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CO2 and Temperature Effects on Maize Yield and Protein Content

Paper Reviewed
Abebe, A., Pathak, H., Singh, S.D., Bhatia, A., Harit, R.C. and Kumar, V. 2016. Growth, yield and quality of maize with elevated atmospheric carbon dioxide and temperature in north-west India. Agriculture, Ecosystems and Environment 218: 66-72.

Writing as background for their study, Abebe et al. (2016) state that maize is "one of the most versatile cereal crops, cultivated in nearly 150 million hectares (Mha) in more than 160 countries, contributing 782 million tons (Mt) i.e., 36% of the global foodgrain production (FAO, 2010)." However, they add that "there are very limited studies on the impacts of elevated CO2 concentration and temperature interactions on this important cereal crop under field conditions." Thus it was that they set out to remedy this situation by evaluating "the impacts of elevated atmospheric CO2 and temperature on growth, yield and quality of maize in north–west India under field conditions." More specifically, Abebe et al. (2016) grew the C4 plant (Zea mays L.) out-of-doors in open-top chambers in New Delhi, India, to determine the effects of atmospheric CO2 enrichment (from 400 to 550 ppm) and warming (by 0.5 and 1.0°C) on the crop's growth and grain protein content.

And what did they learn by so doing?

The six Indian scientists report that the 150-ppm increase in the atmosphere's CO2 concentration increased maize photosynthetic rates by 23.49%, which led to the grain yield of maize rising by a whopping 53.7%. The elevated temperatures of 1.5 and 3.0°C, on the other hand, decreased grain yield, but by only 4.9%. In addition, Abebe et al. found that "elevated CO2 reduced the negative effects of elevated temperature on yield and yield components of maize." And as a bonus, as it were, they report that by the time of harvest, the elevated temperatures of 1.5 and 3.0°C were found to have increased the crude protein contents of maize by approximately 6.5%.

FAO. 2010. Agricultural data. Food and Agriculture Organization of the United Nations, Rome Online at

Posted 9 September 2016