Using Herbicides to Reduce the Risk of Forest Fires


Wildfire Burning on Forest Floor


Spraying Weeds on Forest Floor

Forest floors can be covered with many weeds that dry out and become a source of fuel
for forest fires. Many weed species dry quickly during drought creating hazardous “flashy” fuels in wildfire situations.  Studies have shown a significant reduction in fire intensity in areas where herbicides are applied to remove weeds. Incorporating herbicides into land management plans helps to decrease fuel loads and reduce the risk of forest fires.

“Exotic annual grasses such as cheatgrass, medusahead, and Ventenata can produce large amounts of fine fuel loads creating favorable conditions for wild fires… Herbicides imazapic and propoxicarbazone sodium have been particularly effective in controlling or suppressing exotic annual grasses, depending on rates and time of application. The main limitation for extensive use of these herbicides, particularly in rangelands, is the cost. However, if the fuel load from exotic annual grasses is reduced, the risk of wild fires will also decrease as a result of the herbicide applications. This could help create lower fire risk sections or corridors in order to protect more sensitive areas such as installations, roadsides, buildings, animal shelters, etc. The cost of herbicide applications for these areas would be compensated by the value of the saved resources and reduction in the cost of controlling frequent wild fires. The use of herbicides would only be justified if a significant reduction of the fuel load is achieved. The objective of this study was to quantify the impact of herbicides and application timings on invasive annual grass fuel load production.

…Although every treatment had an impact on the produced litter, the most significant biomass reduction, 53 percent, was observed with the application of Plateau®.

These preliminary results suggest that herbicides have the potential be used to reduce fuel loads from annual weedy grasses, particularly in recently burned fields.”

Authors: Sbatella, G., and Twelker, S.
Affiliations: Oregon State University
Title: Impact of herbicide applications for exotic annual grass control on fuel load production.
Source: Rangeland Research Reports, available at:

US Drought Effects Would Be Worse Without Pesticides

The current drought has received extensive media coverage. There will be no Dust Bowl this year thanks to the use of pesticides. Farmers have been using herbicides instead of tilling the soil for weed control. By not disturbing the soil, they have conserved soil moisture. Corn yields would be worse if it were not for herbicide technology, a point made in an editorial by David Bridges, President of Abraham Baldwin Agricultural College in Tifton, GA.

“The Midwest ‘flash drought’ is withering much of our 2012 corn crop. … Now is the perfect time to consider the benefits to farmers, consumers and the environment of something routinely demonized by activists – pesticides. Pesticides? Yes. Without them, things would be worse, on all ends of our current dilemma.”

“Between 1980 and 2011, corn yields here grew by 64 percent while soil loss dropped 67 percent, energy use dropped 43 percent and carbon emissions fell 36 percent. Of vital importance this year: Irrigation water use for corn dropped 53 percent in the same period.”

“Pesticides and other technologies conserve natural resources while providing a production buffer that limits the effects of natural disasters and the disruptions of unforeseen shortages.”

USA Today echoed these sentiments on August 20.

“The severe drought that has hit the Farm Belt does not immediately threaten to create another Dust Bowl or widespread crop failure, thanks to rapid innovations in the past 20 years in seed quality, planting practices and farming technology, farmers and plant scientists say. … In the past 20 years, farmers have transformed from plowing fields 8 to 11 inches deep to ‘no-till’ or ‘conservation-tillage’ practices designed to minimally disturb the ground. That exposes the soil to less wind erosion, preserves natural nutrients, and captures and retains what moisture does fall.”

Author: David Bridges
Affiliation: Agronomist and President of Abraham Baldwin Agricultural College, Tifton, GA
Headline: Drought Would Be Worse Without Pesticides
Publication: Des Moines Register, Wednesday, July 25, 2012.

Author: Chuck Raasch
Headline: Another Dust Bowl for Farm Belt Unlikely
Publication: USA Today, Monday, August 20, 2012