<P> In the Altiplano, potatoes provided the principal energy source for the Inca Empire, its predecessors, and its Spanish successor . In Bolivia and Peru above 10,000 feet altitude, tubers exposed to the cold night air turned into chuño; when kept in permanently frozen underground storehouses, chuño can be stored for years with no loss of nutritional value . The Spanish fed chuño to the silver miners who produced vast wealth in the 16th century for the Spanish government . </P> <P> Potato was the staple food of most Pre ‐ Columbian Mapuches, "specially in the southern and coastal (Mapuche) territories where maize did not reach maturity". </P> <P> Sailors returning from the Andes to Spain with silver presumably brought maize and potatoes for their own food on the trip . Historians speculate that leftover tubers (and maize) were carried ashore and planted: "We think that the potato arrived some years before the end of the 16th century, by two different ports of entry: the first, logically, in Spain around 1570, and the second via the British Isles between 1588 and 1593...we find traces of the transport of potatoes travelling from the Canaries to Antwerp in 1567...we can say that the potato was introduced there (the Canary islands) from South America around 1562...the first written mention of the potato (is)... a receipt for delivery dated 28 November 1567 between Las Palmas in the Grand Canaries and Antwerp ." In 1553, in the book Crónica del Peru, Pedro Cieza de León mentions he saw it in Quito, Popayán and Pasto in 1538 . Basque fishermen from Spain used potatoes as ships' stores for their voyages across the Atlantic in the 16th century, and introduced the tuber to western Ireland, where they landed to dry their cod . The English privateer Sir Francis Drake, returning from his circumnavigation, or Sir Walter Raleigh's employee Thomas Harriot are commonly credited with introducing potatoes into England . In 1588, botanist Carolus Clusius made a painting of what he called "Papas Peruanorum" from a specimen in the Low Countries; in 1601 he reported that potatoes were in common use in northern Italy for animal fodder and for human consumption . </P> <P> The Spanish had an empire across Europe, and brought potatoes for their armies . Peasants along the way adopted the crop, which was less often pillaged by marauding armies than above - ground stores of grain . Across most of Northern Europe, where open fields prevailed, potatoes were strictly confined to small garden plots because field agriculture was strictly governed by custom that prescribed seasonal rhythms for plowing, sowing, harvesting and grazing animals on fallow and stubble . This meant that potatoes were barred from large - scale cultivation because the rules allowed only grain to be planted in the open fields . In France and Germany government officials and noble landowners promoted the rapid conversion of fallow land into potato fields after 1750 . The potato thus became an important staple crop in northern Europe . Famines in the early 1770s contributed to its acceptance, as did government policies in several European countries and climate change during the Little Ice Age, when traditional crops in this region did not produce as reliably as before . At times and places when and where most other crops failed, potatoes could still typically be relied upon to contribute adequately to food supplies during colder years . </P>

When was the potato first introduced to ireland