Trees in Kenya

There were two interesting articles about trees in Kenya in the Money section of this morning’s Daily Nation. Not online, though, so I’ll have to summarize. One piece describes how farmers in Nyeri are adopting a number of short-statured mango varieties from South Africa and Israel, apparently including things called Apple, Kent, Vydke and Tommy. This is not a mango-growing region, but these particular varieties have been found to be a good fit on the small farms of the area, to yield heavily and early, and to be good for juice. So now there’s no need to truck mangoes in from the coast. Good for Nyeri farmers, perhaps not so good for coast farmers? This may not be a zero-sum game: I don’t know enough about the supply of, and demand for, mango in Kenya to predict what will happen, but I would try to conserve those coastal varieties ex situ somewhere just to be on the safe side.

Then there was also a piece on how the Tree Biotechnology Project has been successful in cloning a number of indigenous trees (including for example Prunus africana, whose bark feeds a large international market for a prostate cancer drug) and providing planting materials to farmers. It seems previously the project’s focus has been on eucalypts. This is expected to take pressure off wild populations and contribute to reforestation, but there was nothing in the Daily Nation article about the downside of planting large areas of genetically identical clones. However, this is clearly a problem the project recognizes, as you can see for example by reading on page 28 of this brief on some of its activities:

Planting large areas of single clones will have the effect of decreasing rather than increasing biodiversity, and the risk of narrowing the genetic base needs to be managed to avoid growing pest and disease problems. Mondi has a policy to restrict planting of a single clone to no more than 5% of any planting area, and the project is adhering to this policy. In order to maintain biodiversity, the project team will select a wide range of local tree species of economic value and will feed these into the clonal production system through adaptive tissue culture research. Once the capacity to adapt the techniques of micro-propagation to different species is fully in place, there will be great potential for the project to multiply and disseminate a wide range of improved germplasm of different tree species, including those that are under threat of over-exploitation and extinction, such as ebony.

Broadening the genetic base of cucumbers

An American cucumber breeder, Jack Staub, is collaborating with Chinese scientists to bring fresh DNA into the modern cucumber. The hope is that this will give new cucumber varieties the genetic breadth to withstand droughts and diseases. The story started 12 years ago, when Staub crossed domestic cucumbers with a newly-discovered wild Chinese variety. It wasn’t easy to get the results of the cross to grow, but now the hybrids are being evaluated to see what they might contribute to domestic cucumbers. The next step, says Staub, is to cross the cucumber with wild melons, which are closely related and which might also be able to donate valuable traits to the crop.

The story is just one of several about vegetable breeding in the latest USDA magazine.

An appreciation of the importance of crop diversity

There’s an important post entitled Vegetables of Mass Destruction over at The Daily Kos, a blog. Important not so much for the content, most of which is familiar, well-meaning and just a tad parochial, but for the location. The Daily Kos is one of the most popular sites in the blogosphere, averaging around half a million visits a day. If just some of those readers go away with a slightly better appreciation of the value of agricultural biodiversity, that will be A Good Thing. So thanks to cookiebear and The Daily Kos for their support.

Late blight origins

Ask anyone working in plant genetic resources for an example of the importance of growing genetically diverse crops and chances are that sooner or later they’ll mention the Irish potato famine, caused by the late blight fungus Phytophtora infestans in the 1840s. But for such an important – and iconic – disease, it is amazing how what we think we know about it keeps changing. There’s been a re-think recently about which strain of the fungus actually caused the outbreak in Ireland. And now there’s DNA work to figure out where the pathogen came from. The debate on that point seems now to have been decided in favour of the Andes.

Seeds shared and saved

“When you save your own seeds, you can pick from the best plants and produce varieties that work well on your land,” he says. “You can maintain the background of genetic diversity, while adapting it to what works best for you.”

Own up, you thought that was a quote from an admittedly articulate local farmer sharing indigenous knowledge, didn’t you? Well, it was, except that this farmer has a PhD and farms in North Carolina in the US. Heritage and heirloom seeds are a big and growing deal over there, and this article in The Independent Weekly is a good account of the whys and wherefores of seed saving and sharing in industrialized countries.