Dioxide Concentration May Not be All Good News for Crops


It has been widely recognized for decades that the marketable yield of most crops is increased when they are grown in an elevated CO2 concentration, but a recent field experiment found that attack on soybeans by western corn rootworm, and by Japanese beetle, was increased with elevated CO2. A BER-sponsored research project investigating the underlying cause of this increased insect attack in elevated CO2 recently reported (April 1, 2008, Proc. Nat. Acad. Sci.) that elevated CO2 reduced the effectiveness of normal biochemical systems that plants use to help defend themselves against insects. The researchers concluded that changes in the plant’s natural defense systems caused by the ongoing increase in atmospheric CO2 concentration (which is caused mainly by energy production from fossil fuels) has the potential to exacerbate pest problems in crops of the future.