Soybeans: Powdery Mildew (Microsphaera diffusa)


Pub 812: Field Crop Protection Guide > Pub 812: Soybeans > Powdery Mildew

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

Table of Contents

  1. Integrated Pest Management Options
      • tebuconazole - Folicur 250 EW, Folicur 432 F
      • propiconazole - Tilt 250 E
      • azoxystrobin - Quadris
      • azoxystrobin + propiconazole - Quilt
    1. Related Links...

 

Integrated Pest Management Options

This disease is most noticeable when conditions are wet or humid. Powdery mildew develops on the leaves, usually in August and September. Outbreaks arise when disease symptoms begin in early July and the environmental conditions remain cool, cloudy and humid through to pod fill. Removal of crop residue and rotation with non-host crops, such as corn and wheat, will help prevent both diseases.

 
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 the 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 mLper 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 the 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 propiconazole
Trade name Tilt 250 E
Rate per hectare (product) 500 mL per ha
Rate per acre (product) 200 mLper ac
PHI* 30
Comments Ground and aerial application. First application should be made at the first sign of disease, followed by a second application 14 days after the first application, if environmental conditions are favourable for disease development. Good spray coverage and canopy penetration are important for best results. See label for resistance management strategy. Maximum 2 applications/yr.

 

 
Active ingredient azoxystrobin
Trade name Quadris
Rate per hectare (product) 500 mL per ha
Rate per acre (product) 200 mLper ac
PHI* 15
Comments Ground and aerial application. See label for resistance management strategy. Maximum 2 applications/yr. Re-entry possible once residues have dried.

 

 
Active ingredient azoxystrobin
Trade name Quilt
Rate per hectare (product) 1.0 L per ha
Rate per acre (product) 400 mLper ac
PHI* 30
Comments Ground and aerial application. First application should be made at the first sign of disease, followed by a second application 14 days after the first application, if environmental conditions are favourable for disease development. Good spray coverage and canopy penetration are important for best results. See label for resistance management strategy. Maximum 2 applications/yr.

 


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