Soybeans: Frogeye Leaf Spot (Cercospora sojina)


Pub 812: Field Crop Protection Guide > Pub 812: Soybeans > Frogeye Leaf Spot

Field Crop Protection Guide 2011-2012, Order 2011-2012 publication

Table of Contents

  1. Integrated Pest Management Options
    • Foliar Treatment
      • pyraclostrobin – Headline EC
      • trifloxystrobin + propiconazole - Stratego 250 EC
      • tebuconazole - Folicur 250 EW, Folicur 432 F
      • prothioconazole - Proline 480 SC
      • propiconazole – Bumper 418 EC
      • propiconazole – Tilt 250 E
      • Bacillus subtilis - Serenade ASO
  2. Related links...

 

Integrated Pest Management Options

Foliar Treatment

The economic impact of this disease is minimal. Frogeye leaf spot occurs under hot, humid conditions particularly on very susceptible varieties. Consult with your seed company and the Ontario Oil and Protein Seed Crop Committee Variety Trial Results at www.gosoy.ca for variety profiles. This disease is most frequent in the extreme southwest counties.

 
Active ingredient pyraclostrobin
Trade name Headline EC
Rate per hectare (product) 400-600 mL per ha
Rate per acre (product) 160-240 mL per ac
PHI* 21
Comments Ground and aerial application. First application should be applied at the first sign of disease followed by the second application 14 days after, if environmental conditions are favourable for disease development. Maximum 2 applications/yr. 12-hr re-entry period.

 

 
Active ingredient trifloxystrobin
Trade name Stratego 250 EC
Rate per hectare (product) 500 mL per ha
Rate per acre (product) 200 mL per ac
PHI* 20
Comments Ground and aerial application. Spray between R3 and R4 (early pod fill) or when first symptoms appear. Use 100-200 L/ha of water for ground application, 50 L/ha for aerial application. Maximum 2 appplications/yr. 12-hr re-entry period.

 
Active ingredient tebuconazole
Trade name Folicur 250 EW
Rate per hectare (product) 375-500 mL per ha
Rate per acre (product) 152-200 mL per ac
PHI* 20
Comments Ground and aerial application. Apply when first symptoms of disease can be found or when risk of infection is imminent. Use higher rate when disease pressure is severe. Use a minimum of 100 L/ha of water for ground application, 47 L/ha of water for aerial application. The use of a non-ionic surfactant (Agral 90 or Agsurf) is NOT required as it is built into the formulation. Maximum 1 application/yr. 12-hr re-entry period.

 

 
Active ingredient tebuconazole
Trade name Folicur 432 F
Rate per hectare (product) 220-292 mL per ha
Rate per acre (product) 90-118 mL per ac
PHI* 20
Comments Ground and aerial application. Apply when first symptoms of disease can be found or when risk of infection is imminent. Use higher rate when disease pressure is severe. Use a minimum of 100 L/ha of water for ground application, 47 L/ha of water for aerial application. Always use a non-ionic surfactant such as Agral 90 or Agsurf at 0.125% vol/vol. Maximum 1 application/yr. 12-hr re-entry period.

 

 
Active ingredient prothioconazole
Trade name Proline 480 SC
Rate per hectare (product) 210 mL per ha
Rate per acre (product) 85 mL per ac
PHI* 20
Comments Ground application only. Apply when first symptoms of disease can be found or when risk of infection is imminent. Maximum 1 application/yr. 12-hr re-entry period.

 

 
Active ingredient propiconazole
Trade name Bumper 418 EC
Rate per hectare (product) 300-455 mL per ha
Rate per acre (product) 121-184 mL per ac
PHI* 50
Comments For use on soybeans grown for seed only. Ground application only. Apply when disease first appears. Under severe disease pressure, make a second application 14 days after. Harvested soybean seed should not be used for human food or animal feed.

 

 
Active ingredient propiconazole
Trade name Tilt 250 E
Rate per hectare (product) 500-760 mL per ha
Rate per acre (product) 200-308 mL per ac
PHI* 30
Comments Ground application only. Apply when disease symptoms first appear. Under severe disease pressure, make a second application 14 days after. Harvested soybean seed should not be used for human food or animal feed.

 

 
Active ingredient bacillus subtilis
Trade name Serenade ASO
Rate per hectare (product) 1.0-4.0 L per ha
Rate per acre (product) 0.4-1.6 L per ac
PHI* 0
Comments Provides suppression only. Ground and aerial application. Good option for organically grown soybeans. Under conditions of moderate to high disease pressure, use the higher rate and shorter application intervals. For maximum effectiveness, apply prior to, or at the early stages of disease development. Apply in sufficient water volume to ensure full coverage for effective control. Repeat as necessary on a 7-10 day interval.

 


Related links...

 


For more information:
Toll Free: 1-877-424-1300
E-mail: ag.info.omafra@ontario.ca
Author: OMAFRA Staff
Creation Date: 2 May 2011
Last Reviewed: 12 May 2011