C.O.R.N. Newsletter: 2023-28
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Weather Update: Cranking up the Heat
Ask around and most folks will agree that it has been a peculiar summer when it comes to the weather. Most headlines point out the heat, from Florida to the desert southwest, as the globe just experienced its warmest July on record (1850-2023). For Ohio, we have benefited from numerous cool mornings and comfortable days, but the same northerly wind pattern also brought frequent wildfire smoke filled skies to the region. Overall, temperatures since July 1st are running near to slightly below average (Figure 1-left). Along with the mild temperatures, the latter half of the summer has been considerably wetter than our start, with most areas of Ohio running well above average (Figure 1-right). CoCoRaHS observations over this time include reports of 13-14” in parts of Brown, Clinton, Cuyahoga, and Geauga Counties. On the flip side, dry conditions linger across portions of NW Ohio, where only 4-6” of rain has fallen over this same period in places like Putnam, Paulding, and Allen Counties. For more information, check out the State Climate Office and sign up for our monthly and quarterly climate summaries.
Forecast
A major pattern shift has brought strong high pressure to the region and a significant heatwave across the bulk of the central U.S. With Ohio on the eastern edge of this heatwave, temperatures this week will vary greatly from downwind Lake Erie in the northeast to Cincinnati. Highs on Tuesday and Wednesday in the far northeastern counties will remain comfortable in the upper 70s to low 80s, while the southwestern half of the state bakes under 90-95 degree temperatures. There could be a few showers or storms across the northern counties on Tuesday through Thursday. The heat really pushes into Ohio on Thursday, where locations from Cincinnati to Dayton to Columbus could top 100°F. If these locations do hit 100°F, it will be the first time since the summer of 2012. Overnight lows throughout the period will remain in the upper 60s to mid 70s. High temperatures in the 90s will continue into Friday before a strong cold front and a few showers and storms usher in cooler air for the weekend. The current forecast shows 0.10-0.5 inches of rain is expected this week, with slightly heavier amounts in northeast Ohio (Figure 2).
The Climate Prediction Center’s 8-14 Day Outlook and the 16-Day Rainfall Outlook from NOAA/NWS/Ohio River Forecast Center indicate that probabilities for temperatures and precipitation are leaning toward below average for the period of August 29 – September 4, 2023 (Figure 3). For this time of year, the average high-temperature range is 81-85°F, the average low-temperature range is 61-64°F, and the average weekly total precipitation is about 0.70-0.80 inch.
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Stay Vigilant for Red Crown Rot of Soybean
Red crown rot (RCR) is a soybean disease caused by the soilborne fungus Calonectria ilicicola that is spreading to parts of the Midwest. There have been no confirmed reports of RCR in Ohio, but it has been detected in Kentucky and Illinois. Soybean growers should stay vigilant when scouting fields as RCR can be easily confused with other soybean diseases that cause similar foliar symptoms.
RCR can be misidentified as sudden death syndrome (SDS) or brown stem rot (BSR) as all three diseases can cause yellowing between the leaf veins or interveinal leaf chlorosis (Figure 1). Proper diagnosis will require digging up the plant, scraping the soil off, and inspecting for red discoloration on the outer stem (Figure 2). Also look for small, brick red perithecia (fungal sexual structure) on the lower stem or root crown area. These perithecia will be smaller than the tip of a pencil and more likely to be observed following wet weather.
In general, concentrate scouting efforts for RCR in low-lying, saturated areas of the field between the R3 (beginning pod) and R5 (beginning seed) growth stages. Keep an eye out for scattered patches of plants dying off early. Ohio producers who suspect they may have RCR should contact their county extension office and submit samples for diagnosis at the Soybean Pathology and Nematology Laboratory in Columbus. To submit samples, dig out 3-5 symptomatic plants including the roots, place them in a plastic bag, and submit to the following address:
OSU Soybean Pathology and Nematology Lab
Attn: Horacio Lopez-Nicora, Ph.D.
110 Kottman Hall
2021 Coffey Rd.
Columbus, Ohio 43210
lopez-nicora.1@osu.edu -
Poultry Litter Application
Stockpiles of poultry litter can be seen in farm fields across Ohio. While common each year in wheat stubble fields, there are also stockpiles commonly found in soybean fields. Getting the poultry litter to the fields ahead of spreading makes time makes the whole process more efficient. Poultry litter is an excellent source of plant nutrients and readily available in most parts of the state. With fall harvest just around the corner these poultry litter piles will soon be spread across farm fields.
Poultry litter can be from laying hens, pullets, broilers, finished turkeys, turkey hens, or poults. Most of the poultry litter in the state comes from laying hens and turkey finishers. Typical nutrient ranges in poultry litter can be from 45 to 57 pounds of nitrogen, 45 to 70 pounds of P2O5, and 45 to 55 pounds of K2O per ton. The typical application rate is two tons per acre which fits nicely with the P2O5 needs of a two-year corn/soybean rotation.
Like all manures, the moisture content of the poultry litter greatly influences the amount of nutrients per ton. Handlers of poultry litter have manure analysis sheets indicating the nutrient content.
Poultry manure for permitted operations needs to follow the Ohio Department of Agriculture standards when being stockpiled prior to spreading. These include:
- 500 feet from neighbors
- 100 feet from a public road
- 300 feet from streams, grassed waterways, wells, ponds, or tile inlets
- not on occasionally or frequently flooded soils
- stored for not more than six months
- not located on slopes greater than six percent
- located on soils that are deep to bedrock (greater than 40 inches to bedrock)
Farmers who want to apply the poultry litter delivered to their fields are required by Ohio law to have a fertilizer license, Certified Livestock Manager certificate, or be a Certified Crop Advisor.
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Lep Monitoring Network Update #16 – WBC Numbers Continue to Decrease
The Ohio Lep Network is in our 16th week of monitoring for pests across Ohio. This week we will provide an update on 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) and we hope to provide an update for FAW starting next week.
For more information on these pests and many more, check out our website: https://aginsects.osu.edu
Western Bean Cutworm
This is our ninth week reporting on adult Western bean cutworm (WBC) populations across Ohio. In total, 16 counties monitored using 52 traps. All reporting counties across Ohio are below threshold numbers indicating the peak moth flight has passed and the majority of WBC egg masses have been laid (Figure 1).Western Bean Cutworm Moth Map
August 14th- 20th, 2023
Corn Earworm
This is our eleventh week reporting on corn earworm (CEW) populations across Ohio. This week, 6 counties monitored for CEW, using 6 total traps. Brown county has the highest average this week with 10 CEW moths (Figure 2).Corn Earworm Moth Map
August 14th- 20th, 2023
European Corn Borer
This is our thirteenth week reporting on European corn borer (ECB – IA & NY) populations across Ohio. This week, 6 counties have been monitoring ECBs using 14 total traps, 7 traps for the IA variant, and 7 for the NY variant. Overall there were not ECB-IA moths (Figure 3) and Hardin county was the only county to report ECB-NY, with an average of 2 (Figure 4).European Corn Borer (IA) Moth Map
August 14th- 20th, 2023
European Corn Borer (NY) Moth Map
August 14th- 20th, 2023
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Battle for the Belt: Episode 24
Episode 24 of Battle for the Belt is now available: https://www.youtube.com/watch?v=WO3o-o9ySQQ
In Episode 24, we go to each research location with Taylor Dill and conduct yield estimates on corn. Taylor is a graduate student in the department of Horticulture and Crop science at Ohio State University.
Yield Estimation
Every summer throughout the state, agronomists, extension educators, extension specialists, and farmers do yield estimates on their corn crop. Yield estimations for corn can be accurate to about 20 bushels per acre difference. There are two ways to estimate corn yield, the yield component method and the ear weight method. The ear component method can be used as early as R3, the milk stage. We will only be covering the yield component method in this article.
The yield component method has four simple steps to follow.
- First, we count the number of plants (we assume that there is one good ear per plant). Measure out 17ft and 5 inches (one thousandth of an acre when the crop is grown in 30-inch row width) and count plants or ears in one crop row. If we multiply this by 1,000, we get the number of plants per acre.
- Next, count the number of kernel rows per ear and kernels per row for every fifth ear. Do not sample ears that are abnormal unless that is uniform to the rest of the row. The kernel rows are always an even number because of cell division. When counting kernels per row, do not count the butt or the tip of the ear, instead, begin where there are “complete rings” of kernels (Nielsen, 2021). After counting each component for every fifth ear, average the kernel row number per ear and kernels per row.
- Now, multiply the ear/plant population x kernel row average x kernel per row average and divide by 85. The number we divide by is known as the “fudge factor”. This number accounts for kernel weight. When this method was originally developed a factor of 90 was used but with plant breeding and management practices improving over the years, the updated recommended fudge factor is 85. However, if you notice that the kernels are smaller than usual, then increasing the fudge factor to 90 is warranted.
Example: 33 (plant population or number of harvestable ears) x 16 (average kernel rows) x 38 (kernels per row) ÷ 85 (fudge factor) = 236 bushels per acre.
- Finally, for an accurate estimation for a field, repeat this process four or five times.
A reminder that this is a tool for estimation and kernel size and weight can change depending on the environment, which affects overall yield. In drought years and environments causing poor pollination, yields can be overestimated. In environments with outstanding grain fill, the yield can be underestimated.
Battle For the Belt Location Updates
Last week, we did yield estimations for each location specifically looking at planting date one and planting date three. All locations had a noticeable yield difference between the two planting dates. After harvest, we will dig into the data and try to explain yield differences among the five planting dates.
For planting date one at the Wooster location the population was 29,000 plants per acre with an average of 14 kernel rows and 31 kernels per row, coming out to an estimated yield of 140 bushels per acre. Planting date three had a more optimistic outlook. The population was 33,000 plants per acre, with an average of 16 kernel rows and 38 kernels per row. The estimated yield comes out to 223 bu/acre. This location was wet and cold during the planting of planting date one and has had more disease than other planting dates at R1. Planting date three also has a significant height difference (taller plants) in comparison to planting date one.
At the Western location planting date one had a population of 33,000. The yield components were an average of 14 kernels per row and an average of 28 kernels per row. The estimated yield comes out to be 152 bu/acre. In this planting date, there have been many short and small ears, which may be causing the lower estimation. For planting date three the population was 30,000 plants per acre. The average kernel rows were 16 and the average kernels per row was 31. The estimated yield for this planting date is 175 bu/acre. At this location, at the R1 stage, there was low disease pressure but over time there has been an increase in Gray Leaf Spot to about a 10% severity on the ear leaf. This disease is more severe at Western than at Northwest or Wooster.
The Norwest location planting date one had a population of 32,000 plants per acre. The yield components were 14 kernel rows and 32 kernels per row. This comes out to an estimated yield of 169 bu/acre. Planting date three had a population of 31,000 plants per acre. The average kernel rows were 16 and the average kernels per row was 36. The estimated yield was 210 bu/acre. This location has had the least disease pressure across planting dates thus far, but has had tar spot come in late for our early planting dates and at R1 for planting date four and five.
Overall, planting date three is expected to out yield planting date one in corn at each location by 85, 25, and 40 bushels per acre, respectively. It is also interesting to note the consistent difference in kernel rows. Planting date one at each location averaged 14 kernel rows per ear and planting date three averaged 16. This trait is determined by V12 and is also influenced by genetics. The environment of the early season has the potential to affect this yield component.
Table 1. Planting dates one, two, three, four and five in the trial at all three locations with day of planting, soil, air temperature averages, and Growing Degree Days (GDDS). Information from CFAES Weather System, https://weather.cfaes.osu.edu/.
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.
Reference:
R.L. Nielsen. 2021. Estimating Corn Grain Yield Prior to Harvest. Agronomy Dept, Purdue Univserity. www.agry.purdue.edu/ext/corn/news/timeless/YldEstMethod.html
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Register Today for Northwest Agronomic Field Day
Don’t miss out on your chance to interact with OSU Extension Specialists and take a deep dive into new corn and soybean practices at the 2023 Northwest Agronomic Field Day on Thursday, August 31 at the Northwest Agricultural Research Station.
Topics will include managing slugs with cover crops, adjusting corn nitrogen rates following a cover crop, intensive corn management, corn diseases, and updates from the Battle for the Belt program.
Registration will start at 8:30 a.m. with the programing beginning at 9:00 a.m. followed by a free lunch courtesy of the Ohio Soybean Council at 12:00 p.m. RSVP for the 2023 Northwest Agronomic Field Day at go.osu.edu/nwfieldday23 or by contacting Nick Eckel at eckel.21@osu.edu or 419-354-9050.
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.
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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.