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Agronomic Crops Network

Ohio State University Extension


C.O.R.N. Newsletter 2013-24

Dates Covered: 
July 29, 2013 - August 6, 2013
Rob Leeds

Weather Outlook: Below Normal Temperatures And Normal To Below Normal Rainfall

The trend is for continued below normal temperatures and normal to below normal rainfall in early August. It does appear we will have a chance of rain every 3-4 days across Ohio but with the core of the heat to our southwest it will be rainfall events will be on the light side and likely yield rainfall at or below normal. However, with temperatures continuing below normal into early August this will yield below normal evapotranspiration. This means we will also not need even normal rainfall for things to remain in a good and ample moisture state.

The latest 14 day temperature outlook can be found at:

The latest 16-day rainfall outlook can be found at:

Soybean Aphid UpdateSoybean Aphid Update

Soybean Aphid Update

Surveying fields in areas of northern Ohio suggests that the soybean aphid continues to build up in numbers and in fields infested.  A revisit in a field near Toledo indicated that over half the plants in that field are now infested, albeit at low numbers.  Scouting in Geauga, Wayne, and Wood Counties suggests that aphids are probably also throughout northeast Ohio.  However, these newer finds showed very low aphid numbers, with only a small portion of the fields infested at the current time.  Most aphids are being found in the new growth at the top of the plant. 

These observations suggest that a close watch should be kept on fields in the northern third of Ohio to prevent aphid populations from reaching economic levels.  Whether future build ups come from aphids currently in the field or from migrations from states (esp. Michigan) and provinces (esp. Ontario) to our north where economic populations are already occurring remains to be seen.  But there is no doubt that we will have fields in Ohio that reach economic levels in August.  Remember that the threshold for treatment is 250 aphids per plant.   See the fact sheet at for more information.

August Is An Opportunity To Establish Perennial Forages

Rain and wet soil conditions condensed the spring planting season this year and some planned alfalfa plantings got moved to the back burner.  August provides another window of opportunity to establish a perennial forage stand and it fits nicely into rotations after wheat grain harvest.  Typically the main risk with an August planting is a question of sufficient moisture for seed germination and plant growth.  This year if soil moisture is a concern, it is from the standpoint of too much rather than too little moisture. 

There are some advantages to late summer forage planting as compared to a spring planting. One big plus is that planting time and field preparation is not competing with corn and soybean field work. No-till planting following a small grain crop often works well. Late summer planting means forage seedlings are not competing with the flush of annual spring and summer weed emergence/growth. The soil borne root rot and damping off disease organisms that thrive in cool, wet soils are not an issue. However, late summer forage planting has some other risks that must be managed.

Ideally, planting should be completed by mid-August in Northern Ohio and by the end of August in Southern Ohio. These timelines are based on average frost dates and the time needed for forage plants to develop a root system capable of overwintering.   For example, at about 8 to 10 weeks after emergence alfalfa plants pull the growing point below the soil surface, a process is called ‘contractile growth’.   Once contractile growth occurs the alfalfa plant is considered a true perennial.  The alfalfa plant needs to reach this growth stage to overwinter. Clover plants also need to have a crown formed, and grasses should be at least in the tillering stage of development before the onset of winter. 

If the fall is warm and extended, similar to what we have experienced the past few years, it might be possible for successful establishment with later planting dates.  Some alfalfa growers believe that the late summer planting deadline dates can be moved back by several weeks due to climate change.  But who can predict the weather? How lucky do you feel? Late summer and early fall planting dates of forages were tested in Pennsylvania in the mid-1990’s at two locations that historically are a little milder than most of Ohio’s winters. The year after seeding legumes, forage yield declined as planting dates were delayed after early August. For each day planting was delayed after August 1, total forage dry matter yields the next year were reduced by an average of 158, 105, and 76 lbs/acre for alfalfa, red clover, and birdsfoot trefoil.  Grasses were usually less affected by later planting dates. For example, orchardgrass yields only decreased significantly when planting was delayed past late-August and perennial ryegrass yields were actually greater in late-August than in early August. However, for each day planting was delayed after August 30, yields declined 100 lb/acre for orchardgrass and 153 lb/acre for perennial ryegrass. Reed canarygrass, a slow establisher, was more sensitive to planting dates. Reed canarygrass yields the year after seeding declined 120 lbs/acre for each day planting was delayed after August 1.  So the best policy is usually to plant most perennial forages as soon in August as possible, when soils conditions allow and when soil moisture is present.

Sclerotinia crown and stem rot is a concern with no-till seedings of alfalfa in late summer and especially where clover has been present in the past. This is a pathogen that causes white mold on alfalfa seedlings. They become infected during cooler rainy spells in late October and November, the disease develops during the winter, and seedlings literally "melt away" in winter and early spring. It can be devastating where the pathogen is present. No-till is especially risky where clover has been present because the sclerotia germinate from a shallow depth. Early August plantings dramatically improve the alfalfa's ability to resist the infection. Late August seedings are very susceptible, with mid-August plantings being intermediate.

In a no-till situation, minimize competition from existing weeds by applying a burndown application of glyphosate before planting. Post-emergence herbicide options exist for alfalfa. After the alfalfa is up and growing, late summer and fall emerging winter annual broadleaf weeds must be controlled. A mid- to late fall application of Butyrac, Pursuit or Raptor and Buctril are the primary herbicide options. Fall application is much more effective than a spring application for control of these weeds especially if wild radish/wild turnip are in the weed mix. Pursuit and Raptor can control winter annual grasses in the fall but should not be used with a mixed alfalfa/grass planting. Consult the 2013 Ohio and Indiana Weed Control Guide and always read the specific product label for guidelines on timing and rates before applying any product.

If tillage is used to prepare the soil for planting, a firm seedbed is needed to ensure good seed-to-soil contact. Follow the "footprint guide" that soil should be firm enough for a footprint to sink no deeper than one-half inch. A pre-plant herbicide is not needed for a tilled seed bed.  Generally, the risk associated with establishing a tilled seed bed for a late summer planting is the loss of moisture.  Bearing some type of dramatic change, that does not appear to be the case this year.  Finally, keep in mind that any time forages are planted the following factors must be managed:

·  Soil fertility and pH: The recommended soil pH for alfalfa is 6.8. Forage grasses and clovers should have a pH of 6.0 or above. The minimum or critical soil phosphorus level for forage legumes is 25 ppm and the critical soil potassium level is somewhere between 100 and 125 ppm for many of our soils.

·  Seed selection: Be sure to use high quality seed of adapted, tested varieties and use fresh inoculum of the proper Rhizobium bacteria. “Common” seed (variety not stated) is usually lower yielding and not as persistent, and from our trials the savings in seed cost is lost within the first year or two by lower forage yields.

·  Planter calibration: If coated seed is used, be aware that coatings can account for up to one-third of the weight of the seed. This can affect the number of seeds planted if the planter is set to plant seed on a weight basis. Seed coatings can also dramatically alter how the seed flows through the drill, so be sure to calibrate the drill or planter with the seed being planted.

·  Seed placement: The recommended seeding depth for forages is one-quarter to one-half inch deep. It is better to err on the side of planting shallow rather than too deep.

·  Do not harvest a new perennial forage stand this fall. The ONLY exception to this rule is perennial and Italian ryegrass plantings, which should be mowed or harvested to a two and a half to three-inch stubble in late November to improve winter survival. All other species, especially legumes, should not be cut.

What is the value of wheat straw?

Now that wheat harvest is complete, we often get questions about the nutrient value of straw.  The nutrient value of wheat straw is influenced by several factors including weather, variety, and cultural practices.  Thus, the most accurate values require sending a sample of the straw to an analytical laboratory.  However, “book values” can be used to estimate the nutrient values of wheat straw.  In previous newsletters, we reported that a ton of wheat straw would provide approximately 11 pounds of N, 3 pounds of P2O5, and 20 pounds of K2O.

As a comparison to these “book values”, we measured the nutrient value of wheat straw in one of our studies this year at the OARDC in Wooster.  In our studies, one ton of straw contained 14-18 pounds of N, 3-4 pounds of P2O5, and 20-23 pounds of K2O.  These values are across four wheat varieties and three nitrogen application rates (60, 90, and 120 lb N/acre).  Our 2013 values correspond fairly well with the previously reported “book values.”  Nitrogen values in our study were slightly greater than “book values” which may have been a result of wheat height/size.  If plants are shorter/smaller, percentage nitrogen tends to be greater than taller/larger plants due to a dilution factor as the plant grows.

Besides providing nutrients, straw has value as organic matter, but it is difficult to determine the dollar value for it.  Removal of straw does lower soil potash levels.  If straw was removed after heavy rainfall, some of the potash may have leached out of the straw, lowering the nutrient value of the straw.  However, a soil test should be done to accurately estimate nutrient availability for future crops.

2013 Ohio Wheat Performance Test Preliminary Results Now Available On-Line

Preliminary results from the 2013 Ohio Wheat Performance Test are now available on line at:   Single and multi-year yield results are currently available for all locations. The results can be accessed by following the links on the left side of the page. Information regarding the growing season, evaluation procedures and disease resistance will be available shortly. Additional varieties will be added as soon as marketing information becomes available.

Aug 6th Northwest Ohio Precision Ag Technology Day

Farmers and crop consultants interested in seeing the newest planter technology or precision technology that can be retrofitted on existing planters are encouraged to attend the Aug 6th Northwest Ohio Precision Ag Technology Day at Fulton Co Fairgrounds in Wauseon. 

The day will focus exclusively on planters including seed, steel and related technology.  In the morning, producers will hear sessions on precision planter agronomics, all the newest planter technology, data management and a precision planter panel. In the afternoon, Case IH, Horsch, John Deere and Kinze planters will provide live demonstrations in a nearby wheat stubble field (conditions permitting). 

Event runs from 8:15 am to 3:30 pm and is free to the public but registration to or 419-337-9210 is needed for accurate lunch count. See for flyer and more details.

Manure Science Review on Tuesday, August 6th

The annual Manure Science Review, featuring new and better ways to manage livestock manure and wastewater, takes place at the Hord Livestock farm south of Bucyrus on Tuesday, August 6th. The site is wheat stubble field about a quarter mile west of intersection of State Route 98 and State Route 294.  

Morning educational presentations start at 8:50am and include:

• “Nutrient Management: Hord Livestock Overview,” which includes information on managing odors and nutrients and brokering liquid manure, by Pat Hord and David Neef of the host farm.

• “Benefits of the Four Rs” -- the right nutrient at the right rate, time and place by Steve Prochaska of OSU Extension.

• “Nutrient Variations in Stored Manure” and how to compensate for differences in nitrogen, phosphorus and potassium by Kendall Stucky of the Crawford, Seneca, Sandusky and Wyandot soil and water conservation districts.

• “Growing the Application Window,” featuring research on using manure to side-dress corn and increase yields and manure storage capacity, by OSU Extension’s Glen Arnold.

• The “Nitrogen Potential Assessment Test,” which determines residual nitrogen available to corn during the growing season, by Tom Menke of Menke Consulting.

• “Livestock Stewardship: Telling Our Stories,” a look at ways to build public trust on nutrient management and water quality issues, by David White of the Ohio Livestock Coalition.

The field demonstrations are from 1-3 p.m. and will feature mortality composting, edge-of-field bioreactors, cover crops for Ohio’s soils, optical nitrogen detection, the new Subsurfer Applicator for injecting poultry manure, applicators for liquid manure injection, rapid transfer of liquid manure, side-dressing with liquid manure and the Nutrient Boom for applying liquid manure to standing crops.

Registration, which includes a continental breakfast and lunch, is $30 per person by July 29 and $35 per person after July 29. To register, participants should send their name, affiliation, address, e-mail address, telephone number and payment (with checks made payable to OARDC/OSU) to Mary Wicks, OARDC/OSU, 1680 Madison Ave., Wooster, OH 44691.

For more information, contact Wicks at 330-202-3533 or An agenda and registration form may be downloaded at (pdf).

Manure Field NightManure Field Night

Manure Field Night

The Evening of August 6th following the Manure Science Review, OSU Extension and the area Soil and Water Manure Management Specialist will be hosting a Manure Field Night. It will consist or many of the field demonstrations that were done during the afternoon session of MSR. The field demonstrations will start at 6 p.m. and will feature, edge-of-field bioreactors, cover crops for Ohio’s soils, optical nitrogen detection, the new Subsurfer Applicator for injecting poultry manure, applicators for liquid manure injection, rapid transfer of liquid manure, side-dressing with liquid manure and the Nutrient Boom for applying liquid manure to standing crops. The evening’s events will be free of charge and a great way to stay up to date on the latest manure application technology and how cover crops (15 different blends are planted) and manure can fit into an agronomic cropping system. For more information contact Jason Hartschuh at or 419-562-8731. The Field night will be held at the Hord Livestock farm south of Bucyrus. The site is wheat stubble field about a quarter mile west of intersection of State Route 98 and State Route 294.

Southwest Ohio Corn Growers & Fayette County Agronomy Committee Field Day August 13, 2013

The Southwest Ohio Corn Growers Association & Fayette County Agronomy Committee’s annual field day and test plot demonstrations will take place on Tuesday, August 13, 2013.  The field day will be held from 9:30 a.m. to 3 p.m. at the Fayette County Demonstration Farm at 2770 State Route 38, in front of the Fayette County Airport.

The public is invited to this free event to hear from expert speakers and attend the trade show.  Services offer to the community include health screenings by the Fayette County Health department & Fayette County Memorial Hospital from 9 a.m. to Noon, skin damage screenings by the OSU Extension Office of Fayette County, also from 9 a.m. to Noon. 

The morning session will feature Dr. Steve Prochaska of Ohio State University Extension speaking on 4 R Nutrient Management, Dr. Andy Michael of Ohio State University Extension speaking on Current and Future Issues for Corn and Soybean Insect Management, Dr. Peter Thomison of Ohio State University will give a presentation on Taking a Second Look at Planting Depths, and Jim Hoorman with Ohio State University Extension will answer questions about cover crops and how to make them work in your operation.

This year we have been able to team up with FCA Flight Training and offer airplane rides to any interested parties at a price of $30/person for a 30-minute flight. Please register by calling 740-335-1150. If interest is high enough we do have the possibility of accessing a second plane, so please call early. The second new exhibit that will take place is a UAV Crop Sensing demonstration and presentation by Precision Hawk. Please join us in learning about this new technology and how it may help on your farm. Demonstrations will take place at 10 a.m., 11:30 a.m., and 2 p.m.

Lunch is provided during the noon session.  Mr. Hanaoka from the Hana Ma Ruki Company will address the group following lunch about the handling of Non-GMO Soybeans in Japan and Tadd Nicholson, the Ohio Corn Growers Association (OCGA) Executive Director, will give an update on the OCGA.  After lunch will be a drawing for two $500 gift certificates for Ohio Corn Grower Members.  Memberships for the OCGA will be available all day at the event check-in table.  See for more information regarding membership.

For further questions regarding the Southwest Ohio Corn Growers & Fayette County Agronomy Field Day, contact the Fayette County Extension Office at 740-335-1150.  CCA Credits will be offered.

Western Forage Field Day- Aug 21 Leafhopper Resistant Alfalfa

Western Forage Field Day- Aug 21

Those interested in forages should join us August 21 for a day filled with the latest forage varieties, methods and technologies for increasing production. The morning will begin with a wagon tour of all the research plots at the OARDC Western Branch in South Charleston. Specialists will discuss their research and how it may benefit your operation. These include grass interseeded into alfalfa, leafhopper resistant alfalfa, alfalfa management inputs for high yield, red and white clover variety trials and native grasses for biofuels. Speakers include Bob Henershot, retired USDA-NRCS State Grasslands Conservationist, Dr. Mark Sulc, OSU Forage Specialist and Amanda Douridas, OSU Champaign and Union Counties Extension Educator.

The morning will also include several different warm season annuals planted after wheat harvest. The planting methods include conventional, no-till and slurry seeding (seed mixed with manure). The nutritional values of the warm season annuals with respect to corn silage will also be discussed. After lunch a presentation on the best methods for forage preservation will be given by OSU’s Dr. Bill Weiss. Attendees will then be able to view the Byron Seeds grass variety trial, which is one of the largest variety trials ever done on the farm, presented by Chad Hale. The day will end with a few equipment demonstrations including mowers, tedders and rakes. A few passes will be mowed ahead of time to compare different windrow widths and drying times.

For more information, including registration, visit:



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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.