New sugarbeet seed treatments will be helpful in controlling seedling Rhizoctonia, but will not provide full season disease control.
By Steven Poindexter
Posted December 19, 2013 by Michigan State University Extension
In 2014, three new seed treatments will be available for use on sugarbeets that will offer seedling protection against Rhizoctonia. Kabina ST, Metlock Suite with Rizolex and Cruiser Maxx appear to offer some disease protection early in the growing season, approximately 30 days. These products do not offer long-term control of Rhizoctonia and are not a replacement for Quadris applied T-band in-furrow. These products will be applied to seed in addition to our standard seed treatments. This will allow us a wider spectrum of seedling disease control than we have had in the past.
These products have the best fit for growers that are not applying Quadris in-furrow and apply a foliar application of Quadris. The seed treatment can be useful to help bridge the susceptibility gap when using Rhizoctonia-resistant varieties. The resistance traits of these varieties are not expressed at an early plant growth stage.
Research conducted in 2013 by Michigan State University Extension Sugarbeet Advancement program indicated that higher seedling sugarbeet populations were achieved when Metlock Suite with Rizolex was used when compared to our standard seed treatment. However, the highest populations were achieved when Quadris was used as a T-band application with or without the addition of Metlock Suite with Rizolex. Also, Rhizoctonia levels in August were significantly lower when Quadris was applied in-furrow compared to the Metlock Suite + Rizolex seed treatment. The Metlock Suite with Rizolex treatment was no different than the untreated check for August counts of Rhizoctonia. In Michigan, we would expect similar results with Kabina ST and Cruiser Maxx.
In summary, new seed treatment options can help protect seedlings from Rhizoctonia for up to 30 days. In-furrow T-banded Quadris applications appear to be superior to new seed treatments in both seedling and long-term control of Rhizoctonia. Quadris applied in-furrow in combination with Metlock Suite with Rizolex seed treatments did slow down early emergence, but had no adverse effect on final stands. Combination seed treatments of Apron/Thiram, Tach-20 and Kabina ST or Metlock Suite with Rizolex will offer short-term, broad spectrum seedling disease control.