Plant Health Week – day 5

Humble spuds have a very interesting history. Originating in South America, the earliest finds date from about 2500 BCE. It subsequently became a staple food for indigenous people in Andes region, the main energy source for those living in the Inca Empire. It arrived in Europe as early as mid-16th century but the acceptance as the food was initially low. It took the efforts of the French and German governments and landowners in the second half of the 18th century for the potato to become a staple crop in northern Europe. Perhaps the famines of 1770s helped as well. The crop was resistant to spoilage, easy for cultivation even on small fields and gardens, and a good source of calories and some vitamins and minerals. It appears to have arrived in the US via Ireland. Today, potatoes are grown across the globe, but with the highest concentration in Europe, India, China and the US.

Frederick the Great encouraging potato planting. By Robert Müller – www.dhm.de, Public Domain, https://commons.wikimedia.org/w/index.php?curid=3754769

King of Prussia, Frederick the Great, is sometimes called der Kartoffelkönig – potato king – as he was instrumental in introducing the crop into Prussia and Eastern Europe. By 1840s, potatoes accounted for 11% of Prussian and 14% of Belgian arable land, but it was Ireland that adopted the plant as the main source of food (32% of arable land). A whole Irish (or British, or German, or Polish) family could survive by growing potatoes on a single acre of land. It could also be grown in city gardens, supplementing the diet of Industrial Revolution workers.

Symptom of late blight on the underside of a potato leaf
Phytophthora infestans symptoms. By Howard F. Schwartz, Colorado State University, United States – http://www.forestryimages.org/browse/detail.cfm?imgnum=5362902, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=7933322

The rapid growth of potato cultivation was not, however, associated with good biosecurity practices. The American and European crops were dominated by a single variety (called Lumper; it was not resistant to blight but with a high yield), so it was a disaster in waiting. Indeed, in the early 1800s, potato blight (Phytophthora infestans) started spreading in Central and North America and it arrived in Europe in 1840s.

The map of approximate potato blight spread in 1845.Source unknown.

Starting in northern France and Belgium in June 1845, it rapidly spread throughout Europe, reaching Ireland in September-October. A catastrophic failure in the crop that supported the Irish combined with the failure to help the starving population led to a million deaths and possibly two million leaving the country.

Population of Ireland. Source unknown.

Scotland, and particularly Scottish Highlands, were affected as well leading to migration. US and Canadian people celebrate their Irish and Scottish ancestry, perhaps not realising that their origins are due to a plant pathogen.

However, it was not only the populations of Ireland and Scotland who were affected, as the famine spread throughout Europe resulting in losses as high as 80% in Belgium and 50% in Denmark and parts of German Empire. As other crops (wheat, rye, oats) also failed in 1845 and 1846, there was a general shortage of food. Food prices were rising and the demand for goods produced in newly industrialising nations fell. Unemployment led to general dissatisfaction with the governments. The Spring of Nations, the Revolutions of 1848 followed suit.

Philippoteaux - Lamartine in front of the Town Hall of Paris rejects the red flag.jpg
By Henri Félix Emmanuel Philippoteaux, Public Domain, https://commons.wikimedia.org/w/index.php?curid=260827

While it is perhaps a stretch of the imagination to say that the 1848 revolutions were the result of the potato famine, the loss of food security – caused by Phytophthora infestans – certainly contributed to people’s dissatisfaction with the governments.

The potato blight is still a huge problem, even though we now have ways to treat it. Some pesticides are based on copper. Because of the shortages of the metal during World War 1 (used to produce shells and wires), a major outbreak devastated potato crop in Germany, leading to mass starvation. Using resistant varieties is one way to battle it, as is using good quality seed potatoes (Scottish ones are best in the world!).

Visit The Grave Of Frederick The Great - Berlin Experiences
Frederick the Great’s grave. https://berlinexperiences.com

And, people still remember the Prussian King, Frederick the Great and his contribution to potato cultivation by placing tubers on his grave (thanks to Agnieszka for this link!).

[The previous version associated the 1848 Revolution with Les Miserables, but of course the events in Victor Hugo’s book are the 1832 uprising, not the 1848 revolution; apologies for the mix-up! In fact, the 1832 uprising was also associated with harvest failures and cholera outbreaks – epidemics are everywhere!]