By Jamie Martin
A new international research study suggests that improvements in crop yields from plant breeding may not be as large as previously believed.
Scientists examined how wheat yields have improved over time and found that a common method used to measure breeding progress may not clearly show the true genetic gains in crops.
The research team included scientists from several institutions around the world, including researchers from the University of Nebraska–Lincoln. The findings were based on data from 849 wheat cultivars tested across 17 locations in Argentina, France, the United Kingdom, and the United States.
“The increases in crop productivity we see year by year can be explained mainly by two factors,” said Patricio Grassini, Sunkist Distinguished Professor of Agronomy and one of the researchers involved in the study. “One is improved agronomic factors like, for example, fertilizers, pest control and so forth. The other is genetic improvement.”
The analysis showed that wheat yields increased by about 73 kilograms per hectare per year. However, researchers discovered that only about half of this increase came from improvements in the genetic yield potential of newer wheat varieties.
The remaining gains were largely the result of maintenance breeding. This type of breeding focuses on helping crops remain productive as environmental challenges change over time.
As pests, plant diseases, and climate conditions evolve, older crop varieties may lose their ability to perform well. Plant breeders respond by introducing new traits that protect crops against these threats. While these improvements help maintain yields, they do not necessarily increase the crop’s maximum yield potential.
The commonly used method of growing older and newer crop varieties together and comparing yields does not clearly separate these two factors. Because of this limitation, the method may overestimate how much breeding alone has raised crop productivity.
Researchers say understanding this difference is important for future agricultural planning. Accurate information about genetic gains helps guide research funding and breeding priorities.
With global food demand expected to continue rising, experts stress the need for balanced investment in both crop genetics and agronomic management practices.
The study recommends improved evaluation systems that use multi-environment trials and proper comparison varieties. These approaches would allow scientists to better separate yield potential gains from improvements related to crop adaptation.
Such knowledge will help researchers develop better strategies to support future crop production and strengthen global food security.
Photo Credit: gettyimages-ianchrisgraham
Categories: National