Crop and Pest Report: Plant Pathology

ISSUE 1 May 14, 2009

NDSU EXTENSION PLANT PATHOLOGY WEB SITE

The NDSU Extension Plant Pathology web site can be found at: www.ag.ndsu.edu/extplantpath/

This site currently has links to new extension publications on crop disease management and has the link to the 2009 Field Crop Fungicide Guide, NDSU Ext. Publication PP-622. The on-line version of the Fungicide Guide is updated as information on product changes becomes available throughout the year.

NEW PLANT PATHOLOGY PUBLICATIONS AVAILABLE

Several NDSU extension publications on economically damaging diseases have become available since this time last year.

Blackleg of Canola (PP-1367, June 2008)

Ascochyta Blight of Chickpea (PP-1362, June 2008)

Rust Diseases of Wheat in ND (PP-1361, June 2008)

Row Crop Diseases in Drought Years (PP-1371, July 2008)

Fusarium Head Blight (Scab) of Small Grains (PP-804, September 2008)

Ground Application of Fungicide for the Suppression of Fusarium Head Blight in Small Grains (AE-1314, November 2008)

2009 North Dakota Field Crop Fungicide Guide (PP-622, December 2008)

Fungal Leaf Spot Diseases of Wheat: Tan Spot, Stagonospora nodorum blotch and Septoria tritici blotch (PP-1249, February 2009)

Downy Mildew of sunflower (PP-1402, May 2009)

These and other NDSU Extension Service publications related to plant diseases are available online at http://www.ag.ndsu.edu/pubs/plntdise.html.

Sam Markell
Extension Plant Pathologist
samuel.markell@ndsu.edu

Marcia McMullen
Extension Plant Pathologist
marcia.mcmullen@ndsu.edu

CEREAL RUST NEWS FROM THE CEREAL DISEASE LAB, ST. PAUL

Wheat leaf rust: The USDA Cereal Disease Lab’s latest Cereal Rust Bulletin, Report No. 4, May 5^th, indicated that wheat leaf rust was found at low levels in fields in central Texas. A May 8^th update from Kansas State University indicated that crops were in the heading to flowering stages in south central Kansas and leaf rust was detected on flag leaves of susceptible winter wheat cultivars, such as Overley, Jagalene and Jagger. So, leaf rust appears to still be at low levels in commercial fields in the southern plains states. The Cereal Disease Lab says, however, that ideal conditions for rust development are now occurring in these states, because of recent abundant rains.

Wheat stem rust: A race of wheat stem rust commonly found in the United States has been detected in Texas and Louisiana. The Cereal Disease Lab has an active detection program in place for wheat stem rust, as well as wheat leaf rust, and they provide maps of both stem rust and leaf rust occurrence. The Cereal Rust Bulletin can be found in at the following web address: www.ars.usda.gov/Main/docs.htm?docid=9757

SMALL GRAIN PLANTING AND LEAF DISEASES

Rains across the state and some warmer temperatures this week will favor initial development of early season tan spot in susceptible winter wheat cultivars, so growers with winter wheat should start scouting their winter wheat crops for this fungal leaf spot soon. Most spring wheat may not yet be emerged or certainly not ready for a herbicide + fungicide tank mix.

Marcia McMullen
Extension Plant Pathologist
marcia.mcmullen@ndsu.edu