Small Grains XII

Glume Blotch and Septoria Glume Blotch (wheat)

John E. Watkins

Cause:  (Stagonospora nodorum)  Occurrence: May  July.  Brown irregularly-shaped blotches on leaves.  Purple-brown lesions on glumes.  Black specks absent from lesions.

Management Approaches

Cultural Management Practices      

·        Crop rotation, where practical.

·        Stubble management that leaves a residue cover but hastens residue breakdown within a year.

·        Plant wheat into corn or soybean stubble in a conservation tillage system.

 

Fungicide Program

Apply a fungicide based on the following criteria:

·        Severity of leaf spotting on leaves during tillering.

·        Presence of infested wheat residue adjacent to the field (source of spore inoculum).

·        Earliness or lateness of the winter wheat crop (late crops more at risk).

·        Current and 30-day weather forecast (wet weather favors leaf spotting).

·        Potential yield of crop should be 45 bu/a dryland and 75 bu/a irrigated.

 

Goal of a spray program is to keep the flag and flag-1 leaves free of infection since they contribute significantly to yield.

 

 Product list Septoria Leaf and Glume Blotch Rust:

Product2

Target diseases

Product rate/acre

Application timing

Headline

(BASF)

Leaf rust

Stem rust

Stripe rust

Tan spot

Septoria leaf spot

Septoria glume blotch

Powdery mildew

Spot blotch

6-9 fl oz

Up to Feekes 10.5 (late heading emergence) plant stage

Quadris (Syngenta)

Leaf rust

Stripe rust

Stem rust

Septoria leaf blotch

Septoria glume blotch

Tan spot

Powdery mildew

6.2-10.8 fl oz

Feekes 6 (immediately after jointing) to 10.5 (late head emergence)

Quilt (Syngenta)

Leaf rust

Stem rust

Stripe rust

Tan spot

Septoria glume blotch

Septoria leaf blotch

Powdery mildew

Spot blotch

Helminthosporium

  leaf blight

7-14 fl oz

Up to Feekes 9 (ligule of flag leaf just visible)

plant stage

Stratego (Bayer)

Leaf rust

Stripe rust

Stem rust

Septoria leaf blotch

Tan spot

Powdery mildew

10 oz

Feekes 8 (emerging flag leaf)

Tilt (Syngenta)

Leaf rust

Stripe rust

Stem rust

Septoria leaf spot

Septoria glume blotch

Tan spot

Powdery mildew

4.0 fl oz

Feekes 8 (emerging flag leaf)

PropiMax EC

(Dow AgroSciences)

Leaf rust

Stripe rust

Stem rust

Septoria leaf spot

Septoria glume blotch

Tan spot

Powdery mildew

4.0 fl oz

Feekes 8 (emerging flag leaf)

Manzate 75DF

(Griffin L.L.C.)

Leaf rust

Septoria glume blotch

Septoria leaf spot

Tan spot

2.0 lb

Feekes 10 (boot) and again at 10.5 (late head emergence)

Dithane DF

             F-45

             M-45

(Dow AgroSciences)

Leaf rust

Septoria glume blotch

Septoria leaf spot

Tan spot

2.1 lb

1.6 qts

2.0 lb

Feekes 10 (boot) and again at 10.5 (late head emergence)

Penncozeb 80WP

                  75DF

(Elf Atochem)

Leaf rust

Septoria glume blotch

Septoria leaf spot

Tan spot

1.0-2.0 lb

Feekes 10 (boot) and again at 10.5 (late head emergence)

 

The information herein is supplied with the understanding that no discrimination is intended and that listing of commercial products, necessary to this guide, implies no endorsement by the authors or the Extension Services of Nebraska, Colorado, Wyoming or Montana. Criticism of products or equipment not listed is neither implied nor intended. Due to constantly changing labels, laws and regulations, the Extension Services can assume no liability for the suggested use of chemicals contained herein. Pesticides must be applied legally complying with all label directions and precautions on the pesticide container and any supplemental labeling and rules of state and federal pesticide regulatory agencies. State rules and regulations and special pesticide use allowances may vary from state to state: contact your State Department of Agriculture for the rules, regulations and allowances applicable in your state and locality.

 

Categories: Small grains, Diseases, Septoria Leaf Blotch, Septoria Glume Blotch

 

Date: 03/21/2005


Supported in part by:
Western Region IPM Center, EPA Region Vlll, National Plant Diagnostic Network, Great Plains Diagnostic Network, USDA CSREES, Colorado State University, Montana State University, South Dakota State University, the University of Nebraska - Lincoln,and the University of Wyoming.