The study examined rice yields and atmospheric conditions from 1966 to 2016
A study of the relationship between temperature and yields of various rice varieties, based on 50 years of weather and rice-yield data from farms in the Philippines, found that warming temperatures negatively affect rice yields.
Recent varieties of rice, bred for environmental stresses like heat, showed better yields than both traditional rice varieties and modern varieties of rice that were not specifically bred to withstand warmer temperatures. But the study found that warming adversely affected crop yields even for those varieties best suited to the heat. Overall, the advantage of varieties bred to withstand increased heat was too small to be statistically significant.
Roderick Rejesus, a professor and extension specialist of agricultural and resource economics at North Carolina State University and the corresponding author of a paper that describes the study, says that teasing out the effects of temperature on rice yields is important to understand whether rice-breeding efforts have helped address the environmental challenges faced by modern society, such as global warming.
The study examined rice yields and atmospheric conditions from 1966 to 2016 in Central Luzon, the major rice-growing region of the Philippines.
The study examined three general rice varieties planted during those 50 years: traditional rice varieties; “early modern varieties” planted after the onset of the Green Revolution, which were bred for higher yields; and “recent modern varieties” bred for particular characteristics, like heat or pest resistance, for example.
Perhaps as expected, the study showed that, in the presence of warming, recent modern varieties had the best yields when compared with the early modern and traditional varieties, and that early modern varieties outperformed traditional varieties.
