Global warming boosts crop disease
Pastor Dale Morgan
Global warming boosts crop disease*
PARIS, Aug 14 (AFP) Aug 14, 2007
Global warming will fuel a disease that annually causes hundreds of
million dollars in damage to rapeseed plants, used to make canola oil,
according to a study released Tuesday.
Using weather-based computer models, researchers in Britain predicted
that climate change will expand the range and increase the severity of
phoma stem canker, which already accounts for 900 million dollars (650
million euros) in losses each year.
The study, published in the Royal Society journal Interface, found that
warmer winters have significantly advanced the date of stem canker
appearance in spring, giving it more time to spread before harvest.
Eleven of the past 12 years rank among the dozen warmest years on
record, while mean global atmospheric temperature have risen by 0.8 C
(1.44 F) over the last century.
Plant pathologist Neal Evans, who led the research, forecast that the
disease would move from England north to Scotland, where it does not
currently exist.
The computer model "was developed as a tool to help guide fungicide
applications timing by farmers," he said. "We realised we could extend
its use ... to examine how global warming might impact on future epidemics."
The top rapeseed growers in the world are China, Canada, India, Germany,
France and Britain, accounted for nearly 80 percent of worldwide harvests.
The United Nations authority on climate change has said earlier this
year human activity is almost certain to blame for global warming, and
warned that the Earth's average surface temperature could rise between
1.1 and 6.4 degrees by 2100.