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Posted 29 June 2011. PMN Crop News.

Stripe Rust Pressure Rising in Winter Wheat Across Montana

Source: Syngenta Press Release.

Greensboro, North Carolina (June 23, 2011)--Currently, Montana State University is tracking stripe rust progression in Hill, Prairie, Big Horn, Lake and Flathead counties in Montana. According to a report from the Montana State University Department of Plant Sciences and Plant Pathology, winter wheat is severely infected with stripe rust in these counties. Barley in Hill, Yellowstone and Big Horn counties is starting to show spot signs of net blotch, too. Syngenta reminds cereal growers to actively scout fields and monitor disease-tracking websites to assess the need for a fungicide application, like a Quilt® brand fungicide.


Based on observations made by Dr. Mary Burrows, extension plant pathologist at Montana State University, winter wheat affected with stripe rust is presently in flag to early boot stages of growth. Winter wheat that is not tainted with stripe rust, however, is experiencing severe tan spot or Septoria, instead. She also notes growers are currently employing applications of fungicides, particularly Tilt® fungicide, to protect cereal crops from these yield-robbing diseases. Studies she conducted determined spraying for stripe rust increases yields by an average of 10 bushels an acre.

Diseases in wheat and barley can cause devastating yield loss up to 40 percent and, in some cases, complete crop destruction. It is vital for growers to monitor disease pressure throughout the growing season.

“There are many online tools available to help cereal growers monitor the latest disease-outbreak patterns in their region,” said Grant Aldridge, Syngenta fungicide brand manager. “In addition, they should use timely scouting to assess disease levels in their own fields. We know there are two stages that are critical to end yield – Feekes Growth Stages 2 to 5 and Feekes Growth Stages 8 to 10.5. Growers should develop a disease-management plan that includes preventive and curative fungicide options to protect their crop.”

FGS 2 to 5: Spikelet Formation

Although the Montana winter wheat crop is past FGS 2 to 5, spring wheat growers should be on alert as disease pressure in the winter wheat crop could serve as a source for early spring wheat infection. Disease control is critical during the reproductive stages of FGS 2 to 5 as the number of spikelets and size of kernels are determined at that time.

“Protecting tillers during this timeframe will help them become more efficient and possibly help the plant put on several more tillers, as well,” explained Jon Rich, Central Plains AgriPro wheat breeder with Syngenta Seeds. “A fungicide application during this time helps protect plants from early, cool-season diseases like tan spot, Septoria and powdery mildew.”

“Fungicides like Tilt can help make the plant more productive and perform at a higher level. You’re reducing disease pressure at that time, and you’re enabling the plant to produce more spikelets per head,” Rich added.

Syngenta offers a comprehensive fungicide program for cereal growers, recommending an application of Tilt, which has both systemic and some curative properties against certain diseases at FGS 2 to 5. At a rate of 2 ounces per acre, Tilt will suppress powdery mildew, late blight, glume blotch and tan spot.

This early timing also coincides with herbicide or foliar fertilizer applications to maximize the trip across the field. Tilt can easily be tank mixed with Axial® XL herbicide to provide one-pass disease and mixed grass control.

FGS 8 to 10.5: Flag Leaf

As the crop closes in on maturity, FGS 8 to 10.5 become the most critical point as this is when the flag leaf emerges. Protecting the flag leaf is important for maximizing yield potential – the highest yield is normally obtained when fungicide is applied as the flag leaf reaches 50- to 70-percent full emergence.

“The flag leaf, being the leaf that is right below the head, is the one that is feeding the grain the most, which makes it the most important contributor to final grain yield,” said Tim Murray, Ph.D., professor of plant pathology at Washington State University.

Quilt brand fungicides help protect the valuable flag leaf from yield-robbing foliar diseases like rusts, tan spot, powdery mildew and Septoria. By combining the Power of Two™ proven brands, Quilt delivers broad-spectrum, preventive and curative disease control up to FGS 10.5.

In addition to disease protection, Quilt brand fungicides provide plants with certain physiological benefits. These Plant Performance™ benefits include:

• Improved plant growth for higher yields

• Increased water-use efficiency resulting in more crop growth

• Extended grain fill as the final step in optimizing yields

In fact, research has shown that Quilt can increase yields an average of 7 to 12 bu/A in cereal crops, in part due to these benefits. This can represent a sizable profit bump for growers.

As Montana State University continues to track stripe rust and other diseases through wheat-growing counties across Montana, cereal growers should ensure their crops are protected from diseases from planting to harvest. Careful preparation, disease monitoring, sound scouting techniques and preventive and curative fungicide programs are available to aid growers in implementing a successful disease-management plan throughout the growing season.

Wendell Calhoun