Corrected, April 4 — A combo fungicide best known for disease control in wheat, oats and barley has picked up approval for use against soybean leaf diseases including Asian soybean rust.
Previously available for use on cereal crops at 202 ml per acre (500 ml per hectare), Bayer CropScience’s Group 3 and 11 combination Stratego 250 EC is now available for use at the same rate on soybean crops to control Asian soybean rust and frogeye leaf spot.
The product includes propiconazole, the Group 3 active ingredient in fungicides such as Syngenta’s Tilt and Quilt, and trifloxystrobin, the Group 11 active in seed treatments such as Bayer’s Prosper FX and Trilex AL.
The company recommends applying Stratego before disease is present for best results, but said a preventive application should occur at the very early stages of disease development or between growth stages R1 to R5.
“Crop scouting for soybean diseases is important, but in practice the decision to use a fungicide often comes down to economics. By the time disease effects are visible, it is often too late to spray,” the company said.
That is, an application should be considered “if your soybean crop looks good, with the potential for high yields and high quality,” Bayer said.
Soybean leaf diseases are responsible for an estimated 10 per cent yield loss, according to Bayer, citing data from independent trials as well as its own tests between 2007 and 2010.
Sixteen on-farm trials in Ontario and Quebec during a “mostly disease-free 2010” turned up an average yield increase of two bushels per acre with Stratego, compared to untreated soybeans.
“Growers are realizing the benefits of including a fungicide in their soybean crop protection plans,” Greg Good, Bayer’s portfolio manager for row crops, said in the company’s release.
CORRECTION, April 4, 2011: A previous version of this article incorrectly stated the application rate for Stratego on soybeans was 500 ml per acre. We regret the error.