Fungicides Prevent Significant Yield Losses in Argentinian Wheat Fields

Wheat Rust is a Common Problem in Argentina

Wheat Rust is a Common Problem in Argentina

Argentina is one of the countries with the largest wheat-growing area in the world with more than 5 million hectares spread all over the country.

The grain production region has experienced severe tillage changes in the past twenty years, mostly due to the increased interest in maintaining soils covered with plant residues.

No tillage can reduce costs by decreasing fuel consumption required to produce a crop. However, in the wheat/soybean system under no tillage, as in wheat following wheat, the inoculum of fungi may survive until the next wheat season. Therefore, the use of fungicides is essential to decrease the severity of diseases.

Fungicides are usually applied on foliage to control diseases but they are also used for seed treatments to prevent seed decay. Leaf rust, septoria leaf blotch, and tan spot are the most important diseases in terms of potential yield reduction in Argentina.

“Planting resistant cultivars is one of the least expensive and most effective management strategies to prevent diseases. However, cultivars with an adequate genetic resistance level to necrotroph foliar diseases are scarce, and usually resistance to leaf rust is complete, conditioned by one or a few genes and has a low level of durability in Argentina. Therefore, chemical protection together with cultural practices is a common method of control. In addition, fungicides are also important because Argentinian wheat region combine high yield potential cultivars with high infection pressure, both deriving from adequate temperature and moisture levels, large application of N fertilizers and rotations dominated by cereals, which promote progression of some foliar diseases.

The results of experiments carried out in Argentina indicate that sowing wheat following wheat in no tillage is possible without significant yield losses if effective disease management practices including moderately resistant cultivars, N fertilization and fungicides are applied.”

Authors: Simon, M. R., et al.
Affiliation: National University of La Plata, Argentina.
Title: Recent Advances on Integrated Foliar Disease Management with Special Emphasis in Argentina Wheat Production.
Source: InTech. Fungicides – Showcases of Integrated Plant Disease Management from Around the World. Available at:

National Academy of Sciences Credits Herbicides for Adoption of Conservation Measures in the U.S

Tillage vs. Herbicides

Tillage vs. Herbicides

In the early 20th century, American farmland was eroding at an alarming rate. The cause of this erosion was continuous plowing of fields to keep weeds out. When herbicides were introduced to control weeds, farmers could reduce tillage. As a result, there have been major reductions in soil erosion in the United States. The National Academy of Sciences has pointed out that this improvement in conserving the soil would not have occurred had it not been for herbicides…..

“The use of herbicides has reduced the need for growers to cultivate to control weeds and that reduction has led to an increase in the practices associated with conservation tillage. These include no-till, ridge-till, strip-till, and mulch-till—practices that leave at least 30% cover after planting. Leaving cover after planting reduces soil loss due to wind and water erosion up to 90%, and it increases crop residue (organic matter) on the soil surfaces up to 40%. Conservation tillage in the United States has increased from 26.1% of the total acreage in 1990 to 37.2% of the total acreage in 1998. Without herbicides, widespread adoption of conservation tillage would likely not have taken place.”

Author: Committee on the Future Role of Pesticides in US Agriculture
Affiliation: National Research Council
Title: The future role of pesticides in US agriculture
Source: Board on Agriculture and Natural Resources and Board on Environmental Studies and Toxicology Commission on Life Sciences. 2000.

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