Got Crazy Top?

Crazy top, named for the odd formations of the leaves or tassel due to hormonal effects of the disease, is typically found on corn plants that were submerged for a few days early in the growing season. A description of the disease and of its symptoms can be found at http://bulletin.ipm.illinois.edu/pastpest/articles/200220c.html

While a lot of corn was submerged during early growth in Illinois this year, we haven’t been seeing a lot of this disease. It may be that corn in many fields was submerged so long that growth never recovered, making plants a poor host for the disease. The disease may be more likely to show up in parts of fields where the water rose then went away within a few days, after which the crop grew normally.

Some researchers at the USDA-ARS lab in Peoria are looking for infected plants so they can isolate the fungus that causes this disease. If anyone has found infected plants that they could travel to sample, please send me an email and I’ll put you in touch.


Brownstown Agronomy Research Center Field Day – August 5, 2015

The 2015 Brownstown Agronomy Research Center Field Day, presented by the University Of Illinois Department Of Crop Sciences, will be held on Wednesday, August 5. Extension researchers and specialists will address issues pertinent to the current growing season. The tour will start at 8 a.m. and will last approximately three hours. It will be followed by lunch provided by U of I Extension. 2.5 hours of Certified Crop Adviser CEUs have been approved.

Shaded tour wagons will take participants to each stop. These topics will be addressed:

  • 2015 Cropping Season Challenges – Dr. Emerson Nafziger, U of I
  • Weed Management: The Simple Days are Over – Dr. Aaron Hager, U of I
  • Soybean Sudden Death Syndrome – Dr. Angie Peltier, U of I
  • Update on Statewide Insect Surveys & Potential Implications – Dr. Mike Gray, U of I
  • Factors Contributing to a Healthy Soil – Russ Higgins, U of I

The 208-acre Brownstown Agronomy Research Center has been conducting crop research on the claypan soils of southern Illinois since 1937. More than 30 research and demonstration projects are conducted at the Center each year. Visitors are always welcome.

The research center is located south of Brownstown on IL Route 185, approximately 4 miles east of the IL Route 40/185 junction.

For more information, contact Robert Bellm (618-427-3349); rcbellm@illinois.edu
Visit us on the web at http://web.extension.illinois.edu/barc/


Corn disease update and farewell

Last week, I visited all of the University of Illinois corn variety trials in the northern half of the state.  Gray leaf spot and northern leaf blight were beginning to appear in most of the locations, but were the most obvious at the trial located near Perry, IL (Pike County).

DSCN0119

“Young” lesions of northern leaf blight beginning to develop on a corn leaf.

DSCN0128

Gray leaf spot lesions developing on a corn leaf.

With the amount of rainfall received in the past few weeks, it is not surprising that these diseases were beginning to appear.  Since hybrids differ in their level of susceptibility to these diseases, not all hybrids in the trials had symptoms.  If the rainy conditions continue, then a foliar fungicide application sometime between tassel emergence and silking may need to be considered on hybrids that are the most susceptible.  Some general guidelines that may help make a foliar fungicide application decision follow:

  • On susceptible to moderately-susceptible hybrids:  consider a foliar fungicide if disease is present on the third leaf below the ear or higher on 50% of the plants prior to tasseling.
  • On intermediate hybrids:  consider a foliar fungicide if the field has a history of disease, if the previous crop was corn with at least 35% of the ground covered with residue, if disease is present on the third leaf below the ear or higher on 50% of the plants prior to tasseling, and if warm and humid weather has persisted.
  • On moderately-resistant to resistant hybrids:  foliar fungicides generally are not recommended, but scouting is important to confirm that diseases are not present.

The presence of diseases does make a difference in how profitable a fungicide application may or may not be.  From trials conducted at the University of Illinois from 2008 to 2014 at many environments (45 total environments) in Illinois, the results indicate that the overall yield response to foliar fungicides was 5.3 bushels/acre (see chart below).  However, this yield response was 9.5 bushels per acre when disease developed to affect at least 10% of the leaf area in untreated controls (in 17 of the environments).  In situations with low disease severity (disease developed to less than 10% of the leaf area in untreated controls), the average yield response was only 2.8 bushels per acre (in 28 of the environments).  Obviously, the marketing price of corn and the fungicide and application costs will determine if fungicide applications were profitable.  The chart below shows the profitability of fungicide applications under different yield response goals (3, 5, 8, and 11 bushels per acre).  The bottom line is that it takes a higher yield response to be profitable when corn marketing prices are lower.

Corn fung results 2014

Results from University of Illinois corn fungicide trials conducted from 2008 to 2014. All applications were made at tassel emergence (VT).

On a final note, my last day at the University of Illinois is today (June 30).  I will be moving to a similar position at the University of Kentucky, and will be based out of the Princeton Research and Education Center in the western part of Kentucky.  I want to thank the University of Illinois for my opportunities here and thank many of you for your support and interest.  There are no current plans to replace my position as Extension Plant Pathologist at the University of Illinois.  If you have field crop disease questions, the following contacts may be useful:

University of Illinois Plant Clinic

1102 S. Goodwin Ave.

Urbana, IL 61801

Tel: 217-333-0519

Email: plantclinic@illinois.edu

 

Commercial Agriculture Extension Educators:

Robert Bellm

Brownstown Agronomy Research Center

1588 IL 185

Brownstown, IL 62418

Tel: 618-427-3349

Email: rcbellm@illinois.edu

 

Dennis Bowman

Crop Sciences Research and Education Center

1102 S. Goodwin Ave.

Urbana, IL 61801

Tel: 217-244-0851

Email: ndbowman@illinois.edu

 

Russ Higgins

Northern Illinois Agronomy Research Center

14509 University Road

Shabbona, IL 60550

Tel: 815-824-2029

Email: rahiggin@illinois.edu

 

Angie Peltier

1000 North Main Street

PO Box 227

Monmouth, IL 61462

Tel: 309-734-5161

Email: apeltier@illinois.edu


Stripe rust and Fusarium head blight (scab) concerns in Illinois

Stripe rust of wheat has been observed in different parts of Illinois within the last week. Although some varieties have very good resistance to stripe rust, there are still several varieties that are susceptible. Stripe rust is able to flourish under the cooler temperatures we’ve had over the last few days. With rain in the forecast in parts of the state over the next few days, favorable conditions for this disease likely will continue.

Although some wheat fields in the state are already past the critical period for applying a fungicide for protection against Fusarium head blight (a.k.a. scab) (beginning flowering up to 6 days after beginning flowering), some fields in the state are just beginning to flower or will within the next week. For the fields that are just beginning to flower or will within the next week, an application of Prosaro or Caramba fungicide should be considered for protection against Fusarium head blight and stripe rust. Multi-state university research has indicated that Prosaro and Caramba are the best products available for managing Fusarium head blight and the associated mycotoxin, deoxynivalenol (DON; a.k.a. vomitoxin). Both of these fungicide products also have efficacy against the stripe rust pathogen.

Light-orange colored stripe rust pustules on wheat leaves (Photo by C. Bradley).

Light-orange colored stripe rust pustules on wheat leaves (Photo by C. Bradley).

 


2015 Season at the University of Illinois Plant Clinic

What pests will the 2015 growing season feature? Let the Plant Clinic help you diagnose them. Samples havePreview been gradually filling up the lab here at the Clinic in our 40th year of operation. On the field front, there have been concerns with root and virus disease diagnosis in wheat. On the home landscape front, there has been a steady influx of fungal disease.

 
The University of Illinois Plant Clinic accepts samples year-round. We are located in the Jonathan Baldwin Turner Hall building on the south end of the Urbana campus. Plant Clinic services include plant and insect identification, diagnosis of disease, insect, weed and chemical injury observation (chemical injury on field crops only), nematode assays, herbicide resistance testing for glyphosate and PPO inhibitors in pigweed, and help with nutrient related problems, as well as management recommendations involving these diagnoses. Microscopic examinations, laboratory culturing, virus assays, and nematode assays are some of the techniques used in the clinic. Many samples can be diagnosed within a day or two. Should culturing be necessary, isolates may not be ready to make a final reading for as much as two weeks. Nematode processing also requires about 1-2 weeks depending on the procedure. We send your final diagnoses and invoices to you through both the US mail and email. If you provide your email address on the sample form you will get your information earlier.

 
Please refer to our website http://web.extension.illinois.edu/plantclinic/ for additional details on sampling, sample forms, fees and services offered. If you have questions about what, where, or how to sample call us at 217-333-0519, leave a voicemail if you can’t get through. Whenever submitting a sample, provide as much information as possible on the pattern of injury in the planting, the pattern on individual affected plants, and details describing how symptoms have changed over time to cause you concern.

Our fees vary depending on the procedure necessary. General diagnosis including culturing is $15, ELISA and immunostrip testing is $25, Nematode analysis for SCN or PWN is $20, Specialty Nematode testing (such as corn) is $40. Please include payment with the sample for diagnosis to be initiated. Checks should be made payable to the University of Illinois or to the Plant Clinic. Companies can setup an account, call and we will accommodate you. Call if uncertain of which test is needed.

Photo 1:

Photo 1:Example of a great sample: Sample form, symptomatic plant, protected root ball and payment

Sending a sample thru US mail or delivery service address to:
University of Illinois Plant Clinic
1102 S. Goodwin, S-417 Turner Hall
Urbana, IL 61801

Email: We have a new email address plantclinic@illinois.edu. Use this address to send .jpg pictures to accompany your samples or to contact a diagnostician.

Drop off a sample:
You can also drop off a sample at S-417 Turner Hall. Park in the metered lot F 28 on the east side of Turner Hall or at the ACES library metered lot on the west side of Turner. Come in the South door. Take the elevator located in the SE corner of the building. Turn left when exiting the elevator; we are located along the SE corridor of the 4th floor. Please use the green drop box located just outside S-417 if we are temporarily out of the office.

Plant Clinic location, S-417 Turner Hall, 1102 S. Goodwin, Urbana IL 61801

Photo 2: Plant Clinic location, S-417 Turner Hall, 1102 S. Goodwin, Urbana IL 61801

Suzanne Bissonnette


Wheat disease outlook

As the weather begins to warm up, wheat is beginning to grow at a faster pace.  Symptoms of some diseases also are beginning to appear or will likely be appearing soon.  Below are some diseases to look for right now.

Stagonospora and Septoria leaf blotch: Although caused by two different pathogens, symptoms of these two foliar diseases look very similar and both can be managed with an appropriate foliar fungicide application.  Most results from University of Illinois wheat foliar fungicide trials conducted since 2008 have shown that an application of an effective fungicide for control of Fusarium head blight (scab) when wheat is beginning to flower also provides good protection against common foliar fungal diseases on the flag leaf.  However, if a variety is very susceptible and if conditions are favorable (frequent rainfall / damp conditions), then an application of a fungicide when the flag leaf emerges may be needed.  On a side-note, the 2015 multi-state university foliar fungicide efficacy table for wheat diseases can be found here: NCERA 184 Wheat fungicide table 2015_V3.

Septoria leaf blotch symptoms on a wheat leaf. (Photo by C. Bradley)

Virus diseases: Surveys of viruses affecting wheat in Illinois conducted in recent years indicate that Barley yellow dwarf virus (BYDV) is the most commonly detected virus affecting wheat in the state.  However, other viruses, such as Wheat spindle streak mosaic virus (WSSMV), Soilborne wheat mosaic virus (SBWMV), Wheat streak mosaic virus (WSMV), and a few others also have been detected.  Virus symptoms (yellowing, purpling, yellow streaks, etc.) can be confused with other disorders, and it can be extremely difficult identifying a virus disease by symptoms alone.  Therefore, specific laboratory tests must be conducted to determine if a virus is responsible for these symptoms.  The University of Illinois Plant Clinic (https://web.extension.illinois.edu/plantclinic/) does not currently test for viruses in wheat, but can help make a determination if virus testing is needed.  Plant virus testing can be done at the Purdue University Plant & Pest Diagnostic Laboratory (http://www.ppdl.purdue.edu/ppdl/index.html) and at a private lab known as Agdia, which is located in Elkhart, IN (https://www.agdia.com/).  Unfortunately, no in-season control options are available for managing virus diseases.

Symptoms caused by Barley yellow dwarf virus on wheat. (Photo by C. Bradley)

Symptoms caused by Soilborne wheat mosaic virus on wheat. (Photo by C. Bradley)

Stripe rust: To my knowledge, stripe rust has not yet been detected in Illinois during the 2015 season.  However, there have been reports of stripe rust from states to the south of Illinois, such as Arkansas and Tennessee.  Since rust spores have the capability of moving many miles, stripe rust could be on its way to southern Illinois.  If stripe rust is observed on plants, a foliar fungicide may be needed to protect the flag leaf, depending on the susceptibility of the variety.  Applications at early flowering for control of Fusarium head blight also may be effective in managing stripe rust; however, an earlier application of a fungicide may be needed if stripe rust is found prior to heading and if disease is developing rapidly.

Early symptoms of stripe rust on a wheat leaf. (Photo by C. Bradley)

Orange-colored pustules of the stripe rust fungus on a wheat leaf. (Photo by C. Bradley)

Fusarium head blight (scab): Although it cannot be observed yet, Fusarium head blight is the most important wheat disease in Illinois, and thinking about how to manage this disease cannot occur too early.  In years in which weather is favorable for infection (frequent rains, moderate temperatures, and cloudy weather – such as 2014 for southern IL producers), this disease can wreak havoc.  This is especially true because the fungus that causes this disease also produces toxins, such as deoxynivalenol (DON; also known as “vomitoxin) that will contaminate grain and will result into major dockage when grain is delivered to the elevator.  Infection of the scab fungus occurs when wheat heads begin to flower.  The beginning flowering stage also is the best timing for applying an effective fungicide to managing Fusarium head blight and DON.  Results of university fungicide trials across multiple states have shown that Prosaro (Bayer CropScience) and Caramba (BASF) are the best products currently available for reducing Fusarium head blight and DON in grain.  One thing to keep in mind with these fungicides is that 100% control cannot be achieved, and susceptible varieties cannot be “fixed” by applying a fungicide when conditions are very favorable for Fusarium head blight.  University research has shown that Fusarium head blight and DON can be reduced by approximately 40%-60% with Prosaro or Caramba (relative to a non-treated check); therefore, the bottom line is that fungicides will reduce disease and DON levels in grain, but don’t expect a complete reduction with fungicides alone.  The forecasted risk of Fusarium head blight can be observed by going to the Fusarium head blight Prediction Center website (http://www.wheatscab.psu.edu/).

Fusarium head blight (scab) affecting a wheat field. (Photo by C. Bradley)


Spring Cover Crop Field Day March 26th – Ewing Demonstration Center

Join us on Thursday, March 26th, 2015 for the  Spring Cover Crop Field Day at the University of Illinois Extension Ewing Demonstration Center.  Registration will start at 8:30 a.m. and the program will begin at 9:00 a.m., rain or shine.  The Ewing Demonstration Center is located at 16132 N. Ewing Rd; Ewing, IL 62836, on the north edge of the village of Ewing, north of the Ewing Grade School on north Ewing Road.  Watch for signs.

Cover crops have many benefits to the soil, environment, and overall crop production and management.  Topics covered during this field day program include:

Challenges of Grazing Lush Spring Forage

–          Travis Meteer, Extension Educator, U of I Extension

Techniques for Planting into Cover Crop Residue

–          Mike Plumer, Private Consultant

Understanding the Soil Profile Beneath Your Feet

–          Bryan Fitch, Resource Soil Scientist, NRCS

Which One to Choose? Cover Crop Species Selection and Demonstration Trial Tour

–          Nathan Johanning, Extension Educator, U of I Extension

Some of the program highlights will be the demonstration trial planting of cover crops, including 17 different cover crops and combinations illustrating first hand the characteristics of the cover crops and what benefits they bring to your soil and crop production system.  Also, (weather and soil conditions permitting) we will have a soil pit dug, exposing the soil profile, where NRCS Resource Soil Scientist, Bryan Fitch will lead us through the characteristics of our southern Illinois soils to enhance understanding of the importance of a healthy soil.  Also Certified Crop Advisor CEU credits will be available (2.0 Soil & Water Management & 1.0 Crop Management) for the program.

This field day will be free and open to anyone interested in learning more about cover crops.  A light lunch will be provided and this is a great way to talk to fellow growers to learn more from their challenges and successes incorporating cover crops into their cropping systems.  Please call the Franklin County Extension Office at 618-439-3178 for more information and to register by March 24th.  We hope to see you there!


Ewing Demonstration Center Fall Cover Crop Field Day – Nov. 6th

Join us on Thursday, November 6th, 2014 for the the Ewing Demonstration Center Fall Cover Crop Field Day.  Registration and refreshments will start at 8:30 a.m. and the program will start at 9:00 a.m., rain or shine.  The Ewing Demonstration Center is located at 16132 N. Ewing Rd; Ewing IL 62836, on the north edge of the village of Ewing, north of the Ewing Grade School on north Ewing Road.  Watch for signs.

Cover crops have many benefits to the soil, environment, and overall crop production and management.  Topics included in this field day program are:

Establishment Challenges and Successes

– Robert Bellm, Extension Educator, University of Illinois Extension

Calibrating Success:  Drill and Planting Calibration

– Marc Lamczyk, Program Coordinator, University of Illinois Extension

Which One to Choose? Cover Crop Species Selection and Demonstration Trial Tour

– Nathan Johanning, Extension Educator, University of Illinois Extension

In addition, we also have a demonstration planting of cover crops established late this summer so you can view the growth and characteristics of the cover crops first hand and learn more what benefits they bring to your soil and crop production system.

This field day will be free and open to anyone interested in learning more about cover crops.  Please call the Franklin County Extension Office at 618-439-3178 for more information and to register.  We hope to see you there!


Destructive diseases of soybean – sudden death syndrome and white mold – observed in the state

Signs and symptoms of a few soybean diseases have begun to show up in the last few weeks in some areas of the state.  Two of these diseases, sudden death syndrome (SDS) and Sclerotinia stem rot (a.k.a. white mold) certainly are going to cause economic losses in some growers’ fields this year.

Symptoms of SDS that currently are being observed are interveinal chlorosis and necrosis of the leaves (veins remain green while the tissues between the veins turn yellow and then brown).  These symptoms look exactly like the foliar symptoms caused by a different disease, brown stem rot.  Brown stem rot, however, will cause internal browning of the pith in soybean stems, while SDS does not affect soybean stems.  On SDS-affected plants, the leaves will fall off eventually, while the petioles will remain attached to the stems and branches.  In some cases, a bluish-white mass of spores of the SDS fungus (Fusarium virguliforme) may be observed on the roots.  Although the foliar symptoms of SDS are now being observed, infection by the SDS fungus occurred during the seedling stage, not long after planting.  The symptoms that are now being observed are the effect of toxins that the SDS pathogen produces that are phytotoxic.  Cool and wet weather after planting and the recent rainfall received in parts of the state were favorable for infection and disease development, and are the reasons why SDS incidence is high in some areas this year.  The primary method of managing SDS is to choose the most resistant soybean varieties available.  Some evidence has shown that high soybean cyst nematode (SCN) egg populations may also increase the likelihood of severe SDS; therefore, managing SCN populations through resistant varieties and crop rotation may also reduce the risk of SDS.  Unfortunately, there currently are no fungicide products registered that are effective in managing SDS, but an experimental fungicide seed treatment known as “ILeVO” that is currently making its way through the EPA registration process has shown efficacy against SDS in University of Illinois field trials.

Symptoms of sudden death syndrome of soybean (Photo by C. Bradley).

 

A bluish-white mass of spores of the SDS fungus (Fusarium virguliforme) on a soybean root (Photo by C. Bradley).

 

White mold can be observed in fields located in the northern half of Illinois this year.  The appearance of this disease also is weather-related.  Areas in the northern half of the state, that were cooler and wetter than normal after soybean plants began to flower, are the areas that are affected the most severely.  Unfortunately, once white mold signs and symptoms are detected in the field, fungicide applications generally will be futile, as the damage has already been done.  Management of white mold was discussed in an earlier article of the Bulletin this year (http://bulletin.ipm.illinois.edu/?p=2412).  Growers with severe levels of white mold may encounter some discounts at the elevator this year for high levels of foreign matter.  Some sclerotia (dark survival structures produced by the white mold fungus – Sclerotinia sclerotiorum) that are formed on plants may similar in size to the seed, and will make their way to the hopper and eventually the elevator, where discounts may be received.

 

Soybean plants dying prematurely because of white mold in a field in Champaign County (Photo by K. Ames).

 

White mycelia of the white mold fungus (Sclerotinia sclerotiorum) on a soybean plant (Photo by C. Bradley).


2014 Ewing Demonstration Center Fall Field Day

2014 Ewing Demonstration Center Fall Field Day

The University of Illinois Extension will host its annual Ewing Demonstration Center Fall Field Day on Thursday, September 11, 2014 at 9 a.m.  The Ewing Demonstration Center at is located at 16132 N. Ewing Rd; Ewing IL 62836, on the north edge of the village of Ewing, north of the Ewing Grade School on north Ewing Road.  Watch for signs.

The ongoing research plots this year consist of a soybean cover crops trial, LibertyLink soybean variety trial, insecticide/fungicide trial on soybeans, corn population study, drought tolerant corn hybrid evaluation, and new this year a pumpkin variety trial.

 

The topics to be discussed at Field Day include:

Fusarium Head Blight (Scab) and Vomitoxin Management in Wheat

  • Carl Bradley, Extension Specialist, Plant Pathology, University of Illinois Extension

Sky High Crop Scouting; Unmanned Aerial Drones

  • Dennis Bowman, Extension Educator, University of Illinois Extension

Alternative Forages and Harvesting Methods

  • Teresa Steckler, Extension Educator, Commercial Ag, University of Illinois Extension

Palmer Amaranth: Coming (Soon) to a Field Near You

  • Robert Bellm, Extension Educator, Commercial Ag, University of Illinois Extension

Cover Crops and Weed Management

  • Nathan Johanning, Extension Educator, Small Farms Local Foods, University of Illinois Extension

Refreshments will be provided by Franklin County Farm Bureau.

The field day is free and open to anyone interested.  A light lunch will be provided and registration is recommended by September 8, 2014 for an accurate meal count.

For additional information or to register, contact Marc Lamczyk at University of Illinois Extension Office in Franklin County at 618-439-3178 or lamczyk@illinois.edu.