A group of European researchers, including professor Jørgen E. Olesen from the department of agroecology at Aarhus University in Denmark, has found that current wheat breeding programs and cultivar selection practices do not provide the needed resilience to climate change.
The current breeding programs and cultivar selection practices do not sufficiently prepare for climatic uncertainty and variability, the authors wrote in a paper published recently in Proceedings of the National Academy of Sciences. Not only that, but the response diversity of wheat on farmers' fields in most European countries has worsened in the past 5-15 years, depending on the country, Aarhus said.
The researchers predict that greater variability and extremeness of local weather conditions will lead to reduced yields in wheat and increased yield variability.
"Needless to say, decreased yields are not conducive to food security, but higher yield variability also poses problems. It can lead to a market with greater speculation and price volatility. This may threaten stable access to food by the poor, which in turn can enhance political instability and migration," Olesen said.
The researchers based their assessments on thousands of yield observations of wheat cultivars in nine European countries for qualifying how different cultivars respond to weather, Aarhus said. The researchers identified the variation of wheat response diversity on farmers' fields and demonstrated the relation to climate resilience.
The yield responses of all cultivars to different weather events were relatively similar within Northern and Central Europe as well as within Southern European countries, particularly with regard to durum wheat, Aarhus said. There were serious gaps in wheat resilience across all Europe, especially with regard to yield performance under abundant rain.
"The lack of response diversity can pose serious problems with regard to food security. Therefore, farmers, breeders and dealers in seeds and grain need to pay more attention to the diversity of cultivars grown," Olesen warned.
Climate resilience is imperative
Wheat is an important staple food crop in Europe and is the leading source of plant protein in the global diet, so it is important to ensure that there are climate-resilient wheat cultivars on hand, the researchers said.
Rain, drought, heat or cold at vulnerable times during the growing season can seriously damage yields. Wheat yield is generally sensitive to even a few days of exposure to waterlogging and to wet weather that favors disease. In addition, heat stress rather than drought sensitivity appears to be a limiting factor for wheat's adaptation to climate change in Europe, the announcement said.
The dominant approach of adapting crops to climate change by tailoring genotypes to the most likely long-term change is likely insufficient. The capacity of a single crop variety to maintain good yield performance under climatic variability and extremes is limited, but diversity in responses to critical weather events can effectively enhance climate resilience, Aarhus said. Therefore, a set of cultivars with diverse responses to critical weather conditions is prerequisite to promoting crop climate resilience.
The researchers emphasized that the need for climate resilience of staple food crops such as wheat must be better articulated. Increased awareness could foster governance of resilience through research and breeding programs, incentives and regulation.
The article, "Decline in Climate Resilience of European Wheat," can be found here.