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Agronomic Crops Network

Ohio State University Extension


C.O.R.N. Newsletter 2008-41

Dates Covered: 
December 16, 2008 - January 6, 2009
Greg LaBarge

Hybrid Corn Response to Foliar Fungicide Treatment: A 2008 Update

Authors: Pierce Paul, Dennis Mills

The trends seen in 2008 corn fungicide yield results were similar to those seen in 2006 and 2007. The 2008 Ohio results were also comparable to the rest of the Corn Belt. Corn hybrid yield response to foliar fungicides continues to be highly variable and unpredictable.

In 2008, corn fungicide trials were conducted at four locations across the state (Western Research Station, near South Charleston; the Northwest Research Station, near Hoytville; the Snyder Farm, Wooster, and the ATI Research Farm in Apple Creek), providing us with a total of 20 trials for disease and yield comparisons. At each location, multiple hybrids with different levels of resistance to gray leaf spot and yield potential were planted, allowing us to evaluate hybrid corn yield response to fungicides for a combination disease pressure, weather, and hybrid scenarios.

All trials were planted no-till or reduced-till into fields previously planted with corn, except at the Snyder Farm site. In all trials, foliar fungicides were applied between tassel and silk emergence (VT – R1) at label-recommended rates, using high-clearance spray equipment calibrated to deliver approximately 20 GPA.

At the time of fungicide application, only trace amounts of foliar disease were observed on the lower leaves. The actual disease levels were well below the recommended fungicide application thresholds and disease levels remained low through the growing season at all locations. Gray leaf spot and common rust were observed towards the end of the season, especially at South Charleston and Apple Creek. Averaged across the ear leaf and the two leaves below the ear, gray leaf spot severity at the R4 growth stage (dough) in untreated plots of the most susceptible hybrid was 2.9% and 5%, at South Charleston and Apple Creek, respectively, and less than 2% at Wooster and Hoytville.

Yields in the untreated checks ranged from 73.6 to 177.96 bu/A, with an average of 109.8 bu/A, whereas in fungicide-treated plots, yields ranged from 68.19 to 188.49 bu/A, with an average of 109.55 bu/A. In 12 of the 20 trials, treated plots had numerically higher yields than the checks, however, the magnitude of the yield difference varied considerable from trial to trial. Yield differences between treated and untreated plots (treated minus untreated) ranged from -16.70 to 10.53 bu/A across all 20 trials, with an average difference of -0.28 bu/A.

Similar fungicide trials conducted by university researchers across the Corn Belt had similar results. Depending on the fungicide, average yield differences between treated and non-treated were between -1.2 and 4 bu/A when foliar disease severity was less than 5% and between 1.6 and 10 bu/A when severity was greater than 5%.

2008 Organic Corn Performance Test

Authors: Allen Geyer, Peter Thomison, Deb Stinner, Rich Minyo

Although the acreage of corn planted to transgenic Bt and herbicide tolerant hybrids has accelerated in recent years, interest in organic corn production in Ohio is also increasing. In 2008, we continued evaluations of corn hybrids marketed for organic producers at the Hirzel Sustainable Systems site, a certified organic farm located near Bowling Green in Wood county and on certified organic land at OARDC Badger Farm, near Apple Creek in Wayne county. We added a transitional site near South Charleston in 2008. For 2008, four open pollinated (OP) varieties, three OP varietal crosses and two conventionally produced, untreated hybrids were included in the tests. No fertilizers or pesticides were applied to the Bowling Green or Apple Creek sites. Three tons of liquid hog manure were applied to the South Charleston site. Weed control was provided by mechanical cultivation.

Results for Bowling Green and South Charleston are not presented. At these sites, drought stress and variable field conditions contributed to inconsistent yields. At Bowling Green, yields averaged less than 40 bu/A. At South Charleston, a rain storm immediately after planting caused poor emergence and uneven stands. On September 14, record high winds associated with hurricane Ike caused severe root and stalk lodging at the test sites, especially South Charleston.

The report includes cultural practices used at the site and 2008 and 2006-2008 data.

Grain yields at Apple Creek ranged from 32 to 136 bu/A; stalk lodging ranged from 5-100%; and grain moisture at harvest ranged from 15.0-32.8%. Twelve seed companies and suppliers participated in the 2008 test. The relative maturity ratings of the hybrid entries varied from 88 to 114 days.

The results for the 2008 Organic Corn Performance Test can be viewed at: under the corn tab on the left hand side.

Please contact Allen Geyer (phone: 614-292-1393; if you would like additional information regarding the test.

Crop Performance Trial Information

2008 crop performance trial information for corn, soybeans, forages and corn silage can be found at the crop performance page located at

The forage trials include results for Alfalfa, Potato Leafhopper Resistant Alfalfa, Red Clover, Orchardgrass, Tall Fescue, Perennial Ryegrass, Annual Ryegrass and Warm Season Annual Grasses.

The silage trials are a cooperative effort of MSU Extension and OSU Extension with the Ohio site located in Wood County.

Upcoming Agronomy Training, Meetings and Workshops

Details for the following agronomy events can be found at All events are open to all and registration is requested. Cost vary and can be found along with other events scheduled for February and March at

January 5
Three County Agronomy Day
Start Time: 8:30 a.m. (registration) 9 a.m. (program)
County of Meeting Location: Ross Co.
Ross County Service Center
475 Western Ave
Chillicothe, OH
Phone Number: 740-702-3200

January 7
Crop Production Conference
Start Time: 8:30 a.m.
County of Meeting Location: Franklin
Fawcett Center
2400 Olentangy River Rd
Columbus, OH 43210
Phone Number: 614-326-7520

January 8
Advanced Agronomy School for CCA's
Start Time: 8:00 a.m.
County of Meeting Location: Franklin
Fawcett Center
2400 Olentangy River Rd
Columbus, 43210
Phone Number: 614-326-7520

January 12
Western Ohio Agronomy Day
Start Time: 9 a.m. and 6 p.m.
County of Meeting Location: Shelby
Sidney American Legion Hall
1265 Fourth Avenue
Sidney, OH 45365
Phone Number: 937-498-7239

January 14 & 15
Certified Crop Advisor Pre-Exam Training Session
Start Time: 9 a.m.
County of Meeting Location: Shelby
OSU Extension-Shelby
810 Fair Rd
Sidney, OH 45365
Phone Number: 937-599-4227

January 15
Putnam County Agronomy Night
Start Time: 6:30 p.m.
County of Meeting Location: Putnam
Kalida Knight of Columbus Hall
PO Box 138, Napoleon Rd
Kalida, OH 45853
Phone Number: 419-523-6294

January 16
Corn/Soybean Day
Start Time: 8:30 a.m. to 3:40 (optional CORE session adjourns 4:40)
County of Meeting Location: Fulton
Founder’s Hall at Sauder Farm and Craft Village
22611 St Rt 2
Archbold, OH
Phone Number: 419-337-9210

January 21 & 22
Yield Maps to Management Maps-Precision Farming Workshop
Start Time: 9:30 am
County of Meeting Location: Fairfield County
Fairfield County Extension Office
831 College Avenue
Lancaster, 43130
Phone Number: 740-653-5419

January 21
Agronomy School
Start Time: 9:30 a.m. to 3:30 p.m.
County of Meeting Location: Ashtabula
Williamsfield Community Center
Intersection of Route 7 and Route 322
Phone Number: 440-576-9008

January 23
Paulding County Agronomy Day
Start Time: 8:30am
County of Meeting Location: Paulding
Paulding County Extension Office
503 Fairground Dr
Paulding, 45879
Phone Number: 419.399.8225

Insect/Pathology Workshop

Authors: Dennis Mills

The Entomology and Plant Pathology Departments are offering an Insect/Pathology Workshop for CCA’s, consultants, agronomists, etc, February 4, 2009 at OARDC Wooster. Topics will include: IPM-Back to the basics; Measuring disease levels; Soybean aphid and population genetics-applications for management; Seed treatments; Insect resistance management; Frogeye, rust and plant health; Wheat scab and fungicides. Sessions will be conducted by Dr. Ron Hammond, Dr. Anne Dorrance, Dr. Pierce Paul and Dr. Andy Michel. 4.5 CCA CEU’s are available along with applicator recertification credits of 4 hours in 2A and 0.5 hour in Core. The workshop will be held in 203 Selby Hall on the Wooster campus from 9 – 3. To register contact Dennis Mills, , 330-202-3566. There will be a $50 registration fee at the door and space is limited. Registration can be found at

Archive Issue Contributors: 

State Specialists: Ann Dorrance, Pierce Paul and Dennis Mills (Plant Pathology), Ron Hammond, Andy Michel, and Bruce Eisley (Entomology), and Mark Loux (Weed Science). Extension Educators: Roger Bender (Shelby), Harold Watters (Champaign), Todd Mangen (Mercer), Gary Wilson (Hancock), Howard Siegrist (Licking), Glen Arnold (Putnam) Bruce Clevenger (Defiance), Greg LaBarge (Fulton), and Mike Gastier (Huron).

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.