Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Techniques available to detect soil that inhibits destructive soybean pest

04.07.2005


Female soybean cyst nematodes, attached to the roots of the plants and filled with eggs, are white. The nematodes turn brown as their bodies become cysts harboring the eggs that hatch into juveniles, which continue the cycle of stealing nutrients from the plants. (Photo/Andreas Westphal, Purdue University)


Identification of soils that inhibit a tiny soybean-destroying organism is an important tool in reducing yield losses, according to a Purdue University plant pathologist.

Soybean cyst nematodes cause between $800 million and $1 billion annually in crop losses in the United States, according the American Phytopathological Society. However, techniques are available to find soils that specifically suppress these microscopic roundworms, said Andreas Westphal, assistant professor of plant pathology. The female nematodes are white, lemon-shaped parasites that become dead brown shells filled with maturing eggs. Some soils have as yet not-understood characteristics that don’t foster development of the pests.

Westphal, whose research focuses on soybean cyst nematodes and ways to thwart them, said that using nematode-suppressive soils is an easily implemented, environmentally friendly weapon in fighting the parasites, which are found worldwide in soybean-producing areas.



"Using plants bred to resist pests is not the complete answer, so it’s important to find suppressive mechanisms," Westphal said. "Bio-control is much more desirable than using chemicals in order to limit damage to the environment."

In a paper published in the just-released March 2005 issue of the Journal of Nematology, Westphal summarizes the techniques for identifying soil that specifically suppresses soybean cyst nematodes. He also discusses how to use nematode-suppressive soils to battle the root-dwelling pests and the limitations of the techniques.

In previous research on a different cyst nematode, Westphal and his colleagues determined that mixing 1 percent to 10 percent of nematode-suppressive soil into the top layer of a soybean field plot effectively decreased nematode activity. In addition, they know that viability of plants and soil richness, moisture and temperature can affect how active and numerous soybean cyst nematodes are in particular fields.

"A key find was that a small amount of suppressive soil or a cyst from a suppressive soil can lower nematode numbers," Westphal said. "We promote conditions in soil to suppress the nematode, and we also study the soil so that we can determine the mechanisms that create suppression."

Some types of fungi and other organisms help keep the soil healthy by feeding on nematodes. Whether a field is tilled can affect nematode population density, but it’s not yet known whether this is related to a change in the number of nematode-eating microbes, Westphal said. Further study is needed on how microbial communities function in order to determine conditions that contribute to nematode development.

Westphal was able to confirm the nematode supressiveness of soil by using treatments to eliminate soil organisms and other elements that inhibit nematode development. Another confirmation technique was to add suppressive soil to soils conducive to nematode development. The researchers also were able to document reduced nematode reproduction, population density, and whether certain types of soil were suppressive to specific pathogens.

"Currently, we are extending this research to finding ways to create more nematode suppression in soil," Westphal said. "This is important because nematode populations constantly change so they can overcome certain types of resistance, including even plants that are bred to be resistant to the organisms."

Westphal and his research team conducted a survey throughout Indiana to locate nematode-suppressive soils in an effort to make this tool more available and to further study the mechanisms that create its effectiveness against the pathogen.

Soybean cyst nematodes, one of a large, diverse group of multicellular organisms, are the most destructive soybean pathogen in the United States. The nematodes were first documented in Japan in the early 20th century and first reported in the United States in 1954. However, evolutionary biologists believe the pests were probably present in both areas as much as thousands of years earlier.

The females of the species use a short, hypodermic needle-like mouth to pierce soybean roots and suck out the nutrients. As the adult female ages, she fills with eggs, turns yellow and then brown to become the nematode cyst. At that point her body is a case to protect hundreds of eggs while they mature, hatch into juveniles and leave the cyst to further attack the plant roots. Swollen females can be seen with the naked eye, but worm-like juveniles and males can best be seen with a microscope.

As nematodes steal nutrients from the roots, the plants are weakened and don’t grow well. Subsequently, plants may be more vulnerable to attack by other stresses, such as insects, diseases and drought.

It’s often impossible to see symptoms of soybean cyst nematode damage, so soil and roots must be tested to reveal or confirm the pests’ presence. Infestation gradually causes progressively lower yields and the worst cases result in yellow and stunted soybean plants. Plants with severe, visible damage can occur in patches in highly infested fields.

There are no pesticides that will eradicate soybean cyst nematode, which also preys on other legumes and some grasses.

The United States Department of Agriculture is providing funding for Westphal’s study of the soybean cyst nematode.

Susan A. Steeves | EurekAlert!
Further information:
http://www.purdue.edu

More articles from Agricultural and Forestry Science:

nachricht Plasma-zapping process could yield trans fat-free soybean oil product
02.12.2016 | Purdue University

nachricht New findings about the deformed wing virus, a major factor in honey bee colony mortality
11.11.2016 | Veterinärmedizinische Universität Wien

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>