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Uses for giant earthworms

A comment on the threat to the Banaue rice terraces prompted me to go Googling, and it seems the story has legs. Unlike the giant earthworms, which may or may not be an all-female species related to a worm called Polypheretima elongata. SciDev.net reports on the efforts of an Indian scientist, Ravindra Joshi, to help the villagers to get rid of the giant earthworms and the rats 1.

To tackle the earthworms, Joshi’s team taught the Ifugao a method of ‘worm farming’ that is popular with small-scale entrepreneurs in the lowlands. The Ifugao collect the worms and rear them in a mixture of soil and old newspapers. They then harvest the worms and process them into feeds used by fish farmers.

Elsewhere in the Philippines people eat worm sausages and burgers, but the Ifugao people who built Banaue have a taboo against soil dwelling creatures. There wasn’t such a taboo against eating rats, so Joshi worked with the locals to develop a community system of rice traps that uses a particularly aromatic rice planted early as a trap crop to lure the rats to their death.

There’s another rodent, though, that eats the giant earthworms. So the villagers have learned to distinguish Rattus tanezumi from Chrotomys whiteheadi, eating the former but releasing the latter to eat the giant earthworms.

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Big coffee study on the Big Island

The Garden Island News reports on a US$120,000 comprehensive study of coffee agroforestry that has just begun. The point seems to be to quantify the costs and benefits of growing coffee under an upper story of diverse forest trees. The article says that Pacific islanders traditionally grew crops in agroforestry systems, and that many are returning to similar practices. Benefits range from cooler air to fewer pests and diseases to greater resilience, all of which will be investigated.

The study will look at 12 existing shade-grown coffee orchards and compare them with five open-grown coffee orchards based on five key indicators: soil organic matter, major insect pests, yield and bean quality, production costs and market values, and environmental conditions such as shade levels, tree density and plant species present.

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Animal diseases reviewed

Thanks to Danny Hunter for pointing to two recent posts at CABI’s blog, one on bovine spongiform encephalopathy (mad cow disease to you and me), the other on bluetongue disease. BSE seems to be running its course and to be more or less under control, even though many mysteries still surround it. Bluetongue, however, is altogether more menacing, because it seems to have reached Britain at least partly as a result of climate change, which has allowed the midges that spread the virus to expand their range. This could be the start of something big. I don’t believe there is any resistance associated with different breeds of cattle, but I could be wrong.

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Agrobiodiversity in China

Back now from Kunming and Beijing, I discover that there is a rather massive Sino-German collaboration on Sustainable Management of Agrobiodiversity. It apparently runs from June 2005 to May 2009, and is certainly casting its net wide in both Hunan and the island province of Hainan. The project web site is rather neat, although I personally found the content just a little confusing. It is hard to get a sense of timing, and the use of acronyms is downright confusing. I clicked on PVP Training in Hunan Province Successfully Held fully expecting it to be about plant variety protection, only to discover it was about participatory village planning. Still, that’s minor. There’s plenty to explore and I’m sure the project will have an impact. Now, if only I can persuade the project to establish an RSS feed and to change the name of one of the organisations the web site links to, I’ll be even happier.

p.s. Just to pull all my recent posts from China together (just in case someone somewhere is Googling “china agrobiodiversity”) here they are:

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Bottlegourd to the rescue

Zucchini yellow mosaic virus (ZYMV) does not, alas, restrict itself to zucchini, or even courgettes. It attacks most cucurbits, including cucumbers, melons, pumpkins, squash, bottlegourds and watermelons. One of those, however, the bottlegourd Lagenaria siceraria may also hold the antidote to ZYMV. Scientists at the Agricultural Research Service of the USDA grew seeds of 190 different accessions from a USDA genebank and inoculated the seedlings with virus.

To their surprise, 36 accessions of the 190 screened—33 from India alone—were completely resistant to ZYMV infection, and another 64 accessions were partially resistant. They also found that ZYMV resistance is heritable in crosses between different bottlegourd accessions, enabling the development of bottlegourd varieties with enhanced virus resistance.

Breeding resistance from Lagenaria into other cucurbits may be difficult, although if they can isolate the gene(s) responsible other options become possible. And even they may not be needed. Growers can graft watermelons, for example, onto bottlegourd rootstocks and benefit from the resistance that way.

Wl020 p.s. I shouldn’t get snitty, of course, but Wikipedia’s entry on bottlegourd in China is bizarre in the extreme. I’m not going to wonder what a “remedy for health” is, though it sounds to me a lot like a disease. I am going to wonder why there is absolutely no mention of the presence absolutely everywhere of a jillion small bottlegourds as good luck charms. The Buddha used one to carry “life’s essentials”.