Crops yields around the world could fall within a decade unless we introduce new varieties

Crops yields around the world could fall within a decade unless action is taken to speed up the introduction of new varieties. A study says temperatures are rising faster than the development of crop varieties that can cope with a warmer world.
In Africa, researchers found that it can take 10-30 years before farmers can grow a new breed of maize.
By the time these new crops are planted, they face a warmer environment than they were developed in.
The scientists behind the study, published in the journal Nature Climate Change, looked closely at the impact of temperature rises on crop duration - that's the length of time between planting and harvesting.
They found that in a warmer world durations will be shorter meaning these varieties will have less time to accumulate biomass and yields could be affected.
In their paper, the researchers write that crop duration will become significantly shorter as early as 2018 in some regions but by 2031, the majority of maize-growing areas of Africa will be affected.

http://www.bbc.com/news/science-environment-36579125