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Agronomic Crops Network

Ohio State University Extension


C.O.R.N. Newsletter: 2017-33

  1. The outlook for October does include some rain chances finally as expect between Oct. 4-10.

    Author(s): Jim Noel

    September ended warmer and drier across Ohio for the most part. But it was the tail of two months. The first half of September was 5-10 degrees below normal and the second half of the month was 10-15 degrees above normal.

    For October we expect slightly warmer than normal conditions. Confidence is rather high on the temperature outlook. As for rainfall, more and more weather and climate models indicate above normal rainfall but confidence is low on this. Therefore, we expect near normal to slightly below normal rainfall until we see rain on the ground. The good news for wheat planting is there should at least be some rain between Oct. 4-10. If we do not get it then it might not be until almost early November before we turn wetter so let's hope for some rain in the next week.

    The week of October 3-8 will see above normal temperatures, no frost or freeze conditions and rain chances. Rainfall will average 0-0.50 inches southeast half of Ohio and 0.50 to 1.00 in northwest half with isolated 1+ inch total north and west areas.

    The week of Oct 9-15 will turn normal to cooler than normal with drier weather returning starting Oct. 10.

    The second half of the month will feature a return to above normal temperatures with below normal rainfall.

    Early indications are November will be a warmer month with conditions turning wetter especially in the north half of the state. The south half may stay at or below normal rainfall.

    There is some risk for a minor frost and freeze about the middle of the month between Oct. 10-20. If we do not see it then, it may wait until almost the end of the month then.

    The two week NOAA/NWS/OHRFC rainfall total can be seen on the attached graphic.

  2. Soybean Pod Shattering and Harvest Moisture

    Author(s): Laura Lindsey

    Pre-harvest and harvest loss of grain can result in significant yield reductions. Pre-harvest pod shatter (breaking of pods resulting in soybeans on the ground) can occur when dry pods are re-wetted. This year, in our trials, we’ve seen very little pre-harvest loss.

    At grain moisture content less than 13%, shatter loss at harvest can also occur. As soybean moisture decreases, shatter and harvest loss increase. In some of our trials, we’ve seen approximately 8% loss when harvesting at 9% moisture content. At 13% moisture content, we still see some loss, but at a much lower level (1-2%). Four soybean seeds per square foot equals one bushel per acre in loss (see picture). The seeds are often covered by soybean residue and chaff which need to be brushed away to look for seed losses.

  3. Marestail Control in Wheat and Some Other Weed Stuff

    Author(s): Mark Loux

    Marestail control in wheat and some other weed stuff

    There are several methods for management of marestail in wheat, and following any of these will take care of most winter annual weeds as well. Keep in mind that where wheat will be planted following soybeans, the large marestail that may be present in soybeans are not a concern since they are finshing their life cycle anyway. The plants of concern are the seedlings that emerge in late summer into fall, which can overwinter. A few options to consider follow. This is not an all-inclusive list of herbicide options, but some that make the most sense to us. It’s possible that some of the newer broadleaf products for wheat also have a fit, although none have residual activity.

    • Tillage. Does not guarantee the complete absence of marestail but usually takes care of the problem for the season. Tillage should thoroughly and uniformly mix the upper few inches of soil to uproot existing plants and bury any new seed. Scout in spring to make sure control is adequate.
    • Preemergence burndown + residual. The combination of glyphosate + Sharpen + MSO will control existing marestail and also provide residual control into fall. We suggest Sharpen rates of 1.5 to 2 oz/A. Spray volume of 15 to 20 gpa is required.
    • Late fall POST. We have generally applied these in early November, and wheat should have 1 to 2 leaves depending upon the product. Options include Huskie, and combinations of dicamba (4 oz) with tribenuron (Express) or similar product. Do not apply products or mixes containing 2,4-D POST to wheat in fall.
    • Spring POST. In our research, spring herbicide plus the competition from an adequate wheat stand has been effective, even though 2,4-D can be weak on overwintered marestail plants. Options include Huskie, 2,4-D, 2,4-D + dicamba, or combinations of 2,4-D with an ALS-inhibiting products, such as thifensulfuron/tribenuron (Harmony Xtra etc). The rate of dicamba that can be used in spring is too low to control marestail on its own. Most marestail populations are ALS-resistant, so in the ALS mixtures indicated above, the partner herbicide is carrying the load for marestail control.

    Fall is also a good time to work on poison hemlock infestations. Hemlock is a biennial (2-year life cycle). The large plants that become evident in spring were actually present in a low-growing form the previous fall, when they are in their first year of growth. Control of this weed is often ignored until late spring when it is large and fairly difficult to control, but it is much more easily controlled in late fall. In areas, fencelines, etc where poison hemlock is known to occur annually, consider a late fall application of 2,4-D + dicamba, glyphosate + 2,4-D, etc.

    Finally, some reminders on burcucumber control as herbicide programs for next year get planned this fall and winter. Palmer amaranth notwithstanding, burcucumber remains among the most difficult weeds to control. A number of preemergence and postemergence herbicides have substantial activity on it, but its ability to emerge in great numbers in mid-season allows it to escape even effective programs. It’s worth reviewing the burcucumber information in the “Problem Weeds” section of the “Weed Control Guide for Ohio, Indiana, and Illinois”. We have historically had more questions about control in corn, possibly because it can emerge in tall corn that is difficult to get through with a sprayer. A combination of preemergence and postemergence applications is certainly necessary in both corn and soybeans. POST options in soybeans include Classic, glyphosate, and glufosinate – multiple POST applications are most effective. We conducted a two-year study on control in corn, and found that inclusion of mesotrione (Callisto etc) in the POST application offered the most hope for limiting late-season emergence, although we still observed emergence in July where this was used. Mesotrione has both foliar and residual activity on burcucumber, whereas all other POST herbicides lack residual activity. Most effective residual control following planting occurs with products that contain isoxaflutole (Balance, Corvus) or mesotrione (Lexar, Acuron, Resicore, etc), which should be supplemented by the addition of atrazine.

  4. Harvest Safety Tips while Travelling Ohio Roadways

    Author(s): Dee Jepsen

    As urban development expands into the rural countryside, so too does the need to practice safety on public roadways. During harvest season there is an increased traffic flow on rural roads with agricultural implements and grain trucks. Protecting property and saving lives - of both the farm family and the general public - are the underlying goals for roadway safety.

    Understanding rules of the road is a shared responsibility between the farm machinery operators and the motoring public. Oftentimes blame falls on either party, when in fact it may be a mutual misunderstanding for the Ohio Revised Code.

    Here are common roadway violations and misunderstandings frequently addressed by the OSU Extension Agricultural Safety Office.

    Lighting and Marking requirements:

    The Slow Moving Vehicle (SMV) Emblem was developed at Ohio State University, and is required by Ohio law on all pieces of farm machinery and implements of husbandry. It is an early detection device to signal motorists that a vehicle is travelling at slower speeds. The orange fluorescent center is best seen in daylight hours while the outer red reflective border is noticed more at night. Additional requirements for the emblem are:

    • it is visible to the rear at 1000 feet,

    • it should be mounted with the point up, and no more than 10 degrees off vertical placement,

    • it should be mounted in the center of the vehicle, or as near left-center as possible,

    • it should be placed between 2 – 10 ft above the ground,

    • it must be kept in good condition where it is clean, unfaded, and undamaged.


    Other lighting and marking requirements include:

    • headlights and rear taillights are required from sunset to sunrise,

    • amber flashers and amber reflective tape marks the front and sides of the implements,

    • red reflectors and reflective tape marks the rear of the implements,

    • extremity lighting over dual wheels is required to mark the widest points of the tractor,

    • Speed Identification Symbols (SIS) are required on high-speed tractors, in conjunction with the SMV emblem


    If towed implements block the lighting scheme of the tractor, the implements must replicate the lighting and marking of the tractor, at a minimum red taillights, red reflectors, and SMV emblem.


    Weight Limits:

    In Ohio, there are three different weight limitations that can be enforced on agricultural machinery.

    1. The maximum overall gross weight is 80,000 pounds.
    2. Per tire limit, where 650 pounds per inch of inflated tire.
    3. Per axle limit, where there is both an Ohio law and a bridge weight formula. Single axle weight limit is 20,000 lbs. Any two successive axles, weighed simultaneously that are up to 4ft apart may have 24,000lbs; if the axles are more than 4ft apart, they may have 34,000lbs.
    • The federal bridge formula will allow 2 consecutive sets of tandem axles to carry gross loads of 34,000lbs each when there is a distance of 36ft between the first and last axle.
    • A bridge weight formula calculator can be accessed at:


    Ohio laws allow a 7.5% variance from the weight laws when farm commodities are transported from where they were produced to their first place of delivery where title is transferred. However this variance is not permitted on interstate highways, or during the months of February and March, or on roads and bridges where there is a posted maximum weight restriction.


    Restricted Parking on Highways

    Ohio law does not allow for vehicles to be parked on paved or main travelled roadways when it is practicable to be stopped, parked, or off the roadway. The vehicle should provide a clear and unobstructed portion of the roadway opposite the vehicle for free passage of other vehicles, and a clear view of stopped vehicles from a distance of 200ft in either direction. Other parking restrictions include:

    • Vehicles cannot block a public or private driveway;

    • Vehicles cannot park within an intersection;

    • Vehicles cannot park within 30 ft of a flashing beacon, stop sign, or traffic control device;

    • Vehicles cannot park within 50ft of a railroad crossing or the nearest rail of an operating railroad.


    Dimension Limits:

    Wide implements don’t always have the right of way. Farm operators must be cautious when and respectful of traffic flow when they are outside of these general size recommendations:

    • Vehicle’s width should not exceed 8.5ft (102 inches)

    • Vehicle’s height should not exceed 13ft, 6inches

    • Vehicles length should not exceed 40ft (single vehicle) or 65ft (combination vehicles)


    Farm machinery is exempt from width, length and height requirements when the equipment is being moved on the roads. These exemptions do not apply when machinery is being hauled on the roads. However, it is recommended for machinery to be transported in the smallest possible configuration – meaning the use of combine header carts is encouraged.


    Tips for the motoring public during harvest season include:

    • Be alert and patient for slow moving farm machinery and flashing lights.

    • Realize that farm equipment cannot always “ride the berm” when mailboxes and road signs are mounted near the roadside – in this case tractors may occasionally swerve over the center line.

    • Farm implements are not required to move off of the road to allow traffic to pass.

    • Motorists should only pass on a double yellow line when:

    - The slower vehicle is proceeding at less than half the speed of the speed limit applicable to that location.

    - The faster vehicle is capable of overtaking and passing the slower vehicle without exceeding the speed limit.

    -There is sufficient clear sight distance or center line of the roadway to meet the overtaking and passing provisions of the slower vehicle.

    • Farm trucks, semi trucks and grain carts carrying a full load of grain cannot stop easily. Do not merge into their lane, do not cross into their paths, and do not expect them to stop abruptly.


    For both the farm operator and the motoring public, it is important to reduce stressful situations whenever possible. Practicing roadway safety during harvest season makes for a better place for all travellers. For more information, visit:

  5. Application of Manure to Newly Planted Wheat Fields

    Several livestock producers have inquired about applying liquid dairy or swine manure to newly planted wheat fields using a drag hose. The thought process is that the fields are firm (dry), there is very little rain in the nearby forecast, and the moisture in the manure could help with wheat germination and emergence.

    The manure nutrients could easily replace the commercial fertilizer normally applied in advance of planting wheat. The application of fall-applied livestock manure to newly planted or growing crop can reduce nutrient losses compared to fall-applied manure without a growing crop.

    Both swine and dairy manure can be used to add moisture to newly planted wheat. It’s important that the wheat seeds were properly covered with soil when planted to keep a barrier between the salt and nitrogen in the manure and the germinating wheat seed. It’s also important that livestock producers know their soil phosphorus levels, and the phosphorus in the manure being applied, so we don’t grow soil phosphorus levels beyond what is acceptable.

    If the wheat is planted at its typical one-inch depth and swine or dairy manure is surface applied there should be no problem applying 5,000 gallons per acre of swine manure or 8,000 gallons per acre of dairy manure. If the wheat is emerging when manure is being applied, there is the possibility of some burn to the wheat from swine manure. If the wheat is fully emerged, there is little concern for burning.

    If incorporating manure ahead of planting wheat, try to place the manure deep enough (at least three inches) so the manure does not impact the germination and emergence of the wheat crop. Another option is to incorporate the manure and wait a few days before planting the wheat. If incorporated, the opportunity to carry some of the manure nitrogen through the winter could allow for a reduction in the amount of topdress nitrogen needed for the wheat crop next spring.

    The application of 5,000 gallons of swine finishing manure could contain 200# of nitrogen, 75 pounds of P2O5 and 100 pounds of K2O. The application of 8,000 gallons of dairy manure could contain 175 pounds of nitrogen, 60 pounds of P2O5 and 150 pounds of K2O. Manure nutrient content can vary tremendously from one manure storage facilitate to another but stay reasonably consistence from the same facility year after year.

    As always, print out the weather forecast when surface applying manure. Remember the “not greater than 50% chance of 0.5 inches of rainfall in the next 24 hours” rule in the western Lake Erie watershed.

  6. Some Thoughts on Slugs

    Kelley Tilmon and Andy Michel

    As the 2017 field season winds down farmers are reflecting on how things went this summer and are looking ahead to next season.  Many Ohio farmers experienced significant slug damage this spring and are thinking about future practices to mitigate slug damage including cover crops and crop rotations.  We are conducting some preliminary on-farm research to look at the effect of different cover crops on slugs, but some interesting work has already been done by our colleague at Penn State, Dr. John Tooker.  Tooker and his team have found that slug populations tend to be lower in more diverse rotations than the typical corn/soy rotation – the longer and more diverse the rotation schedule the better.  Diversified rotations help promote a healthy field ecology where pests and predators can maintain a balance with each other.  Ground beetles in particular are effective slug predators.  Other practices which protect ground beetles have also been shown to help keep slugs down, for example avoiding insecticidal seed treatments or foliar applications unless they are warranted by pest-scouting and thresholds.  Studies have shown that these insecticides harm beetle populations without harming the slugs and slug populations can actually increase.  Dr. Tooker has also begun work with farmer-cooperators looking at “planting green” – planting corn or soybean into living cereal rye and terminating the cover slowly so that slugs have something to eat besides the cash crop.  This is potentially a tricky approach so visit with somebody with experience in this approach if you want to give it a try.

    To learn more about slug biology and life cycles, visit our factsheet at

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.


Amanda Douridas, CCA (Educator, Agriculture and Natural Resources)
Beth Scheckelhoff (Educator, Agriculture and Natural Resources)
Bruce Clevenger, CCA (Field Specialist, Farm Management)
Chris Zoller (Educator, Agriculture and Natural Resources)
Clifton Martin, CCA (Educator, Agriculture and Natural Resources)
Dean Kreager (Educator, Agriculture and Natural Resources)
Ed Lentz, CCA (Educator, Agriculture and Natural Resources)
Eric Richer, CCA (Field Specialist, Farm Management)
Glen Arnold, CCA (Field Specialist, Manure Nutrient Management )
Greg LaBarge, CPAg/CCA (Field Specialist, Agronomic Systems)
Jim Noel (National Weather Service)
Lee Beers, CCA (Educator, Agriculture and Natural Resources)
Mark Badertscher (Educator, Agriculture and Natural Resources)
Mark Loux (State Specialist, Weed Science)
Mike Estadt (Educator, Agriculture and Natural Resources)
Mike Gastier, CCA (Educator, Agriculture and Natural Resources)
Pierce Paul (State Specialist, Corn and Wheat Diseases)
Sam Custer (Educator, Agriculture and Natural Resources)
Sarah Noggle (Educator, Agriculture and Natural Resources)
Wayne Dellinger, CCA (Educator, Agriculture and Natural Resources)


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.

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