have to spray their crops up to 12 times a year. But Mullins and his colleagues at Teagasc’s research facility in Oak Park, Co Carlow, hope to create a variety that will only need to be sprayed four times a year.

The decreased use of pesticides would in turn mean less damage to the environment.

Mullins said farmers relying on normal potato crops would also be affected by new EU regulations aimed at reducing use of pesticides and fungicides. “If we were to reduce chemicals by up to 40% on our potato crop, that would challenge potato growers,” he said. “We [think] GM is worth investigating from that point of view.

“GM seed costs more and it comes down to choice. Farmers will decide if they want to pay or not. It costs more because a tremendous amount of research has gone into it.”

The genetically modified lines developed by Teagasc cannot be sold by law and are not for commercial use. “We are developing them for research, to investigate the potential of the technology,” said Mullins in an interview with RTE’s Ear to the Ground programme, to be broadcast on Thursday.

“The GM debate has gone on 15 years, but I think because of the new challenges we’re facing it’s something we’re more aware of. You have 21 countries growing GM crops; 240m acres of it. It is timely to have the debate.”

Because of public concern over the risk associated with their co-existence alongside non-GM crops, Teagasc is investigating the environmental impact of a number of GM crops and whether they could provide an economic benefit to farmers via reduced chemical costs.

Researchers are examining clover and herbicide-tolerant oilseed rape. Teagasc has already created the Rooster, which was introduced to the potato market in 1991 and now has a share of more than 50%. Newer varieties bred in Oak Park, including Romeo, Setanta and Orla, are more disease resistant.

The research into potato blight is being done in association with Queen’s University in Belfast. The blight organism, Phytophtora infestans, is spread as spores by the wind. These spores land on leaves, creating new infections.

The new strain that arrived in Ireland last year reproduces sexually and creates oospores which can survive in the soil up to four years. Scientists fear that they could infect a crop before it even emerges above ground. Sexually produced spores may be stronger and more resistant to fungicides.

Potato varieties grown during the famine were particularly susceptible to blight and many people depended on one type — lumpur. More than 2.5m acres were given over to potatoes then, compared with almost 30,000 acres now.

Irish people on average consume about 107kg of spuds a year, more than most western Europeans but not as many as the average person in Britain.

With world food prices soaring, experts think increased consumption of spuds could be the answer to shortages because they are easy to grow, quick to mature, require little water and have much higher yields than wheat or rice.

But there is still much hostility in Ireland to GM crops. In 1998, campaigners sabotaged a GM sugar-beet crop in Co Wexford, part of a trial by Monsanto, an American company. Others attacked a GM trial plot at Oak Park.

Last year another chemical firm, BASF, abandoned plans to grow GM potatoes in Ireland, moving its research operations to Britain. The company had been given approval for field trials in Co Meath.

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