The Irish Potato Famine 1845 – 1852
No other European nation has a more special relationship with the potato than Ireland. The Irish were the first Europeans to accept it as a field crop in the 17th century, and the first to embrace it as a staple food in the 18th century. The potato emerged strongly in Ireland because it suited the soil, climate and living conditions remarkably well.
The potato was seen as a safeguard against the tandem social plagues of unemployment, poverty, overpopulation and land hunger. By 1780, at a population level of four million, those afflictions had helped push the potato to dominance. In 1830, young adult males in Ireland were consuming 5 kgs per capita per day. By 1841, four years before the Famine, the population had literally doubled to 8.15 million – a phenomenal increase by any standard.
The only problem with potatoes is their susceptibility to disease, the worst of which, Phytophtora infestans, is known more commonly as blight. Before 1842, potato blight was only known in Mexico, where it began in the Toluca Valley on the central plateau. That year, however, it turned up in New Hampshire and Vermont and three years later it appeared in Belgium.
By Mid-August 1845, it had spread to northern France and southern England; it arrived in Ireland in September, with demographic consequences which have shaped our history ever since. Irish dependence on a single crop for sustenance was devastating.
Once established, the spread of the disease is highly weather dependent. It has been found that the ideal conditions for the spread of the disease are a relative humidity greater than about 90 per cent, and temperature in excess of about 10c, both occurring simultaneously over an extended period. Nowadays, potato blight can be controlled – but it has not, as some city-dwellers might suspect, become extinct.
The events of 1845-52 which ensued in Ireland became known as the Great Famine and constituted a cataclysm unequalled in Irish history. With more than a million dead from starvation and disease, and more than a million in exodus from Ireland to Britain, North America and Australia, today Ireland remains one of the few European nations whose population is smaller than it was during the nineteenth century. One to one and a half million people left Ireland between 1845 and 1851 and as many as a further two million in the subsequent twenty years.