JASPER – An infestation of tropical soda apple, a thorny plant on the
federal noxious weed list, has been verified on a private ranch here.
Called alternately the "plant from hell" and "Sodom’s apples" in
Florida, the thorny weed can quickly take over pastures, first
displacing the grass, then the cattle, said Dr. Mary Ketchersid, Texas
Cooperative Extension pesticide safety specialist.
Ketchersid said she doesn’t want to sound like an alarmist,
but the weed has caused economic disaster for agricultural producers in
"I think we need to be scared. People need to be watching for it," she said.
Dr. Larry Redmon, Extension forage specialist based in East Texas, agrees.
"I think people need to be very concerned because it has the
potential to cover a lot of acres in East Texas in a short period of
time," he said.
A rapid response team comprised of Extension range management, weed and
forage specialists, U.S. Department of Agriculture pest survey
personnel and a Texas Department of Agriculture entomologist, visited
the Jasper farm soon after being alerted by Ricky Thompson, Extension
agent for Jasper County.
The hope is, Ketchersid said, to contain the weed to the
original site. But she warns that since it’s a perennial, eradicating
it isn’t likely to be easy.
"We’ve been trying to eradicate mesquite since before the
1960s, and it’s still the subject of brush control programs," she said.
Before they spray a suspect infestation, producers should first send a
sample to Ketchersid for positive identification. Take a generous
sample and seal it up in a gallon plastic storage bag. Be sure to
include leaves, stems and fruit. Don’t add any water. Using a sturdy
cardboard box, mail the bag to Mary Ketchersid, 115 Agronomy Field Lab,
2488-TAMU, College Station, Texas 77843-2488.
Alternately, producers may also call Ketchersid at 979-845-6531, or e-mail digital photos of the suspect plant to her at firstname.lastname@example.org.
It’s important that landowners act promptly if they suspect they have the weed for it can spread rapidly, Ketchersid said.
"The landowner told us in a meeting that he had probably brought it in
with a load of Louisiana hay in 1998. He’s been trying to control it
himself for years, and now it’s a real mess," she said.
Many treatments are likely to look good at first, killing most of the
weed’s foliage. But with perennials, if the herbicide isn’t carried to
the roots, the plant may soon recover by the next growing season.
"The control can look really good right now, but in the next year, if
the roots haven’t died, the plant can come back," Ketchersid said.
The perennial weed produces small fruit about inch in diameter, dark
green with light green stripes. Resembling small striped watermelons,
the fruit or "apples" contain more than 100 seeds and are readily eaten
by cattle and wildlife, including deer, wild hogs, raccoons and birds.
The seeds, which are not digested, may be quickly distributed over a
wide area, Redmon said.
The weed is native to Argentina and central Brazil. In the United
States, it was first found in Florida. Infested areas there increased
from a couple of thousand acres to more than a million in six years,
Redmon said. The weed has taken over hundreds of thousands of acres in
Florida, Alabama, Arkansas, Georgia and Louisiana.
"Because TSA produces an unpalatable foliage that goes ungrazed by
livestock, the plant can rapidly spread over pastures and in woodlands,
thus reducing stocking rate and negatively affecting livestock
production systems," Redmon said.
When mature, tropical soda apple can reach 6 feet in height and have a stem 1 inch in diameter.
Stems, leaves and flower stalks have white to yellowish spines up to an
inch long. Young leaves are 4 to 7 inches long and 2 to 6 inches wide,
deeply divided into broad pointed lobes and usually about as long as
they are wide.
Flowers are white with yellow stamens and are located beneath the leaf canopies.
"Tropical soda apple may be confused with Carolina horsenettle;
however, horsenettle usually does not grow as tall as TSA," Redmon
Also, he noted, the flower of the Carolina horsenettle is usually purple, not white.
"But you do occasionally see a white flower on horsenettle," Ketchersid said.
recommendations in other states are to mow the infestation as early as
possible to a 3-inch stubble. Wait 60 days until it’s in the flowering
stage, then mow again. When plant growth is in the first flower stage
actively growing, spray with a broadleaf herbicide such as Remedy. Use
one quart per acre with labeled rates of nonionic surfactant in 40
gallons/acre of water, Redmon said.
By the time the task force learned about the Jasper
infestation, it was too late in the season to follow these
recommendations, said Dr. Paul Baumann, Extension weed control
specialist and another member of the task force.
Baumann took the opportunity to try 13 treatments including
nine over-the-top broadcast and various spot treatments to see what
looked most effective.
"We know what works in other states, but we don’t know for certain
what works here on our soils and environment," he said. "We want to
find the most economical solution, one that uses the least amount of
herbicide (for effective control.)"
The testing went well, Baumann said.
"Preliminary results two weeks after treatment indicated several products showed promise," Baumann said.
These treatments included:
1 pint/ acre of Tordon 22K gave 60 percent to 70 percent control.
3 pints/acre of Surmount, a new product, gave 75 percent to 80 percent control.
In both cases, plants were 12 to 36 inches tall, and Baumann used a 0.5 percent non-ionic surfactant, he said.
"This was only after two weeks. I expect some improvement in control as these products have longer to work," Baumann said.
spot treatments a 2 percent solution of Roundup provided excellent
control, Baumann said. (In spot treatments, Roundup also has 14-day
haying and 14-day grazing restrictions.) Remedy at 1 percent solution
provided 75 percent to 90 percent top kill as a spot treatment.
"We’d expect to get some root kill from all these products, but we
won’t know for sure until this fall or next spring," Baumann said.
For Web site images and articles from other states, Ketchersid recommended http://www.invasive.org/tsa/ and http://www.ceris.purdue.edu/napis/pests/tsa/.
"If it’s out there and it spreads, it could be a real economic disaster," Ketchersid said.
Texas A&M University – Agricultural Communications. Public release date: July 7, 2004.