USDA

Process Turns Barley into High-protein Fish Food

USDA Agricultural Research Service - Mon, 07/14/2014 - 08:10
Process Turns Barley into High-protein Fish Food / July 14, 2014 / News from the USDA Agricultural Research Service
Read the magazine story to find out more.

 Three rainbow trout swimming over rocks. Link to photo information
A patented new process turns barley into a perfect high protein feed for carnivorous fish like salmon and rainbow trout as a plant-based alternative to fishmeal, which is made from small ocean fish. Click the image for more information about it.


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Process Turns Barley into High-protein Fish Food

By Sandra Avant
July 14, 2014

A process that improves the nutritional value of barley for use in fish feed has been developed by scientists at the U.S. Department of Agriculture (USDA) and Montana Microbial Products LLC (MMP) of Missoula, Montana.

Barley typically contains about 10 to12 percent protein, but 40 to 60 percent protein is needed in diets of carnivorous fish like rainbow trout and salmon. The new enzymatic process patented by the Agricultural Research Service (ARS) and MMP concentrates protein by removing the carbohydrates in barley and turning them into an ethanol coproduct, utilizing all the nutrients in the grain.

ARS is USDA's principal intramural scientific research agency, and this research supports the USDA priority of promoting international food security.

The new high-protein product produced by this technology should help fill the gap for more plant-based protein sources as alternatives to fishmeal, which is made from small ocean fish, according to fish physiologist Rick Barrows, with the ARS Small Grains and Potato Germplasm Research Unit in Aberdeen, Idaho. In addition, barley protein concentrate has less variability in composition and is less expensive than most fishmeals.

Barrows, who works in Bozeman, Montana, and his team tested barley protein concentrate in rainbow trout and found digestibility—the percentage of nutrients available to the fish—to be as high as 95 percent. The product also was tested in Atlantic salmon by research leader William Wolters and fish physiologist Gary Burr at the ARS National Cold Water Marine Aquaculture Center in Franklin, Maine.

Atlantic salmon were fed a diet containing either 11 percent or 22 percent barley protein concentrate. The growth of those salmon was not significantly different from salmon fed a standard fishmeal diet. Also, the fish that ate the 22 percent barley protein concentrate diet had significantly greater energy retention compared to fish fed the other diets. Higher energy retention demonstrates that the fish are using the feed more efficiently.

MMP has built a commercial prototype plant in Montana to produce barley protein concentrate for trout feeding trials. The company also plans to build a commercial facility in the near future.

Categories: USDA

Reducing Fertilizer Use with a More Accurate Soil Test

USDA Agricultural Research Service - Thu, 07/10/2014 - 12:03
Reducing Fertilizer Use with a More Accurate Soil Test / July 10, 2014 / News from the USDA Agricultural Research Service
Read the magazine story to find out more.

 Hands holding soil. Link to photo information
An ARS soil scientist has developed a more precise test for how much fertilizer a farmer needs to add to a field, reducing costs by about $10 to $15 per acre and the chances there will be excess running off into surface water. Click the image for more information about it.


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Reducing Fertilizer Use with a More Accurate Soil Test

By Dennis O'Brien
July 10, 2014

Soil tests that determine fertilizer needs measure nitrate in the soil, but they don't sufficiently account for soil microbes, which mineralize organic nitrogen and make more of it available to a crop. As a result, farmers often apply more fertilizer than they need.

Richard Haney, a U.S. Department of Agriculture (USDA) soil scientist in Temple, Texas, has developed a soil test that replicates some of the natural processes that occur in a field and accounts for that microbial activity, along with measuring nitrate, ammonium (NH4), and organic nitrogen.

Haney is with the USDA Agricultural Research Service (ARS) Grassland, Soil and Water Research Laboratory in Temple. ARS is USDA's principal intramural scientific research agency.

The new soil test is known as the Soil Health Tool. It involves drying and rewetting soil to mimic the effects of precipitation. It also uses the same organic acids that plant roots use to acquire nutrients from the soil. The tool measures organic carbon and other nutrients, accounts for the effects of using cover crops and no-till practices, and will work for any crop produced with nitrogen or other types of nutrient fertilizer.

Haney has made it available to commercial and university soil testing laboratories and has worked with farmers to promote it. Growers who use it receive a spreadsheet that shows the amounts of nitrogen, phosphorus, and potassium available to crops. On average, they reduce fertilizer costs by about $10 to $15 per acre. With less fertilizer applied, there is less of it running off into surface water.

Haney and Daren Harmel, an ARS agricultural engineer at the Temple lab, evaluated the tool in fields where they raised wheat, corn, oats, and grain sorghum at nine Texas sites over four years. They applied traditional fertilizer rates; no fertilizer; and the amounts dictated by the Haney soil tests. They planted and harvested on the same dates at each site, and kept track of fertilizer costs and application dates, crop prices, and overall profits.

They found that the tool reduced fertilizer use by 30 to 50 percent and reduced fertilizer costs by up to 39 percent. The enhanced testing methods had little effect on corn production profits, but increased profits by 7 to 18 percent in wheat, oat, and sorghum fields. The results were published in the Open Journal of Soil Science.

Read more about this research in the July 2014 issue of Agricultural Research magazine.

Categories: USDA

Calcium Makes for an Environmentally Friendly Pickle

USDA Agricultural Research Service - Mon, 07/07/2014 - 08:14
Calcium Makes for an Environmentally Friendly Pickle / July 7, 2014 / News from the USDA Agricultural Research Service
Read the magazine story to find out more.

 A cheeseburger on a bun with container of pickle slices. Link to photo information
ARS scientists have developed a way to replace most of the salt in pickle processing with calcium chloride, solving one of the industry's major environmental problems. Click the image for more information about it.


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Calcium Makes for an Environmentally Friendly Pickle

By Kim Kaplan
July 7, 2014

U.S. Department of Agriculture (USDA) scientists have developed a way to help pickle producers replace most of their pickling salt with calcium chloride. This is helping turn an environmental problem into an environmental plus for the pickle industry.

The U.S. pickle industry has been facing growing environmental troubles with disposing of the salty brining solution used to turn cucumbers into pickles. Americans consume nine pounds of pickles per capita each year. Brine disposal was one of the factors that helped push the California olive pickling and processing industry out of that state and overseas in the 1980s.

But microbiologist Ilenys Pérez-Díaz, food technologist Suzanne Johanningsmeier and chemist Roger F. McFeeters (now retired) at the Agricultural Research Service (ARS) Food Science Research Unit in Raleigh, North Carolina, have developed a way to replace most of the sodium chloride in the brine—the pickling liquid—with calcium chloride. Used calcium chloride solution can be a desirable soil amendment rather than a pollutant disposal problem.

ARS is USDA's chief intramural scientific research agency.

Using calcium chloride not only retains desirable firmness in cucumbers as they pickle, but also speeds up the microbiological work of fermentation, according to the researchers.

The technology has already been put to work commercially at the Mt. Olive Pickle Company of Mt. Olive, North Carolina, the largest independent pickle company in the United States, where 66,000 bushels of cucumbers were turned into hamburger dill chips and several flavors of pickle relishes and salad cubes in 2013, using the calcium chloride. While that represented only a small part of the company's annual production, it proved there is a workable answer to at least part of the industry's environmental problem.

The lowered salt is strictly a processing issue and has no impact on the dietary salt content of a pickle.

Now Pérez-Díaz and Johanningsmeier are modifying the calcium chloride technology as a way to preserve gherkin pickles that are imported in acid solution from India. Currently, gherkins undergo a 40-day Atlantic transit packed in vinegar, salt and sulfite; the last ingredient has come to be considered an undesirable ingredient, as some people are sensitive to it. Sulfite would not be needed with new brine formulation.

The United States is a major gherkin market, but India also supplies gherkins to many other countries, so improving the health and environmental circumstances of this product could have worldwide impact.

Read more about this research in the July 2014 issue of Agricultural Research magazine.

Categories: USDA

ARS Scientists Help Improve Soil Carbon Calculations

USDA Agricultural Research Service - Thu, 07/03/2014 - 06:40
ARS Scientists Help Improve Soil Carbon Calculations / July 3, 2014 / News from the USDA Agricultural Research Service
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 A field of crop residues.
ARS scientists have identified factors affecting the measurement of soil carbon sequestration, which is important in assessing how farming practices can reduce carbon emissions. Photo courtesy of NRCS-USDA.


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ARS Scientists Help Improve Soil Carbon Calculations

By Ann Perry
July 3, 2014

A potential source of error in calculating soil carbon budgets has been identified by scientists at the U.S. Department of Agriculture (USDA).

Agricultural Research Service (ARS) soil scientist Hero Gollany has used these findings to refine methods for assessing farming practices that retain carbon in the soil and thus mitigate carbon emissions that contribute to global climate change. ARS is USDA's chief intramural scientific research agency, and these findings support the USDA priority of responding to climate change.

Rates of soil carbon retention, known as sequestration, are often measured and estimated by tracking changes in total soil carbon over time. Carbon from crop residues or other decaying plant material is present in soil samples collected for these sequestration studies. But this "accrued" carbon is not actually sequestered in the soil until after the carbon becomes attached to soil mineral particles, a process that can take several decades.

Until that happens, the accrued carbon from decomposing plant material can readily be lost from the soil, because it is not bound or associated with soil particles. Inadvertently adding the accrued carbon to measurements of sequestered carbon results in overestimates of how agronomic practices affect sequestration levels.

Gollany and Washington State University soil microbiologist Ann-Marie Fortuna used data from another soil carbon field study to see how levels of a specific type of carbon called "light-fraction" carbon affected measurements. Using this method, the scientists determined that carbon sequestration levels measured in the study included carbon from fine crop residue materials that passed through sieves during sample processing—carbon that had accrued in the soil, but was not yet sequestered via decomposition.

This accrued carbon ranged from 13 percent to 19 percent of the total soil carbon in the samples. This, in turn, skewed attempts to use carbon data from the samples to model soil carbon sequestration levels.

Gollany, who works at the ARS Soil Conservation Research Unit in Pendleton, Oregon, published her findings in 2013 in the Soil Science Society of America Journal.

Read more about this work in the July 2014 issue of Agricultural Research magazine.

Categories: USDA

Orange-fleshed Honeydew: Ripe for Beta-carotene Analysis

USDA Agricultural Research Service - Tue, 07/01/2014 - 06:54
Orange-fleshed Honeydew: Ripe for Beta-carotene Analysis / July 1, 2014 / News from the USDA Agricultural Research Service
Read the magazine story to find out more.

 Orange-fleshed honeydew melon. Link to photo information
Orange-fleshed honeydew melon and cantaloupe are both comparable sources of dietary provitamin A, on par with carrots, which are known to be a major source of provitamin A. Click the image for more information about it.


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Orange-fleshed Honeydew: Ripe for Beta-carotene Analysis

By Rosalie Marion Bliss
July 1, 2014

Orange-fleshed honeydew melon is a cross between cantaloupe and green-fleshed honeydew. Orange-fleshed honeydew melon is sweeter and stores longer than the typical cantaloupe. To learn more about the melons, U.S. Department of Agriculture (USDA) plant physiologist Gene Lester and his colleagues measured the beta-carotene concentrations in orange-fleshed honeydew and cantaloupe melons grown under the same greenhouse conditions.

Carotenoids such as beta-carotene are also known as provitamin A. Beta-carotene is the most potent precursor of vitamin A for humans, which means the body breaks down beta-carotene into vitamin A.

Lester is with the USDA Agricultural Research Service (ARS) Office of National Programs in Beltsville, Maryland. ARS is USDA's principal intramural scientific research agency.

The team found that orange-fleshed honeydew had significantly higher beta-carotene concentrations than cantaloupe, but the two melon types had similar beta-carotene bioaccessibility. Before the human body can make use of a fruit's nutrients, the nutrients must first be released from the fruit tissues, becoming "bioaccessible," and then the nutrients can be absorbed into the circulation, becoming "bioavailable." This means that both melons appear to be comparable sources of dietary provitamin A for humans, on par with carrots, which are known to be a major source of provitamin A.

When testing orange-fleshed melons, the team also noticed indications of compounds not seen before, so they used more sophisticated instrumentation to show that these compounds were apocarotenoids. This is significant because apocarotenoids are metabolized directly into vitamin A. Previously, the researchers did not know apocarotenoids were in orange-fleshed melons.

Lester's team detected and measured levels of the apocarotenoids beta-apo-13-carotenone, beta-apo-14-carotenal, beta-apo-12-carotenal, beta-apo-10-carotenal, and beta-apo-8-carotenal in the orange-fleshed melons.

Read more about this published research in the July 2014 issue of Agricultural Research magazine.

Funding support for the study was provided by USDA and by grants from the National Institutes of Health.

Categories: USDA

Nanoparticle-based Coating Helps Stop Water from Beading

USDA Agricultural Research Service - Mon, 06/30/2014 - 07:13
Nanoparticle-based Coating Helps Stop Water from Beading / June 30, 2014 / News from the USDA Agricultural Research Service
Read the magazine story to find out more.

 Only the right half of this plastic container has been treated with a new coating that prevents water from beading. Link to photo information
ARS scientists have developed a new coating, beginning with either a bovine protein or a wheat protein as a building block, that keeps water from beading up on windows. Click the image for more information about it.


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Nanoparticle-based Coating Helps Stop Water from Beading

By Marcia Wood
June 30, 2014

Rainwater pounding on the glass windows of an office building or a home is less likely to bead up and reduce visibility if the windows are treated with a new, transparent coating from U.S. Department of Agriculture (USDA) chemist Sanghoon Kim and his colleagues.

Besides its potential use on windows, the coating might also be applied to solar panels to help keep dirt from interfering with their performance, Kim notes.

What's more, Kim and his colleagues have observed that the coating works well on other materials, including Plexiglas and metals such as stainless steel.

Kim, along with research chemist Atanu Biswas and physical scientist Kervin Evans—all with the USDA Agricultural Research Service (ARS) National Center for Agricultural Utilization Research in Peoria, Illinois—created the coating's nanoparticles by using only a few off-the-shelf laboratory chemicals, including a protein from agriculture.

From start to finish, production of the nanoparticles takes less than an hour, involves simple procedures with inexpensive chemicals, and doesn't require specialized equipment or costly heating.

In a proof-of-concept experiment, the researchers used bovine serum albumin, which is a cattle industry byproduct, as the protein, and ethyl cyanoacrylate, a major component of "super glue," as the starting material that is key to creating the nanoparticles.

Applying the coating is quick and easy. All that's needed is to spray it onto clean glass or other recommended surfaces, then rinse with water.

In a follow-up study, Kim and his colleague Yeon Seok Kim of the National Institute of Standards and Technology, used gliadin, a protein from wheat, to demonstrate that their process for making the coating is applicable to both plant- and animal-derived proteins.

Peer-reviewed scientific articles published this year in the Journal of Nanoparticle Research and in 2013 in Colloids and Surfaces B: Biointerfaces have details about the work.

Informal cost estimates suggest that the new coating, made with either a plant or an animal protein, could be produced at the same or less cost than coatings already on the market.

The Peoria coating is rain-ready in about a minute, a feature that apparently makes it unique. ARS is seeking a patent for the research; the scientists are looking for industry partners to commercialize it.

Read more in the May/June 2014 issue of Agricultural Research magazine.

ARS is the USDA's chief intramural scientific research agency.

Categories: USDA

Researchers Study New Class of Animal Deworming Agent

USDA Agricultural Research Service - Mon, 06/23/2014 - 07:01
Researchers Study New Class of Animal Deworming Agent / June 23, 2014 / News from the USDA Agricultural Research Service
Read the magazine story to find out more.

 Three pigs in a pen. Link to photo information
A new environmentally friendly deworming agent derived from Bacillus thuringiensis was found to be effective against intestinal roundworms in pigs, according to new research. Click the image for more information about it.


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Researchers Study New Class of Animal Deworming Agent

By Rosalie Marion Bliss
June 23, 2014

After two moderate doses of a bacteria-derived protein were fed to worm-infected swine in an experiment, all intestinal roundworm larvae in the swine were damaged or destroyed and the infection was nearly completely eliminated, according to U.S. Department of Agriculture (USDA) and University of California-San Diego scientists.

The research team included microbiologist Joseph Urban and his colleagues at the USDA Agricultural Research Service (ARS) Beltsville Human Nutrition Research Center in Beltsville, Maryland, and Raffi Aroian and Yan Hu at the University of California-San Diego. ARS is USDA's chief intramural scientific research agency.

The parasitic roundworm that commonly infects pigs is Ascaris suum, which is genetically similar to A. lumbricoides, a roundworm species that infects about 1 billion people worldwide. A. suum infection in pigs is considered a good model for A. lumbricoides infection in humans because of its similar migration through the body and to the intestines.

During the experiments, the team used a crystal protein called "Cry5B," provided by Aroian's group, which is derived from the soil bacterium Bacillus thuringiensis. Cry5B protein is considered nontoxic to vertebrates and mammals.

The dosage the team provided in the study is comparable to the dose range used in existing commercial antiparasitic drugs. The results show the potential of Cry5B to treat Ascaris infections in pigs and other livestock and to work effectively in the human gastrointestinal tract, according to authors. The team described the research in a 2013 article published in PLOS: Neglected Tropical Diseases.

There is a need for more practical delivery systems for antiparasitic drug treatments, according to the scientists, and further cooperative research is planned.

Read more about this research in the May/June 2014 issue of Agricultural Research magazine.

Categories: USDA

Peter Raven Receives U.S. National Arboretum's Medal of Excellence

USDA Agricultural Research Service - Tue, 06/17/2014 - 13:06
Peter Raven Receives U.S. National Arboretum's Medal of Excellence / June 17, 2014 / News from the USDA Agricultural Research Service

 Peter H. Raven, president emeritus of the Missouri Botanical Garden. Link to higher resolution photo.
The U.S. National Arboretum bestowed its Medal of Excellence on Peter H. Raven, president emeritus of the Missouri Botanical Garden, for his career promoting gardens and ornamental horticulture as a way to interest the public in plant conservation and biodiversity. Photo courtesy of Missouri Botanical Garden. Click for high resolution.

Peter Raven Receives U.S. National Arboretum's Medal of Excellence

By Kim Kaplan
June 17, 2014

WASHINGTON, June 17, 2014—The U.S. National Arboretum has awarded its Medal of Excellence to botanist and environmentalist Peter H. Raven in recognition of his career and scientific accomplishments as one of the world's foremost advocates for biodiversity. The Arboretum is operated in Washington by the Agricultural Research Service (ARS), the chief intramural scientific research agency of the U.S. Department of Agriculture.

"What Peter Raven has done to encourage people from the highest levels of policy making to the general public to care about protecting plants is remarkable," said Colien Hefferan, director of the Arboretum. "He literally transformed public gardens into tools of outreach to help people understand the value of science in preserving biodiversity and the conservation of plants. As a scientist and a person, he has made enduring contributions to the planet and its inhabitants."

Raven has promoted gardens and ornamental horticulture as a way to interest the public in conservation and supporting sustainable environments. Time magazine described Raven as a "Hero for the Planet" for his career as an outspoken leader championing research around the world to preserve endangered plants.

His scientific accomplishments encompass the fields of plant systematics, evolution and ecology. He may be best known scientifically for his important article entitled "Butterflies and Plants: A Study in Coevolution," published in the journal Evolution in 1964. He also wrote the widely used textbook "Biology of Plants."

Raven led the Missouri Botanical Garden from a quiet city garden to one of the world's great centers for horticultural research, education, and display during his 40 years as its director from 1971 until 2011. He is now the president emeritus of the Missouri Botanical Garden.

He has received many other prizes and awards, including the U.S. National Medal of Science, the nation's highest honor for scientific achievement; Guggenheim and John D. and Catherine T. MacArthur Foundation fellowships; and the International Cosmos Prize. He was also a member of President Clinton's Committee of Advisors on Science and Technology, and served as home secretary of the National Academy of Sciences.

The arboretum's 446 acres in northeast Washington, D.C., serve the public need for scientific research, education, and gardens that conserve and showcase plants to enhance the environment.

This is only the third time the U.S. National Arboretum has given its Medal of Excellence. The first time honored former First Lady Lady Bird Johnson and her Committee for a More Beautiful Capital in 2002 for their sustained contributions in beautifying Washington, D.C., and other areas of the country with trees, flowers and other ornamental plantings as part of the Arboretum's 75th anniversary.

The other medal was awarded in 2011 to Robert Bartlett, chief executive officer of Bartlett Trees, who has dedicated himself and his company to researching and conserving trees on public and private lands through the development of science-based, sustainable management practices to protect and improve the tree canopy across the nation, including at Arlington National Cemetery.

Categories: USDA

Using Tree Tannins to Target Manure Odor

USDA Agricultural Research Service - Mon, 06/16/2014 - 07:52
Using Tree Tannins to Target Manure Odor / June 16, 2014 / News from the USDA Agricultural Research Service
Read the magazine story to find out more.

 Microbiologists Terry Whitehead checks a manure sample from a pig. Link to photo information
Tannins from the quebracho tree may be able to quell the smell of swine manure pits, according to research by ARS microbiologist Terry Whitehead. Click the image for more information about it.


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Using Tree Tannins to Target Manure Odor

By Ann Perry
June 16, 2014

Tannins from the quebracho tree can control the production of compounds that cause manure odors, according to studies by U.S. Department of Agriculture (USDA) scientists. This research may someday give livestock farmers options for odor control that help protect animal health and restore harmony between rural producers and nearby residents.

The study was done by Agricultural Research Service (ARS) scientists in Peoria, Ill. ARS is USDA's chief intramural scientific research agency.

Hydrogen sulfide and other sulfur compounds make up about half of the offensive odorants from swine manure. Scientists have determined that a group of microbes called sulfate-reducing bacteria generate these compounds as part of the process of breaking down manure. Bacterial activity in manure pits also generates methane and nitrous oxide, which are both greenhouse gases.

Research conducted by scientists elsewhere indicated that tannins-compounds naturally present in tree leaves and other feed materials-can block bacterial activity in the guts of ruminant livestock. Drawing on this research, ARS microbiologists Terry Whitehead and Mike Cotta, who work at the agency's Bioenergy Research Unit in Peoria, conducted a laboratory study to see if quebracho tree tannins could suppress odor-generating bacterial activity in manure.

The scientists incubated swine manure under laboratory conditions that mimic on-farm conditions, which allowed them to monitor gas emissions and sulfate-reducing bacteria populations. Seven days after the researchers added quebracho tannins to the manure, they found hydrogen sulfide and methane production had been reduced more than 90 percent and that production continued to dwindle for another three weeks. Populations of sulfate-reducing bacteria also significantly declined, by 70 percent to 90 percent, in the tannin-enriched mix.

Field studies are now needed to determine if using quebracho tannins in manure pits can significantly reduce the activity of sulfate-reducing bacteria and hydrogen sulfide and methane levels under commercial conditions. If successful, this approach would provide producers with a cost-effective method of mitigating odors and greenhouse gas emissions, and the added tannins would not pose a risk to the environment when the manure is eventually spread onto the fields as fertilizer.

Whitehead and Cotta published their results in the December 2012 issue of Applied Microbiology and Biotechnology. Read more about this work in the May/June 2014 issue of Agricultural Research magazine.

Categories: USDA

USDA Research on Climate Change, Effects of Warmer Winters Published in PLOS ONE

USDA Agricultural Research Service - Wed, 06/11/2014 - 15:16
USDA Research on Climate Change, Effects of Warmer Winters Published in PLOS ONE / June 11, 2014 / News from the USDA Agricultural Research Service

 Link to photo information
Warming temperatures linked with global climate change may mean that growers will need to use more pesticides to hold off pests and maintain soybean production levels, according to new ARS research. Click the image for more information about it.


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USDA Research on Climate Change, Effects of Warmer Winters Published in PLOS ONE

By Ann Perry
June 11, 2014

WASHINGTON, June 11, 2014—Findings from research at the U.S. Department of Agriculture (USDA) conducted by Agricultural Research Service (ARS) plant physiologist Lewis Ziska and published today in the scientific journal PLOS ONE project changes in crop production as air temperatures increase due to climate change. ARS is USDA's chief intramural scientific research agency, and the research supports the USDA priority of responding to climate change.

In the study published today, researchers observed one of the effects that agricultural producers may see as air temperatures increase is a corresponding increase of insects, weeds and fungal pests because of milder winter temperatures. One possible result is growers may need to increase their pesticide use to respond to these pests and maintain soybean production levels.

"One of our most crucial challenges is finding ways to maintain and increase crop production levels in the face of climate change," said ARS Administrator Chavonda Jacobs-Young. "These studies underscore the importance of conducting research that helps us confront these challenges and facilitates the development of cost-effective options for the environmentally sustainable production of food, feed, and fiber."

In temperate regions, the distribution and survival of agricultural pests is often kept in check by low winter temperatures. Ziska, who works at the ARS Crop Systems and Global Change Laboratory in Beltsville, Maryland, examined average pesticide applications since 1999 for commercial soybean grown over a 1,300-mile longitudinal transect from Minnesota to Louisiana. Minimum daily temperatures in this study area ranged from -20 degrees Fahrenheit to 23 degrees Fahrenheit.

Although soybean yields per acre did not vary by state, increases in total pesticide applications were positively correlated with increases in minimum winter temperature. This suggested that rising minimum temperatures could be a good proxy for increased pesticide use.

Ziska determined that from 1977 through 2013, minimum winter temperatures were increasing throughout the transect, although the rate of increase was greater for northern states like Minnesota than for southern states like Louisiana. This observation is consistent with the Intergovernmental Panel on Climate Change projections regarding enhanced warming with increasing latitude.

Using these findings to project future pesticide use, Ziska determined that if these temperature trends continue, soybean pesticide use by region in the next 10 years may also change, with herbicide use increasing in the north and insecticide and fungicide use increasing in the south. Overall, according to Ziska, these results indicate that increases in pesticide application rates may be a means to maintain soybean production in response to potential increases in pest pressures associated with rising minimum daily temperatures and climate change.

Categories: USDA

New Approach to Studying Fungus' Attack on Soybeans

USDA Agricultural Research Service - Mon, 06/09/2014 - 06:49
New Approach to Studying Fungus' Attack on Soybeans / June 9, 2014 / News from the USDA Agricultural Research Service
Read the magazine story to find out more.


ARS plant pathologist Shuxian Li has made the fungus that causes a serious disease in soybeans glow under ultraviolet light so researchers can now study how the infection process unfolds within the tissues of the seeds for the first time. Click the image for more information about it.


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New Approach to Studying Fungus' Attack on Soybeans

By Jan Suszkiw
June 9, 2014

A new laboratory technique developed by Agricultural Research Service (ARS) scientists could speed the search for soybean plants with resistance to the fungus that causes Phomopsis seed decay (PSD) in the legume crop.

A disease primarily caused by the fungus Phomopsis longicolla, PSD physically degrades soybean seed and reduces the quality of its protein and oil. In 2012, outbreaks of PSD and other fungal diseases cost soybean producers in 16 southern states more than 2 million bushels in losses.

Applying fungicides, rotating soybeans with nonhost crops and tilling the soil are among strategies used by growers to prevent PSD. However, breeding for resistance to PSD is the most effective long-term strategy, according to Shuxian Li, a plant pathologist with the ARS Crop Genetics Research Unit in Stoneville, Mississippi.

As part of a Phomopsis resistance program there, Li has sought to learn more about how the fungus inflicts harm at the cellular level. Towards that end, she and colleagues enlisted the aid of Agrobacterium tumefaciens, a species of soil bacteria commonly used in genetic engineering procedures to endow plants with new traits.

In this instance, the team used the bacterium to "shuttle" genes for an antibiotic marker and green fluorescent protein (GFP) into the nucleus of the fungus' cells. This resulted in new P. longicolla strains that produce the protein and emit a green glow when exposed to light in the blue-to-ultraviolet range.

Li plans on inoculating soybean seedlings with the modified strains to study how the infection process unfolds within the tissues of both resistant and susceptible soybean germplasm lines. The approach should also facilitate the identification of sources of PSD resistance that may escape detection using conventional disease-screening methods, such as those requiring field observation of symptoms.

The research was published in the Journal of Microbiological Methods.

Read more about this research in the May/June 2014 issue of Agricultural Research magazine.

ARS is the U.S. Department of Agriculture's chief intramural scientific research agency.

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