2017 UW Extension Pest Management Update Meeting Series

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Be sure to get the latest field crop pest management updates, by attending the 2017 PMU Meetings!

Damon L. Smith, Extension Field Crops Pathologist, University of Wisconsin-Madison

Mark your calendars as the UW Extension’s Pest Management Update meetings are just around the corner (November 6-10). This year’s program will follow the same format as in 2016. Meetings will either be in the morning or afternoon and will run for 3 hours. Morning meetings will begin promptly at 9am and run to 12pm. Afternoon meetings will begin at 1pm and conclude at 4pm.

The full schedule with dates, meeting locations, and registration contact information are in the link below. Please register with the host agent at least 1 week prior to the meeting at the location you wish to attend.

Please attend the meeting location at which you registered. Each meeting in the series is a separate county-based event and host agents cannot interchange registrant fees or meal counts.

Three hours of Certified Crop Advisor CEU credits in pest management are requested for each session.

The speakers will be extension specialists Mark Renz, weed scientist, perennial cropping systems; Dan Heider, IPM outreach specialist, Bryan Jensen, entomologist, and Damon Smith, field crop pathologist.

2017 Pest Management Update Topics:

  • Integrated Pest Management Updates in corn, soybeans, alfalfa, and small grains: Update on new products and/or use of existing products as well as brief highlights of the 2017 pest situations in each crop.
  • Wisconsin herbicide resistance update by Mark Renz
  • In-depth weed diagnostic and management training by Mark Renz and Dan Heider

CHECK OUT THE FULL MEETING SCHEDULE BY CLICKING HERE!

Wisconsin Winter Wheat Disease Update – June 30, 2017

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Stripe rust in a “striped pattern” on winter wheat leaves.

Damon Smith, Extension Field Crops Pathologist, Department of Plant Pathology, University of Wisconsin-Madison

Brian Mueller, Graduate Research Assistant, Department of Plant Pathology, University of Wisconsin-Madison

The Wisconsin Field Crops Pathology team has nearly finished all of our assessments of wheat and wheat disease for the year in Wisconsin. Winter wheat is well on its way to maturing. The few spring wheat acres we have seen have mostly completed anthesis throughout much of the state, with just a few late-planted locations still completing anthesis.

Overall, the spring 2017 wheat season can be defined mostly by the widespread presence of stripe rust. We have been in fields where stripe rust has caused significant widespread damage on susceptible varieties that were not treated with fungicides. We have also observed fields that either had a resistant variety, received a fungicide application, or both. These fields appear to be doing quite well and the crop will yield well. Clearly areas where we suspect that there was overwintering of the stripe rust pathogen, saw the occurrence of the epidemic very early, resulting in quick spread of stripe rust this season. We have completed rating of stripe rust in the wheat variety trials in Wisconsin and these data will be published later this year in the variety performance report. I would encourage you to study these results carefully and choose varieties that performed well in your area and had low levels of stripe rust. This is the second year in a row that we have had a substantial stripe rust epidemic and choosing resistant varieties is a cheap method of stripe rust management.

We have also been looking for Fusarium head blight (FHB or scab) in commercial fields and variety trials. For a second year in a row, FHB incidence and severity is extremely low statewide. In many fields we struggle to find even one symptomatic head. Fusarium head blight incidence in the far southwest part of the state is nearly undetectable and approaches about 1% incidence in fields in the north-central and northeastern portions of the state. I expect that DON (vomitoxin) levels will be relatively low in finished grain in Wisconsin, this season. The low level os FHB in winter wheat this season is likely due to the unseasonably hot, dry weather we had in early June, which coincided with anthesis in many wheat fields. This type of weather is not conducive for the fungus and likely resulted in very few successful infection events.

Other diseases have been extremely hard to find. We have seen some fields with low levels of Septoria/Stagonospora, but in general these epidemics will not limit yield to a significant extent. Powdery mildew can be found infrequently on a few plants in some fields. In the southern portion of the state, we were able to find some leaf rust just this week. The arrival of leaf rust is likely too late to affect yield this season. We have not observed any stem rust in our scouting trips to commercial fields or in variety trials.

 

Wisconsin Winter Wheat Disease Update – June 2, 2017

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Damon Smith, Extension Field Crops Pathologist, Department of Plant Pathology, University of Wisconsin-Madison

Brian Mueller, Graduate Research Assistant, Department of Plant Pathology, University of Wisconsin-Madison

Figure 1. Fusarium Head Blight Prediction Center Risk Map – June 2, 2017

Many winter wheat varieties in Wisconsin are headed out and at, or will be at, anthesis (flowering) this weekend. Currently, the Fusarium Head Blight Prediction Center is ranking much of the primary winter wheat growing area of Wisconsin at medium risk with many pockets of high risk for FHB on susceptible varieties (Fig. 1). Warm temperatures and the threat of rain this weekend will make conditions further favorable for FHB. In addition, stripe rust is quickly increasing in many fields on susceptible varieties. I have observed 20% stripe rust severity on flag leaves in several fields with high incidence across those fields.

The primary fungicides for control of FHB are Caramba and Prosaro. These same products are rated as “excellent” on stripe rust. I would urge you to verify anthesis has begun in your field before applying either product. We have observed poor control of FHB where application of these effective fungicides was made before anthesis. In fact, we have observed improved control of FHB and lower levels of DON in finished grain where fungicide application was delayed 4-5 days after the beginning of anthesis, compared to applications at the start of anthesis. Also, remember that application of fungicides should be made no later than 6-7 days after the start of anthesis. After this time, fungicide efficacy on FHB is much reduced. Finally, DO NOT use any fungicide products that contain a strobilurin fungicide after the “boot” stage in wheat. Some studies have demonstrated that using strobilurin fungicides at, or after heading, can result in increased vomitoxin (DON) levels in finished grain. Get out there and SCOUT, SCOUT, SCOUT!

Wisconsin Winter Wheat Disease Update – May 28, 2017

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Damon Smith, Extension Field Crops Pathologist, Department of Plant Pathology, University of Wisconsin-Madison

Brian Mueller, Graduate Research Assistant, Department of Plant Pathology, University of Wisconsin-Madison

Figure 1. Severe stripe rust on winter wheat prior to head emergence.

The Wisconsin Field Crops Pathology crew spent some time this past week scouting wheat and rating wheat variety trial plots, between planting soybeans and dodging rain storms. Despite the challenging week, the crew was able to get around to several sites and take a look at winter wheat. Wheat ranges from fully emerged flag leaf to emerging heads across the sites visited. As predicted, stripe rust is progressing to epidemic levels on susceptible and moderately susceptible varieties (Fig. 1). We were able to find many plots with stripe rust on the L2 leaf (leaf immediately below the flag leaf) with some varieties already showing 20% or more severity on flag leaves (Fig. 2). We were also able to find many varieties still showing no symptoms of stripe rust. We also have had several reports of disease-free winter wheat across the state. Further inquiry suggests that many did their homework last summer and fall, and chose varieties with excellent stripe rust resistance. This will more than pay for itself this season in fungicide spray savings.

Figure 2. Stripe rust on a flag leaf of winter wheat.

We are quickly approaching head emergence and anthesis on many varieties in the state of Wisconsin. I predict that anthesis (flowering) will take place within the next week or so in Wisconsin. Farmers should focus on making a decision on fungicide application to control Fusarium head blight (FHB or scab). At this point, I think farmers should hold off on a fungicide application specifically for stripe rust. The major focus for fungicide application on winter wheat in Wisconsin should shift to managing FHB. With this said, the two primary products that have performed well in Wisconsin for FHB, also perform well on stripe rust and are ranked excellent in the Small Grains Fungicide Efficacy Table. This means that spraying for FHB will also control stripe rust, as long as the stripe rust epidemic has not advanced to high levels on the flag leaves. Currently, the Fusarium Head Blight Prediction Center is ranking much of the primary winter wheat growing area of Wisconsin at medium-to-high risk for FHB on susceptible varieties (Fig. 3). Plenty of rain and adequate temperatures are making conditions ripe for FHB in the major wheat production area of the state.

Figure 3. Fusarium Head Blight Prediction Center Risk Map – May 28, 2017

The next 7-10 days poses a critical time to make a decision for fungicide application to control FHB and stripe rust. The primary fungicides for control of FHB are Caramba and Prosaro. I would urge you to wait until anthesis has begun in your field before applying. We have observed poor control of FHB where application of these effective fungicides was made before anthesis. In fact, we have observed improved control of FHB and lower levels of DON in finished grain where fungicide application was delayed 4-5 days after the beginning of anthesis, compared to applications at the start of anthesis. Data from a fungicide efficacy trial to support this observation can be found by clicking here and scrolling down to pages 16 and 17. Also, remember that application of fungicides should be made no later than 6-7 days after the start of anthesis. After this time, fungicide efficacy on FHB is much reduced. Finally, DO NOT use any fungicide products that contain a strobilurin fungicide after the “boot” stage in wheat. Some studies have demonstrated that using strobilurin fungicides at, or after heading, can result in increased vomitoxin (DON) levels in finished grain. Get out there and SCOUT, SCOUT, SCOUT!

Wisconsin Winter Wheat Disease Update – May 2, 2017

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Stripe rust on lower leaves of winter wheat plants at the Feekes 5 growth stage.

Brian Mueller, Graduate Research Assistant, Department of Plant Pathology, University of Wisconsin-Madison

Damon Smith, Extension Field Crops Pathologist, Department of Plant Pathology, University of Wisconsin-Madison

The Wisconsin Field Crops Pathology crew continues to scout wheat stands in various locations in Wisconsin. The primary disease of focus, remains stripe rust. Late last week we identified yet another stand of winter wheat with early stripe rust in a production field near Arlington, WI. The entire stand was planted to the variety Kaskaskia and had moderate levels of severity on the lower leaves (see picture). Incidence was spotty, but correlated to the greenest plants in the stand that were protected over the winter by snow cover. Other areas of the field that clearly were not insulated by snow and were further behind in growth stage, did not have visible symptoms of stripe rust. This observation reinforces the fact that stripe rust overwintered in this location during the winter of 2016/2017.

At this point in the season many growers have made their herbicide applications and either applied fungicide or held off. Growers and consultants should remain diligent in scouting for stripe rust and other diseases as the crop moves toward flag leaf emergence. As I look into my “crystal ball” I think that a decision to spray fungicide at the flag leaf growth stage is going to be critical in Wisconsin, especially on susceptible varieties. Weather has been very wet and temperatures are becoming more conducive for spread of the stripe rust pathogen. As these conditions persist, and we approach the flag leaf growth stage, a decision will need to be made to spray to control stripe rust. Remember that the flag leaf is responsible for much of the yield that a wheat plant will make. Our work in Wisconsin in 2016, demonstrated that for every 10% increase in stripe rust coverage on the  flag leaf alone, we lost almost 5.5 bu/acre in grain yield across the Wisconsin winter wheat variety trials. Thus, protecting this leaf is extremely important. On stripe rust-susceptible varieties, we have seen much benefit in flag applications to control stripe rust, especially when the pathogen is active.

Remember that there are many fungicide options for stripe rust control. Also, fungicide applications directed toward Fusarium head blight (FHB or scab) will also protect against stripe rust. So as you make your decision to spray at the flag leaf growth stage, choose a product that fits your pocketbook and consider that you might spray a strobilurin-containing product at this earlier growth stage. Later in the season, you will want to rotate to a non-strobilurin-containing product for your FHB control (Prosaro or Caramba). Hopefully we won’t have to make two applications of fungicide this year, but be prepared should the conditions necessitate this practice. Get out and scout, scout, scout!

Wisconsin Winter Wheat Disease Update – April 21, 2017

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Two small Stripe rust pustules on a winter wheat leaf.

Brian Mueller, Graduate Research Assistant, Department of Plant Pathology, University of Wisconsin-Madison

Damon Smith, Extension Field Crops Pathologist, Department of Plant Pathology, University of Wisconsin-Madison

The Wisconsin Field Crops Pathology crew has continued to scout wheat in various locations around the state of Wisconsin. Wheat in the southern part of the state is near or at jointing. Wheat in the central zone is also near jointing.

We have now confirmed stripe rust in a production winter wheat field near Arlington Wisconsin (April 20, 2017). The variety is Pro Seed 420 which is known to be susceptible to stripe rust. We suspect that stripe rust has overwintered in this location, in addition to the Sharon Wisconsin location that we reported several weeks ago. We have also received a report of stripe rust from Kenosha Co.

In all cases where stripe rust has been found, it is at low incidence and severity. However, the weather is becoming conducive for the stripe rust pathogen, so these areas of active rust should be monitored closely so that an informed management decision can be made. Many are considering a tank-mix of fungicide with their herbicide application. However, be aware that this application will only be effective for 2-3 weeks at most. We have found that when it comes to application of fungicide for stripe rust control, applications that coincide with the introduction of stripe rust that also protect the flag leaf, are most beneficial on winter wheat in Wisconsin. This has been investigated and reported by our laboratory and presented at the Wisconsin Agribusiness Classics.  You can find that report here.

At this point in the season, growers and consultants should continue to scout carefully for stripe rust. Also, consider the susceptibility rating of your wheat varieties. In fields where stripe rust is active and you have a susceptible variety, careful monitoring will be required and earlier spraying necessary. In fields with no confirmed rust and resistant varieties, continued monitoring of the situation will be necessary. Fungicide application should be saved until as close to flag leaf emergence as you feel comfortable waiting. You can find efficacy ratings of various fungicide products against stripe rust here.

Get out and scout, scout scout!!

Stripe Rust Found to be Present and Already Active in Wisconsin Winter Wheat

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Brian Mueller, Graduate Research Assistant, Department of Plant Pathology, University of Wisconsin-Madison

Damon Smith, Extension Field Crops Pathologist, Department of Plant Pathology, University of Wisconsin-Madison

Shawn Conley, Extension Soybean and Small Grains Agronomist, Department of Agronomy, University of Wisconsin-Madison

Figure 1. Urediniospores of the stripe rust fungus. Red arrow indicates a germinating, viable spore.

On March 29, 2017 the Field Crops Pathology Team observed the first signs of stripe rust in Wisconsin for the 2017 field season. Plots were located in the Wisconsin Winter Wheat variety trial in Sharon, Wisconsin. A sample was brought back to the Field Crops Pathology lab and placed on water agar to test for spore viability. The red arrow in figure 1 points toward a germ tube extending from the base of a urediniospore, indicating a viable spore. Very low levels of disease incidence and severity were detected in the plots scouted (Fig. 2 and 3). It is speculated that the pathogen that causes stripe rust overwintered on wheat leaves that remained green through the winter of 2016/2017. These same plots were scouted and confirmed to have active stripe rust infection this past fall (Fall 2016). However, application of fungicide was not recommended because stripe rust typically does not overwinter in the northern U.S. To our knowledge this is the first time that overwintering of the stripe rust fungus has been observed in Wisconsin winter wheat fields and is likely due to the mild winter season.

Figure 2. A single pustule of the strip rust fungus on a wheat leaf.

Stripe rust of wheat is caused by the fungus Puccinia striiformis. Stripe rust can be identified by orange/yellow pustules that typically occur in a striped pattern on the surface of the wheat leaf. However, under low severity, single, or very few sparsely spaced pustules may be observed. Subsequent infections can arise from a single pustule as seen in Figure 2. Disease is favored by prolonged periods of rain (or dew), high relative humidity, and cool temperatures ranging from 50 to 60 ºF. For more information visit the USDA Cereal Disease Lab website.

Management of stripe rust includes using resistant cultivars and applying fungicides. Although it is too late to make decisions on a cultivar, scouting should be prioritized to fields where you know there was a susceptible cultivar planted. Considering the early start to the stripe rust epidemic, careful and frequent scouting will be critical this season. If stripe rust pustules are observed, consider sending samples to the University of Wisconsin Plant Disease Diagnostic Clinic for positive identification. If stripe rust is confirmed and it appears to be active, a fungicide application might be necessary.

Figure 3. Low incidence and severity of stripe rust on winter wheat.

While we typically don’t recommend an application of fungicide at the Feekes 5 growth stage, an application might be necessary this season if you find stripe rust in your wheat stand. This fungicide application could be tank-mixed with your last herbicide application. You should scout prior to this treatment, as it will only be necessary if active rust is observed. Products labeled for control of stripe rust can be found in publication A3646 – Pest Management in Wisconsin Field Crops. Many fungicides are labeled with excellent efficacy on stripe rust. So, find a product rated excellent, that also fits your pocketbook. Finally, remember to stick with labeled rates. Get out there and scout!

New Resource Available for Grain Production in Low-Margin Years

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Damon L. Smith, Extension Field Crops Pathologist, University of Wisconsin-Madison

A new resource “A4137 – Grain Management Considerations in Low-Margin Years” is now available online for download. This fact sheet is meant to assist you in making informed decisions about your production system in a low-margin production year.

To further complement this new resource, the authors which are team Grains specialists, are hitting the road with a series of talks, “Grain Management in Low-Margin Years” that address how to best handle different aspects of production during low-margin years. The talks will start in in February of 2017 and will take place at locations throughout the state. Each talk is about a half-hour long with time for Q& A. If one of the presenters is not available for any of the dates, the talks will also be available as high quality video presentations. A hardcopy of the A4137 fact sheet will also be handed out at each meeting.

Talks and speakers (authors) include: 

  1. Soybean Inputs that Deliver the Highest ROI in a Low-Margin Year – Shawn Conley, UW Agronomy, Soybean and Small Grains Specialist 
  2. Practical Weed Management for Low-Margin Years – Dan Smith, UW NPM, Southwest Regional Specialist 
  3. Fundamental Soil Fertility Strategies for Success – Carrie Laboski, UW Soil Science, Soil Fertility/Nutrient Management Specialist 
  4. How to Survive and Thrive on Current Corn Price Projections – Joe Lauer, UW Agronomy, Corn Specialist 
  5. Low Grain Prices = Smart Disease Management Decisions – Damon Smith, UW Plant Pathology, Field Crops Pathology Specialist 
  6. Managing Insects Economically Using Conventional Hybrids and Thresholds – Bryan Jensen, UW Entomology, Field Crops Entomology Specialist 
  7. Machinery/Technology Management and Tillage Considerations to Reduce Operational Costs – Francisco Arriaga, UW Soil Science, Soil Science Specialist and Brian Luck, UW Biological System Engineering, Machinery Specialist 
  8. Partial Budget Analysis: A Practical Tool for Low Margin Years – Paul Mitchell, UW Ag & Applied Econ, Cropping Systems Specialist 

CLICK HERE For information on specific locations and host agent contact e-mail.

For additional information, contact Ted Bay at ted.bay@ces.uwex.edu or Damon Smith at damon.smith@wisc.edu

2016 Wisconsin Field Crops Pathology Fungicide Tests Summary Now Available

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Damon L. Smith, Extension Field Crops Pathologist, University of Wisconsin-Madison

The 2016 Wisconsin Field Crops Pathology Fungicide Tests Summary is now available online as a downloadable PDF. This report is a concise summary of pesticide related research trials conducted in 2016 under the direction of the Wisconsin Field Crops Pathology program in the Department of Plant Pathology at the University of Wisconsin-Madison.  We thank many summer hourlies and research interns for assisting in conducting these trials.  We would also like to thank Carol Groves, Jaime Willbur, Megan McCaghey, Bryan Jensen, John Gaska, Adam Roth and Shawn Conley for technical support.

Mention of specific products in this publication are for your convenience and do represent an endorsement or criticism.  This by no means is a complete test of all products available.  You are responsible for using pesticides according to the manufacturers current label.  Follow all label instructions when using any pesticide.  Remember the label is the law!

To download the current report, or past reports visit the SUMMARIES page by clicking here.

Team Grains Tackles Profitability in Low-Margin Years

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General AgronomyTeam grains specialists are hitting the road with a series of talks, “Grain Management in Low-Margin Years” and an accompanying fact sheet that address how to best handle different aspects of production during low-margin years. The talks will start in in February of 2017 and will take place at locations throughout the state. Each talk is about a half-hour long with time for Q& A. If one of the presenters is not available for any of the dates, the talks will also be available as high quality video presentations. For each location, the agent or sponsor can decide what topics to include and a flyer template is available to customize and promote the event. 

Talks and speakers include: 

  1. Soybean Inputs that Deliver the Highest ROI in a Low-Margin Year – Shawn Conley, UW Agronomy, Soybean and Small Grains Specialist 
  2. Practical Weed Management for Low-Margin Years – Dan Smith, UW NPM, Southwest Regional Specialist 
  3. Fundamental Soil Fertility Strategies for Success – Carrie Laboski, UW Soil Science, Soil Fertility/Nutrient Management Specialist 
  4. How to Survive and Thrive on Current Corn Price Projections – Joe Lauer, UW Agronomy, Corn Specialist 
  5. Low Grain Prices = Smart Disease Management Decisions – Damon Smith, UW Plant Pathology, Field Crops Pathology Specialist 
  6. Managing Insects Economically Using Conventional Hybrids and Thresholds – Bryan Jensen, UW Entomology, Field Crops Entomology Specialist 
  7. Machinery/Technology Management and Tillage Considerations to Reduce Operational Costs – Francisco Arriaga, UW Soil Science, Soil Science Specialist and Brian Luck, UW Biological System Engineering, Machinery Specialist 
  8. Partial Budget Analysis: A Practical Tool for Low Margin Years – Paul Mitchell, UW Ag & Applied Econ, Cropping Systems Specialist 

CLICK HERE For information on specific locations and host agent contact e-mail.

For additional information, contact Ted Bay at ted.bay@ces.uwex.edu or Damon Smith at damon.smith@wisc.edu