Powdery mildew showing up late in a sugar beet field in south central Montana (Cropland Diseases)
Description:

A sugar beet field with the majority of plants showing a dusty appearance on leaves was identified in south central Montana, near Billings, on September 9. Plants exhibited the symptoms both on the upper and underside of leaves at moderate to high levels of severity. Close observation of the symptoms suggested they corresponded to the disease known as powdery mildew, which is caused by the fungus Erysiphe polygoni. Leaf samples were taken to an MSU lab for microscopic observation and confirmation of the pathogen identity. Scattered, whitish mycelial mats were observed on both leaf surfaces containing abundant, cylindrical to elliptical conidia (asexual spores of the fungus) that originated singly from straight, short conidiophores. No chasmothecia (sexual stage of the fungus) were present in the observed leaves. Occurrence of the disease in this field coincides with a period of suitable weather conditions for disease development in this location, namely: warm, dry weather, and large diurnal temperature changes towards end of August-beginning of September. At this stage, since the crop in the scouted field is near harvest, a fungicide treatment is not justified. In situations where the disease is detected early in the season, a fungicide treatment would be recommended upon detection to reduce a potential rapid disease increase. Presence of the disease in this location constitutes a source of inoculum for healthy neighboring fields, though according to communication with the Yellowstone agriculture extension agent and area agronomists, no other fields with similar symptoms have been observed as yet. Disease presence in this location suggests future imminent risk for seasonal incursions of pathogen spores into the area from afar overwintering sites.

For questions and further discussion please contact Dr. Oscar Perez-Hernandez, MSU Extension Row Crop Pathologist (oscar.perezhernandez@montana.edu; 406-994-4091)

 


Alert Period: 09/17/2021 - 09/17/2022
Submitted By: Uta McKelvy

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Pest Management Tour offers Private Applicator Opportunities across Eastern Montana (Pesticides)
Description:

The Montana State University Pesticide Education Program with assistance from the Montana Department of Agriculture is offering the Pest Management Tour for pesticide applicators across Eastern Montana from October 4th – 8th. Montana Private (Farm) Applicators within PAT District 4 (eastern MT) should ensure they have attained 6 private applicator credits prior to the December 31, 2021 deadline to avoid losing their private applicator certification. Private applicators may opt to attend only a morning or afternoon session for 3 private applicator credits, or both for 6 credits. See attached for more information.  


Alert Period: 09/08/2021 - 10/21/2021
Submitted By: Cecil Tharp

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The 2021 Montana Pesticide and Waste Disposal Program Sites (Pesticides)
Description:

Pesticide applicators should be aware of the 2021 Montana Pesticide and Waste Disposal Program sites. Delaying removal of unused pesticide products often leads to corroded containers that pose unnecessary risk towards the environmental and human health. By following a few simple steps applicators can ensure unused pesticides are discarded and disposed of legally and safely.

 


Alert Period: 08/27/2021 - 10/14/2021
Submitted By: Cecil Tharp

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MSU Extension Drought Resources in Montana (General)
Description:

On July 1st, 2021, Governor Greg Gianforte issued an executive order declaring a statewide drought emergency in Montana.  The U.S. Drought Monitor indicates 98.7% of Montana faces drought conditions as of July 29th. Approximately 49% of the state is in either D4 (exceptional drought) or D3 (extreme drought), 31% in D2 (severe drought), and 19% in D1 (moderate drought). Conditions are expected to worsen over the next eight to ten weeks. Conditions are forcing agricultural operations to make difficult decisions due to high nitrates in forage, contaminated and limited water sources, lack of forage for livestock, insect infestations and many other related issues. This Ag Alert is a reminder of the many resources through MSU Extension that are available to assist individuals making difficult drought decisions across multiple disciplines.   


Alert Period: 07/31/2021 - 11/23/2021
Submitted By: Cecil Tharp

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Physiological Leaf Spots on ‘Bobcat’ Winter Wheat (General)
Description:

We are receiving many reports of MSU winter wheat variety ‘Bobcat’ showing foliar leaf spots across the state. The leaf spots are tan to brown in color with yellow halos around them and resemble those associated with tan spot disease or chloride deficiency. Lesion from chloride deficiency tend to have more discrete margins between affected and nonaffected tissue while the margins of fungal lesions tend to be more diffuse. We have observed leaf spot symptoms in Bobcat in previous years, as well, but this year’s drought conditions and temperature extremes have likely exacerbated this phenotype.

At the Schutter Diagnostic Lab we have assessed several ‘Bobcat’ samples for the presence of the tan spot pathogen (Pyrenophora tritici-repentis) or other pathogenic causes. At this point, we have no convincing evidence that the observed spotting is caused by a fungal pathogen. The leaf spots are more likely of physiological nature (physiological leaf spot, PLS), which is often caused by chloride deficiency. If disease is ruled out, then chloride deficiency is suspect. In most winter wheat fields this year, it’s likely too late to have a large benefit with a chloride treatment, but if you decide to try, 10-20 lb potash (0 0 60) per acre should be sufficient (5-10 lb Cl/acre) or a similar amount of chloride applied as a liquid (for example calcium chloride or ammonium chloride).

If you observe leaf spot symptoms we encourage you to drop a sample (whole plant) at your local Extension office or submit directly to the Schutter Diagnostic Lab and await diagnosis before applying fungicides (sample submission instructions and forms can be found on the Diagnostic Lab website). If you want to rule out or rule in chloride deficiency, the suggested critical level in plant material (entire plant) is between 0.1 and 0.4%, with large yield increases and leaf spot decreases when chloride was applied at tissue Cl concentrations below 0.1%. Please note that the Schutter Diagnostic Lab does offer tissue analysis or soil testing services.

See https://store.msuextension.org/publications/AgandNaturalResources/NM7.pdf for more information.

Don't hesitate to reach out with any questions or concerns.

 

Best,

Uta McKelvy

Extension Field Crop Pathologist

406-994-5572

uta.mckelvy@montana.edu

 

Clain Jones

Extension Soil Fertility Specialist

406-994-6076

clainj@montana.edu


Alert Period: 06/16/2021 - 06/16/2022
Submitted By: Uta McKelvy

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Abiotic (Non-Infectious) Symptoms in Wheat Widespread Across Montana (Cropland Diseases)
Description:

Our colleagues at North Dakota State University publish a weekly "Crop & Pest Report" throughout the growing season. This weeks' newsletter contains an informative article by Andrew Friskop and Joe Ikley discussing various abiotic symptoms observed in wheat across the state. You can find the article under "Alert Details."

The entire NDSU "Crop & Pest Report" from June 10, 2021, and older reports can be found following this link: https://www.ag.ndsu.edu/cpr

 

If you are interested in receiving the Crop and Pest Report, you can sign up for free at: http://www.ag.ndsu.edu/cpr/subscribe-to-crop-pest-report-pdf-version

Happy Friday!

Uta


Alert Period: 06/11/2021 - 06/11/2022
Submitted By: Uta McKelvy

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Expect frost damage from recent cold snap (Cropland Diseases)
Description:

We are starting to receive samples that show symptoms of frost injury which are associated with the winter comeback last week. Frost damage often occurs in patches in the field, for example in low-lying areas where cold air settles. If and how severely your crop was affected by the cold temperatures depends on the developmental stage of the crop, the duration and low of the temperatures in your location. This alert discusses symptoms of freeze injury on wheat, barley, and pulse crops and includes links for further information.

Call the Schutter Diagnostic Lab at 406-994-5150 or visit our website at diagnostics.montana.edu if you have any questions about how to submit a good sample. Instructions are also on the website.

Best,

Uta McKelvy

406-994-5572

uta.mckelvy@montana.edu


Alert Period: 05/27/2021 - 05/27/2022
Submitted By: Uta McKelvy

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Herbicide Carryover Concerns in 2021 (Cropland Weeds)
Description:

Our colleagues at North Dakota State University publish a weekly "Crop & Pest Report" throughout the growing season. This weeks' newsletter contains an informative article by Joe Ikley discussing the effects of drought and soil properties on herbicide breakdown and carryover. You can find the article under "Alert Details."

The entire NDSU "Crop & Pest Report" from May 6, 2021, and older reports can be found following this link: https://www.ag.ndsu.edu/cpr

If you are interested in receiving the Crop and Pest Report, you can sign up for free at: http://www.ag.ndsu.edu/cpr/subscribe-to-crop-pest-report-pdf-version

Happy Friday!

Uta

 


Alert Period: 05/07/2021 - 05/07/2022
Submitted By: Uta McKelvy

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Foliar Fungicide Efficacy Ratings for Wheat Disease Management Updated (Cropland Diseases)
Description:

Happy Wednesday everyone!

An updated version of the foliar fungicides table for wheat disease management and associated efficacy ratings has been posted on the MSU Extension Plant Pathology Resources website: http://plantpath.msuextension.org/resources/2021-ncera184-wheat-fungicide-table.html

This table was developed and updated by the North Central Regional Committee on Management of Small Grain Diseases (NCERA-184) for use by the grain production industry in the U.S. The table is provided as a guide to inform you of fungicide options for control of commong wheat diseases. It includes most widely marketed products and is not intended to be a list of all labelled products.

 

Please reach out to your local extension agent or Uta McKelvy with any questions or comments (email: uta.mckelvy@montana.edu; phone: 406-994-5572)

Happy spring!


Alert Period: 04/28/2021 - 04/28/2022
Submitted By: Uta McKelvy
Seed and foliar fungicide tables for pulse crops (Cropland Diseases)
Description:

We have updated tables listing available fungicide products (seed treatments and foliar products) for managmeent of widespread fungal diseases of pulse crops. The tables can be found at the MSU Extension Plant Pathology Resources website.

Fungicide Seed Treatment Table: http://plantpath.msuextension.org/resources/2021-fungicides-for-pulse-crop-seed-treatment.html

Foliar Fungicide Table: http://plantpath.msuextension.org/resources/2021-fungicides-for-pulse-crop-foliar-treatment.html

Please reach out to Dr. Uta McKelvy with any questions or comments (email: uta.mckelvy@montana.edu; phone: 406-994-5572)

Happy planting!


Alert Period: 04/12/2021 - 04/12/2022
Submitted By: Uta McKelvy