Rhizoctonia Root and Crown Rot Control in Sugarbeet

Rhizoctonia Management Strategies

Rhizoctonia infections to sugarbeet are responsible for direct losses to grower root yield and quality in addition to losses related to beet storage issues.  Managing Rhizoctonia requires an integrated strategy involving consideration of crop rotation, variety selection, soil temperature, and soil applied and/or POST fungicide use. Consult your local sugarbeet Ag-Staff for specific recommendations.

Industry Fungicide Strategies and Best Management Practices:

  1. Variety selection is the most important Rhizoctonia management strategy.
  2. Quadris®, Aframe®, Headline®, Proline®, and Priaxor® are among currently labeled fungicides that provide Rhizoctonia control or suppression when used in accordance to label instructions.
  3. T-Banded fungicide applications of labeled products have provided good control.
  4. In-furrow applications can be effective but may have specific precautions (see below).
  5. POST band applications of Quadris have been effective when applied at or prior to average daily 4” soil temperatures of 65 degrees F (approximately 6 to 8-leaf stage). Priaxor fungicide can also be used at this application timing and possesses a novel MOA.
  6. Sugar cooperative research data has suggested that use of a non-ionic surfactant such as Trophy Gold® with Proline can provide suppression when applied to beets when the soil temperature reaches 65 degree F or if applied early for cercospora leaf spot control.

Relatively new seed treatment products are also available through sugarbeet seed pelleting facilities to offer suppression to early Rhizoctonia infections.  However, these seed treatment products do not provide season-long suppression and are not considered to be a stand-alone strategy without use of a POST fungicide and/or use of resistant varieties.

Use of fungicide Products and Application or Mixing Strategy concerns:

  1. Consult with Beet Sugar Cooperative Ag-Staff personnel for specific information and recommendations involving the mixing of certain fungicides and starter fertilizers for potential compatibility and phytotoxicity issues in addition to assessments of cost to benefit ratios for mixing products versus using alternative strategies.
  2. Issues relating to fungicide application, mixing, or phytotoxicity are related to product formulation. SC formulations have greater risk of mixing and compatibility issues.
  3. If mixing Quadris or Headline with Redline™ or 10-34-0, constant agitation is mandatory in order to avoid separation and precipitation.
  4. Unload or empty out fungicide and fertilizer tank mixes within about four hours of mixing, and do not allow tank mix to sit without agitation for extended time periods.
  5. Quadris alone, when applied in the seed furrow, can impact sugarbeet emergence and when applied in-furrow with fertilizer can cause injury.

Fertilizer starters may fluctuate in quality and analysis which can magnify mixing difficulties.

 

Redline is a trademark of West Central.

Headline is a registered trademark of BASF Corporation.

Quadris and Aframe are registered trademarks of Syngenta Co.

Priaxor is a registered trademark of BASF Corporation.

Proline is a registered trademark of Bayer CropScience LP.

Trophy Gold is a registered trademark of Van Diest Supply Co.

 

Always read and follow label directions relating to precautions, rates, premixing instructions, and tank-mixing procedures prior to use.