ISSUE #540

540 - Cercospora Control 2010

6-24-10

Cercospora remains our most serious foliar disease of sugarbeet in Minnesota and North Dakota. Although yields losses have not been widespread in recent years properly sequencing fungicides can definitely enhance productivity and profitability of your crop. Improper fungicide use strategies can negatively impact crop yield and quality, suitability of the crop for long term storage and reduce revenue.

Management Strategies

The 2010 Cercospora control program should be centered on a late August application of Headline. The plant health benefit of Headline is real and improved frost tolerance is vital to delivery of frost free beets and successful crop storage, Figure 1.

540.1

  • Apply Headline in late August or very early September
  • If a fungicide needs to be applied in late July or early August this first application should be one of the Triazoles; Eminent, Inspire, or Proline.
  • If considering a 3-spray program the Triazole should be followed by a tin fungicide, then use Headline last.
  • Don't use any class of compound more than once per season.
  • July and early August Headline applications have limited prepile plant health benefits
  • Two and three fungicide programs usually result in improved revenue/acre - see Figure 2.

540.2

Tips for Maximizing Fungicide Benefits

  • Scout fields for incidence and severity of CLS
  • Monitor weather data from the NDSU NDAWN system
  • Timing of fungicide applications is critical
  • Use sufficient water volume
  • Contact your agriculturist to discuss management strategies

540.3

Resistance Management

If only Headline was used in 2009 and only one late fungicide application will be used in 2010. Inspire would offer best plant health benefits and still be appropriate for resistance management

High Yield Potential

High yield potential and a strong sugar market enhance the likely benefits from fungicide use in 2010.