Are we losing the ‘Weed War?’

July 8, 2011

Agriculture

By Wally Northway

The state has just lost an important weapon in its all-out war against cogongrass, which poses a threat to the economy, environment and even public safety.

The loss of a federal assistance program could not have come at a worse time, and now some experts believe the non-native, invasive weed is winning the nearly century-old battle.

Dr. John Byrd, weed scientist with the Mississippi State University Extension Service, said, “If we don’t get a handle of this thing now, we are going to leave a problem for our grandchildren that will be impossible to remedy.”

Imperata cylindrical, or cogongrass, arrived in the U.S. from Asia via Mobile, Ala., in 1911. Asian exporters used the reedy grass as shipping material for fruit. When the fruit was uncrated in Mobile, the cogongrass was carelessly tossed aside.

The weed, which has no natural enemies in the U.S., quickly took hold, and at first was thought to have some benefits. It was introduced into Mississippi as an alternative forage sometime before 1920.

Cogongrass, with its attractive seed head, was even sold in lawn and garden centers as an ornamental plant.

It was already spreading before it was found that no animals would eat it. It squeezes out native plant species making it totally unsuitable for erosion control, and it is difficult to control and harder to kill.

In addition, scientists learned cogongrass is a wildfire hazard, posing a threat to the environment as well as the general public.

Despite efforts to control the weed, it is now documented in 62 of Mississippi’s 82 counties. The area with significant infestation runs from the Coast through East Central Mississippi.

This has put land managers and farmers in the Pine Belt in Southeast Mississippi in the weed’s crosshair. The pine industry is the second-most valuable agriculture commodity in the region behind poultry.

Anthony Cran is employed by Scotch Land Management, LLC, a unit of Scotch Plywood, managing tens of thousands of acres of pine trees for owners spread across the Pine Belt.

“Corporate America is just as concerned — maybe more so — about cogongrass as private landowners,” said Cran.

The main threat cogongrass poses to pine tree is the weed’s density. It produces a toxin that eradicates competition from native, more desirable vegetation. The weed’s blades grow so densely that pine seedlings are crowded out, impacting trees’ ability to regenerate.

It also poses a fire hazard. Many types of pine trees need fire to thrive. But research has found that cogongrass burns four times hotter than native plant species. Cogongrass-fed fires have been documented killing pine trees up to 14” in diameter.

Once ablaze, cogongrass is difficult to extinguish. Jim Hancock, Invasive Plant Control Program coordinator with the Mississippi Forestry Commission, said it burns “like a fuel fire.”

Local firefighters report a cogongrass-fed fire can burn as much as 50 acres in less than an hour even on windless days.

This is of special concern currently as parched Southeast Mississippi continues to report numerous wildfires and many counties have enacted burn bans.

The plant also could cost cattlemen. Research has found that if the plant is closely trimmed, livestock will grave it. Left unchecked, however, and cattlemen can find their pastures unsuitable for livestock.

The weed also impacts wildlife. In addition to being inedible, its density threatens the chicks of ground-loving game birds such as quail and turkey that find the weeds impossible to navigate. Because insects will not feed on it, chicks are also deprived of a protein source.

In order to beat back cogongrass, land managers must apply a blend of herbicides. Usually, it takes more than one application — sometimes as many as three — to eradicate the weed.

The average cost for eradication efforts is $250-$500 per acre.

The state’s timber industry has been in decline for over a decade now. Weak stumpage prices and soaring input costs have left tree farmers with little or no money for fighting cogongrass.

The state received a boost two years ago when a $1.1-million federal earmark created a Landowners Assistance Program that covered 100 percent of the cost of controlling cogongrass. The program saw more than 1,200 applicants over its two-year run.

But, that program has ended.

This has left experts wondering — is cogongrass winning? Cran believes it is.

“I say that because if you have one landowner who has cogongrass and is unwilling to try and control it, it threatens all of his neighbors,” he said. “It’s extremely discouraging.

Hancock called the war a draw thus far.

Byrd is the only source that believes landowners are beating cogongrass. He pins his optimistic view on the rise in public awareness of the problem.

But he did qualify his position.

“I never use the words ‘eradication’ and ‘cogongrass’ in the same sentence,” Byrd said. “I believe we are controlling it, but eradication might be an unrealistic goal.”

For more on cogongrass, including how to identify it, visit the Mississippi Forestry Commission’s web site at www.mfc.ms.gov/.

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