Resilience II: Food Crops

For years, there has been concern expressed (in select quarters) about the lack of diversity in our food crops. This may not have been obvious to consumers in any one place, because improvements in transportation and refrigeration meant that eacn person had access to a wider variety of food crops than they would have had any time before - say - the Second World War. But globally, the number of food species and food families has been declinig steadily about as long as we have any good idea of what people ate.

This leads to brittleness in food supply. We've seen some examples: the potato blight in Ireland destroyed the crop, nationwide, because effectively all the potatoes in the country were genetically identical, and so the first blight that happened to be virulent against that genotype wreaked havoc. (It's important to note that the famine that followed the blight was at least partly created by the policies of the occupying government.) The Gros Michel used to be the market-dominant banana variety. It was almost compeltely wiped out by a plant virus and supplanted by the familiar Cavendish. I am not engaging in any argument about which is a "better" banana: the point is that the Cavendish will inevitably be decimated by a virus/fungs/whatever, because it too is a single genotype propagated vegetatively around the world. And in the lag time between the outbreak of the Cavendish-killer and the time that plantations of a new variety or varieties come into production, there will be a world-wide banana shortage. Doea anyone care if Jamba Juice runs out of smoothies? Maybe not - but consider the labor dislocations in banana-growing countries, leading to spreading poverty, political destabilization, and the mvoement of refugees. Also perhaps rapid conversion of intact or second-growth rainforest to new plantations, with the accompaying loss of ecological diversity and impact on climate change.

Myabe we've learned. Lately different varieties of bananas have been appearing in our supermarkets. Our best guess is that marketers are trying our different varieties to see which will be the most popular when - not if - the Cavendish is no longer viable. My hope is that banana marketing moves toward supporting a range of varieties as a normal business model: it makes sense, from their point of view, to spread the risk.

It's a peculiarity of banans taht they can only be propagated vegetatively. Most crops can be grown from seed, but that doesn't make them immune to the fate of the Gros Michel. Many crops now - for example, most of the maize grown in the US - are sterile-hybrid, meaning that the plants on farms are crosses between two varieties that can produce a vigorous offspring, but the offspring is itself sterile - think of it as the plane equivalent of a mule. This means farmers can't save some of their crop and use it to plant next year's fields, because the seeds are sterile. That not only means they have to go back to the store with cash every year, it means that crops can't evolve to fit the soil or weather conditions of an area, and the genetic diversity of these sterile hybrid crops is and remains extremely low.

There are some encouraging signs. Heirloom varieties of many crops have become popular both with home gardeners and with farms that cater to the high-end, slow-food restaurant trade. These are mostly open-pollinated, turning every farm into a small evolution lab. Locally, last year we ate a lot of apricots, but they all seemed to be of the same variety. This year, we've noticed at least four different varieties, all grown here in the Pacific Northwest.


On a slightly different note, have you seen how lately there's coconut in everything? I predicted at least 10 years ago that this would happen. Coconut is one of the few crops whose range is expanding: it thrives in hot weather and poor soils, and doesn't need a lot of water. We're also seeing other tropical crops, like mangoes and pineapples, appearing more often and in more different varieties. I'm expecting the next step to be grain crops that tolerate hot, dry conditions, like sorghum, millet, and perhaps teff. Modern maize requires huge amounts of water and fertilizer, but we may see a resurgence of older varieties native to the desert southwest (open-pollinated, yay!) that don't yield as high, but also don't fail if there's a heat wave. (Or as we call it now, a heat dome.)

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