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Agronomic Crops Network

Ohio State University Extension


C.O.R.N. Newsletter 2013-10

Dates Covered: 
April 23, 2013 - April 29, 2013
Glen Arnold
Identifying Wheat Growth Stage for Early Management Decisions Identifying Wheat Growth Stage for Early Management Decisions

Identifying Wheat Growth Stage for Early Management Decisions

Due to colder, wetter conditions, wheat growth throughout the state has been a bit slower this spring than the past several years, however, the crop is still greening up and as such growers will need to pay attention to crop growth stage in order to make adequate management decisions. Wheat growth stage identification it critical for effective timing of fungicide, insecticide, herbicide, and fertilizer applications. Hence, crop growth stage identification is extremely important, since failure to correctly identify these stages may lead to inadequate timing of applications, which may result in violation of pesticide label restrictions (products being applied off label), inferior efficacy or product performance, and injury to the crop.

If you have not done so already, now is the time to check fields in order to identify crop growth stage. Most of the wheat across the state is at Feekes growth stage 5 (green-up), the ideal stage for top-dressing nitrogen and to finish up herbicide application. However, some earlier planted fields in southern Ohio are probably already at early stem elongation or jointing (Feekes' growth stage 6). This growth stage can be identified by examining the large tillers in the fields for the presence of the first node. Pull multiple large tillers, strip down the lower leaves and leaf sheaths on the stem, and check for the presence of the first node at the base of the stem. If this node is visible (or can be felt), your wheat is at jointing (growth stage 6). At growth stage 6, the node is above the soil line and appears as a slightly swollen area of a slightly different shade of green from the rest of the stem. If the node is not yet visible, the wheat is probably at Feekes growth stage 5.

Growth stage 6 signals the end of tillering and the beginning of stem elongation. Nitrogen should be applied by this time to maximize yield. This is also the growth stage when some herbicides can no longer be applied. For instance, herbicides such as 2,4-D, Banvel, or MCPA should not be applied after Feekes growth stage 6.0, as these materials can be translocated into the developing spike, causing sterility or distortion. Although sulfonylurea herbicides are still safe at this growth stage, growers should try to complete weed-control before growth stage 6.

A severe and extended freeze after growth stage 6 may affect yield since the tissue that will become the spike or head is now above the protection of the soil. Fortunately, wheat is tolerant to moderately cold temperatures (such as a frost) at this time and we should be past the period of severe freezes.

For more on wheat growth stage identification visit:

Insecticide Seed Treatments on Field Crops Seedcorn maggot

Insecticide Seed Treatments on Field Crops

Although almost all corn and a majority of the soybean seed now come with insecticide seed treatments, growers should not assume they will get much benefit from their application.  Seed treatments have shown great control of seedcorn maggot, but only if and when that insect pest occurs.

Research over 20 years has shown that maggot populations only reach economic levels when a green, living organic crop such as an alfalfa field, grass cover crop, or heavy weed growth, or possibly manure, is incorporated into the soil.  Tillage of green matter is what draws female flies into the field for egg laying, resulting in possible higher numbers.  In those situations, seed treatments have been shown to work very well.  However, for most of the other secondary pests, grower experience has shown the lack of adequate control.

True grubs and grubs of the Asiatic garden beetle are able to greatly damage corn that has been treated with the various seed treatments.  Although labeled for black cutworm control, we still see significant injury from larvae, often needing  an insecticide foliar treatment for control;  thus, the reason we state the need to always scout for black cutworm injury in no-still situations especially when winter annual weeds are present.

In soybean, we do have good evidence that because of the systemic activity of seed treatments, they will offer control of foliar feeding insects such as the bean leaf beetle or soybean aphid in early spring.  However, these pests are seldom if ever at high enough levels to cause concern in the spring in Ohio; the seed treatments are no longer effective and do not offer meaningful control in mid to late summer.  In terms of bean pod mottle virus vectoring by the bean leaf beetle in the spring, the jury is still out.  At most, we only advise farmers growing seed or food grade soybean to consider using them for this purpose, and at best that would only provide a limited amount of success.  Thus, when given a choice, we usually do not recommend application of an insecticide seed treatment except for those specific situations mentioned above.

Concerns about Nitrogen Loss in WheatConcerns about Nitrogen Loss in Wheat

Concerns about Nitrogen Loss in Wheat

Growers are concerned that they may have lost some of their nitrogen from the heavy rains that occurred after wheat topdress. Urea applications would unlikely have losses from these rains since N should be still in the ammonium form and held by the soil. The relatively cool temperatures over the past month would have also limited the conversion of ammonium to nitrate N.

Urea volatilization losses are generally minimal because of cooler temperature and frequency of rain events around topdress time. However, there was a time early in the month that conditions were abnormally hot and may have allowed volatilization losses. The weekend of April 5, conditions were dry in some parts of the state for about five days. If urea had been applied on the first or second day of that period, volatilization losses may have occurred when temperatures reached the upper 70s and low 80s during the latter part of that period before the heavy rains came the next day. Urea that was applied toward the end of that period probably received rain before significant volatilization losses.

Heavy rains may have caused some loss with urea-ammonium nitrate (UAN).  When you apply UAN, about a quarter of what you apply is already in the nitrate-N form.  This fraction of N is subject to loss, and there is really very little you can do to protect it.  Inhibitors will not protect nitrate-N from loss and crop uptake is very slow until early stem elongation. Thus nitrate-N may be lost with water leaving the field. This loss potential is greater for sandy soils than clays. The urea component of UAN also has a potential for volatilization losses. However, dribble bars and other band applications of UAN would reduce the potential for this type of loss.

For some, heavy rains may have prevented earlier applications of N. Research has shown that yield is not affected by later applications as long as N is applied by Feekes Growth Stage 7. All N sources would be appropriate at this growth stage except ESN, which may not have adequate time to release N.  A urease inhibitor should be used if the forecast is for an extended warm and dry period. Little benefit would be expected from a nitrification inhibitor at this time since wheat should be actively taking up all forms of N including nitrate-N.

What’s Happening with the Weather

As discussed last week and in late March, the risk of late season freezes are elevated in 2013. We did get the freezes this weekend as the National Weather Service Ohio River Forecast Center discussed last week. Going forward it looks like some areas may see another freeze event by this Friday AM.

As for temperatures, the week of April 22 will see below normal temperatures. The week of April 29 will see above normal temperatures which will extend into early May. By mid May, temperatures will retreat to below normal. Mother Nature since early April has been behaving quite normal in Ohio.  Temperatures in April are normal to 2 degrees above normal so we are working out of the cold March with 4 inch soil temperatures still lagging due to the March weather.

As for rainfall, the week of April 22 will be near normal and the week of April 29 will be slightly below normal. Rainfall for early to mid May will be normal to below normal.

Another review of our outlook from last fall showed winter 2012/2013 would be slightly warmer and wetter than normal and that is exactly where the numbers came in. Our outlook for spring was for slightly warmer with normal to slightly wetter conditions. Based on where we are at, it looks like spring is on a target for near normal temperatures when averaged out due to the cold March and precipitation normal to slightly wetter. Overall, a fairly good outlook from late 2012.

Most data suggests May will see normal or slightly warmer than normal temperatures and precipitiation turning back to slightly drier than normal. Soil moisture is in good conditions across most of the corn and soybean belt in 2013. The exact opposite of 2012. Data continues to suggest a good growing year compared to 2012.

The summer outlook continues to indicate an overall wash from June to August of not far from normal. However, within there are some important details. It looks like the summer starts warmer than normal and trends back to normal by August while the summer starts drier than normal in June and trends to above normal rainfall by August but averages out to a wash.

The long-term trends over many years looks to hold this year where we get a dry burst in either May or June each year then a wet burst often in late summer or fall. 2013 looks on track to see something like that with each year's magnitude changing. This years does not look as extreme as 2011 or 2012 which we have been saying since last summer and fall.

Burning Crop Debris is Legal, Isn’t It?

It’s the time of year when farmers clear fields and fence rows of corn stalks, branches and other debris and use a common management practice--piling the debris and burning it in the field.  Because outdoor fires such as this create air emissions and wildfire concerns, Ohio has laws that regulate open burning activities.   Burning certain materials at certain times in certain places may violate the open burning laws and cause a health or safety issue.  It’s important to know when open burning of crop debris and field residue is permissible, and to take precautions to minimize risk and liability.

There are several areas of law in Ohio that address open burning.  The Ohio Environmental Protection Agency (OEPA) oversees regulations on the open burning of materials that may produce harmful air emissions that affect human and environmental health.  Ohio also has laws that regulate open burning to minimize the danger of wildfires; these laws may be enforced by the Ohio Department of Natural Resources (ODNR) Division of Forestry or local law officials.

Additionally, a local government might have local ordinances that regulate open burning.

In regards to crop debris in farm fields, it is typically permissible for a farmer to burn the debris.  However, the law creates duties to conduct the burn responsibly and imposes some conditions on what, where and when to burn.  Violating the laws can lead to criminal charges, fines and civil liability to harmed parties.

What can you burn?

Ohio law allows the burning of “agricultural wastes” under certain conditions.  The definition of agricultural waste includes materials such as crop debris, as well as other materials.

According to Ohio law, agricultural waste includes:

Waste material generated by crop, horticultural, or livestock production practices, landscape wastes that are generated in agricultural activities and woody debris and plant matter from stream flooding.

Bags, cartons, structural materials and containers for pesticides, insecticides, fungicides, rodenticides, miticides, nematocides, fumigants, herbicides, seed disinfectants and defoliants, if the manufacturer has identified open burning as a safe disposal procedure.  Farmers may add seed bags and cartons to the burn pile as long as the label states that open burning of the materials is safe.

Agricultural waste does not include:

Standing or fallen buildings, building materials, food waste, dead animals, materials made from petroleum or containing plastic, rubber, grease or asphalt.   A farmer may not add these materials to the burn pile.

Debris resulting from the clearing of land for new agricultural, residential, commercial or industrial development—this type of waste is defined as “land clearing waste.”  Open burning of land clearing waste requires prior written notification to Ohio EPA.

Where can you burn?

Several regulations determine acceptable locations for burning crop debris and other agricultural waste:

Agricultural waste may only be burned on the property where the waste is generated; the waste may not be taken to a different property for burning and a farmer cannot receive and burn waste from another property.

If the burning is inside a “restricted area,” then prior written notice to Ohio EPA must be provided at least ten days in advance of the burning.  A “restricted area” is an area where there is higher population density.  The law defines a restricted area as:

Any area inside city or village limits.

Any area within the 1,000-foot zone outside of a city or village with a population of 1,000 to 10,000.

Any area within a one-mile zone outside of a city or village with a population of more than 10,000.

The fire must occur in a location where it will not obscure visibility for roadways, railroad tracks or air fields.

The fire must be more than 1,000 feet from any neighboring building inhabited by people, such as homes, stores, restaurants, schools, etc.

When can you burn?

There are definite times when burning of crop debris and other agricultural waste is not permitted unless certain conditions are met.

Ohio’s wildfire laws limit open burning in rural areas during the months of March, April, May, October and November, when wildfire risk is highest due to dry vegetative conditions and dry winds.  During these months, open burning in rural areas is completely prohibited between the hours of 6 a.m. and 6 p.m., when winds are high and volunteer fire departments are not well-staffed.  One exception to this prohibition applies to farmers:

Open burning may occur in a plowed field or garden, if the burn pile is at least 200 feet from any woodland, brush land or field containing dry grass or other flammable material.  If a farmer can’t meet this 200 foot buffer zone requirement, the farmer should wait until after 6 p.m. to conduct the burn.

Open burning should only occur when atmospheric conditions will readily dissipate any smoke and potential contaminants.  If weather conditions are foggy, rainy or causing air inversions, smoke and contaminants will not readily disperse and the farmer should not burn the materials.

Even if all other legal requirements for open burning are met, open burning is not allowed when air pollution warnings, alerts or emergencies are in effect.

What about prescribed burning?

Both the ODNR and Ohio EPA have authority over prescribed burning—intentional burns for horticultural, silvicultural, range or wildlife management practices.  Prescribed burning requires prior written permission from Ohio EPA and--if taking place during March, April, May, October or November--the burn must be conducted by a Certified Prescribed Fire Manager with permission by the Chief of ODNR’s Division of Forestry.  See the Division of Forestry’s website for more information on becoming a Certified Prescribed Fire Manager and requesting permission for prescribed burns.

Prior notice to Ohio EPA

For burns that require advance notice to the Ohio EPA, farmers may use the notification form on the Ohio EPA website at  The form seeks information about what will be burned and when and where the burn will take place; this allows the EPA to ensure that the burn is permissible.

Legal duties for conducting open burning:

Ohio law also imposes duties for managing open burns. Ohio Revised Code 1503.18 establishes a duty to prevent fire escape.   The law requires any person who starts a fire near trees, woodland or brush land to take steps to prevent the fire from escaping.  All leaves, grass, wood and inflammable material surrounding the place must be removed to a safe distance and all other reasonable precautions must be taken to keep the fire under control.   The law also states that a person should extinguish or safely cover an open fire before leaving the area.

Ohio EPA’s regulations impose several other duties for managing burns.  As mentioned above, burning of agricultural waste should take place at least 1,000 feet from any neighbor’s inhabited buildings. The wastes should be stacked and dried to provide the best practicable condition for efficient burning and weather conditions should not prevent dispersion of the smoke and emissions.  If the size of an agricultural waste pile exceeds 20 feet in diameter by 10 feet in height (or 4,000 cubic feet),  the farmer must provide written notification of the burn to the Ohio EPA at least ten days before burning.

Local laws

The above analysis explains Ohio’s laws on open burning; remember that the local government might have a local law that also regulates burning activities.  Check with your local fire department to know whether any local regulations apply to the situation.

What if a farmer violates open burning laws?

Violation of the open burning laws creates several risks for farmers.  Ohio EPA has the authority to issue fines of up to $1,000 per day per offense.  The EPA states that it takes enforcement action against repeat offenders or violations that cause significant harmful emissions.  Otherwise, EPA enforcement officers prefer to issue warnings to first-time offenders and educate on how to conduct open burns that minimize pollution impacts.  EPA enforcement officers regularly patrol their districts, investigate fires they see and investigate complaints from neighbors or others who report burning activities.  According to the EPA, the most common violations by farmers include burning substances that are not “agricultural wastes” such as tires and plastics, failing to meet the 1,000 foot setback requirement and burning waste from another property.

Conducting open burns that violate Ohio’s wildfire prevention laws can result in third degree misdemeanor charges, which carry penalties of up to $500 and 60 days of jail time per violation.   Any person may report a potential illegal burn that creates wildfire risks to the local law enforcement or Division of Forestry.

Equally and perhaps more important is the risk of civil liability from an open burning incident.  We all know that the “burn police” can’t observe everyone all the time, but civil liability doesn’t require intensive monitoring—it requires harm.  Where an open burn causes harm to people or property, civil liability may arise.  An open burn that reduces roadway visibility and results in an auto accident, escapes the property and harms neighbors or neighboring property or significantly interferes with other owners’ property use could result in a negligence or nuisance lawsuit.  The farmer who violated open burning laws or failed to properly manage the fire could be liable for all harm resulting from the fire.

For more information on Ohio’s open burning laws, visit the websites of the Ohio EPA Division of Air Pollution Control and ODNR Division of Forestry.

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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.