Q Can the USA ever run into the same issues with potato blight that Ireland did? I read that because Idaho only grows one variety, the Russet Burbank, that this could happen here. True or False?
A. False. On a couple of levels.
First, the most obvious misconception… Idaho does grow mostly the Russet Burbank variety; it is about 60% of our production. It is a real workhorse variety for fresh, frozen fries and dehydrated potatoes. However, Idaho grows over 30 different varieties on about 300,000 acres. By the way, potatoes are grown in nearly every state in the U.S.
Now, contrary to what was written recently by author Michael Pollan about single variety crops and how they could be completely wiped out with a disease, the Irish crop was not just one variety of potato subject to late blight. They actually grew several, with the Champion and the Black Skerry most prevalent.
In the relatively small country of Ireland, they once farmed 618,540 acres of potatoes (in 1904). The quantity produced was an essential part of the Irish diet; they ate about four to five times more potatoes per person than we do currently in the USA. Their menu was very limited, to about a half dozen crops, so the loss of most of the potato crop to disease was indeed devastating and caused a great migration to other countries including America.
A couple of issues caused the problem in Ireland. Poor crop rotation was one. This affects yield and can leave potato diseases in the ground to be an issue the next year. In Idaho we try to rotate potatoes with other crops to replenish the nutrients, as well as cut down on disease opportunities from volunteer potatoes that may not be killed by a winter frost.
Potato seeds… the typical Irish farmer relied on setting aside some of the crops potatoes for next years seed. If these had disease or other issues it did not go away by storing for next season. We use certified seed, which is inspected for potential problems and rejected, rather than perpetuating an issue.
Not storing good potatoes in a different area than diseased potatoes caused the problem to spread… every heard the quote one bad apple will spoil the rest?
Late blight was discovered in 1842 as phytophthora infestations in Germany and then shortly thereafter in Canada and the United States, and then in 1845 on the Isle of Wight and England. By 1846, according to the book The Potato, published in 1912 by EH Grubb and WS Guilford: “Famine in Ireland followed” till 1850. The authors also felt that “the efficacy of a sulfphate of copper and lime under the name Bordeaux mixture combated the disease”. While we may never know all the exact details of the Irish potato disease and its spread, it is safe to say that we are so much further advanced at detecting issues with potatoes nowadays and can address them so much quicker.