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Science Update
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Kudzu KO'd by Fungus
A fungus from the sicklepod plant, Arabis canadensis, found in the
southeastern United States, effectively controls kudzu. This invasive weed from
southeast Asia covers more than 7 million U.S. acres and spreads across about
120,000 more each year.
Both greenhouse and field studies have shown the fungus Myrothecium
verrucaria to be lethal to kudzu. Applied at different plant growth stages
and under varying physical and environmental conditions, it proved to be 100
percent effective in controlling this fast-growing weed.
Originally, kudzu was promoted in the 1800s as an erosion control and cheap
livestock forage for the eastern and southern United States. Now its control
costs increase by nearly $6 million each year, and homeowners struggle to curb
its quick growth up the sides of buildings, along fences, and on telephone
poles. Typical controls include treating with herbicides and mowing, but they
are not highly efficient.
Testing of the fungus on several economically important hardwood and softwood
trees showed no harmful effects. And even though the fungus can injure and kill
soybean plants, proper timing and application techniques minimize injury. In
fact, directed-spray applications of the fungus to sicklepod seedlings in
soybeans showed no resulting injury. Researchers will seek a patent.
C. Douglas Boyette, USDA-ARS
Southern Weed
Science Research Unit, Stoneville, Mississippi; phone (601) 686-5217.
Deconstructing Cotton's Fibers
Defects in processed cotton fabrics resulting from lint fiber imperfections
cost U.S. textile makers millions annually. Now researchers are closing in on
the biochemical bases for cotton lint's success as a durable, widely used
natural plant fiber. This may help them further improve strength, uniformity,
and other fiber properties desired by textile and clothing makers.
The scientists—working with Glycozyme, Inc., of Irvine,
California—are modeling lint fiber's biochemical and physiological
development in cotton bolls. Using samples collected from California,
Mississippi, and South Carolina cottonfields, they're compiling data to show
how environmental factors like day length, drought, or temperature changes
affect fiber properties—especially imperfections like variable fiber
thickness that can plague lint processing.
Ultimately, growers with such information will be better able to predict their
crop's chief fiber properties before harvest and take steps to market it
accordingly.
Judith Bradow, USDA-ARS
Cotton Fiber
Quality Research Unit, New Orleans, Louisiana; phone (504) 286-4479.
Gretchen Sassenrath-Cole, USDA-ARS
Application
and Production Technology Research Unit, Stoneville, Mississippi; phone
(662) 686-3289.
High-Tech Soy From Back-to-Basics Breeding
Oil from the new soybean called Soyola needs no hydrogenation to improve its
usefulness for cooking, extend its shelf life, or harden it for baking and
margarine. That's good news, because hydrogenation produces the bulk of dietary
trans fats increasingly recognized as unhealthy for the heart. Also, Soyola
evolved from conventional plant breeding methods. It's the first release under
the Better Bean Initiative (BBI) launched in 1998 by the United Soybean Board.
The initiative includes 22 scientists working in 11 public soybean-breeding
programs.
Developed for the southern United States, Soyola yields oil with about half the
linolenic acid of today's commercial varieties. This is the polyunsaturated
fatty acid that degrades easily and causes "off" or rancid flavors in
soyoil, especially after extended heating. Developers think Soyola—ideal
for frying and salad oil markets—will help keep market options open and
enhance the competitiveness of U.S. soybeans in world trade.
Future BBI plans call for breeding soybeans with reduced levels of both
linolenic and palmitic acid (a saturated fat) and increased levels of
heart-healthy oleic acid that's abundant in olive and canola oils.
Joseph W. Burton,
USDA-ARS Soybean
and Nitrogen Fixation Research Unit, Raleigh, North Carolina; phone (919)
515-2734.
Microbes in Transplant Mix Boost Yields
By adding two naturally occurring soil microorganisms—Paenobacillus
macerans and Bacillus amyloliquefacien—to a transplant mix
called BioYield 213, scientists are reducing yield losses caused by soilborne
pathogens. The mix gives the beneficial microorganisms the environment they
need to grow on seedling roots. The microbes then stimulate vigorous growth and
improve the health of transplanted seedlings by triggering the plants'
resistance mechanisms.
Greenhouse producers can expect to grow seedlings in less time, and farmers can
anticipate 5- to 20-percent yield increases in tomatoes, bell peppers, and even
strawberries. When the beneficial microorganisms are combined with other
alternative soil treatments, such as Telone II and Plantpro 45, levels of crop
productivity approach those achieved with methyl bromide. This research is part
of the ongoing ARS effort to provide farmers with alternatives to the soil
fumigant methyl bromide, which is slated for phaseout by 2005.
Nancy K. Burelle, USDA-ARS
U.S. Horticultural
Research Laboratory, Fort Pierce, Florida; phone (561) 462-5861. |
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"Science Update" was published in the
October 2000
issue of Agricultural Research magazine.
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