C.O.R.N. Newsletter: 2025-11
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Favorable Planting Weather
Climate Summary
Precipitation over the last week has been hit or miss. Although systems have moved through at a pace of every 2-3 days, some areas received much more rain than others (Figure 1). Particularly hard hit this week was northeast Ohio, where a swath of 2-5 inches of rain fell from eastern Medina County through Trumbull County. Pockets of heavy rain were also felt in Paulding, parts of west central Ohio (with a tornado reported near Greenville), and a few counties across the south. Temperatures were mild this past week with reports of scattered frost, but no major freeze events occurred. Growing degree days (base 50) now range from about 220 units in Ashtabula to more than 425 across southern Ohio. Daily average soil temperatures range from the upper 50s across the north to the low 60s in southen counties. Soil moisture and stream flows are elvated in the Cincinnati area but close to normal elsewhere. For the latest up-to-date conditions, seasonal outlooks, and monthly climate summaries, please visit the State Climate Office of Ohio.
Weather Forecast
The weather pattern this week offers several chances of rainfall but not everyone will see rain each day. A strong cold front with windy conditions on Tuesday will lead to some showers and storms. A few storms could be severe with large hail, damaging winds, and isolated tornadoes. Highs will soar into the upper 70s to mid 80s across the state. Cooler air will filter in on Wednesday with a few scattered showers possible across the south. Thursday will be another breezy day with scattered showers and storms likely as another cold front moves toward Ohio. This front will move through on Friday with scattered showers possible. The weekend will be dominated by high pressure with drier and cooler conditions. Patchy frost cannot be ruled out both Saturday and Sunday mornings. Overall, the the National Weather Service is currently forecasting 0.5-1.5 inches of precipitation for Ohio over the next 7 days, with higher isolated amounts with some thunderstorms (Figure 2).
The 6-10 day outlook from the Climate Prediction Center and the 16-Day Rainfall Outlook from NOAA/NWS/Ohio River Forecast Center show strong probability of above normal temperatures and below normal precipitation (Figure 3). Climate averages include a high-temperature range of 66-70°F, a low-temperature range of 46-50°F, and weekly total precipitation of 0.90-1.10 inches.
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Alfalfa Weevils are Active Statewide
Alfalfa weevil larval activity is beginning its peak activity across the state. Alfalfa weevil feeding activity is driven by the accumulation of growing degree days (GDD) and reaches their peak feeding and damage when heat units for the area are between 325 and 575 (accumulation from a base of 48°F starting January 1st). The warm temperatures over the past week have contributed to a significant jump in GDD and ramped up alfalfa weevil larval feeding. As of writing this (Jan. 1 – April 28), heat units range from 499 in southcentral Ohio to 267 in northeast Ohio.
Scouting is key to the proper management of alfalfa weevil. Scouting is an easy process and was covered in an article written earlier this spring “Alfalfa Weevil Scouting and GDD.” Additionally, this video resource outlines the process: Alfalfa Weevil Scouting Video.
To monitor alfalfa weevil development, county educators from across the state scout fields in their respective counties as shown in Table 1.
Table 1: County alfalfa weevil scouting reports for April 22-28
County
Alfalfa Height (inches)
Larvae Count per Stem
Allen
6-12
0.3
Defiance
8-13
0.7
Fulton
6-12
0
Mercer
10-20
0.05
Ross
6-19
0.8
The county averages listed don’t warrant utilizing a control method, but individual fields can be highly variable. Scout your fields and use Table 2 to help make management decisions.
Stand Height
(Inches)
Indication of Problem
(% Tip Feeding)
Problem Confirmation
(Larvae per Stem)
Recommended Action
6
25
1
Recheck in a week
9
50
>1
Spray
12
75
>2
Spray
16
100
>4
Harvest early
For more information on control methods consult the OSU and MSU “Field Crops Insect Pest Management Guide” (https://aginsects.osu.edu/extension-publications/msuosu-ipm-guide)
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Battle for the Belt: Season 3, Episode 5: Weather and Planting Update
Season 3, Episode 5 of Battle for the Belt is now available: https://www.youtube.com/watch?v=ZVYGuSdz2Vw&list=PLYlh_BdeqniI74ycivSl_yVOjWJjdjg2X&index=7
When will we be able to plant? That’s the question on many farmers’ minds as we head into late April and early May. In Episode 5 of Battle for the Belt, we get an update on weather conditions from Dr. Aaron Wilson, OSU Extension Ag Weather & Climate Field Specialist and State Climatologist of Ohio.
Planting has picked up across Ohio under mild, favorable conditions. Soil temperatures are mostly in the mid-50s to 60°F, aiding progress despite a wetter-than-average month. Strong winds have helped dry soils, and most areas are in good shape. This week brings several rain chances, possible severe weather, and cooler conditions with a frost risk. A drier, warmer window from May 5–11 should offer a good planting opportunity.
For more information, please read Aaron’s C.O.R.N. article from this week “Favorable Planting Weather.”
What’s happening in the field?
Progress continues across all Battle for the Belt locations! As a reminder, the second planting date was successfully completed at both the Northwest and Wooster sites between April 16th and 18th (Table 1). Looking ahead, plans are in place to move forward with the third planting date, roughly three weeks after the second. These plans are subject to change pending weather and field conditions. Planting date 1 (March 27), corn and soybean, at Northwest and Wooster locations, are showing promising signs, with emergence out of the ground visible (Figure 1). These early-planted crops benefited from a recent warmup that contributed to additional growing degree days (GDDs) accumulation (Table 1).
The Western Agricultural Research Station was also able to get in on the action, completing planting date one on April 18th. These crops have germinated and are now beginning to emerge (Figure 2). Within the next ten days, the second planting date at Western will be planted, if soil conditions allow. This location is scheduled to be planted every two weeks.
Table 1. Precipitation, soil temperature, average air temperature, and cumulative GDDs at the Western Agricultural Research Station, the Northwest Agricultural Research Station, and Wooster Campus. Weather data retrieved from: https://weather.cfaes.osu.edu/.
As a recap, this research project includes five planting date windows, 1) Ultra early = late March to early April; 2) Early = mid to late April; 3) Normal = early to mid-May; 4) Late = late May-first week of June; and 5) Very late = mid to late June.
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.
Authors: Maria Kessler, Laura Lindsey, Osler Ortez, Aaron Wilson, Taylor Dill, Diego Miranda, Lynn Ault
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Wheat Yield Contest Entry Deadline May 15th
Attention wheat growers…the National and Ohio Wheat Yield Contest is open for entries until May 15th! Wheat growers with at least 50 total acres of wheat in production and with a minimum 5-acre contest field may participate. Complete rules can be found at the Wheat Yield Contest website.
In Ohio, first place is awarded a 1 year lease on a J&M seed tender, while another 9 winners at the state level are recognized at the annual Celebration of Ohio Corn & Wheat. Further recognition is given at the national level for top producers in various classes. Be sure to enter the contest here https://www.yieldcontest.wheatfoundation.org/.
The National Wheat Yield Contest was created in 2015 by the National Wheat Foundation to promote new ideas and experimentation for wheat production, enable knowledge transfer between growers and identify top wheat producers in each state. Since the competition’s inception, Ohio has had good participation in the national contest, ranking in the top five in the number of entries.
The contest is a friendly competition that will help farmers stay focused on raising high quality, high yielding wheat while evaluating agronomic and economic decisions at the field level. Each registered contestant ($100) must be a member of their state’s wheat growers association (in Ohio, www.ohiocornandwheat.org). Entering the National Wheat Yield Contest automatically enters you in the Ohio contest at no additional cost.
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Lep Monitoring Network – Black Cutworm and True Armyworm Update # 1
The Ohio Lep Network is back for a fourth year of monitoring Lepidopteran pests in ag crops across Ohio. Similar to last year, we will be monitoring black cutworm (BCW), true armyworm (AMW), corn earworm (CEW), western bean cutworm (WBC) and fall armyworm (FAW) throughout the growing season.
To start off the year we have 15 counties monitoring for BCW and AMW. This is our first year using green bucket traps to monitor to BCW and AMW – in past years we have used wing traps. I want to note that using different trap types this year makes it difficult to compare moth numbers from previous years. Traps are placed along fields that will be planted to corn and monitored weekly for about 7 weeks. Last week was our first consistently warm week in Ohio and we did see our moth numbers spike especially in northwest and northern Ohio counties. Read more below for specific details.
Black cutworm
Over the past week BCW moth trap numbers were high in Ohio, with many monitoring counties reporting moths in their traps. Overall, we monitored a total of 43 traps in 15 counties. Our statewide average was 20.1 moths. We recommend keeping a close eye on fields in counties with averages of 7 moths or more, which included Auglaize, Defiance, Henry, Huron, Lorain, Van Wert and Wood (Figure 1).
Some information on BCW: The moths are dark brown to black with a small black dagger mark two-thirds of the way toward the outer edge of the wing (Figure 2). Adults are specifically attracted to fields with broadleaf weeds, such as chickweed (Figure 3) and purple dead nettle (Figure 4). The moths will fly into these area and lay eggs, which then hatch in 5 – 10 days, and larvae go through 6 instar stages over the next 28 – 35 days. Counties with high trap numbers should plan to scout for BCW larvae after corn is planted until V6 stage, especially in fields with a lot of broadleaf weeds (such as chickweed and purple dead nettle). For more information on how to scout BCW please visit: https://aginsects.osu.edu/sites/aginsects/files/imce/ENT_35_14 BCW.pdf
Black cutworm moth map
Week 1
April 21st to April 27th, 2025
True Armyworm
True armyworm was also monitored from April 21st to April 27th using 42 traps in 15 counties (Figure 5). Our statewide average for the week was 15.3 moths. Counties with a weekly average of 7 moths or more included: Auglaize, Henry, Lucas, Putnam, and Van Wert. Adult AMW are tan to reddish brown and have a single white mark in the center of their wing (Figure 6). Adults lay eggs in grasses and rye cover crops. The eggs hatch and the feed on young corn plants. Counties with high trap numbers should monitor for AMW larvae after corn is planted, especially in areas of grassy no-till fields or fields that had rye cover crop.
True Armyworm moth map
Week 1
April 21st to April 27th, 2025
One more side note - in addition to BCW and AMW, our county educator in Van Wert also observed variegated cutworm activity beside a clover cover crop field and egg masses on some wing traps and telephone poles nearby (Figure 7). While we are not monitoring for variegated cutworm in our network, it is another Lep to keep an eye out for and confirms that females are active and laying egg masses in our area.
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
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 an accessible format of this publication, visit cfaes.osu.edu/accessibility.