Will disease devastate spud production?
The ease of growing and storing potatoes allowed it to spread around the world and onto our cultural menu. The delicious spud, McDonald’s #1 selling items are their French fries (and Big Mac, together accounted for 75% of worldwide sales in 2007), reached European cuisine after Spanish Conquistadors brought potatoes back from Peru in 1536. Peru’s Inca tribes had cultivated potatoes for millennia growing roughly 4,000 varieties native to the region.
The spread of potatoes across the globe, make it an important food source. The FAO calculated it was the 4th most produced vegetable in 2013. It’s apparent this crop has become central to many diets. The issue of concern regarding potato production is the reliance on a very small set of genetics. While there are thousands of varieties around the world, cash crop potatoes are often grown in monoculture environments, limiting diversity and the ability to adapt. The Russet Burbank potato accounted for 40% of the fall 2016 planted acres in seven major potato producing US states.
History Vs. Economics
Monoculture is not all evil but it does limit the diversity and adaption of plants genetically and environmentally. We may be too dependent on monoculture potatoes. What makes us think this? If you remember learning about the Irish Potato Famine in the 19th century, fungal blight devastated the staple food and the economy. The nation was devastated due to the extreme dependence on the cheap monoculture crop of potatoes. Without resources of genetic variety (mostly only Irish Lumper grown at this time), Ireland was not able to escape the extremes of blight. According to Cornell’s Alliance for Science, “more than half the world’s potato crop is made up of one variety of potato”. Todays advanced sciences can help combat diseases and pests throughout the potato industry, yet, this isn’t to say that another Irish Potato Famine is not around the corner.
Even though we hope to not repeat history with the potato, the reality of monoculture isn’t going away, we cannot afford for that to happen. As potatoes have become an important part of many of diets as a result of getting a big bang of calories for a buck, high in nutrients low in cost. They are also versatile and let’s not forget DELICOUS! Monoculture is a product of modern agriculture and economies of scale. It’s hard to escape this form of production if you want to keep eating French fries at low costs and anytime of the day. By planting one crop on a large scale (monoculture), the large scale of production drives down costs, providing a homogeneous product, which brands rely on for quality. Every decision has pros and cons, right now monoculture in potatoes seems to be the lesser evil if it means quality, quantity and the availability to feed millions at a low price.
Viruses threatens our future, but could resistant potatoes save the day?
So how can this beloved crop be protected from a future crisis? If we maintain our daily demand of ~9 million lbs. of McDonald French fries, solutions such as disease and pest resistant potato varieties can help in prevent future devastation to potato production.
Rather than discuss the science behind genetically edited potatoes, let’s focus on why they have come to market. Of the numerous pathogens and pests that challenge potato producers, it’s the spread of Potato Virus Y (PVY) and Potato Leaf Roll Virus (PLRV) that has led to 15 GE potato crops approvals across the globe (as of November 2017). Both PVY and PLRV are viruses spread through human contact, shared machinery and animals. The aphid is the biggest culprit, contaminating healthy plants after contracting the disease from another infected potato plant. A number of sources have suggested that PLRV and PVY are the two most damaging virus currently in potato production and therefore managing these viruses is of the utmost importance to the industry.
The industry reduces the presence of the virus from infecting crops through certified seed, breeding resistant or tolerant crops, and the use of insecticides. However, it only takes one plant to become infected to spread the disease, and insecticide use does not ensure that the aphids will be eliminated before they transmit either PVY or PLRV. While the infection of a plant can vary from smaller tubers to extreme yield losses of 80%, they also present economic losses. Agricultural economist, Chris McIntosh, from the University of Idaho has estimated that PVY costs Idaho’s economy $34 million a year ($19.5 million in direct costs), a loss of 2.3 million cwt a year after shrinkage. To put this into context, in 2013, Idaho produced 131 million cwt (6.7 million tonne) of potatoes of the 435 million produced in the US that year, which was 30% of production. If we assume McIntosh’s PVY losses are the same across all of the US, PVY alone could impact the national economy by $113 million[1] to $3.4 million[2].
Economics and consumer demands have heavily influenced agriculture to rely on monoculture. To avoid the downfalls of monoculture, modern agriculture has turned to resistant varieties and a number of land management practices. The question now is whether our gluttony for delicious, quality, yet cheap foods such as the potato can resist the repetition of history? Let’s hope modern agriculture can guide production and technology to avoid the land mines of crop diseases which plagued the potatoes 200 years ago.
[1] At 2.3 million cwt losses from PVY, this accounts for 1.75% loss of Idoha’s 2013 131 million cwt of production. Assuming McIntosh’s calculation of $34 million for 2.3 million cwt in PVY losses, on a national scale this could cost: ($34 million ÷ 2.3 million cwt) × (2.3 million cwt ÷ 30% production) = $113 million US PVY cost for all production losses.
[2] In the case of 80% yield losses of the 435 million cwt produced across the US in 2013 (estimated to cost $4.2 billion), a loss of 348 million cwt could cost as much as $4,222 billion × 80% = $3,378 million.
