An interview with Andy Jarvis, agricultural geographer, CIAT and Bioversity
Q: You say you have two “mantras.” What are they?
A: One is “crop wild relatives.” (Note: A crop wild relative (CWR) is the wild variety of a domesticated food crop.) When you look at the status of crop wild relatives, it’s actually very scary. They’re not conserved in the wild. And the degree of conservation in gene banks is appallingly low. Many have gone extinct already—and we have no idea what genes they might have had—for disease resistance, productivity, drought or salt tolerance….
At the same time, there’s exponential growth in the demand for and use of these genes through biotechnology. In the past, when you bred a wild crop relative with a cultivar you might get what you wanted—say disease resistance—but along with that came a tough seed coat or small pod or other things you don’t want. Now, you can use molecular markers to take just what you want.
Q: If they’re not in the genebanks, how do you find wild crop relatives?
A: We’ve been going through 30 major crop genepools, including beans, potatoes, wheat, rice, sorghum, cassava, some forages, coffee…. We collect all available information, through herbarium and genebank databases, of every point where wild crop relatives have been observed. Then we model the species distribution see what all these habitats have in common, to come up with suitability requirements.
So if, for instance, we know something exists in ten sites with these characteristics—where else in the world has those characteristics? That’s where you’re likely to find the species.
Q: For example…?
A: Geneticists were searching for wild chili peppers in Paraguay. We found records of 18 places with chili populations in the past, but they weren’t there any more, nor in collections So we modeled the conditions in the sites the botanists had described—and came up with 20 places with similar environments where people might look. It worked–they found the chilis in seven of those places.
In beans, there are 70-plus wild species, all in the Americas. There are 170-plus wild relatives of potatoes. But in lots of crops—maize being one of the most notable—there are just a few wild relatives left. Most of the species have been lost.
A massive global initiative is urgent for our major crops. That’s what the Global Crop Diversity Trust, housed at FAO, is trying to do.
Q: And the other mantra?
A: Climate change and crops. We’ve taken the 50 biggest crops, by area, and modeled how climate change will change their geography. After the biggest—rice, maize, wheat and a couple of others—no one has done this. We’re using a simple, niche-based approach: this crop grows in an environment with this rainfall and other characteristics, based on expert knowledge.
The shocking thing is that there are huge changes, for both 2020 and 2050. For instance, the models show that maize goes way down in Africa. But cassava gains area. Already, there’s anecdotal evidence of farmers shifting from maize to cassava or sorghum.
In a few areas farmers will lose all sorts of options. Maybe today they have 20 crop options; in the future, maybe they’ll only have 3. Some regions are in serious trouble: Southern Africa. Parts of Sahel. Eastern Brazil, northern Africa and the Mediterranean, including southern Europe.
But in East Africa—the rainy parts, such as most of Uganda—massive increases in rainfall are predicted. So farmers may have more choices. And they may be able to crop continuously. But the models show that pests and diseases also rise.
The bottom line is that everything’s changing, and quickly. The first users of climate-change information should be researchers themselves. Most agricultural research programs take at least 10 years to come to fruition out in the fields. So researchers need to target a 2020 world for their 2020 research results—not work toward better strategies for a 2009 world in 2020.
Q: Why do you call yourself a “promiscuous geographer?”
A: I use the same geographic tools—but apply them to all sorts of things: what we’ve been talking about, plus forest biodiversity, coffee quality, forage, threats to protected areas…. I’m interested in so many things, I seem to need to keep moving around.
You can hear Andy’s perspective on BBC Digital Planet – available at ICT-KM Blog on Famers’ productivity