Climate change effect on wheat phenology depends on cultivar changeTemperature is the main driver of crop phenology. The recent warming trend resulted in earlier flowering of plants such as winter wheat. Therefore, changing crop phenology is considered an important bio-indicator of climate change. However, little is known about the specific contribution of changes in other factors such as plant breeding and sowing dates to long term trends of crop phenology.
Scientists of the Division Agronomy analyzed therefore almost 500.000 observations of winter wheat phenology obtained in Germany within the last six decades, observations made in a field experiment in which cultivars from the last six decades were grown in parallel and applied a crop phenology model to separate effects of changes in sowing dates, cultivar and climate on changes in the flowering date of winter wheat across Germany. We found that the temperature sum of modern cultivars of winter wheat required to reach flowering reduced by 16% compared to cultivars grown in 1950s. Trends in day of flowering simulated by a crop model parameterized with the field observations illustrated that changes in mean temperature and cultivar properties contributed similarly to trends in day of flowering while the impact of changing sowing dates was negligible.
Consequently, the single-cultivar concept commonly employed in climate change impact assessments results in an over-estimation of winter wheat sensitivity to rising temperature. Changes in cultivar properties should be considered in climate change impact assessment studies.
The article is published in Scientific Reports and available for open access.
Link to the article in Scientific Reports
Link to press release of the University of Goettingen