Cereals: Wheat: Septoria Leaf Spot (Septoria tritici)


Pub 812: Field Crop Protection Guide > Chapter 4: Cereals > Wheat: Late-Season Septoria Spp. (Glume Blotch and Leaf Spot)

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

Table of Contents

  1. Description
  2. Integrated Pest Management Options
      • pyraclostrobin – Headline EC
      • azoxystrobin + propiconazole - Quilt
      • propiconazole – Tilt 250 E
      • propiconazole – Bumper 418 EC
      • prothioconazole - Proline 480 SC
      • tebuconazole – Folicur 250 EW, Folicur 432 F
      • Prothioconazole + tebuconazole - Prosaro 250 EC
      • mancozeb – Dithane DG, Rainshield NT
  3. Related links...

Description

Septoria leaf spot attacks only leaves, whereas Stagonospora glume blotch appears on the leaves and glumes. Initial infections from Septoria leaf spot appear as small, light green-to-yellow spots between the veins of the lower leaves. These spots elongate to form irregular reddish-brown lesions. Embedded in these lesions are small, dark brown-to-black fungal bodies (pycnidia) that can be seen easily with the use of a hand lens.

Plate 118. Septoria leaf spot appears as small, light green-to-yellow spots that elongate to form reddish-brown lesions.

Septoria leaf spot appears as small, light green-to-yellow spots that elongate to form reddish-brown lesions.


Integrated Pest Management Options

Foliar Treatment

Wet, windy weather and moderate temperatures favour the development of this disease. Destroying volunteer wheat, reducing crop residue and crop rotation can help reduce risk of infection. Plant less susceptible varieties. Consult with your seed company and the Ontario Cereal Crops Committee Variety Trials Results at www.gocereals.ca for variety profiles.

See Appendix J. Cereal Growth Stages, on page 136.

Active ingredient pyraclostrobin
Trade name Headline EC
Rate per hectare (product) 300-600 mL per ha
Rate per acre (product) 120-240 mL per ac
PHI* Do not apply at boot stage and beyond
Comments Ground and aerial application. Apply only up to flag leaf fully emerged stage (Zadok's 39). Do not apply at boot stage (Zadok's 47) and beyond. Maximum 2 applications/season. Tank-mixing with insecticide is not recommended, as this fungicide could affect insecticide efficacy.

 

Active ingredient
azoxystrobin + propiconazole
Trade name
Quilt
Rate per hectare (product)
750 mL per ha
Rate per acre (product)
305 mL per ac
PHI* Do not apply at boot stage and beyond
Comments Ground and aerial application. Apply only up to flag leaf fully emerged stage (Zadok's 39). Do not apply at boot stage (Zadok's 47) and beyond. Maximum 1 application/yr. Do not harvest for forage. 12-hr re-entry period.

 

 
Active ingredient propiconazole
Trade name Tilt 250 E
Rate per hectare (product) 250-500 mL per ha
Rate per acre (product) 100-200 mL per ac
PHI* 45
Comments Ground and aerial application. Early application at Zadok's 12-23. Use low rate for early-season disease suppression. Use higher rate for field with high disease pressure history or field conditions favourable for disease development. Later application at first sign of disease (Zadok's 29-37) or before head is half emerged (Zadok's 49-55). Apply only the high rate on any application from Zadok's 29-55. Maximum 2 applications/yr.

Active ingredient propiconazole
Trade name Bumper 418 EC
Rate per hectare (product) 150-300 mL per ha
Rate per acre (product) 60-121 mL per ac
PHI* 45
Comments Ground and aerial application. For early-season disease suppression, use the lower rate at Zadok's 12-23 (as early as the two leaf stage). Use the high rate for fields with a history of disease pressure. For later-season application, apply at eary signs of the disease from the beginning of stem elongation (Zadok's 29-37). If conditions favourable to disease continue, apply again, if necessary, before head is half emerged (Zadok's 49-55). Apply only the high rate from Zadok's 29-55. Maximum 2 applications/yr.

 

Active ingredient prothioconazole
Trade name Proline 480 SC
Rate per hectare (product) 315 mL per ha
Rate per acre (product) 128mL per ac
PHI* 30
Comments Ground application only. Use as a preventative when earliest disease symptoms appear on the leaves and stems. Recommended to be used with the registered non-ionic surfactant, Agral 90 or AgSurf at 0.125% vol/vol. Maximum 2 applications/yr with a minimum 7-day interval between applications. Do not apply within 30 days of harvest.

 

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* 36
Comments

Ground and aerial application. Apply to leaf foliage at the first sign or very early stage of disease, especially if weather conditions are conducive to disease development, up to the end of the flowering stage. Use the higher rate when weather conditions are conducive to heavy disease development. The use of a non-ionic surfactant (Agral 90 or Agsurf) is NOT required as it is built into the formulation. Use a minimum of 100 L/ha of water for ground application, 47 L/ha of water for aerial application. Maximum 1 application/yr. 12-hr re-entry period.

 

Before using Folicur for control of wheat leaf diseases, consider that Folicur can only be applied once per year and has been traditionally used for Fusarium control, where applications are targeted at head emergence.

   

 

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* 36
Comments

Ground and aerial application. Apply to leaf foliage at the first sign or very early stage of disease, especially if weather conditions are conducive to disease development, up to the end of the flowering stage. Use the higher rate when weather conditions are conducive to heavy disease development. Always yse non-ionic surfactant such as Agral 90 or Agsurf at 0.125% vol/vol. Use a minimum of 100 L/ha of water for ground application, 47 L/ha of water for aerial application. Maximum 1 application/yr. 12-hr re-entry period.

 

Before using Folicur for control of wheat leaf diseases, consider that Folicur can only be applied once per year and has been traditionally used for Fusarium control, where applications are targeted at head emergence.

 

Active ingredient prothioconazole + tebuconazole
Trade name Prosaro 250 EC
Rate per hectare (product) 800 mL per ha
Rate per acre (product) 324 mL per ac
PHI* 36
Comments

Ground and aerial application. Use a minimum of 100 L/ha of water for ground application, 50 L/ha of water for aerial application. Maximum 1 application/yr. 12-hr re-entry period.

 

 
Active ingredient mancozeb
Trade name Dithane DG
Rate per hectare (product) Early: 1.1 kg per ha
Rate per acre (product) Early: 440 g per ac
Rate per hectare (product) Late: 2.25 kg per ha
Rate per acre (product) Late: 900 g per ac
PHI* 40
Comments Use lower rate for applications at Zadok's 12-21 growth stage, when crop is in 3rd leaf to tillering. Higher rate for applications at Zadok's 59 growth stage when head is fully emerged but prior to flowering. Do not graze crop or cut for hay. Maximum 2 applications/yr.

 

 
Active ingredient mancozeb
Trade name Rainshield NT
Rate per hectare (product) Early: 1.1 kg per ha
Rate per acre (product) Early: 440 g per ac
Rate per hectare (product) Late: 2.25 kg per ha
Rate per acre (product) Late: 900 g per ac
PHI* 40
Comments Use lower rate for applications at Zadok's 12-21 growth stage, when crop is in 3rd leaf to tillering. Higher rate for applications at Zadok's 59 growth stage when head is fully emerged but prior to flowering. Do not graze crop or cut for hay. 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: 16 May 2011