By the end of the century, scientists expect climate change to significantly reduce maize yields, with some estimated losses of up to 28 percent, but these calculations lack the main factor that could lead to lower maize yields and more weeds.
Expected Wolf ” phys Wet springs and hotter, drier summers, which have already become the norm in the corn belt, press the corn during key reproductive stages, including silk and grain packing, but the same weather conditions can benefit weeds that grow in challenging environments, he said..
“Bad weather and weeds are two factors stressing crop production, but there is very little research on how the combination of these two factors affects crop yield, and computer models that predict future corn yields assume weed-free conditions,” says Marty Williams. Harmful,” a USDA-Agricultural Research Service ecologist, associate professor in the Illinois Department of Crop Science, and co-author of a new study in Global Change Biology. “This is unlikely to be the case without a major shift in the way we manage weeds.”
Complete weed control is rarely achieved in practice, especially if we consider herbicides – the single most common tool used to destroy weeds – as they lose their potency to resistant weeds, and many important weed species, including waterhemp And Palmer amaranth , ignoring the multiple modes of action of herbicides, and with no new classes of herbicides approaching commercial commercialization in corn, prospects for chemical control continue to fade for resistant weeds..
However, late season weed control such as hydrofoil was the most important factor affecting maize yield, greater than any management practice or weather factor..
To reach this conclusion, the research team, which includes crop scientists Christopher Landau and Aaron Hager, analyzed 27 years of experiments evaluating herbicides representing more than 200 unique climatic environments across Illinois..
Williams says: “When researchers want to ag To look at weather variability and crop yields in a controlled way, this is one experiment in two or three environments and if it is a large study, it could be up to six or eight environments,” “Our analysis enabled us to look at a historical data set where there were hundreds of environments, that is Its true beauty.
Machine learning algorithms helped researchers understand large and complex data sets. They considered crop management considerations, including planting history, hybrid selection, and planting density; Percent weed control for multiple weed species; weather data on key growth stages throughout the corn life cycle; and return.
The analysis showed an average loss of 50% at minimal weed control in late season, even with relatively vigorous late season weed control (up to 93%), weeds exacerbated crop losses in hot or dry conditions..
The combination of imperfect weed control and these weather events is where we see crop losses much greater than bad weather alone, achieving 94% of weed control late in the season is a high barrier, and I would be surprised if many fields hit this mark for weed control Weed it regularly,” says Williams.