Corn: Grey Leaf Spot (Cercospora zeae-maydis)


Pub 812: Field Crop Protection Guide > Chapter 1: Corn > Grey Leaf Spot

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

Table of Contents

  1. Integrated Pest Management Options
  • pyraclostrobin - Headline EC
  • azoxystrobin + propiconazole - Quilt
  • prothioconazole - Proline 480 SC
    propiconazole - Tilt 250 E, Bumper 418 EC
  1. Related links...


Integrated Pest Management Options

This disease is becoming more common in Southwestern Ontario. Some hybrids are tolerant/resistant to the disease. Consult with your seed company and the Ontario Corn Committee Hybrid Performance Trials at www.gocorn.net for hybrid selection. Crop rotation and tillage will reduce inoculum levels in surface residues. In reduced tillage systems, rotation and resistance are necessary. Chemical control is usually not economical in field corn.

 
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* 7
Comments Ground and aerial application. Use a minimum water volume of 100 L/ ha. For optimal disease control, begin applications prior to disease development. Do not graze treated crop within 6 days of last application. Maximum of 2 applications/yr. 12-hr re-entry period.

 

 
Active ingredient azoxystrobin + propiconazole
Trade name Quilt
Rate per hectare (product) 0.75-1.0 L per ha
Rate per acre (product) 305-406 mL per ac
PHI* 30
Comments Ground and aerial application. Apply when disease first appears, followed by a second application 14 days after, if environmental conditions are favourable for disease development. Do not apply to field corn or field corn grown for seed after brown silk. Maximum 2 applications/yr.

 

 
Active ingredient prothioconazole
Trade name Proline 480 SC
Rate per hectare (product) 420 mL per ha
Rate per acre (product) 170 mL per ac
PHI* 14
Comments Ground application only. Maximum 1 application/yr. 24-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 mL per ac
PHI* 14
Comments Ground and aerial application. Apply when rust pustules first appear. Under severe disease pressure, a second application 14 days later may be necessary. Only in seed corn, under severe disease pressure can a third application be made 14 days later. Can be tank mixed with Ripcord or Matador insecticide for insect control.

 

 
Active ingredient propiconazole
Trade name Bumper 418 EC
Rate per hectare (product) 300 mL per ha
Rate per acre (product) 121 mL per ac
PHI* 14
Comments Ground and aerial application. Apply when rust pustules first appear. Under severe disease pressure, a second application 14 days later may be necessary. Only in seed corn, under severe disease pressure can a third application be made 14 days later. Can be tank mixed with Ripcord or Matador insecticide for insect control.

 


Related links...

 


For more information:
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E-mail: ag.info.omafra@ontario.ca
Author: OMAFRA Staff
Creation Date: 2 May 2011
Last Reviewed: 10 May 2011