The researchers found a range of effects -- positive, neutral and negative -- when they sprayed the herbicide dicamba on old fields -- ones that are no longer used for cultivation -- and on field edges, according to J. Franklin Egan, research ecologist, USDA-Agricultural Research Service. He said the effects should be similar for a related compound, 2,4-D.
"The general consensus is that the effects of the increased use of these herbicides are going to be variable," said Egan. "But, given that there is really so much uncertainty, we think that taking precautions to prevent herbicide drift is the right way to go."
Farmers are expected to use dicamba and 2,4-D on their fields more often in the near future because biotechnology companies are introducing crops genetically modified to resist those chemicals. From past experience, 2,4-D and dicamba are the herbicides most frequently involved in herbicide-drift accidents, according to the researchers.
Because the herbicides typically target broadleaf plants, such as wildflowers, they are not as harmful to grasses, Egan said. In the study, the researchers found grasses eventually dominated the field edge test site that was once a mix of broadleaf plants and grass. The old field site showed little response to the herbicide treatments.
Herbicide drift was also associated with the declines of three species of herbivores, including pea aphids, spotted alfalfa aphids and potato leaf hoppers, and an increase in a pest called clover root curculio, Egan said. The researchers found more crickets, which are considered beneficial because they eat weed seeds, in the field edge site.
The researchers, who report their findings in the current issue of Agriculture, Ecosystems and Environment, did not see a drop in the number of pollinators, such as bees, in the fields. However, the relatively small size of the research fields limited the researchers' ability to measure the effect on pollinators, according to Egan.
"That may be because pollinators are very mobile and the spatial scale of our experiment may not be big enough to show any effects," Egan said.
Farmers can cut down on herbicide drift by taking a few precautions, according to Egan. They can spray low-volatility herbicide blends, which are less likely to turn to vapors, and use a nozzle design on the sprayer that produces larger droplets that do not easily drift in the wind.
Egan also recommended that farmers follow application restrictions printed on herbicide labels and try to spray on less windy days when possible.
The tests were conducted on two farms in Pennsylvania. One field edge site was located near a forest and alfalfa field. The old field was an acre plot near Penn State's Russell E. Larson Agricultural Research farm.
Egan worked with Eric Bohnenblust, doctoral candidate in entomology; John Tooker, assistant professor of entomology and extension specialist, and David Mortensen, professor of weed and applied plant ecology, all of Penn State, and Sarah Goslee, U.S. Department of Agriculture ecologist.
The Environmental Protection Agency supported this work.
Matthew Swayne | EurekAlert!
Filling intercropping info gap
16.11.2017 | American Society of Agronomy
Climate change, population growth may lead to open ocean aquaculture
05.10.2017 | Oregon State University
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
20.11.2017 | Life Sciences
20.11.2017 | Materials Sciences
20.11.2017 | Life Sciences