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Agronomic Crops Network

Ohio State University Extension


C.O.R.N. Newsletter 2009-30

Dates Covered: 
September 8, 2009 - September 14, 2009
Wesley Haun

Wheat Seed Size, Seeding Rate and Seed Treatment

Authors: Jim Beuerlein, Pierce Paul

Because of the long grain fill this year, our seed supply is good, the seeds are large and of excellent quality. Normally, there are thirteen to seventeen thousand wheat seeds per pound, and because the seeds are large we will have to use more pounds of seed per acre to get enough plants for a good stand. The recommended number of seeds per foot of row is the same as in previous years, but the pounds of seed per acre will be much greater than last year when the seed was very small.

Calibrate the drill for each variety and each seed lot planted. The optimum seeding rate is 1.2 to 1.6 million seeds per acre for 7.5-inch rows when planting during the two weeks following the fly-safe date. During the third and fourth week after the fly-safe date, plant 1.6 to 2.0 million seeds per acre. When wheat is planted on time, actual seeding rate has little effect on yield, but high seeding rates (above 30 seeds per foot of row) increase lodging. There is no evidence that more seed is better, it only costs more money. Do not plant faster than the speed at which the drill was calibrated. The number of seeds per pound and germination rates is critical factors that need to be known before the proper seeding rate can be determined and the drill calibrated. That information should be listed on the bag of seed. The table below shows the pounds of seed needed per acre to accomplish various seeding rates using different sizes of seed.

Even when seeds of excellent quality are being planted, it is always a good practice to ensure that seeds are properly treated. In Ohio, seed-borne wheat diseases such as common bunt and loose smut are rarely ever major concerns because growers routinely plant seeds treated with fungicides. Problems with these diseases usually appear in isolated areas where poorly treated, bin run seeds are planted. Seed treatments can play an important role in achieving uniform seedling emergence and giving seedlings a good head start under certain conditions. The selective use of seed treatments can protect seeds or seedlings from early-season diseases. Fungicides are available to protect seed and seedlings from many seed-borne or soil-borne pathogens. Seed treatments are most beneficial for seeds infected prior to planting or when cool, wet soil conditions, which delay germination, exist at planting. However, seed treatments should not be considered a cure-all for the selection of poor seed lots. Seed treatments will not increase the germination of poor quality seeds, such as seeds with excessive mechanical damage, seeds stored under poor conditions, genetic differences in variety, or other damage. More information on seed treatments can be found on the field crops disease website:

Summary of Western Bean Cutworm for 2009 in Ohio

Authors: Andy Michel, Ron Hammond, Bruce Eisley

Western bean cutworm (WBC) flights are coming to an end this season, so we thought it appropriate to provide a summary for 2009 and predictions for the coming years. Our numbers increased for the 4th straight year, and more than tripled the total from last year: 150 caught in 2008 compared to greater than 550 caught in 2009. Again, just like last year, north-west Ohio caught the most with 249 adults among Defiance, Fulton, Ottawa and Wood counties (see our update map at However, we still have not found eggs, larvae or damage of WBC in Ohio, although Ontario, Canada has reported their first larvae. Still, we recommend inspecting corn during harvest for any signs of WBC infestation such as damaged ear tips or holes in the middle of the corn ear where the larvae has chewed through the husk. See our video from August 17, 2009 - August 24, 2009 CORN newsletter on how to inspect corn. Please report any suspected western bean cutworm damage to entomology specialists or your extension educator.

What can we predict for the years to come? We expect WBC to continue its expansion across the corn belt, as evidenced by Pennsylvania catching a significant number in its first year of trapping ( Our first, and best, course of action remains scouting. Until we find damage, controlling in advance for WBC cutworm may not be worth the investment (currently, products with the Cry1F Bt gene such as Herculex I and Smartstax offer control of WBC). However, WBC seems to have established itself within Ohio, and will probably become one of the more important corn pests.

Late Bean Leaf Beetle Populations in Soybean

Authors: Ron Hammond, Andy Michel, Bruce Eisley

We thought it important enough to again remind growers about late season pod feeding by bean leaf beetles. Although we have not received that many reports of the insect rising to high numbers this summer, nevertheless, growers should continue monitoring soybean fields that remain green and succulent throughout September. Adult beetles that emerge from yellowing soybean fields will move to those that are still green to continue feeding prior to over wintering. This movement might result in abnormally high densities in some late maturing fields. Injury to the pod is the primary concern because of potential yield and seed quality losses, especially with food grade soybeans and those being grown for seed, both situations where seed quality is an issue. If populations are high, beetles are still active and continuing to feed, and pod injury has reached 10-15% and is relatively new feeding, treatment is warranted to prevent further pod damage. Growers should be very careful with their insecticide choice because of the shorter time period from application to harvest. See the following web site, for a list of labeled pesticides along with their pre-harvest intervals.

Those 60 mph Field Surveys

Authors: Anne Dorrance

We have had some great weather for field scouting and now is the perfect time for a drive. The crop is just starting to turn in many areas of the state. A field that is maturing normally – will all turn yellow at about the same time, maybe a bit delayed around the edges but by far every plant will start to mature at the same time. Fields with issues, namely SCN will not. One of the key findings last year in the soybean check-off funded project was this difference in maturity in areas of the study site that had high populations of SCN at the end of the season. These are perfect spots to check for SCN. Sometimes you can see the white pearls (females) on the roots indicative of SCN and sometimes you can’t. If the females have all form that hard shell, which serves as their protective layer that can then help them survive for years in your soil, it is brown in color making them difficult to pick out.

Another caution on these “drive by’s” is that many late season diseases look the same: white mold, sudden death syndrome (SDS), brown stem rot (BSR), Phytophthora and last but not least – stem canker. In addition, often rare in these parts, charcoal rot, can also be present to and adds further insult to injury in areas which are dry. Each of these utilizes a different management strategy – so it is worth doing the “soybean crawl” to get to those spots to check it out. Some short diagnostic features:

White mold – at this point, stems are bleached white and soft like straw with sclerotia (black irregular shaped bodies) both inside and outside the stem.

SDS – leaves are quickly defoliating but some leaves with the irregular bright yellow spots and brown interveinal patters. When you split the tap root, it is gray in color and the pith of the stem is bright white.

BSR – leaves are also quickly defoliating on this one as well. On this when you look at the bottom of the stem it will have a “greasy” appearance, when the stem is cut, the pith will be chocolately brown just like a buckeye.

Phytophthora – leaves will cling to the plant and will fold down, the tell tale sign is the canker that comes from the soil line up the plant.
Stem canker – leaves will also cling, but here the canker is only at that third or fourth node of the plant, and the bottom of the plant – including root system is healthy.

Charcoal rot – some defoliation will begin and early dying of the plants but the tap root will have a peppery appearance often marked by dark lines. This can extend for a short distance up from the soil line.
And yes, you can have more than one pathogen hitting an individual plant, this is Ohio.

September Weather Outlook

Authors: Jim Noel

Rainfall this past week was very scattered. Many areas received under 0.25 inches but some places received 2-4 inches, on an isolated basis.
The outlook for this week is for areas of rain through Wednesday then drier for later in the week. High temperatures will be generally below normal but low will be above normal yielding near average temperatures.
The week of Sept. 15 will see more rain especially Tuesday through Friday. Temperatures will be normal or slightly below normal.
The week of Sept. 22 will be near normal temperatures and mainly dry and high pressure rules.

Overall, Sept. will be near to slightly below normal temperatures and near to slightly below normal rainfall.
We are in a pattern of a few days wet, then some dry days then back and forth again. Temperatures will also do the typical autumn swings, but with a preference to cooler daytime highs and warmer nighttime lows compared to normal.
September weather looks very reasonable from an agricultural and hydrologic cycle perspective.

Fall Cutting of Alfalfa

Authors: Mark Sulc

Every year many Ohio alfalfa producers take a fall cutting. Unfortunately, cutting alfalfa in mid-September to mid-October can carry serious risk to the health of the stand. Cutting during this period interrupts the process of storage of energy and proteins in alfalfa taproots. When alfalfa is cut during this period and if soil moisture is adequate, the plant will regrow and utilize those precious taproot energy and protein reserves that are needed for winter survival and spring regrowth next year.

Fall cutting may not result in real obvious stand loss, although that can occasionally happen. The more common occurrence is for fall-cut alfalfa stands to suffer some loss of vigor and yield next year that is not so obvious. One could only see such loss of vigor and yield next year if side-by-side comparisons were made within the same field, where strips of alfalfa are cut or not cut this fall. Often, the yield gained by fall cutting is lost in reduced yields the following year.

If producers are in need of additional hay supplies this year, they can minimize the potential for damage from cutting alfalfa stands this fall.
A late fall harvest is a safer alternative than cutting mid September to mid-October. By late harvest, I mean as close as possible to a killing frost of alfalfa, which happens when air temperatures reach 25 F for several hours. This often does not happen until sometime in November in Ohio. But I recommend this late harvest option only if the soil is well-drained, the stand is healthy, a variety is planted that has excellent winter hardiness, and the soil has good fertility status.

I know that the weather is usually lousy in November for cutting forage, but waiting to get closer to the killing frost will prevent the late fall regrowth that “burns up” energy reserves. Thus, cutting late when fall regrowth is less likely will reduce the risk of loss of vigor next spring. A fall harvest after a killing frost is relatively safe if the soil is well-drained and there is no history or risk of heaving on that particular soil. Without residue cover, the temperature at the soil surface will fluctuate more, so the potential for heaving injury is greater.

I am often asked whether leaving a large amount of fall growth can harm the alfalfa stand in the winter. The fear is that the alfalfa will “smother itself out”. I have let pure stands of alfalfa go into the winter with a lot of growth, even more than we see this fall, and I have never experienced a problem or seen the crop “smother out”.

Fall management of alfalfa is one of the few controllable factors that will potentially influence the health of your alfalfa stand next year. It could play a determining role in how much yield you get next year. If you don’t need the forage, walk away from it this fall and let it insulate those alfalfa crowns this winter. The stand won’t smother out because of excessive alfalfa growth.
If you do need the forage now and to get through this winter, then taking a cutting in early November or after a killing frost will reduce the risk of injury to the stand. But try to limit late cutting of alfalfa to well-drained soils with good pH and fertility status. Also leave a 6-inch stubble.
Finally, if you do cut alfalfa this fall, leave several different strips or areas within the same field where you do not cut. You might learn something interesting next spring about fall cutting on your farm.

FSR CCA College Sign Up Due This Week

Authors: Harold Watters

The Ohio State University Agronomic Crops Team in cooperation with Purdue University will be presenting a Certified Crop Adviser program at the Farm Science Review, the FSR CCA College. While we call this the CCA College, anyone who makes recommendations for growers is encouraged to attend. This is a corn year for the demonstration site, and I have hand sprayed about three acres of corn at the late vegetative stage and beyond to set up some possible injury symptoms for your evaluation. We will start in the tent on the FSR Exhibit area grounds and then move to the demonstration site.

Planned program:
Winter runoff, a P challenge
- Robert Mullen, OSU Extension Soil Fertility Specialist Robert will summarize some of the Ohio work on winter nutrient loss. Jon Rausch, Manure Management Specialist will also give us an overview of his new "Nutrient Management Workbook".

Yield predicaments of growing corn in 2009
- Bob Nielsen, Purdue Extension Corn Specialist
- Peter Thomison, OSU Extension Corn Specialist
The Bob & Peter team are back, this year to help you walk through in-season corn application impacts.

Fungicide use in corn, real or imagined
- Pierce Paul, OSU Extension Corn & Small Grains Plant Pathology Specialist Pierce will discuss disease issues in Ohio and expectations for economic return.

The program will start with breakfast on Thursday of the Farm Science Review, September 24th, and end at noon followed by lunch.
- Registration is $75.00
- Please register now through September 11th
- You must register in advance to attend

To register this year you may download a registration form and the program details from: , or call Harold Watters or Sheila Callicoat at the Champaign County Extension office 937 484-1526 or email

Soybean Cyst Nematode Field Night

Authors: Mark Koenig

Are Soybean Cyst Nematodes stealing from your soybean yields? Are you sure you know all the signs? Dr. Anne Dorrance, OSU Extension Plant Pathologist, has been doing research on Soybean Cyst Nematodes and the different resistant packages. Sandusky County is one of the counties for her research, so this will be an excellent chance to learn about this pest. The field night will be hands on so come and learn the symptoms of Soybean Cyst Nematodes and their management. September 16, 2009 6:00 to 8:00 p.m. at Gary Davenport Farm 3555 Limerick Road, Clyde, Ohio
Need additional information call our office 419-334-6340 or e-mail Research sponsored by the Soybean Check-off Fund.


Archive Issue Contributors: 

State Specialists: Pierce Paul, Anne Dorrance, Bruce Eisley (Plant Pathology), Ron Hammond and Andy Michel, (Entomology), Mark Sulc,(Extension Forage Specialist), James Beuerlein, (Extension Soybean and Small Grain Specialist), James Noel (NOAA/NWS/OHRFC). Extension Educators and Associates: Glen Arnold (Putnam), Roger Bender (Shelby), Mike Gastier (Huron), Wes Haun (Logan), Ed Lentz (Seneca), Harold Watters (Champaign), Howard Siegrist (Licking), Greg LaBarge (Fulton), Suzanne Mills-Wasniak (Montgomery), Bruce Clevenger (Defiance), Mark Koenig (Sandusky)

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.