Month: February 2010

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Locating agricultural origins in Mexico and Italy

I know that domestication is not an event, but a process. I know that most crops and livestock were probably domesticated more than once, in more than one area. I know all this, but I’m still a sucker for papers that come up with specific times and places for the origin of agriculture. Papers such as Daniel Zizumbo-Villarreal and Patricia Colunga-GarcíaMarín‘s in the latest GRACE:

Sympatric distribution of the putative wild ancestral populations of maize, beans and squash indicate the extreme northwest Balsas-Jalisco region as a possible locus of domestication.

The paper is a review. It synthesizes a host of paleoecological, archaeobotanical and molecular data. Meanwhile, another paper, this time in the Journal of Archaeological Science, applies matrix mathematics to a somewhat different, though related, problem: the arrival of wheat in Italy. The authors looked at a selection of old emmer landraces from all around Italy stored in the German and ICARDA genebanks. 1 They developed a matrix of genetic distances among these based on microsatellite data. They then calculated matrices of geographical distances among the landraces based on different putative places of arrival of the crop around the coast of Italy. The two matrices showed the closest correlations for arrival sites located in northern Puglia, the heel of Italy. That corresponds with where the earliest Neolithic sites are found.

Now, I wonder, when will someone apply this method to maize, beans and squash molecular data and test mathematically Zizumbo-Villarreal and Colunga-GarcíaMarín more “qualitative” inferences?

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Fertilizers: downside seen in China

It really does seem tragic that people need to make their own mistakes, rather than learn from others’. Latest case in point: soils in China are being destroyed by excessive use of fertilizers, which is making the soils too acid to support plant growth. Yields have already dropped 30-50% in some places. The conclusion that profligate and ignorant use of fertilizers comes from a paper published in Science by F.S. Zhang at China Agricultural University in Beijing and colleagues. That is behind a paywall, but there is a report in Nature News.

“They see the green leaves but they don’t see the impact on the soil. If they have a poor crop they think more fertilizer is needed, making matters worse,” Zhang says. Farmers routinely apply double and sometimes triple the necessary amount, he says. Better education could provide a simple solution to the fertilization problem.

People who promote “more fertilizers” as a panacea should consider that they need to deliver more than merely fertilizers.

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Nibbles: Farmers’ Rights, Seed Breeder, Genebanks, Pigeon Pea, Cheese

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Patenting systems good for vegetable diversity

Here’s a turn-up for the books. Our friends at the CAS-IP blog link to a couple of papers that examine the influence of intellectual property rights on vegetable diversity. I’m going to come right out and admit that I haven’t read the papers. But like CAS-IP, I’m intrigued by this quote:

More than 16% of all vegetable varieties that have ever been patented were commercially available in 2004.

Or, to put it another way, less than 84% of all vegetable varieties that have ever been patented were no longer available in 2004.

The primary argument for maintaining crop diversity 2 is based on the need to maintain a safety net of genetic diversity, to have a broad supply of genes available to breeders who can create more productive, weather-hardy, insect resistant, fungus resistant, and better-tasting crops. … If the meaning of diversity is linked to the survival of ancient varieties, then the lessons of the twentieth century are grim. If it refers instead to the multiplicity of present choices available to breeders, then the story is more hopeful.

The crucial part, of course, is how to measure diversity, and how you interpret it. I deliberately snipped out what I consider the money quote from the passage above. Here it is:

We hope our findings stimulate a discussion about the proper measure for that diversity.

Off you go. Discuss away.