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A new line of long grain rice that fends off two key fungal diseases
has been released to breeders and seed companies. Few cultivars grown
today by American farmers can withstand both of the diseases. ARS
researchers developed, tested and released the line, dubbed B82-761. It
resists Rhizoctonia solani and nine races of Pyricularia
grisea. R. solani causes sheath blight; P. grisea is the
culprit behind a disease called blast. Throughout the South, the two
diseases can cause yield losses of 10 to 50 percent in rice fields.
Breeders can use B82-761 to develop rice that fends off both. ARS
scientists produced the resistant line by crossing Vista, a medium grain
rice, with Lebonnet, a long grain variety. In 1992-93 field tests, it
showed better disease resistance than Gulfmont, Lemont and other leading
commercial cultivars. Plants of B82-761 grow four-and-one-half-feet high
and mature in about 17 weeks. The grain is high in amylose, is an
important starch component, and has excellent cooking and processing
properties.
Rice Research Unit, Beaumont, TX
Anna M. McClung, (409) 752-5221
Black Ruby is a new Japanese-type plum that grows well in the humid
climate of the southeastern United States. Bearing large,
high-quality fruit in late June to early July, this plum has reddish-black
skin and firm, yellow flesh. Black Ruby withstands plum leaf scald and is
moderately resistant to bacterial diseases that attack plums in the
southeast. Trees will be available this winter from nurseries in
Tennessee and are recommended for testing in states that have a similar
climate.
Southeastern
Fruit and Tree Nut Research Laboratory, Byron, GA
W.R. Okie, (912) 956-6405
A new, automated system for applying pesticide on greenhouse plants
eliminates the need for hand-held sprayers. Under standard safety
regulations, greenhouse workers must wear masks and heavy protective
suits. But in a hot, humid greenhouse, the temperature inside a
protective suit can quickly soar to the boiling point. That can lead to
dizziness and fainting. To eliminate this hazard, ARS mechanical
engineers built a system in which compressed air forces pesticides through
flexible pipes and special nozzles, misting the chemicals onto plants. A
worker only mixes the pesticide with water according to the manufacturer's
specifications, then flips a toggle switch. This temporarily closes the
greenhouse's exhaust fans and ceiling windows, preventing pesticides from
escaping. The new system can be set--using a delay timer--to spray at
night or on weekends. In tests in research greenhouses, it reduced the
annual cost of pesticide and related-application costs--from $1,400 to
$130 per greenhouse. The new system could also benefit commercial
greenhouses, in which pesticides are sprayed to curb plant pests.
Crop Science
Research Laboratory, Mississippi State, MS
Johnie N. Jenkins/Stan Malone/Quinnia Yates, (601) 323-2230
Valuable cowpea germplasm from Africa is now available to plant
breeders. This new germplasm has great potential because it was
collected in Botswana--considered the center of origin for cowpeas. ARS
scientists screened 109 accessions and declared them free of foreign
viruses that could infect domestic varieties. Another 100 germplasm lines
are being checked for viruses in quarantine at St. Croix and are expected
to be released by early 1996. Breeders will be able to tap the germplasm
for insect and disease resistance--without fear of the seed being
contaminated by harmful viruses. Cowpeas, also called southern peas in
the United States, include the popular blackeyed peas often served with
meat and rice dishes.
Plant
Genetic Resources Conservation, Griffin, GA
A. Graves Gillaspie, (770) 412-4777
Wheat farmers can't stop untimely rain, but an ARS discovery could
someday help them prevent the storms from making wheat kernels sprout
prematurely. In the Pacific Northwest, rains come just before harvest
about one year in five. That can cause ripe wheat kernels to sprout while
they're still on the grain head. The sprouting reduces quality--and
value--of wheat flour for bread, cakes and noodles. ARS scientists found
the part of the hormone abscisic acid, called the 7-methyl group, that
tells the wheat kernel not to sprout. The next step is to discover what
part of the kernel, or seed, receives this message. With both pieces,
scientists should be able to increase the effectiveness of this hormonal
signal, preventing grain quality losses.
Wheat Genetics, Quality,
Physiology and Disease Research Unit, Pullman, WA
Kay Simmons, (509) 335-3632
Floodwaters are being harnessed to disperse seeds of nutritious grasses
and shrubs along rangeland waterways that are usually dry. On the
Jornada Experimental Range in New Mexico, scientists rigged seed
containers on poles stuck into dry streambeds. As water from infrequent
storms flows past, it trips open the container, slowly releasing seeds.
Downstream, the seeds settle, germinate and grow. These waterways are the
most favorable sites for successful seed germination because they receive
more moisture, organic matter, soil and nutrients from the surrounding
areas. Scientists have successfully dispersed and germinated alkali
sacaton, blue panicgrass, other grasses and fourwing saltbush, a shrub.
In another tactic under study, scientists are using a portable watering
system to insure that desirable grasses and shrubs are established in the
dry waterways. These serve as "living seed sources" that floodwater
harvests and re-sows downstream. These natural methods are low-cost,
highly efficient ways to increase the value of native western
rangelands.
Rangeland Management Research
Unit, Las Cruces, NM
Jerry R. Barrow, (505) 646-7015
Tractor-mounted planters that sport an ARS-designed accessory will help
growers plant seeds only where they'll get enough water for a good
start. Seeds placed in too-dry soil will shrivel; too-wet soil
encourages rot. And, planting seed uniformly at the proper depth is as
crucial as proper moisture. Both tasks are automated by the invention--an
integrated system of probes and hydraulics that attaches to a
tractor-drawn planter. Electrical current flowing between two rugged,
soil-probing electrodes is monitored continuously. The stronger the
current, the more water available for seeds. In response, a feedback
system linked to the tractor's hydraulics lowers or raises the planter's
scraper blade. The blade descends--to push more soil out of the way--if
the planting site is droughty. If the electrodes detect soil that's too
wet, the blade rises to seek drier soil. Once the blade exposes the
appropriate surface, seeds are planted at the depth chosen by the grower.
The invention is intended for growers who plant seeds into raised seedbeds
or ridges already wetted with rain or a pre-plant irrigation. (PATENT
APPLICATION 08/352,650)
Western Integrated Cropping Systems Research Unit, Shafter, CA
Lyle M. Carter, (805) 746-6391
Degraded rangeland recovers just as quickly with a managed, moderate
level of cattle grazing as with no grazing at all. ARS scientists
came to this conclusion by comparing data collected in 1936, 1991 and
1993. Overgrazing in the early part of the century damaged rangeland
across eastern Oregon. Later, in the 1930s, cattle were excluded from 13
five-acre research plots located throughout the 16,000-acre Northern Great
Basin Experimental Range in southeastern Oregon. In the 1990s, scientists
looked for differences between grazed and ungrazed plots. They found that
plants and soil in both types of sites had recovered, with comparable
shrubs, grasses and wildflowers in each. Grazed areas had smaller plants,
but more of them.
Sustainable Management of Great Basin Rangelands Unit, Burns, OR
Tony Svejcar, (503) 573-2064
Last updated: October 28, 1996
Return to: Quarterly Report
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