|
|
|
 |
New ARS Projects
To meet
the crisis that elimination of methyl bromide will impose on U.S.
agriculture, the Agricultural Research
Service has redirected funds from other research programs to create
five new full-time positions for developing viable alternatives. One of
these positions is located at Fort Pierce, Florida; three are in
California, at Fresno, Davis, and Salinas; and one is at Wenatchee, Washington.
These positions have been filled by scientists who are backed by years of
dedicated training and research in plant pathology and physiology--all
essential in finding ways to keep our agriculture productive and
competitive in world markets.
FLORIDA
ARS plant physiologist David Patterson is addressing the problem of
weeds. Patterson recently transferred from the ARS Plant Physiology
Research Unit at Raleigh, North Carolina, to the Fort Pierce, Florida,
future site of the ARS
Horticultural Research Laboratory at Orlando. He received his
undergraduate degree from North Carolina State University and master's and
Ph.D. degrees from Duke University.
Patterson's assignment involves the biology and control of
nutsedges, weeds that are rampant wherever vegetables are grown. Methyl
bromide is currently the most effective control for yellow and purple
nutsedge. Purple nutsedge is known as the world's worst weed.
"Neither of these species produces much viable seed, so they
must move more slowly than other weeds to infest vegetable crops,"
Patterson says. "We'll study the biology and epidemiology of these
pernicious weeds, hoping to find ways to slow their spread in the field
and reduce their emergence."
He expects to evaluate cultural practices, composting, and different
types of mulches that might offer weed control.
CALIFORNIA
ARS
plant pathologist Cynthia G. Eayre has a research background in soilborne
pathogens of horticultural crops. After receiving a Ph.D. from North
Carolina State University, she held postdoctoral positions at the
University of Florida and the ARS Crop Quality and Fruit
Insects Research Unit in Weslaco, Texas.
Now assigned to the
ARS Postharvest Quality and Genetics Research Unit at Fresno, California,
Eayre will work on biologically based alternatives to methyl bromide as a
soil fumigant for strawberries and stone fruits.
"We will
try to identify the causes of strawberry root rot so we can reproduce the
disease in control experiments," Eayre says. She and colleagues will
test beneficial bacteria--recently found to ward off disease in
cantaloupe--to try to induce plant resistance to the rot. She plans to
work with the ARS Water
Management Unit to try drip-trickle irrigation as a delivery system
for this and other control agents.
Eayre is particularly
interested in root knot nematode resistance in peaches and in working with
a fungus, Hirsutella, that attacks the ring nematode, another pest
of
stone fruit. She plans trials of combinations of biological control agents
and chemical treatments.
ARS recently added plant pathologist
Greg Browne to the research team at the Crops Pathology and Genetics
Laboratory in Davis, California. Browne received a Ph.D. in plant
pathology from the University of
California at Davis and later worked for UC's Cooperative Extension,
specializing in diseases of vegetable crops.
At the ARS-Davis
lab, Browne will investigate ways to control soilborne diseases that
affect fruit and nut trees and grapes. His research will help develop
methyl bromide alternatives.
"An important part of my program will be to find and evaluate
genetic resistance to important soilborne pathogens in rootstocks of fruit
and nut trees like peaches, almonds, and walnuts," he says.
"Also, we need to learn more about the biology and control of
soilborne pathogens like Phytophthora that affect plant vigor and
productivity. We'll need this kind of information to effectively integrate
methyl bromide alternatives."
Browne says cultural, genetic, and chemical strategies will all play
important roles in finding methyl bromide replacements.
Plant
pathologist Frank Martin will tackle the problem of finding alternatives
to methyl bromide from an ecological perspective. Martin is now part of
the research team at the ARS Crop Improvement and Protection Research Unit
at Salinas, California. He received his Ph.D. degree in plant pathology
from the University of California,
Berkeley, and came to ARS from the University of Florida where he
worked as an assistant professor on the ecology, biocontrol, and genetics
of fungal soilborne pathogens as they affect a wide range of vegetable
crops.
At Salinas, Martin's research objectives include investigating the
ecology and biology of soilborne pathogens and developing biocontrol
strategies from an ecological perspective. In addition, he will continue
research on controlling damping-off of vegetable transplants using a
biocontrol agent developed while at the University of Florida.
Damping-off, caused by fungi, is a serious disease of seeds and seedlings
that can kill young plants as they emerge from the soil.
WASHINGTON
Plant pathologist Mark Mazzola has a background in forestry and
plant pathology research and received both undergraduate and master's
degrees from the University of Vermont and a Ph.D. in plant pathology from
Washington State University.
From a temporary research position
studying soilborne pathogens of wheat with ARS at Pullman, Washington,
Mazzola was recently assigned to work full-time at the Tree Fruit Research
Laboratory in Wenatchee, seeking biologically based alternatives for
methyl bromide as a soil fumigant.
"My concern is with an
old phenomenon--apple replant disease--that to date hasn't been very well
characterized," he says. "In the absence of methyl bromide,
growers and nurserymen can lose up to 20-30 percent of new orchard
plantings to this disease."
Methyl bromide is now used to
fumigate soil to eliminate potential soilborne pathogens in orchards that
are being renovated by removing old trees and planting new apple
varieties. It's difficult to treat this disease with other materials,
Mazolla says, because the exact cause is not known and may vary between
geographic regions.
While seeking a causal agent, Mazzola plans
to investigate the potential role of fungal pathogens in apple replant
disease and evaluate biological agents to control it. He is looking at the
biological control capabilities of Trichoderma, a common soilborne
fungus
that has been used experimentally to control other plant diseases.
[October 1995 Table of Contents]
[Newsletter
Issues
Listing]
[Methyl Bromide Home
Page]
[ARS Home Page]
[USDA Home Page]
Last Updated: October 25, 1996 |
|
|
|
Printable Version
E-mail this page
