Friday, 6 February 2009

Wet rice

My mental picture of rice growing is of paddy fields and water, plenty of water.  I thought all that water was an essential requirement for its growth.  Well, it is, but not too much.  Apparently as much as $1 billion worth of rice is lost each year in south and south-east Asia as a result of flooding.

Photo from IRIN/Jason Guttierez

When rice grows in the normal way, it tries to outgrow the water, to rise above it.  When there are floods, this elongation continues until the plants run out of carbohydrates, causing tissue damage and death.  But scientists at the International Rice Research Institute in the Philippines have discovered some naturally occurring  rices which can tolerate flooding.  The plants become dormant, and while they can't stay in this state for ever, they can survive under water well enough in most flood conditions.

Using natural breeding methods, the flood tolerance has been bred into existing strains of rice.  The three new new strains are just as productive as established ones so there is no penalty in using the flood-tolerant varieties.  People tend to become complacent when there is no existing problem -  so the new must be every bit as good as the old to encourage their use.

The scientists have produced the strains of rice but the problems now lie more in distribution:

  • producing a sufficient quantity of seed quickly
  • distribution of the seed to some very remote areas
The initial breeding work was supported by the German government, and the Gates Foundation is helping with distribution and further development.

The areas most likely to suffer flooding are also those where poverty tends to be a major problem.  The new varieties could make a substantial difference to places like Bangladesh where there is an annual shortfall in rice production.
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  1. Interesting post A. I know this sometimes happens in Thailand. Equally a lack of water is also sometimes a problem. Since a lot of the farmers are extremely poor this can be devastating.
    Andrew on Thai Girl covered some of this recently.

  2. Hope José Bové isn't one of your readers ;-)

    Bangladesh will suffer extremely badly wit rising sea levels - though there are rice types that will tolerate salinity. It's also a country that became dependent on food aid for a long time after the catastrophic cyclone in the seventies - US gave so much free rice that it wasn't economically viable for local farmers to replant - will have to dig and check but I'm led to believe that it's still a net importer of us US rice


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