Non-native grass threatens La. forests

Schultz Bruce, Dozier, Hallie

News Release Distributed 02/25/11

ALEXANDRIA, La. – Forestry industry representatives attending an LSU AgCenter forum Tuesday (Feb. 22) at the Dean Lee Research Station were warned that a non-native grass threatens Louisiana forests.

The plant cogongrass is a weed that displaces native vegetation and prevents establishment and growth of young trees, said Hallie Dozier, assistant professor in the LSU AgCenter School of Renewable Natural Resources,

“This is a big, bad super plant,” Dozier said. “You really don’t want to do battle with cogongrass.”

The plant is native to Southeast Asia, and it is among the top 10 weeds in the world, she said. “It is one of the reasons farmers in Africa never get ahead.”

The weed has been a severe problem in Florida, she said, and it could be a serious threat to the timber business if it gets a foothold into the rich soil of Louisiana woodlands. “If we don’t catch it in time in Louisiana, we are going to be sorry in 20 to 30 years.”

It was first brought to the United States in 1912 as packing material and later as cattle forage in Mississippi and Florida.

Several factors make this plant a worrisome threat, Dozier said.

It is drought tolerant. And unlike many native plants that slow down growth in extremely hot weather, it continues to grow, allowing it to out-compete native species, she said.

A new plant can grow up to 4 feet tall from a short piece of root. Mowing or burning only results in a lusher regrowth, Dozier said. And the plant leaves burn at a higher temperature than native grasses.

Cogongrass tolerates some shade, giving it the ability to encroach on forest edges and take advantage of canopy openings, such as those that may occur after a storm or harvesting. It is suspected of producing substances that retards the growth of other plants.

Dozier said her graduate studies included research on cogongrass in Florida.

“I don’t ever want to see cogongrass infestations here like I saw in Florida,” she said.

The plant can be attacked with the herbicides glyphosate and imazypyr, combined with deep tillage, revegetation and making sure that equipment used in areas with cogongrass has been cleaned to remove any plant materials.

“The time to act is now, so that if you spot a patch, you can take care of it while it’s small.”

Dozier’s general descriptions of the plant’s appearance include an off-center, white mid-rib. Details can be found online at A map of where the weed has been found in Louisiana is also available there as well as an article by LSU AgCenter weed scientist Dearl Sanders.

Wade Dubea, state forester with the Louisiana Department of Agriculture and Forestry, said 35 employees who fight forest fires will be laid off Friday (Feb. 25). That will leave only a statewide staff of 100.

“It’s not much, and it concerns me greatly,” Dubea said. Local volunteer fire departments will be asked for help when more personnel are needed.

Also at the forum, Public Service Commissioner Clyde Holloway said proposals for using woody biomass to generate electricity will be reviewed this year by the PSC. He said a pilot plant that will use wood as a feedstock has been proposed near the town of Olla.

“I truly believe we have a good chance to get that facility,” Holloway said. The plant will be used to determine the cost of using renewable fuels to generate power.

But he opposes a facility that would require higher electricity rates.

North Louisiana is more suited for a power plant that would rely on wood as a fuel, Holloway said, because it has more of the feedstock and jobs are needed there.

Jody Bordelon of Cleco said the company’s new Madison 3 power plant at Boyce has the capability of using wood to generate power in combination with the fuel petroleum coke, a byproduct of oil refining. He said a test burn using wood will be conducted this year, and potential suppliers of wood for the plant are being contacted.

The facility has the potential requirement of 1.6 million tons of wood, he said, but the intended supply will be wood not otherwise used for saw timber or pulp.

Bruce Schultz
2/25/2011 10:50:12 PM
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