Weed control encourages better pine yields, AgCenter researchers say

(12/20/17) SHREVEPORT, La. — Pine tree height and growth can be improved for up to 28 years by controlling weeds during site preparation, LSU AgCenter researchers said at the Western Gulf Silvicultural Technology Exchange meeting Dec. 14 in Shreveport.

The researchers presented results from a long-term study on loblolly pine yields at the meeting, which drew more than 100 forest industry leaders and landowners.

AgCenter forestry professor and extension specialist Michael Blazier said controlling weed growth in the first years of a stand’s life promoted pine growth for 15 to 28 years, depending on how broadly the herbicide mixture suppressed weeds and how frequently it was applied.

“Competition control has an extremely long-lasting effect and is one of the best returns on investment in terms of forestry management,” Blazier said.

Getting weeds under control before planting, then keeping the site as weed-free as possible, is one of the best practices landowners of any size can do to promote tree growth, Blazier said. He added that landowners can qualify for cost-share assistance to cover almost 50 percent of costs for the first year.

Because they encourage increased volume and production, intensive control treatments may prove cost-effective for companies and large landowners, said AgCenter economist Shaun Tanger. But variability within sites and control treatments should be considered.

“Standard operational treatments did better from a cost perspective than herbicide mixtures applied repeatedly in the first five years of a loblolly pine plantation,” Tanger said.

The comprehensive study looked at how early-rotation vegetation control intensity and frequency can affect loblolly pine plantation yields.

“It is rare to be able to conduct a project for 28 years because it takes both sustained funding and good communication between the two generations of scientists who conduct the study,” Blazier said.

Retired AgCenter forestry specialist Terry Clason led the initial research team that began the study in May 1984 at a site in the Kisatchie National Forest in central Louisiana. Blazier, who took over the project in 2003, was in contact with Clason until it concluded.

“This is one of the few times I’ve seen data from cradle to grave on actual stand rotations,” Tanger said.

Other presenters at the silviculture conference gave information on research projects and new products. The event was sponsored by ArborGen and IFCO Systems, with scientists from the AgCenter and several other universities participating.

“The forest industry is big in Louisiana, particularly in the northwestern part of the state, so this meeting is a good opportunity to update our producers and industry professionals on new information available in forestry and forest production,” said Patrick Colyer, director of the AgCenter Northwest Region.

Topics addressed by others on the program included:

— Herbicides. Jon Lunsford with Crop Production Services talked about product availability, formulations, manufacturers and distributors. Eric Taylor, Texas A&M Forest Service silviculturist, discussed chemical site preparation options for pine.

— Computer tools. Taylor demonstrated a program called My Land Management Connector, which helps landowners find contractors to harvest and manage their timber. Kyle Cunningham, University of Arkansas assistant professor of forestry, introduced a tool currently under development that will aid with decisions related to fertilization, thinning, risk management, drought cycles and climate change.

— Competition control. Cunningham and Robby Keen, Red River Specialties area manager, discussed control options and management strategies.

— Invasive species. Rick Williams, Natural Resource Conservation Service Louisiana state forester, discussed chemical control options for shrubs, trees and grasses.

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LSU AgCenter forestry professor and extension specialist Michael Blazier, center, and Louisiana Tech forest economics professor Gordon Holley, right, speak with AgCenter Northwest Region director Patrick Colyer at the Western Gulf Silviculture Technology Exchange held Dec. 14 in Shreveport. Photo by Karol Osborne/LSU AgCenter

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AgCenter researchers Shaun Tanger, left, and Michael Blazier, second from right, discuss findings from their report on the effects of early-rotation vegetation control on pine yield and financial performance with Crop Production Services manager Greg Hay, second from left, and AgCenter Northwest Region director Patrick Colyer, right, at the Western Gulf Silviculture Technology Exchange meeting. Photo by Karol Osborne/LSU AgCenter

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AgCenter forestry professor and extension specialist Michael Blazier, left, and AgCenter economist Shaun Tanger, center, talk with Weyerhaeuser early-rotation manager George Tiley about forest product prices. Photo by Karol Osborne/LSU AgCenter

12/20/2017 2:43:48 PM
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