Plant Scientist Urges Proactive Palmer Amaranth Prevention

Plant Scientist Urges Proactive Palmer Amaranth Prevention

September 27, 2014

By Colby Tibbet, Cal Ag Today reporter

Palmer amaranth, aka Amaranthus palmeri S. watson or carelessweed, is an annual herb of the pigweed species that is native to California where it thrives and poses a serious threat to farming.

Amaranth

Amaranthus palmeri S. Watson - carelessweed (Source on USDA Website: Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions.
 

Lynn Sosnoskie, a project scientist in the UC Davis Department of Plant Sciences who focuses on weed ecology and biology, says Palmer amaranth, spotted on the edge of fields in California, is remarkably aggressive both in growth rate and spread amidst field crops. It develops a lot of wind-blown seeds that spread rapidly.”

“I would suggest that growers in the state of California be particularly diligent about this plant,” said Sosnoskie. “It is a desert annual and is particularly well-adapted to dry environments where it can out-compete, create root growth and achieve stability well. And the recent drought has only escalated the problem.”

“Preventive measures are absolutely essential before this plant becomes established,” continued Sosnoskie. “We found out the hard way in the Southeastern U.S. that Palmer amaranth produces an exceptional number of seeds; if even one plant is missed by applications or escapes regular herbicide applications, that plant can essentially repopulate an entire field.”

“So its absolutely essential that growers here and everywhere become familiar with the weed and remove all plants quickly from a field before it hits reproductive maturity and forms seed,” she said.

Sosnoskie added that some cotton fields in the south have suffered up to 50 percent yield losses and worse. “Some growers have actually abandoned their fields and haven't harvested their cotton for those years,” said Sosnoskie.

Sources and Resources:

Illustration Source: Amaranthus palmeri S. Watson - carelessweed (Source on USDA Website: Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions. 3 vols. Charles Scribner's Sons, New York. Vol. 2: 2. Courtesy of Kentucky Native Plant Society. Scanned by Omnitek Inc. Usage Requirements.

USDA Natural Resources Conservation Service

Palmer Amaranth

Compensatory growth and seed production: A tale of two weeds

More California Ag News

BIG WATER RALLY SCHEDULED FOR JAN. 16! Thousands Needed To Participate In Big Water Rally on Jan. 16  
Solano County 4-H Clubs Win Big at Skills Day When Life Gives you Lemons, Make Lemon Curd! Showmanship winner Tyler Scott of the Wolfskill 4-H Club DIXON--Tyler Scott of the...
California Ag News UC To Help Ranchers UC to Help Ranchers Survive Winter 2013-14 The first agricultural operations to feel the impact of a drought are dryland ranchers, many of whom r...
MONTEREY FARM BUREAU WARNS CPUC ON WATER ISSUES Desalination Plant Could Jeopardize Groundwater Supply California American Water could threaten the ground water supply of the Salinas Valley where u...