ARS News Service
Agricultural Research Service, USDA
Jim DeQuattro; 301-344-2756; [email protected]
May 31, 1997
Heat Wave Forecasts Could Help Save Cattle
MINNEAPOLIS, May 30--Strings of scorching days and muggy nights could push
feedlot cattle perilously close to death unless feedlot managers keep a
close eye on weather forecasts and take precautions to protect the animals,
a U.S. Department of Agriculture scientist warns.
G. LeRoy Hahn, an agricultural engineer with USDA's Agricultural Research
Service said hot weather management options may include having water
sprinklers available to provide relief, avoiding handling or transporting
cattle, providing adequate shade, ensuring that livestock waterers are
clean and working well, and providing at least two waterers per pen. Hahn
conducts research at the Roman L. Hruska U.S. Meat Animal Research Center
in Clay Center, Nebraska.
Speaking here at the Fifth International Livestock Environment Symposium
sponsored by the American Society of Agricultural Engineers, Hahn reported
on an ARS-led study of the impact on livestock from the July 1995 heat wave
in the mid-central United States. That heat wave is estimated to have cost
the U.S. cattle industry $28 million in animal deaths and reduced livestock
performance. But it also gave researchers an opportunity to more closely
study temperature and humidity conditions linked to livestock deaths.
In his studies on the effect of heat stress on cattle, Hahn used a
Temperature-Humidity Index (THI) chart that can be viewed on the World Wide
Web at: http://ianrwww.unl.edu/ianr/pubs/extnpubs/animgen/g57.htm
Scientific contact: G. LeRoy Hahn, Roman L. Hruska U.S. Meat Animal
Research Center, Clay Center, NE 68933, phone (402) 762-4271, fax 762-4273,
[email protected].
Fungus Is a Crop-Friendly Weed Whacker
A new biological control agent offers a natural alternative to chemicals
now used to combat sicklepod and coffee senna, two major weeds in southern
crops such as soybeans, cotton and peanuts.
Scientists with USDA's Agricultural Research Service say two applications
of a mixture of corn oil, water and spores of the fungus Colletotrichum
gloeosporioides killed 95 percent of newly emerged sicklepod in soybeans.
Three years of field tests showed overall weed populations were reduced 90
percent. Plant pathologist C. Douglas Boyette led the tests at ARS'
Southern Weed Science Laboratory, Stoneville, Miss.
Scientific contact: C. Douglas Boyette, ARS Southern Weed Science
Laboratory, Stoneville, Miss., http://nola.srrc.usda.gov/usdadsrc/swsl.htm,
phone (601) 686-5217; fax 686-5265, e-mail [email protected].
Potato Late Blight May Be Arrested Earlier
Growing potatoes without fungicides to control late blight may be only
about 5 years away, because of research progress at finding potatoes with
natural resistance.
Scientists at the Agricultural Research Service and universities evaluated
17 potato clones reported having some natural resistance. Of the top four
clones, three came from the ARS Vegetable Lab, Beltsville, Md., and one
from the ARS potato breeding program at Aberdeen, Idaho. ARS has released
two Beltsville clones to other breeders. These two selections resist the
most virulent late-blight strains. Some less-resistant clones still would
need less fungicide than commercial varieties.
Several years ago, ARS scientists in Madison, Wis., discovered natural
resistance in a wild Mexican potato species. They combined its genes with
those of commercial potatoes. The resulting breeding line, grown without
fungicides, yielded 20 tons of spuds per acre in field tests last year. The
scientists recently developed a gene probe from the wild species. It may
let breeders determine if potato seedlings are resistant even before
they're planted. This would speed availability of resistant varieties for
farmers.
Scientific contacts: Kenneth L. Deahl, ARS Vegetable Laboratory,
Beltsville, Md., phone (301) 504-7380, fax 504-5555,
[email protected]; and John P. Helgeson, ARS Plant Disease Resistant
Research Unit, Madison, Wis., phone (608) 262-0649; fax 262-1541; e-mail
[email protected].
Trickle-L Group Offers Online Expertise to Growers, Gardeners
Growers and gardeners with questions about drip irrigation can turn to an
Internet discussion group called Trickle-L for fast help.
Trickle-L was launched in 1994 by the Agricultural Research Service's
Water Management Research Laboratory in Fresno, Calif. Today, Trickle-L
links about 500 scientists, farmers, golf course managers, irrigation
equipment manufacturers and others interested in drip irrigation.
Sometimes called trickle irrigation or micro-irrigation, drip irrigation
systems rely on tiny sprayers to deliver precise amounts of water to
plants.
Scientific contact: Thomas J. Trout, USDA-ARS Water Management Research
Laboratory, 2021 S. Peach Ave., Fresno, CA 93727, phone (209) 453-3101,
fax 453-3211, e-mail [email protected].
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