The next time you eat a baked spud you might want to think of the agricultural scientists who are hard at work trying to help the humble potato deal successfully with some significant diseases.

Students of history will remember the Irish potato famine of 1845-1852. The denizens of Ireland had come to depend on potatoes as their main staple crop. The plant did well in the wet Irish climate, and the potato produced a lot of food for each acre that was planted. But a crisis arose when whole potato fields fell victim to the blight, a disease that wiped out any hope of harvest all over the island.

In the end, more than a million people died and another million had to leave Ireland as the blight held sway. Perhaps never has a single disease of plants produced such misery in a concentrated period of time. 

Fighting corky ringspot

But there’s more to potato disease than blight, and therein hangs an interesting and much more modern tale.

Potatoes are important to us for reasons that go beyond the lip-smacking taste of a French fry. The tubers are a source of carbs, and they also are rich in potassium, iron and Vitamin C. They contain protein, and when baked or boiled, potatoes harbor no fat.

But potato plants face some significant challenges out in the field where they grow. One of them is a disease with the slightly comical name of "corky ringspot.” The name sounds a bit like a child’s game, but CRS, as it is sometimes known, is a serious threat to potatoes and the farmers who grow them. It leads to mars and marks in the tubers, including dark arcs about the size of a fingernail you may have seen in potatoes when you peeled them. Other abnormalities are granular regions, the type of flaw that gave the name "corky” to the disease.

CRS is caused by a virus that sickens the potato plant. Just as you can become sick from a viral infection like influenza, so can a plant – in fact, one of the main thing certain agricultural scientists do is try to help plants resist viruses. The virus that causes CRS appears to infect the plant by way of a microscopic worm in the soil called a nematode. In other words, the nematode’s actions around the roots and tubers of the plant make it possible for the virus to infect the unlucky potato plant. Dark mars and corky areas in the tuber then develop.