Excess usage of glyphosate-resistant crops has led to weeds, such as marestail, that also are resistant to glyphosate, the herbicide used in Roundup. Bill Johnson, a Purdue associate professor of weed science, said changing management practices can almost eliminate resistant marestail and its viable seeds in the soil.
"Another herbicide application is expensive, and it means more trips across the field," Johnson said. "But we can reduce the population and density of resistant weeds, which increases the crop yield potential."
The results of Johnson's five-year study were published in the journal Weed Science.
Marestail, also known as horseweed, was the first weed to develop resistance to glyphosate. Other weeds also are adapting, Johnson said, reducing the effectiveness of products such as Roundup, the most widely used herbicide on the market.
It is Roundup's popularity that is contributing to its diminished effect. Johnson said farmers have come to rely on Roundup Ready crops that resist glyphosate as an easy way to control weeds. But overuse of any herbicide allows weeds to adapt and develop resistance.
Johnson's study found that farmers should diversify the herbicides they use. Using a variety of herbicides in addition to Roundup before planting and alternating between Roundup and other herbicides in corn can significantly reduce marestail.
Fields that had three resistant weeds for every susceptible weed while using only Roundup and Roundup Ready crops saw weed populations drop to one resistant weed for every six susceptible weeds while rotating herbicides as Johnson suggests. That rotation also may lead to a 95 percent decrease in the number of viable marestail seeds in the soil.
Continuing with only Roundup and Roundup Ready crops can intensify the problem, Johnson said.
"Glyphosate-resistant marestail develops very quickly in a field. Populations reach staggering levels of infestation in about two years after it is first detected," Johnson said. "For us, marestail being the first weed that developed resistance showed that a weed-management system that is solely reliant on glyphosate is starting to break down. However, a system that incorporates other herbicides with glyphosate can be sustainable for quite some time."
The Indiana Soybean Alliance, BASF, Dow AgroSystems, Monsanto and Syngenta funded Johnson's study. His next step is looking at management strategies that reduce the prevalence of other weeds that have built up resistance to glyphosate.Writer: Brian Wallheimer, (765) 496-2050, email@example.com
Brian Wallheimer | EurekAlert!
Energy crop production on conservation lands may not boost greenhouse gases
13.03.2017 | Penn State
How nature creates forest diversity
07.03.2017 | International Institute for Applied Systems Analysis (IIASA)
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
24.03.2017 | Materials Sciences
24.03.2017 | Physics and Astronomy
24.03.2017 | Physics and Astronomy