Varieties of climate change

by Jeremy Cherfas on June 18, 2013

Something is up, no doubt about it. First off, PBS in the US has a longish news report on how farmers in India “find promise in ancient seeds”.

Watch Struggling Farmers in India Find Promise in Ancient Seeds on PBS. See more from PBS NewsHour.

Strangely, although the farmers are able to find promise in ancient seeds, the report claims that seeds stored at IRRI in the 1960s are too ancient to be viable. Not sure how that works.

One of the protagonists of the PBS video, Debal Deb, crops up again in another video that came to light on the PAR website. According to PAR: “This film follows the construction of a new seed bank premises in Odisha, a venture that provides a potent symbol of Debal’s values”.

With the zeitgeist firmly embracing the idea of agricultural biodiversity, preferably ancient agricultural biodiversity, as a suitable response to climate change, it is good to be reminded that droughts are diverse too. David Lobell looks at two recent scientific papers on drought tolerance. One shows very little difference between specifically “drought-tolerant” maize varieties and other varieties without the drought-tolerance genes.

To me, there are a couple of possible ways to interpret this. One is that the newer varieties being marketed by companies are not really much better in general. Or these results might indicate that the types of droughts the newer varieties were designed for are somehow different than the type of droughts they were exposed to in this experiment. In particular, as we’ve discussed in prior posts, 2012 was a drought characterized by very high temperatures and vapor pressure deficits, the kind of droughts that one expects more of with climate change.

2012, in other words, was not just a dry drought but a hot drought. The other study David looks at compares the two kinds of drought.

What’s really interesting is how remarkably low the correlation between performance in “drought” and “drought+heat” is (0.08).

While not reading too much into either study, Lobell cautions that very hot droughts may require different kinds of varieties from mere dry droughts.

{ 2 comments… read them below or add one }

Jay Bost June 19, 2013 at 5:35 am

Are they not saying that seeds stored since the 60s may have lost their ability to germinate? Seems reasonable, no?

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Luigi June 19, 2013 at 7:51 am

IRRI is a professionally run genebank, one of the best in the world, and as such monitors seed viability regularly and regenerates seedlots as and when necessary to avoid any sample deteriorating in quality below an internationally agreed standard.

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