ISSUE #581

581 - RECOMMENDATIONS FOR 2013

6-26-2013

The 2013 Cercospora control program should be designed using three sequential fungicide applications, at 14 day intervals. Several years of grower practice records continue to show that three fungicide applications return more revenue per ton and more revenue per acre than two applications, Table 1.

Table 1. Number of Fungicide Applications: 5-Year Average (2008-2012)

Number of ApplicatonsHarvested AcresYieldPercent SugarPercent SLMRecoverable Sugar per AcreRevenue per TonRevenue per Acre
1 381,508 22.7 17.22 1.11 7,309 $56.00 $1,271
2 893,970 25.0 17.91 1.14 8,375 $60.15 $1,504
3 535,771 25.7 18.51 1.21 8,892 $63.65 $1,636
  • Tank mixes of fungicides is the primary focus for good Cercospora control and resistance management in 2013. When tank mixing fungicides, only use the full rate of all tank mix partners.
  • Initiate spray programs with the first detection of CLS in your area.
  • In a three spray program, a tank mix of one of the Triazole fungicides (Eminent, Inspire XT or Proline) + TPTH (Super Tin/Agri Tin) should be applied in late July or early August. A tank mix of TPTH + Topsin* should be applied no more than 14 days following the initial fungicide application. The last fungicide application in the three spray program should always be Headline and applied in late August. The plant health benefit and frost tolerance benefit of Headline, observed in both research experiments and grower fields, are vital to the beet receiving operation and best pile storage condition.
  • Only when weather or crop growth conditions favor a later start to the fungicide application season (early to mid-August) should a two spray program be considered. If the 2013 growing season develops this way, then growers should make their initial application, a tank mix of TPTH + one of the triazole fungicides. These two classes of chemistry combined provide excellent Cercospora control and responsible resistance management. Another option may be to utilize a tank mix of TPTH + Topsin*.

    when compared to other fungicides. As in the three spray program, Headline should be applied in late August for maximum plant health and frost benefits.

  • In northernmost areas of the Red River Valley where Cercospora pressure may be light, growers may opt to utilize only one fungicide application. Although the practice of using one fungicide application is contrary to ACSC's recommendation, if a grower chooses this option, then a tank mix of Headline + TPTH or a tank mix of Headline + one of the triazole fungicides should be made on or after August 25. Utilizing a tank mix will prolong the effectiveness of Headline by minimizing the ability of Cercospora to develop resistance to the strobilurin class of fungicides in a one spray program.

Summary Based on Timing of First Application

Late July to Early August (3 Spray Program)

  • Application 1 - TPTH + Triazole
  • Application 2 - TPTH + Topsin*
  • Application 3 - Headline (apply Aug 25 or later)

Early to Mid-August (2 Spray Program)

  • Application 1 - TPTH + Triazole or TPTH + Topsin*
  • Application 2 - Headline (apply Aug 25 or later)

Late August (1 Spray Program)

  • Headline + TPTH (apply Aug 25 or later) or
  • Headline + Triazole (apply Aug 25 or later)

Only use the full rates of all tank mix partners

*Topsin should not be used more than one time per year

Specifications for Proper Fungicide Use

FungicidesREI - HoursPHI - DaysWater Volume - Gal.
Agri Tin 48 7 At least 15 gpa
Eminent 12 14 5 gpa or more
Gem 12 21 Minimum 10 gpa
Headline 12 7 Sufficient water to ensure thorough coverage of foliage
Inspire XT 12 21 15 gpa is reommended
Manzate, Penncozeb 24 14 Minimum 2 gpa
Maneb, Manex 24 14 Minimum 10 gpa
Proline 12 7 Minimum 10 gpa
Super Tin (4L), Super Tin (80WP) 48 7 At least 15 gpa
Topsin 4.5L, Topsin M WSB, Thiophanate Methyl 85 WDG 24 21 Minimum 5 gpa

Always read and follow label directions. 
The pre-harvest interval must be considered when making fungicide application decisions.