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Agronomic Crops Network

Ohio State University Extension


C.O.R.N. Newsletter: 2023-29

  1. Late-season Pigweed Scouting

    Author(s): Alyssa Essman

    Pigweed plants that escaped POST applications or emerged after can now be seen above soybean canopies. Especially important are waterhemp and Palmer amaranth, as these species pose increased economic and management concerns. Waterhemp and Palmer plants can produce upwards of one million seeds per plant in certain situations. Managing these weeds often starts with preventing introductions. Anything we can do from now through harvest to prevent seed from being deposited into the soil seed bank will pay dividends down the road. At this point there are limited control options beyond scouting and hand pulling. Just a few plants left in the field can lead to a total infestation if they produce seeds.

    Viability of pigweed seed is greatly reduced after 3-5 years. Management over a couple of growing seasons can drastically reduce populations. Aside from tremendous seed production, fast growth rates, and lengthy emergence windows, what makes us most nervous about these weeds is their propensity to develop herbicide resistance. In other states, waterhemp has exhibited the ability to resist up to seven different herbicide sites of action, and Palmer amaranth up to nine. Resistance to more than one site of action within a single population is not uncommon. Metabolic herbicide resistance may increase the prevalence of populations with resistance to multiple herbicide groups. Experience would tell us it's only a matter of time until we have these types of resistance issues in Ohio. The status of herbicide resistance in Ohio waterhemp populations was covered in this article.

    We have a ton of resources that can be helpful for scouting, including a pigweed ID guide, pigweed management fact sheet, and YouTube video. More helpful information on the management of pigweeds can be found on the OSU weed science website.

    Late-season scouting will allow us to evaluate how well our programs worked this year and forecast issues for next year. Below are some guidelines for scouting as we approach harvest.

    • Scout all fields at some point between now and harvest. Evaluations of the weed species present and level of infestation can take place from the road or field edge. This can also be a good use of drones and other technology. At this time of year corn mostly hides weed infestations, but weeds can be seen above the soybean canopy.
    • Fields that are suspected to have any level of Palmer amaranth or waterhemp should be evaluated more closely. If you are unsure of whether or not you are dealing with one of these problematic pigweeds, send pictures to us or your local extension educator.
    • Remove waterhemp and Palmer amaranth plants by hand. Cut plants at the soil surface, and where mature seed is present, bag seed heads before removing them from the field. This will help reduce the spread of seed.
    • Where there are severe infestations and hand removal is not realistic, the decision then becomes whether it is best to mow or harvest, both between and within fields. Harvesting fields with waterhemp or Palmer with mature seed heads will contaminate equipment and increase the likelihood of spreading seed to other fields or operations. Mowing before seed is mature can help reduce future populations. Where the decision is made to harvest infested areas, harvest these areas last and thoroughly clean equipment afterwards.
    • Waterhemp is increasing in prevalence across the state. If you discover waterhemp, feel free to reach out to the OSU weed science program or your local extension educator for management recommendations. Palmer amaranth is not quite as widespread at this time. If you discover Palmer amaranth, please reach out to us so we can monitor its location in the state.

    Feel free to reach out to Alyssa Essman (, 614-247-5810) for questions regarding this topic or other concerns related to the identification and control of weeds.

  2. Corn Yield Forecasts as of August 23, 2023

    Author(s): Osler Ortez

    Most of the corn acreage in Ohio is now at grain filling stages. On the last USDA crop progress report (week Ending 08/27/23), it was estimated that corn dough (R4) progress was 79 percent complete, and corn dented (R5) progress was 30 percent complete (a few average points behind schedule but almost on track with last year and the 5-year average).

    A new simulation of 2023 end-of-season corn yield potential and crop staging was performed on August 23, using the UNL Hybrid-Maize crop model in collaboration with faculty and extension educators from 10 universities. Forecasts help researchers, growers, and industry stakeholders to make management, logistics, and marketing decisions during the crop season. Forecasts cover 40 locations across the Corn Belt, including South Charleston (Western Ohio), Custar (Northwest Ohio), and Wooster (Northeast Ohio). Table 1 and Figure 1 summarize the results for the state of Ohio as of August 23, 2023.

    Table 1

    Figure 1

    Figure 1. On the left figure, simulated developmental stage for rainfed corn at each location (left figure). R1: silking; R2: blister; R3: milk; R4: dough; R5: dent; R6: physiological maturity.
    On the right figure, probability of the 2023 yield potential to be below, near, and above the long-term (2005-2022) average yield potential at each location. Larger color sections within the pie chart indicate higher probability that end-of-season corn yield will be in that category. Source: Grassini et al., 2023.


    As of August 23, 2023, the projected results for Ohio have improved. Despite a rough growing season with development variability and dry periods, the chances of below-average yield potential are low (3% for Custar, 3% for South Charleston, and 16% for Wooster). Current projections show 45% to 66% probability of near-average yield potential for Ohio. The Custar and South Charleston sites show 53% and 42% probability of being above the long-term average yield potential, respectively. Wooster’s conditions are not as optimistic as the other two locations, only 18% chances of above long-term average yield potential.

    Adequate solar radiation, temperatures, and precipitation during the rest of the grain fill period will determine the final outputs. Regionally projections show that yield potential is highly variable, but most sites in the eastern part of the Corn Belt have increased chances for near or above-average yields, compared to earlier forecasts this season. On the other hand, places in the western/central Corn Belt show high chances of below-average yields (northern MO, eastern IA, south-central NE, and north-central KS).

    The forecasts do not consider other yield-limiting factors such as crop stand issues, storm damage, replanting, disease, or nutrient losses. Likewise, results can deviate with varying planting dates or hybrid maturities. Yield forecasts are not field specific and represent an average yield estimate for a given location and surrounding area. As more corn yield and phenology forecasts become available this crop season, short briefs will be released via the OSU C.O.R.N. Newsletter.


    Grassini, P., Andrade, J., Rizzo, G., Yang, H., Rees, J., Coulter, J., Licht, M., Archontoulis, S., Ciampitti, I., Singh, M., & Ortez, O. (2023). Corn Yield Forecasts as of Aug. 23. UNL Nebraska CropWatch. Available from:  

  3. Meet Your Soil Fertility Extension State Specialist- Dr. Manbir Rakkar

    Dr. Manbir Rakkar

    We are excited to introduce Dr. Manbir Rakkar as the new Soil Fertility Extension State Specialist. Manbir started her position in the School of Environment and Natural Resources on August 15 and will be an active member of Extension’s AgCrops Team.

    Manbir has expertise in soil fertility and health, nutrient management, cropping systems, and agroecology. She received her PhD in Agronomy from University of Nebraska- Lincoln in 2018 and MS in Soil Science from North Dakota State University in 2015. Prior to her appointment at Ohio State University, Manbir was an Assistant Research Professor at Montana State University.

    We are very excited to have Manbir as part of our Extension team! Welcome, Manbir!

  4. Lep Monitoring Network Update #17 – Fall Armyworm Monitoring Starting Across Ohio


    The Ohio Lep Network is in our 17th week of monitoring for pests across Ohio. This week we will provide an update on fall armyworm (FAW), Western bean cutworm (WBC), corn earworm (CEW), and both variations of European corn borer (ECB - IA & NY). This will be our last week reporting on WBC – many WBC traps are being replaced with fall armyworm (FAW).

    For more information on these pests and many more, check out our website:


    Fall Armyworm

    Starting this week, we have added monitoring for the fall armyworm (FAW) to our Lep Monitoring Network. The FAW is a pest of field crops and turfgrass typically every 3 – 5 years in Ohio. Adult moths will be monitored using green bucket traps with a pheromone lure. Many traps were set last week and/or are being set this week. We plan to monitor for FAW adult moths until the end of September. To learn more about the fall armyworm moth, click here:

    Our first week of FAW monitoring resulted in low numbers, except for Hardin County – which had an average of 20.5 moths and Lucas County with an average of 9. Eleven counties monitored 31 traps, with an overall statewide average of 2.8 moths.

    Fall Armyworm Moth Map

    August 21st - 27th, 2023

    figure 1

    Figure 1. Average fall armyworm (FAW) moths captured from August 21st - August 27th. The bold number on the left indicates the average number of moths captured. The second number on the right indicates the number of traps monitored in each county.

    Western Bean Cutworm

    This is our 9th and final week reporting on adult Western bean cutworm (WBC) populations across Ohio. In total, 8 counties monitored using 30 traps. All counties reported averages less than 3 (Figure 2).


    Western Bean Cutworm Moth Map

    August 21st - 27th, 2023

    Figure 2

    Figure 2. Average western bean cutworm moths (WBC) captured from August 21st - August 27th. The bold number on the left indicates the average number of moths captured. The second number on the right indicates the number of traps monitored in each county.

    Corn Earworm

    This is our 12th week reporting on corn earworm (CEW) populations across Ohio. This week, 11 counties monitored for CEW, using 20 total traps. Lucas county had the highest average with 13 CEW moths (Figure 3).



    Corn Earworm Moth Map
    August 21st - 27th, 2023

    Figure 3

    Figure 3. Average corn earworm moths (CEW) captured from August 21st - August 27th. The bold number on the left indicates the average number of moths captured. The second number on the right indicates the number of traps monitored in each county. Scouting should occur when your county has an average of 7 or more moths.


    European Corn Borer

    This is our 14th week reporting on European corn borer (ECB – IA & NY) populations across Ohio. This week, 9 counties monitored ECBs. Overall there were two counties reporting ECB-IA moths (Figure 4) and no reports of ECB-NY (figure not included).

    European Corn Borer (IA) Moth Map

    August 21st - 27th, 2023

    Figure 4

    Figure 4. Average European corn borer (ECB - IA) moths captured from August 21st - August 27th. The bold number on the left indicates the average number of moths captured. The second number on the right indicates the number of traps monitored in each county.

  5. Join OABA and OSU Extension for the 4R Technology Review Field Day on September 6

    The Ohio Agribusiness Association and Ohio State University Extension invite you to the 4R Technology Review Field Day. This event will bring together experts in the field of agriculture technology and conservation to share their knowledge and best practices for implementing 4R nutrient management. Attendees will have the opportunity to explore the latest technology and techniques in fertilizer management, precision agriculture, and soil health. This is a great opportunity to learn about the latest advances in agriculture and connect with industry experts.

    Join us for a day of informative presentations, field demonstrations, and networking opportunities. This event is perfect for farmers, crop advisors, ag retailers, and anyone else interested in maximizing crop yield and improving the quality of Ohio’s waterways. 6 hours of CCA credits will be offered, along with Ohio fertilizer certification and recertification.

     The event will take place September 6, 2023, 9AM-4PM at the OSU Northwest Agricultural Research Station (4240 Range Line Rd. Custar, OH 43511). The field day is FREE and open to retailers, farmers, Certified Crop Advisors, and other interested parties. Please register at 

    Educational demonstrations and sessions for the day include:

    • Nutrient and Water Management: Subsurface Fertilizer Placement and Drainage Water Management for Water Quality Outcomes with Jennie Pugliese and Jed Stinner, USDA ARS
    • Phosphorus Fertilizer Management- Beyond the Basics with Josh McGrath, OCP and Matt Liskai, Greenfield Ag
    • Drones in Agriculture- Legalities, Opportunities, and Realities with Robert Mullen, Heritage Cooperative
    • Ag Technology for Placement of Fertilizer with the Planter with John Fulton and Elizabeth Hawkins, The Ohio State University
    • Immediate and Significant ROI from Soil Sampling Accuracy and Accountability with ROGO and Suretech Labs
    • Autonomy, Labor Shortages, and the Future of Agriculture with AgInfo Tech, Dr. Scott Shearer, The Ohio State University and Adam Farmer,  Mercer Landmark
  6. Wheat Management and Input Survey

    This fall, with funding from Ohio Corn and Wheat, we will begin a new project ‘The Wheat to Beat’ to identify management practices of interest to farmers that improve wheat yield, profitability, and quality. This project will include a ‘people’s choice treatment’. To vote on management practices and inputs to be examined in this study, please complete this brief survey:

    Please complete the survey by Sunday, September 3.

    Project guidelines:

    Location- A high-yielding wheat variety will be planted in three locations (Northwest Agricultural Research Station in Wood County, Wooster Campus in Wayne County, and Western Agricultural Research Station in Clark County).

    Baseline Treatments- The wheat variety to be planted at all three locations is Seed Consultants 13S22. At all three locations, soil test P and K will be adequate for wheat production. (You may choose to apply additional fertilizer if you wish and can indicate this on the survey.) In the fall, 20-30 lb N/acre will be applied.

    Evaluation- We will be evaluating management and input combinations that result in highest grain yield, highest profitability, and high grain quality at the three research locations.

  7. Battle for the Belt: Episode 25

    Episode 25 of Battle for the Belt is now available:

    In Episode 25, we walk through the Farm Science Review agronomic crops plots with Madison County and Champaign County Extension Educators, Amanda Douridas and Grant Davis.

    The Agronomic Crops Team is at the Farm Science Review (FSR) every year showcasing demonstration plots that are representative of the research questions being evaluated across the state. These research projects can be from eFields, on-farm research, or small plot research done at the University. This year, there are 17 crop plots demonstrations at FSR Ag Crops Team, some of which include Xyway, Pivot Bio, Nitrogen Rates, Soybeans Disease, Biostimulants, and Battle for the Belt.

    Tickets for FSR are sold at local county extension offices, online (here), and at the gate of the FSR. If you are a student (or affiliated at Ohio State) with a BuckeyeID, admission should be free. The dates this year are September 19-21, at the Molly Caren Agricultural Center 135 Ohio 38 NE London, OH 43140. For more information about the review, visit us at


    Battle For the Belt Location Updates


    Figure 1. Planting date one at the Wooster location, flooding conditions, left side.

    The Wooster location received heavy rains like Western and Northwest this last week, leaving some plots with flooding conditions (Figure 1). The soybeans at this location are all at R5. The R5 stage is the reproductive stage that soybeans will stay in for weeks. R5 begins when one pod on one of the four uppermost nodes has seeds that are 1/8 inch long and ends when one pod on one of the uppermost four nodes has a seed that is fully developed. The soybeans at this location had a poor stand which made the existing plants compensate (at least partially) in the open spaces (e.g., more branching). Few hybrids at the early planting dates have reached dent stage (R5). Planting date five at this location finally reached R1 (silking stage).

    *The Wooster location weather was not available for the end of the month, so it is not reflected in Table 1.

    At the Western location planting date one and two are completely at R5 stage (dent). At R5 we are conducting disease assessments to track disease progression throughout the season. The 100-day hybrid has had the most disease severity in both planting dates, however most hybrids have between 5% and 10% severity for Gray Leaf Spot as well. At this location, bouquet ears have been observed (Figure 2). Bouquet ears are considered an abnormal ear symptom. These have more than one ear (2 or more) ears on a single ear shank. Later this season, abnormal ear assessments will be conducted to evaluate if planting date or hybrid effects are present. Another anomaly observed at this site is lodging (aka goosenecking) after high-speed winds several days ago. On the other hand, soybeans are close to being full pod (R4) in planting date one and five in soybeans. At this site, planting date five just reached beginning seed stage (R5).

    Figure 2. Bouquet ear at the Western location.


    The Northwest location has some of the largest ears we have found at the three locations, though this location still has a long way to go before reaching full maturity. The soybeans at this location have more grasshoppers than other locations but the insect damage severity is not generally more than 5%.

    Table 1. Planting dates one, two, three, four and five in the trial the Western and Northwest Research station with day of planting, soil, air temperature averages, precipitation, and Growing Degree Days (GDDS). Information from CFAES Weather System,

    Keep following the ‘Battle for the Belt’ this growing season to learn more and get further updates! You can  find the full video playlist of Battle for the Belt on the Ohio State Agronomy YouTube channel.

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Crop Observation and Recommendation Network

C.O.R.N. Newsletter is a summary of crop observations, related information, and appropriate recommendations for Ohio crop producers and industry. C.O.R.N. Newsletter is produced by the Ohio State University Extension Agronomy Team, state specialists at The Ohio State University and the Ohio Agricultural Research and Development Center (OARDC). C.O.R.N. Newsletter questions are directed to Extension and OARDC state specialists and associates at Ohio State.


Aaron Wilson (Byrd Polar & Climate Research Center)
Alan Leininger (Educator, Agriculture and Natural Resources)
Allen Gahler (Educator, Agriculture and Natural Resources)
Amanda Douridas, CCA (Educator, Agriculture and Natural Resources)
Amber Emmons, CCA (Water Quality Extension Associate)
Andrew Holden (Resigned Educator, Agriculture and Natural Resources)
Barry Ward (Program Leader)
Beth Scheckelhoff (Educator, Agriculture and Natural Resources)
Brooks Warner (Educator, Agriculture and Natural Resources)
Caden Buschur (Educator, Agriculture and Natural Resources)
Clint Schroeder (Program Manager)
Curtis Young, CCA (Educator, Agriculture and Natural Resources)
Dean Kreager (Educator, Agriculture and Natural Resources)
Don Hammersmith (Program Assistant, Agriculture and Natural Resources)
Doug Karcher (Chair, Horticulture and Crop Science)
Gigi Neal (Educator, Agriculture and Natural Resources)
Glen Arnold, CCA (Field Specialist, Manure Nutrient Management )
Grant Davis, CCA (Educator, Agriculture and Natural Resources)
Jason Hartschuh, CCA (Field Specialist, Dairy & Precision Livestock)
Jeffory A. Hattey (Professor)
Jocelyn Birt (Water Quality Extension Associate)
John Barker (Educator, Agriculture and Natural Resources)
Jordan Penrose (Educator, Agriculture and Natural Resources)
Kayla Wyse (Educator, Agriculture and Natural Resources)
Kendall Lovejoy (Educator, Agriculture and Natural Resources)
Kendra Stahl (Extension Educator, Agriculture and Natural Resources)
Lee Beers, CCA (Educator, Agriculture and Natural Resources)
Manbir Rakkar (Soil Fertility, State Extension Specialist)
Marina Miquilini (Educator, Agriculture and Natural Resources)
Mark Badertscher (Educator, Agriculture and Natural Resources)
Nic Baumer (Educator, Agriculture and Natural Resources)
Nick Eckel (Educator, Agriculture and Natural Resources)
Pressley Buurma (Educator, Agriculture and Natural Resources)
Rachel Cochran, CCA (Water Quality Extension Associate, Defiance, Van Wert, Paulding Counties)
Ricardo Ribeiro (Visiting Scholar, Federal University of Parana (Brazil))
Ryan McMichael (Educator, Agriculture and Natural Resources)
Sarah Noggle (Educator, Agriculture and Natural Resources)
Ted Wiseman (Educator, Agriculture and Natural Resources)


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