With the introduction of rust in the United States, soybean growers need
products proven in the fight against rust. In many trials in both Brazil and
the United States, research has shown that a combination of a strobilurin plus
a triazole provides the best protection from this dangerous pathogen.
Strobilurins provide preventive protection before rust infects the plant, while
triazoles protect the plant after the onset of rust.
How do I control this disease?
Experience with soybean rust in South America, southern Africa, Asia and now
the United States has shown that soybean rust can be managed, and research has
shown that a preventive approach and application timing is crucial. If the
disease is allowed to gain a foothold in the crop - even if only a little of
the upper canopy is infected - the results can be damaging. Early timing of
fungicide applications are critical to protecting soybeans and conserving
yields.
A preventive application in the R1 to R2 growth stage is the best
recommendation for protecting fields from rust should the risk of infection be
high. Once symptoms visible to the naked eye are present, it may be too late
for an economically beneficial spray.
* Data from Syngenta research in Brazil.
If soybean rust is found, or if it is reported in your area, apply a fungicide
treatment. After the first application, a follow-up fungicide
treatment may be necessary if conditions are conducive for disease and as the
residual protection of the first application begins to wane. Crop
Susceptibility during the Soybean Growth Cycle
The growth stage of the crop at the time of infection is vital for several
reasons. First, it determines which yield factor or factors the disease can
damage - for instance, pod set, pod filling, or both. Growth stage may also
help us predict the crop’s potential to compensate for damage from soybean
rust.
Based on a study from Brazil and confirmed through research in the United
States, the effectiveness of fungicide treatments was greatly enhanced when
applications were initiated in early growth stages.
* Data from Syngenta research in Brazil. |