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Ohio State University Extension

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C.O.R.N. Newsletter: 2022-08

  1. Chilly Damp April Expected

    NAEFS 16-day Ensemble Mean Total QPF from 4/04/2022
    Author(s): Jim Noel

    It looks like planting season will be a bit more challenging this spring than 2021 was. There is no sign of La Nina leaving us anytime soon which tends to stress crop yields in Ohio from research between NOAA and OSU.

    Another overall chilly week is in store for Ohio with periods of light precipitation.  The good news is the week of April 10th we will experience warmer weather but rain chances will continue. The bad news is below normal temperatures will return again the week of April 17th.

    Overall, April will experience normal to below normal temperatures with rainfall likely above normal. This will mean field work will continue to be delayed at times. This will be a common theme across the eastern corn and soybean belts.

    The outlook for May calls for slightly above normal temperatures to arrive but with it will come above normal rainfall.

    The early summer outlook for growing season indicated above normal temperatures from June through August with a trend from wetter start to a drier finish.

    With the chilly April weather expected, there is a risk of the last freeze for 2022 planting/growing season being later than normal. We will also run the risk of a few mixed rain/snow events still especially for northern Ohio.

  2. CFAES Ag Weather System 2022 Near-Surface Air and Soil Temperatures/Moisture (Update 1)

    CFAES Near-Surface Air and Soil Temperatures

    Figure 1: Daily average air temperature (dashed red), two-inch (green) and four-inch (blue) soil temperatures for spring 2022. Current daily average soil temperatures are noted for each location. Soil type and location of measurements (under sod or bare soil) are provided in the lower right corner of each panel. A map of all locations is in the bottom right.  Data provided by the College of Food, Agricultural, and Environmental Sciences (CFAES) Agricultural Research Stations located throughout the state.

    Despite temperatures running 2-5°F above average for the month of March, damp conditions and below average temperatures to start April have daily average soil temperatures running in the upper 30s across northern Ohio to the upper 40s across the south. This is much cooler than this time last year (~10 degrees). Though a warmup is expected midweek, cooler conditions later this week will likely keep soil temperatures on the cool side through the upcoming weekend.

    Much of Ohio has experienced an active weather pattern since late winter, though the storm tracks have shifted northward of late. Even though much of Ohio is running well above average so far in 2022, March was dry for areas along and southeast of about I-71 (Fig. 2-left), with up to 2.5 inches below normal (or 25-75% of normal). After maxing out above the 80th percentile in soil moisture, conditions are approaching normal for this time of year across the state (Fig. 2-right). As discussed in the forecast article this week, a damp cool pattern is expected to continue which may hamper soil conditions over the next couple of weeks.

    Figure 2

    Figure 2: (Left) March 2022 precipitation difference (in inches) compared to the long-term average. Figure provided by the Midwestern Regional Climate Center. (Right) Calculated soil moisture percentiles as of 4/3/2022 according to the Climate Prediction Center.

    For more complete weather records for CFAES research stations, including temperature, precipitation, growing degree days, and other useful weather observations, please visit https://www.oardc.ohio-state.edu/weather1/.

  3. Status of herbicide resistance in Ohio waterhemp populations

    Author(s): Mark Loux

    We have been screening waterhemp populations over the past few years for their response to various herbicide sites of action.  Our overall goal is to get a sense of the types of resistance that have developed or may be developing, so that growers and agronomists know what they should be looking for.  We summarized some of this in a fairly lengthy C.O.R.N. article last year.  We recommend that readers also view the Take action video, “Why care about metabolic herbicide resistance”, by Dr. Pat Tranel, University of Illinois.  One of the discussion points in this video is that metabolic resistance is likely to be extremely variable, resulting in waterhemp with resistance to anywhere from one to 5 sites of action, and any combination of these.  This is in addition to the target-site based resistance to glyphosate, group 2, and group 14 that already exists in most populations.  Reminder that the Take Action Herbicide Classification chart is a great tool for determining herbicide site of action group number.  

    In the previous C.O.R.N. article, we covered results with populations collected through September 2019.  Results with 2020 populations were overall similar, and we are still in the process of screening populations collected in 2021.  We initially screened for resistance to glyphosate, imazethapyr (group 2), and fomesafen (group 14).  Based on the consistent trends in that screening, and the metabolic herbicide resistance developing in states to the west of us, we dropped the glyphosate and imazethapyr and broadened the screen to include herbicide groups for which metabolic resistance is important.  Screens of 2019 and 2020 populations included atrazine (group 5), mesotrione (group 27), 2,4-D (group 2), fomesafen, and s-metolachlor (group 15).  We used foliar applications ofnemerged plants for the first four and measured mortality.  For the s-metolachlor, we assessed control of plants emerging from seed in treated soil.  In the 2022 screen we have dropped the fomesafen and added glufosinate.  We have not included dicamba because using this in the greenhouse did not seem especially wise, given this it’s potential to volatilize and follow any type of air movement and ruin a lot of other research.  We have also for several years submitted populations to a regional project where waterhemp has been screened for resistance to glufosinate and dicamba.  Our research has been funded by the Ohio Soybean Council, and the regional project is funded by USB.  A summary of findings and implications follows.

    - Most waterhemp populations in Ohio are resistant to glyphosate and group 2 herbicides, and growers should not count on these to provide any control.

    - Depending upon the year of screening, up to 75% of the populations screened had some level of resistance to group 14 herbicides.  This includes not only the POST herbicides – fomesafen, lactofen, acifluorfen – but also the residual herbicides – flumioxazin, sulfentrazone.  Resistance to the residual herbicides is not manifested as a complete lack of control, but rather reduced longevity of control so that there is a loss of overall effectiveness.  Growers trying to control waterhemp in nonGMO or RoundupReady soybeans will have to use group 14 herbicides for POST control, and should take steps to determine whether group 14 resistance is present before counting on these to work.  The abundance of Enlist, XtendiFlex, and LibertyLink soybeans has reduced our use of POST group 14 herbicides overall, which may have slowed the development of additional resistance.

    - We observed some level of variable response to atrazine, mesotrione, s-metolachlor, and 2,4-D among the 38 total populations we screened from 2019 and 2020.  About half the populations had a reduced response (less than 80% control) to foliar application of atrazine at 1 lb ai/A, although most of them were still controlled at 4 lbs/A.  About half of the 2019 populations had a reduced response to mesotrione at 3 oz product/A, but all were controlled at 4 times this, and all of the 2020 populations were controlled by both rates.  The response to 2,4-D was more difficult to assess, because it appeared that the 1X rate of 0.75 lb ae/A was overall less effective in the greenhouse than is usually is in the field.  Regardless, it appeared that a couple of populations had reduced response to 2,4-D.  The same issue with rate occurred for the screening with s-metolachlor.  We observed a similar issue with rate for the s-metolachlor screen, where the 1X rate of 1.5 lb ai/A appeared overall less effective than it should have been.  But – we still observed variable response among populations to both rates, and 20 to 33% of populations had a reduced response to the 4X rate. 

    - A summary of the preceding paragraph would be that we have evidence of resistance developing to those 4 herbicides, with the caveat that we did not do the necessary follow up research to confirm this (does response and heritability studies).  These are mostly populations collected during our annual preharvest survey, from fields where there appeared to be indicators of resistance.  Some populations were poorly controlled at the standard herbicide use rate, and for some of these, using four times that rate still did not result in more than 80% control.  If we have metabolic based resistance developing, it is following the predictions of Dr. Tranel.  The presence of this type of resistance for one site of action does mean that resistance to the others occurs.  However, there were several populations with reduced response to all four sites of action we used, for which metabolic resistance is an issue.

    - The regional project screening did not find reduced response to dicamba or glufosinate in the populations we submitted.  Our feeling is that it’s probably a matter of time until we have populations in Ohio with resistance to these herbicides, and also 2,4-D, given the intensive use of these in POST herbicide programs for soybeans. 

    Putting this in perspective, waterhemp continues a trend of developing resistance to any herbicide used against it repeatedly.  Metabolic resistance introduces the additional problem of having a broader assortment of herbicides and herbicide mixtures select for a single mechanism that confers resistance to multiple sites of action, reducing the effectiveness of a number of control options at once.  It won’t be enough to alternate herbicide sites of action (which doesn’t happen much anyway) and mix multiple sites of action.  Herbicide management does not go far enough toward preventing resistance problems in waterhemp.   Ultimately, we need to scout fields often enough to discover control problems, which could be due to resistance, and prevent plants from going to seed. 

     

  4. Early Season Manure Application

    Tractor applying manure with drag hose
    Author(s): Glen Arnold, CCA

    Last fall was not favorable for manure application to farm fields. Thus, many producers are interested in spring application with an eye on capturing the nitrogen contained in the manure to reduce the need for purchased nitrogen.

    In-crop applications of manure make the best use of the manure’s nitrogen content for crop uptake. At the early vegetative stages, the timing is close to the crop’s maximum nutrient uptake period. In corn, placement of the manure below the surface preserves a higher percentage of nitrogen through reductions in volatilization losses. When used as a substitute for purchased nitrogen fertilizer, the economic case for manure used in this way is very attractive and provides an incentive to haul manure greater distances.

    Preplant applications of manure can work almost as well as in-crop manure application. The challenge is to get the manure incorporated, to capture the nitrogen, without delaying spring planting due to the field being too wet or the field made too rough for planting. An acre-inch of water is 27,154 gallons. Applying 7,000 gallons in the spring is like adding a quarter inch of moisture if spread evenly. If the manure is applied in strips, then the field could take longer to dry.

    The Ohio State University conducted five years of research on preemergent manure application. The manure application was made after corn had been planted the previous day. Yield results were significantly higher than commercial fertilizer applied at the same time. Based on fall stalk-nitrate tests, the manure appears to stay with the growing corn crop much longer than the commercial fertilizer. This should give farmers confidence that spring applied manure can provide the nitrogen needed by the corn crop over the entire growing season.

    The key is to apply the needed nitrogen and get the manure below the soil surface. Most swine finishing buildings contain from 30 to 40 pounds of ammonium nitrogen per 1,000 gallons. But there are exceptions to this guide so be sure to rely on previous manure tests. Dairy manure would be much lower at eight to 15 pounds per 1,000 gallons. Research also shows that some agitation of the manure source prior to application will produce more consistency of the nitrogen, phosphorus, and potash over the course of emptying the manure storage.

    Another key is to do your best to avoid soil compaction. Manure tankers are heavy and soil compaction can be seen throughout the growing season and on combine monitors during the harvest season. This would be a good reason to favor using a drag hose for spring manure application if possible.

    If a producer gets the manure application made, then the producer could utilize a Pre-Side-dress Nitrate Test (PSNT) to determine if additional side-dress nitrogen is needed or utilize tissue testing and Y-drop nozzles to determine if additional nitrogen is warranted.

    The application of manure to corn focuses on the 4R’s of nutrient stewardship. These are the right product, the right rate, right placement, and right timing to maximize crop yield and minimize environmental impacts.

  5. Save the Date for Small Grains

    Field of oats
    Author(s): Haley Zynda

    A small grains field day is to be held at the Snyder and Shaffter Farms of the CFAES Wooster Campus on June 14, 2022. A few topics that will be addressed are specialty wheat lines, variety trial updates, disease identification in regard to growth stages, barley for brewing, and wheat quality. We will take a pause for lunch and interact with graduate students presenting research posters.

    Thanks to the generosity of the Ohio Corn and Wheat Board, this event will be free of charge. More details will be forthcoming with registration forms in early May. We look forward to seeing you there!

  6. Agriculture Breakfast: Water Quality and Conservation Opportunities

    OSU Extension will host three Agriculture Breakfast meetings for different watersheds in Paulding, Putnam, Allen, and Van Wert counties in April. These meetings are places for producers and landowners to chat about water quality conservation, including funding and research opportunities in local watersheds. Breakfast will be provided, but an RSVP is required. The first meeting is this week, Thursday April 7th at the Putnam County Extension Office from 7:30 AM – 9:00 AM. RSVP information for each meeting is included on the flyer!

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.

Contributors

Aaron Wilson (Field Specialist, Ag Weather & Climate State Climatologist of Ohio)
Alan Leininger (Educator, Agriculture and Natural Resources)
Andrew Holden (Resigned Educator, Agriculture and Natural Resources)
Barry Ward (Program Leader)
Beth Scheckelhoff (Educator, Agriculture and Natural Resources)
Chris Zoller (Educator, Agriculture and Natural Resources)
David Marrison (Educator, Agriculture and Natural Resources)
Dean Kreager (Educator, Agriculture and Natural Resources)
Dirk Dempsey (Educator, Agriculture and Natural Resources)
Doug Karcher (Chair, Horticulture and Crop Science)
Elizabeth Hawkins (Field Specialist, Agronomic Systems)
Eric Richer, CCA (Field Specialist, Farm Management)
Gigi Neal (Educator, Agriculture and Natural Resources)
Glen Arnold, CCA (Field Specialist, Manure Nutrient Management )
Greg LaBarge, CPAg/CCA (Field Specialist, Agronomic Systems)
Haley Zynda (Educator, Agriculture and Natural Resources)
Horacio Lopez-Nicora (State Specialist, Soybean Pathology)
Jamie Hampton (Educator, Agriculture and Natural Resources)
Jason Hartschuh, CCA (Field Specialist, Dairy & Precision Livestock)
John Barker (Educator, Agriculture and Natural Resources)
Ken Ford (Educator, Agriculture and Natural Resources)
Lee Beers, CCA (Educator, Agriculture and Natural Resources)
Les Ober, CCA (Educator, Agriculture and Natural Resources)
Mark Badertscher (Educator, Agriculture and Natural Resources)
Mark Sulc (Retired State Specialist, Forage Production)
Mike Estadt (Educator, Agriculture and Natural Resources)
Pierce Paul (State Specialist, Corn and Wheat Diseases)
Rachel Cochran, CCA/CPAg (Water Quality Extension Associate, Defiance, Van Wert, Paulding Counties)
Sarah Noggle (Educator, Agriculture and Natural Resources)
Stephanie Karhoff, CCA (Field Specialist, Agronomic Systems)
Taylor Dill (Graduate Student)
Ted Wiseman (Educator, Agriculture and Natural Resources)
Trevor Corboy (Educator, Agriculture and Natural Resources)

Disclaimer

The information presented here, along with any trade names used, is supplied with the understanding that no discrimination is intended and no endorsement is made by Ohio State University Extension is implied. Although every attempt is made to produce information that is complete, timely, and accurate, the pesticide user bears responsibility of consulting the pesticide label and adhering to those directions.

CFAES provides research and related educational programs to clientele on a nondiscriminatory basis. For more information, visit cfaesdiversity.osu.edu. For an accessible format of this publication, visit cfaes.osu.edu/accessibility.