NEWS for North Dakotans
Agriculture Communication, North Dakota State University
7 Morrill Hall, Fargo, ND 58105-5665
March 16, 2000
Some severe disease problems in cereal grains have occurred throughout the region in recent years, and these problems could have been reduced with seed treatments, says a plant pathologist at North Dakota State University.
For example, the 1999 wheat and barley disease survey conducted by the NDSU Extension Service showed that loose smut of wheat was very common throughout much of North Dakota, and in some fields very severe, with as much as 30 percent of the grain heads infected.
"That disease could have been prevented with proper seed treatment," says Marcia McMullen, extension plant pathologist at NDSU. "Common root rot of wheat and barley also was very common and severe in 1999, and damage from this disease could have been reduced with appropriate seed treatments."
The risk of those diseases is again high this year because of possible loose smut presence in the seed at planting and because the common root rot fungus was active in 1999 and developed a high population that could affect the 2000 crop. McMullen says seedling blights also could occur if seed was diseased at planting or if seed was planted into less than favorable seed bed conditions.
For barley loose smut, the internally borne fungus can be detected in seed with an embryo test, which is done by the North Dakota State Seed Department. If levels in the seed are 2 percent or greater, the seed should be treated with an appropriate seed treatment fungicide, and economic control will be achieved. For barley loose smut, the Carboxin-containing products plus Raxil and Baytan are registered.
McMullen says the embryo test for loose smut in wheat is not available, but if growers saw considerable loose smut in their fields in 1999 or are purchasing seed from an unknown source, seed treatment for loose smut may be warranted. Seed treatments that control loose smut in wheat include those containing Carboxin, such as Vitavax products and Enhance, as well as Dividend, Raxil, Baytan and Benomyl.
Common root rot is suppressed with a number of seed treatment fungicides, including Dividend, Imazalil (several trade names), Raxil, and Baytan. Seed treatment reduces seedling infection, and subsequently, the healthier root system is better able to sustain plant growth and grain fill as the crop matures, McMullen says.
Seedling blights in small grains may be caused by fungi on the seed or in the soil. Seedling blight diseases may be aggravated by cold, wet soils or warm, wet soils or extended exposure to very dry soils. McMullen says seedling blights are controlled by a number of seed treatment fungicides, including Captan, Dividend, Maxim, Imazalil, Mancozeb, Maneb, PCNB, Thiram, TBS, Raxil and Baytan.
Check individual labels for specific rates and crop restrictions. For further information, consult the newly revised NDSU Extension Service Publication titled "Seed Treatment for Disease Control" (PP-447), which will soon be available through county extension offices and via the Internet (http://www.ext.nodak.edu/extpubs/plantsci/crops/pp447w.htm).
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Source: Marcia McMullen (701) 231-7627
Editor: Dean Hulse (701) 231-6136