Yield gaps in wheat: Path to enhancing productivity

Authors: Hatfield, Jerry; BERES, BRIAN - Agriculture And Agri-Food Canada

Submitted to: Frontiers in Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/14/2019
Publication Date: 12/6/2019
Citation: Hatfield, J.L., Beres, B. 2019. Yield gaps in wheat: Path to enhancing productivity. Frontiers in Plant Science. 10:1603. https://doi.org/10.3389/fpls.2019.01603.
DOI: https://doi.org/10.3389/fpls.2019.01603

Interpretive Summary: Wheat is one of the major food staples around the world and the increasing world demand for food will increase the need for greater production. We analyzed the 10 largest wheat producing countries in the world to evaluate their yield trends and yield gaps. Yield gaps are defined as the difference between the actual yield and the yield under optimal conditions. These data were assembled from available data sources and then evaluated for their trends and yield gaps. Wheat yields have been increasing steadily over the past 50 years with variation among the years caused by weather conditions during the growing season. The yield gap has not decreased and is primarily due to the variation of weather during the grain-filling period. When we evaluate the yield gaps and the yield trends it is obvious that we have improved production but have not implemented practices or varieties that have reduced the yield gap. As we begin to understand what causes limitations to wheat yields, we can use this methodology to evaluate practices that have the potential to decrease the yield gap. This information will be of value to wheat growers, agronomists, and policy makers to help them understand what factors affect wheat yield and also derive practices that will preserve the yield potential for each area of the world.

Technical Abstract: Wheat production is required to supply food for the world’s population, and increases in production will be necessary to feed the expanding population. Estimates show that production must increase by 1 billion metric tons to meet this demand. One method to meet future demand is to increase wheat yields by reducing the gap between actual and potential yields. Potential yields represent an optimum set of conditions and a more realistic metric would be to compare actual yields with attainable yields, where these yields represent years in the record where there is no obvious limitation. This study was conducted to evaluate the yield trends, attainable yields and yield gaps for the 10 largest wheat producing countries in the world and more localized yield statistics at the state or county level. These data were assembled from available government sources. Attainable yield was determined using an upper quadrant analysis to define the upper frontier or yields over the period of record and yield gaps calculated as the difference between attainable yield and actual yield for each year. In all countries, the attainable yield increase over time was larger than the yield trend indicating the technological advances in genetics and agronomic practices were increasing attainable yield. Yield gaps have not shown a decrease over time and reflect that weather during the growing season remains the primary limitation to production. Yield gap closure will require local producers adopt practices that increase their climate resilience in wheat production systems.