By Meara Hayden,
Penn State Extension Intern
Storage potatoes
are one of the few veggies you picked up from your local CSA that are still
around in the winter, and will continue to last until spring. They are a staple
of our diets, and can be found growing in huge monoculture farms in Idaho, or
small CSA style organic farms here in Pennsylvania. It is one of the most
widely grown and consumed crops in the world. But how did this starchy tuber
become something we expect from our local markets, and readily consume at our
dinner tables?
Most people,
when asked about the origin of the potato, will reference Ireland. The Irish
seem to have a monopoly on the image of the potato. But the tuber didn’t come
from Ireland, or anywhere in Europe at all, and the Europeans unwise handling
of it is what lead to the great potato famine, and the beginning of the
pesticide industry we know today.
The
potato is found naturally growing in the Andes, and most wild varieties are
poisonous, especially in their raw form. Wild vicunas (wild relatives of the
llama) will lick clay before consuming any part of the potato plant, because
the clay sticks to the harmful substances and passes safely through the
animal’s system. The native people of the Andes (Including the beginnings of
what would be known as the Aztec civilization) emulated this behavior, and ate
potatoes with clay powder. Over time, they selectively bred certain varieties
to be completely safe to eat. In addition to eating them mashed, boiled, and
baked, these ancient people would leave sliced potatoes out to freeze overnight,
then dry during the day. The continuing freezing and thawing process produced
long lasting, if bland, food that sustained the Aztec armies.
The
Aztec people grew a huge variety of potato plants, with every village having
ten or twelve diverse varieties. And a village relatively near, but at a
different altitude, would grow another ten to twelve varieties completely
different from the first village. When the people of the Andes planted their
potatoes, they would use the seeds that came off the top of the plant. This
ensured that their potatoes remained diverse and resistant to disease.
When
the Europeans came to South America and brought the potato back for planting,
they replanted using a “seed potato.” They would just take a potato from a mature
plant, and put it back in the ground, growing a new plant. This method creates
a plant that is genetically identical to its mother plant. When the potato
eventually caught on in Europe, their entire fields were a monoculture. This
made the new crop especially susceptible to disease, because the bacteria would
not have to adapt to hop from plant to plant at all. This problem was not
apparent until Europe, and especially Ireland, had a complete dependence on the
potato for food. By the late 1790’s, about 40 percent of the Irish ate potatoes
as their only solid food. In potato country, a 2,000 mile band in northern
Europe where potatoes thrive, famine had almost disappeared.
It
was at this time that disaster struck the farmers of northern Europe and America,
where the potato had been brought as a staple. They were using guano, imported
from South America, for fertilizer. The guano brought disease with it.
Phytophthora infestans, a type of water mold, is what caused the great potato
famine. By the time the symptoms appear as purple to brown spots on the leaves,
it is too late to save the plant. The first blight struck in 1845, and did not
cease until 1852, after it had wiped out more than a million Irish.
But
the first potato blight was not as industrially important as the second, which
came in the form of the colorado potato beetle. These black and orange bugs
frustrated American farmers beginning in about 1860. Nothing seemed to kill
them. One desperate farmer threw some leftover green paint on his plants. This
worked. The bright green pigment was paris green, which is made mostly of
copper and arsenic. Farmers began mixing it with water or dusting it as a dry
powder.
The use of paris
green in agriculture interested chemists. Are there other chemicals that could
solve agricultural problems? In the 1880’s a french chemist discovered a
solution of copper sulfate and lime would destroy Phytophthora infestans. If farmers sprayed this solution along with
paris green, they would be rid of both the blight and the beetle. Potatoes
marked the beginning of the modern pesticide industry.
Late blight and the Colorado potato beetle are still challenges for growers today, but over the years growers have learned how to manage them by growing resistant varieties and carefully monitoring pests. Today, the United States produces more than 4.2 billion pounds of potatoes annually on around 1.1 million acres!
Support your local
potato farmer!
Resources:
Check this out if you’re looking to plant potatoes in your
garden in the spring!
