Category: Threats

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Spreading diseases one seed at a time

Robert asks whether the kind of experimentation, diversification and exchange that might be fostered by making it easier for people to swap seeds requires some sort of risk control. My simple answer is “I don’t know”. Fungi, bacteria and viruses can all hitch a ride on the outside of the seed, inside the seed coat, and in some cases within the tissues of the seed, and several can be a really bad problem. Many growers control the risk by treating seeds with fungicides and other chemicals. Organic growers have developed other kinds of treatments, including carefully controlled hot water baths. I think there are two problems.

First, will you introduce a new disease to your own plot? Quite possibly, and only you can decide whether that is worth the risk, and what steps you are willing to take to prevent it.

Secondly, will you introduce a new disease to your region or, as Robert puts it, “spread devastating plant diseases across the globe”? This, naturally, is much harder to answer. I’m inclined to believe that individuals swapping seeds pose no greater threat than industrial and government activities, but that is very much a gut feeling. Pests and diseases do slip past almost every control system, although seldom is it possible to pinpoint the specific occasion on which it happened.

Phytosanitary legislation aims to minimize the risks, but I have no idea whether there are exceptions for small quantities, as there are for some other seed laws. Perhaps a reader can enlighten us.

People may want to take precautions before sending or receiving swapped seeds, but I wouldn’t rely on that (or anything else) to protect the world from seed-borne diseases.

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More bad news: the eco-crunch

The other day, Luigi suggested investing in watermelons now that the credit crunch has made banks go bust and stocks worthless. Hold on. Maybe the watermelons will also go belly up, as the BBC reports that we are also heading for an eco-crunch. This unwelcome news is based on The Living Planet Report, produced by the WWF, the Zoological Society of London and the Global Footprint Network. “The global footprint exceeded the earth’s biocapacity by 25% in 2003, which meant that the Earth could no longer keep up with the demands being placed upon it.”

I am torn. Yes, we are depleting our resources. Yes, it is scary. But this is also déjà vu all over again. The predictions made in Limits to Growth, The Population Bomb, and many other gloomy predictions from the 1960-70s, have turned out to be incorrect. Human creativity has outsmarted perceived physical limits; but there are real physical limits too…. Have we really reached them?

In The Population Bomb, Paul Ehrlich predicted that in the 1970s and 1980s hundreds of millions of people would starve to death. Not a strange prediction given the famines that occurred in the years before the book was written. But it never happened; we got the Green Revolution instead.

Food shortages, or at least high food prices, were all of a sudden back on the front pages this year. Is the end near then? Not yet. Now that speculators are retreating, and farmers have responded to higher prices by producing more (25% more wheat produced in Europe! Perhaps largely because the ‘set-aside’ subsidized fallowing policy expired?). Food prices are tumbling again. For how long?