The Crestone Eagle, April 2009:
story & photos by Nicholas Chambers
Hailing from the South American alpine and grown for over forty centuries, the potato has been the staple of the peasant and aristocrat alike. Today, it remains the world’s fourth largest food crop. Boasting a history of wide variation and selection, its Andean homeland has given rise to over 5000 varieties alone. Ironically, the means of this controlled variation is also the Achilles tendon of global potato agriculture.
Since the potato is propagated through planting the same tissue over and over (through seed potatoes), it is susceptible to more diseases than any other major crop. There is no break in the potato tissue lineage as there is in a true seed cycle that goes through a dormancy. As such, dependence on the stalwart potato has given rise to a widespread epidemic, as well as the development of modern practices to keep potatoes diverse and free of disease.
An Gorta Mor—“The Great Hunger”
One story says that the potato found its way to Europe after contact when a Spanish Armada shipwrecked off the coast of Ireland and lost its New World cargo to be washed up on shore. It soon became a mainstay of a Gaelic agrarian population who at once realized the potato’s excellent economy in nutrients and productivity. One acre could feed up to 10 people, which contributed to a huge population boom in the early 1800s.
Under an era of British imperial feudalism: “the pig was to pay the rent, the potato fed the family.” Three hundred years of planting the same potato stock, called the lumper, predisposed not just Ireland but all of northern Europe to a massive blight beginning about 1845. One million Irish people died and another million and a half emigrated to America or Australia, causing one of the world’s greatest exoduses, and inadvertently infusing these countries with Irish culture.
How could such a world-changing migration occur from reliance on a particular food crop? The answer is more political than biological. For one, during these years enough potatoes to feed the entire Irish population were still being exported from Ireland under British trade. The potato blight was all over Europe. Other countries were able to deal with it because they had more autonomy and self-determination.
The other relevant factor was that potato plants do not inherit their parents’ traits through the typical flower-pollination-fruit-seed cycle. Thus, to select this variety over that variety throughout history, people have planted an “eye” of the mother—essentially cloning successive generations of the same plant. This has worked out nicely with being a staple in a household, as what was too small or surplus, you could plant the next spring, much like grain. Thus, when the potato crop is from the same plant tissue year after year, diseases can spread rapidly and extensively.
Here in the San Luis Valley we have more than a 100 years of potato growing history and today average about 57,000 acres under cultivation. Our unique, isolated, cool-night, alpine desert valley echoes the conditions of the high Andes where the potato first went under the yoke of domestication. Modern SLV potato farmers successfully grow many different varieties of healthy potatoes without crossing genetics and without predisposing their seed stock to disease through plant tissue propagation, also called in vitro propagation or phytoculture.
Plant tissue propagation
Nitschka terKuile is a Dutch American who runs an organic family farm near La Jara. Born in Costa Rica, she has been the operations manager for the potato lab and greenhouse at Summit Farms near Center since 1991. With a background in wheat and maize improvement projects in Mexico, and degrees in general agriculture and greenhouse management from Colorado State University, she probably knows this process better than anyone in the valley. “They tried to hire some PhDs to do the job, but they only lasted a few years!”
Plant tissue propagation is a common form of commercial breeding for crops like blueberries, cranberries, sweet potatoes, orchids, and strawberries. It is essentially a disease-free way to quickly and economically produce abundant healthy daughter plants in a small space. Nitschka and her staff start the process two years in advance of the field planting.
First, they must acquire a few certified disease-free plants from the cooperative extension or similar, and bring them to their sterile propagation lab. From the mother plant, they cut pieces with each having a meristem, or lateral growth bud. These pieces are then transferred to a nutrient growing medium and put under lights where the meristem sprouts a new root system and thus a new plant. Now one plantlet has become three. They again take these new plantlets and cut them into pieces with a meristem, and the three now becomes nine. In this very sterile and controlled way (with air filters, breathing masks, disinfectant boot mats, flaming workspaces, etc.), they keep propagating until they have enough plantlets to fill their greenhouse.
Once planted indoors, the plants are allowed to fulfill a full growth cycle (even through the winter with lights) that produces enough disease-free “nuc” seed potatoes to fill their fields with plants that will produce a first generation crop. After the first year in the field, they harvest the very valuable generation 1 seed potatoes, which will then be used the next year for on-farm seed or for sale as seed.
The farmer can go on planting these field grown seed potatoes until generation 5 or 6 when they must then go back to a nuc seed or risk disease. This process is done both by organic and non-organic farmers, as it is a way to keep potato stocks healthy whatever their field growing practices might be. Home growers might not be so concerned by disease, but “the worst thing home gardeners can do is to plant potatoes that come from a store,” says Nitschka. “These potatoes can be 6 or more generations old, coming from regions that have diseases we don’t, and our soils can be easily contaminated. While these store bought potatoes might look okay, their diseases will show up after a season and will remain there for a long time. It is important for people to realize how big a part of the Valley’s economy is in potatoes.”
Next time you get a chance to have a Bliss Triumph, Colorado Rose, or Inca Gold, consider the history that potatoes have gone through and the delicate care that is now employed to keep this major staple healthy and productive.
To buy good disease-free seed potatoes that can be saved for successive generations, try Ronnigers Potato Farm or our Valley’s own White Mountain Farm in Mosca.