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:

Weed from Hell Invades Florida

Tropical Soda Apple

Tropical Soda Apple

Tropical soda apple (TSA) is a weed native to Brazil, Argentina, Paraguay, and Uruguay that has invaded Florida. The pathway of introduction is unknown, but it may have been accidentally introduced with cattle carrying undigested TSA seeds. Currently, more than 404,000 acres are believed infested in Florida. TSA invades pasture, where it reduces livestock carrying capacity. Dense stands of the prickly shrub prevent cattle access to shaded areas, which results in summer heat stress and economic losses from cattle heat stress have been estimated at $2 million. TSA is a reservoir for at least six crop viruses; in addition, major insect pests use TSA as an alternate host. Herbicides are a major management practice for this “weed from hell.”

“Tropical soda apple (TSA) is an invasive weed of agricultural and natural areas in Florida. The plant is native to South America and was first found in south Florida in 1988. Its spiny foliage and stems are unpalatable to livestock, and dense stands of this prickly plant often grow into large impenetrable thickets.

In some areas of central and south Florida, TSA has covered entire pastures, rendering them unusable for grazing livestock. Some have called this weed the “plant from hell”.

The preferred methods of TSA control were chemical herbicides and mowing. On a statewide basis, 20% of cattle producers used herbicides alone, 7% used mowing alone, and 20% used both methods. Triclopyr and glyphosate were the two most commonly used herbicides reported by cattle producers. However, many had begun using amino-pyralid, an herbicide registered for use in pasture and rangeland in 2005, and becoming the new standard for TSA control. With continued TSA spread and the absence of alternative effective control measures, it is likely that the demand for these herbicides will continue to grow.”

Authors: Salaudeen, T., et al.
Affiliation: College of Agriculture, Florida A&M University.
Title: Economic impact of tropical soda apple (Solanum viarum) on Florida cattle production.
Source: Weed Technology. 2013. 27:389-394.