Category: Genetic diversity

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Wheat “blends” out-perform monocultures

This is astonishing. Luigi said that a dominant meta-narrative in our circles is that selection and breeding displace diversity. Another is that well-bred monocultures improve yields. There’s always been an opposing point of view, most closely associated with the name of Professor Martin Wolfe. Now no less a leviathan than the United States Department of Agriculture seems to agree.

In a ground-breaking experiment, USDA scientist Christina Cowger made mixtures — blends — of two or more wheat varieties and planted them in experimental plots in North Carolina. The results?

The blends outyielded the pure varieties by an average of 2.3 bushels per acre. … That’s a 3.2-percent yield advantage. Blends and pure varieties did not differ in test weight or quality across environments, and blends were either beneficial or neutral with respect to diseases.

Blends are also more stable from year to year, a fact that may be behind farmers taking matters into their own hands: 10 to 15 per cent of the wheat area of Kansas and Washington states was planted to mixtures over the past four years.

I’m looking forward to seeing the full published paper.

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Durum wheat erosion

If there’s a dominant meta-narrative in agricultural biodiversity circles it is that modern breeding programmes relentlessly decrease the genetic diversity of crops, increasing yields and quality but also, as new varieties displace landraces and older varieties in farmers’ fields, depleting the very resource on which they are dependent for continued success. But actually there’s not really that much in the way of hard figures on this process. So a recent paper on what breeding has done to diversity in Italian durum wheat is very much to be welcomed.

The researchers used molecular and biochemical markers to compare genetic diversity among five different groups of durum varieties, ranging from landraces from before 1915, to pure lines derived from landraces in the 30s, to genotypes selected from crosses between local material and CIMMYT lines in the 70s. In general, there was indeed a narrowing of the genetic diversity within these groups over time. In fact, the degree of narrowing was probably underestimated, because only a relatively few of the pre-1915 landraces were still available for analysis. Conserving what is left is all the more important.

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Wikiseedia: what is it?

Seedpod There’s a long and detailed message from the folks at WorldChanging about something they call SeedPOD. It isn’t clear exactly what this resource will be. A sort of information exchange, but also a network for exchanging seeds and maybe too a platform for sharing experiments and results in more sustainable agriculture. As they describe it:

an imagined toolkit to keep seeds moving, farmers thriving and communities fed in the face of massive environmental change. Perhaps it will trigger some interesting thinking out there: at very least, we hope you find it briefly diverting.

All this seems to be organized through something called the Wikiseedia, but as far as I can see there is no link to this fabulous beast. Go to www.wikiseedia.com, however, and you see a bare bones installation of a wiki (a special kind of web site that anyone can contribute to and edit) that contains no content (yet?) and that has not been changed since 5 March 2007. WorldChanging’s post is dated 27 April.

There’s something happening out there. What it is ain’t exactly clear. But it will bear watching. At least, I hope it will, because it sounds really exciting.