The Importance of Crop Diversity

Modern crop and livestock varieties are often bred for their yield, disease resistance, uniformity, and ability to withstand shipment. Our large-scale food system needs a productive, pest-resistant, shippable crop to feed a huge and widespread population. I don’t think there’s anything inherently wrong with seeking out these traits and I can understand their importance. However, I think we run into problems when our desire for uniformity and durability forces us to compromise diversity and nutrition.

Let me share a story from the Florida tomato industry to explain myself. As surprising and seemingly random as it is, Florida indeed produces 40-45% of this country’s tomatoes. In 2005, the Procacci Brothers Sales Corporation crossed a French heirloom tomato with a more conventional, disease-resistant Florida tomato. The resulting variety was flavorful and hardy but ugly and wrinkled compared to the industry standard: a smooth, round (and flavorless) tomato. Leader of the company Joe Procacci named his new tomato the UglyRipe and its sales grew steadily once it hit the market. People really liked UglyRipes and were willing to pay a premium for their superior vine-ripened flavor. (The majority of other conventionally grown tomatoes are picked green and ripened with ethylene gas.) Indeed the tomato’s sales began to compete with those of the traditional varieties (Florida rounds, as they are called) grown by the majority of other farmers in the state.

Procacci’s UglyRipe tomato in all of its ugly glory (from Tomato Casual)

Enter the Florida Tomato Committee whose members are made up of Procacci’s competitors, other Florida tomato growers. This committee decides the exact standard of size and shape (down to the millimeter) that any tomato leaving the state must meet. Even though UglyRipes were permitted to sell for a few years as an “experimental crop,” the tomatoes didn’t meet the committee standard and were no longer allowed to be sold. Joe Procacci was forced to throw away 700 acres worth of UglyRipes and lost $3 million. Luckily, with much fighting, Procacci won exemption from the standards. But as you can see, there is something seriously wrong with a food system in which standardization and the norm can beat out a product which is better for the consumers. The idea of growing a few select varieties and excluding others for the mere sake of uniformity is clearly flawed. But the system of regulations that has grown around this idea ––the system in which the Florida Tomato Committee exists–– is even more flawed.

Yes, those are unripe tomatoes and not Granny Smith apples (from the LA Times).

As you can see, US farmers grow only the tiniest fraction of available crop varieties on a large scale. Rural Advancement Foundation International (RAFI) estimates that 97% of the cultivars grown in 1903 are now extinct, largely because of our tendency to seek out and breed those few one-crop-fits-all varieties and forget about the others. As scientist and founder of RAFI Cary Fowler puts it, we can see the thousands of crop varieties as a “genetic resource” for future generations. It is important to preserve these varieties even if they aren’t uniform or don’t seem to be of use at this point. Though one crop variety may seem to work well for a number of solid scientific reasons (like common GE corn variety 34B98 and its outstanding yields), we never know what valuable traits other varieties could offer.

In the future, these varieties may add resiliency to our food system if a new pest appears and a long-existent variety proves to be resistant to it. With this in mind, critics of monoculture argue that growing a single crop over large areas increases vulnerability to factors such as disease and changing climate. The Irish potato famine is an interesting case study to examine when considering this criticism. In the 1840s, most poor Irish farmers were growing only a few potato varieties and were very dependent on them as a source of nutrition and livestock feed. For these reasons, a new disease called late blight was able to decimate their crop and threaten their livelihood. Across the world in Peru, where potato cultivation likely began and 2,800 potato varieties still exist, many late blight resistant cultivars have been found. Though the causes and results of the Irish famine are of course diverse and complex, maybe the famine wouldn’t have been so extreme if farmers were growing several potato varieties and some were resistant to late blight. Also, it would have helped to grow a wider range of crops and therefore have more diverse sources of nutrition.

In a way, our current dependence on corn as livestock feed mirrors the Irish dependence on potatoes pre-famine: corn accounts for 95% of the grains we grow for livestock feed and a few genetically-modified varieties currently dominate our fields. So are our rows of corn plants sitting ducks for any new disease? Not at all. In many important ways, our current agricultural system is completely different from that of 19th century Ireland. Modern agricultural knowledge, techniques, and technology (e.g. pesticides and fertilizers) separate us from an agricultural disaster of that kind. As we now know, any pesticides (even organic ones that were around at the time of the Irish famine) can kill late blight and therefore could’ve helped prevent the disaster.

As a 2009 study of Peruvian farmers shows, the adoption of a disease-resistant potato variety can increase yields, as well as reduce the use of pesticides and therefore their cost to farmers and the environment. Clearly, the use and preservation of diverse crop varieties could build resilience in our food system and help us decrease the use of chemical inputs. However, our current crop varieties and approach to farming make for a food system that is in no way “vulnerable,” despite their lack of diversity.

Monocultures are ubiquitous now as our food system has moved away from subsistence farming toward commodity crops. These large monocultures can be pollutive and in my opinion unsustainable. I think that diversifying crops and varieties could help to do the same job as modern chemical inputs and reduce their use while preserving this important “genetic resource.” As we saw with the UglyRipes though, this change must be preceded by a change in our policy and mindset toward unconventional varieties, especially if we want the change to occur on the large scale farms that make up the majority of our food production. Who knows, maybe the Procaccis have shown that trying out a new variety can even have economic benefits which appeal to the more self-interested corporations out there? Others are hopefully soon to catch on.

-Simon 

Sources:

Tomatoland by Barry Estabrook

The Omnivore’s Dilemma by Michael Pollan

http://www.faminemuseum.com/famine-history/the-famine-potato/

http://impact.cgiar.org/pdf/185.pdf

http://news.bbc.co.uk/2/hi/americas/7231148.stm

http://www.ers.usda.gov/topics/crops/corn/background.aspx#.UoxZHsTrxZE

http://www.uiweb.uidaho.edu/ag/plantdisease/plbclst.htm

http://eatocracy.cnn.com/2011/09/08/why-tomatoes-grow-in-florida/ 

http://www.eatlocal.net/preserving.html

Images:

http://articles.latimes.com/2012/oct/02/business/la-fi-mexico-tomato-war-20121003 

http://www.tomatocasual.com/2009/03/02/60-years-of-tomato-heritage/

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