Multi-Decade Study - Each 1C Increase In Nighttime Temps. Cuts Rice Output 10%

[hatrack]

EDIT

Researchers were serendipitously growing rice in a plot next to a weather station making detailed temperature measurements. The rice was given a stable amount of water and other nutrients, and the only variable factor was the sun.

After about 25 years, the researchers realized that the two data sets could be easily compared to figure out the effect of temperature on rice. "Every 1-degree-Celsius increase in nighttime temperature led a 10 percent reduction in yield," said Kenneth Cassman, a professor of agronomy at the University of Nebraska and a co-author in the IRRI project.

That is a large amount because a major part of the projected 4-degree-Celsius increase in temperature due to climate change will happen at night, said Cassman. In a situation analogous to running a marathon on a hot summer day, the plant finds it difficult to respire and requires more energy.

The plant also releases large amounts of a reactive molecule called a "reactive oxygen species," according to Abdul Razack Mohammed and Lee Tarpley, agronomists at the Texas AgriLife Research and Extension Center. They tested rice at nighttime temperatures of 32 degrees Celsius and found that the released oxygen molecules damage the membranes of the leaf.

EDIT

http://www.nytimes.com/cwire/2010/05/05/05climatewire-warmer-nights-threaten-indias-rice-productio-30379.html

[joshcryer]

1. Rice is a huge source of food for a lot of people, too.

[Nederland]

2. I wonder what the range is for this?

Obviously any plant has an optimal temperature range that maximizes growth. In general, plants do better in warmer weather. The question is, at what point do gains from warmer weather max out and then start dropping?

[pscot]

3. No worries

as the rivers of SE Asia dry up they won't be able to get a crop anyway.