Crop Biotech Update

Carbon Dioxide Reduces Crops' Yield, Study Reveals

December 5, 2012

A variety of rice called IR8 developed by scientists at the International Rice Research Institute (IRRI) in the 1960s caused quite a stir and was considered as part of the "Green Revolution" as it used to produce incredible yields and warded off the food shortages predicted during the period. In the meantime, however, the yields from IR8 have declined by around 15 percent, and the cultivation of this previously very promising plant is no longer seen as worthwhile.

With this, researchers from the Max Planck Institute of Molecular Plant Physiology and the University of Potsdam in Germany conducted a research to fully understand what lies beyond the changes in the IR8 variety's yield. Although nothing has changed in the genetic makeup of the IR8 rice plant in the past 50 years, its yields have declined continuously.

Using the model plant Arabidopsis thaliana (generally known as thale cress), the researchers were able to observe that a higher carbon dioxide concentration results in the unblocking of the capacity of dwarf plant to form gibberellic acid. The carbon dioxide appears to have the same growth-stimulating effect as that triggered by the gibberellic acid. Thus, in the experiment, the dwarf plants gradually lost their advantage and increasingly resembled the control plants.

The cultivation of dwarf varieties is not only common in the case of rice, farmers also prefer short-stalked varieties of wheat; both cereals are the staple food consumed by a majority of the global population. The researchers are now looking for the mechanism through which the gaseous carbon dioxide influences the growth of the plants.

View the Max Planck's institute news release at http://www.mpg.de/6650626/carbon-dioxide-crop-yields.