CORN
Crop Observation and Recommendation Network

December 10 - January 6, 2003
C.O.R.N. 2003-40

In This Issue:

A) Impact of Corn Borer on Ohio Corn Yields in 2003
B) 2003 Ohio Corn Performance Test: An Overview
C) Ohio Soybean Variety Trials Available Now
D) 2003 Ohio Forage Performance Trials Available
E) Fungicide Yield Response in Wheat Depends on Disease Risk
F) Advanced Crop Management Workshop for CCA's and Other Ag Professionals

A) Impact of Corn Borer On Ohio Corn Yields in 2003 - Eisley & Hammond CORN Questions

The 2003 growing season represented the sixth year of replicated trials comparing Bt- corn hybrids specifically, four YieldGard Corn Borer hybrids) to equivalent isolines (without the Bt trait) at the OARDC Western and Northwestern Branch stations. Corn borer injury on the non-Bt isolines at the Western Branch station in 2003 remained low at 0.3 cavities when corn was planted in April. Corn borer injury was also low at the Northwestern Branch Station in 2002 averaging 0.4 cavities per plant. Because corn borer injury has historically been low at the Western Branch when corn was planted on a timely basis, a second later planting (May 24) was made at the Western Branch in 2002. Corn borer pressure was slightly higher in this planting averaging 0.44 cavities per plant.

Average yields from the first planting at the Western Branch station were 158.5 for the YieldGard Corn Borer hybrids and 156.5 for the non-Bt isolines. Average yields from the second planting at the Western Branch station were 172.0 for the YieldGard Corn Borer hybrids and 169.0 for the non-Bt isolines. There were no significant differences in yield between any of the hybrids and their isolines in both the first and second plantings at the Western Branch station. Average yields at the Northwestern Branch station were 225.2 for the YieldGard Corn Borer hybrids and 223.3 for the non-Bt isolines.

In addition to the trials at the branch stations, field trials with the same hybrids were conducted at seven county on-farm sites with the cooperation of OSU Extension agents and growers. Participants included Crawford, Darke, Fayette, Hancock, Knox, Licking and Van Wert OSU Extension county programs. The county trials were not replicated but were planted as paired strip trials.

In the on-farm trials, the difference in yield between the YieldGard Corn Borer hybrids and their non-Bt isolines averaged 0.8 bushel per acre. Average yields of the YieldGard Corn Borer hybrids were higher at 5 of the seven locations this year and the difference in yield was 2.9 bushels/acre. Where the non-Bt isolines out yielded the YieldGard Corn Borer hybrids, the yield difference was 2.6 bushels per acre on average.

The average yield difference from all of the trials conducted 2003 was 1.2 bushels per acre in favor of the YieldGard Corn Borer hybrids. Trials planted after May 15 had an average yield difference of 0.4 bushel/acre in favor of the YieldGard Corn Borer hybrids.
The complete report for 2003 can be found on the web at: http://entomology.osu.edu/ag/reports.htm.

B) 2003 Ohio Corn Performance Test: An Overview - Peter Thomison, Rich Minyo, Allen Geyer, Bert Bishop, and David Lohnes CORN Questions

In 2003, 232 corn hybrids representing 37 commercial brands were evaluated in the Ohio Corn Performance Test. Testing was conducted in three regions of Ohio, Southwestern/West Central (SW/WC); Northwestern (NW); and North Central/Northeastern (NC/NE), with three test sites established within each region. Testing was also conducted at two other Ohio sites that have unique production environments (Coshocton and Piketon). Entries in the regional tests were planted in either an early or full season maturity trial. These test sites provided a range of growing conditions and production environments.

The 2003 growing season was characterized by above average rainfall and below average temperatures. At corn performance test sites where long-term weather data is available, rainfall totals from April to September 2003, ranged from 4.6 to 13.3 inches above normal. Soil conditions at planting were excellent and promoted uniform emergence and good stands. Cool temperatures prevented moisture stress, but slowed crop development. No major disease or insect problems were evident. Grain yields were excellent at most test sites. Stalk lodging was generally negligible. Test weights were lower than in previous years, especially at the northern Ohio test locations. Persistent rains from early May through mid June prevented timely planting of the Mahoning Co. and Bucyrus test sites, and replanting of the full season test at S. Charleston. Results of the these late-planted tests are not presented because frosts occurred prior to maturity and resulted in major yield reductions.

Hybrids were placed in two groups. The early maturity varieties can be summarized as follows. In Southwest/West Central region there were 66 entries with an average yield of 182 bushel per acre (Range of 164-197). Moisture content averaged 17.5% with a range of 15.7 to 22.1%. Test weights were 57.8 average with 53.7 to 61.7. In Northwest, 69 entries averaged 163 bushel per acre (Range of 127-185). Moisture averaged 21.5% with a range of 17.5-25.6%. Test weights were 52.7 average and range of 47.8 to 55.3). In North Central/Northeast the average yield of 44 entries was 205 bushel per acre (Range of 181-242). The average moisture was 21.5% range of 17.6 to 23.8%.Results are in Table 1 below.

Table 1. 2003 Ohio Corn Performance Test - Early Maturity

* Wooster test site only

The second group of late hybrids can be summarized as follows. In Southwest/West Central region there were 63 entries with an average yield of 182 bushel per acre (Range of 161-200). Moisture content averaged 19.7% with a range of 16.7 to 23.6%. Test weights were 57.4 average with 52.8 to 62.0. In Northwest, 68 entries averaged 152 bushel per acre (Range of 132-178). Moisture averaged 23.1% with a range of 20.8-26.0%. Test weights were 52.2 average and range of 48.1 to 56.4). In North Central/Northeast the average yield of 42 entries was 205 bushel per acre (Range of 178-234). The average moisture was 23.4% range of 21.1-25.1%. Test weights averaged 52.5 with a range of 50.0-56.5. Results are in Table 2 below.

Table 2. 2003 Ohio Corn Performance Test - Full Season

* Wooster test site only

Full results of the 2003 Ohio Corn Performance Test are available online at http://www.ag.ohio-state.edu/~perf/

C) Ohio Soybean Variety Trials Available Now - Beuerlein CORN Questions

The Ohio Soybean Trials are available on-line at http://www.ag.ohio-state.edu/~perf/. The results can be sorted by different variety characteristics using the row headings available on the tables. Hard copies of the trials are being shipped to County Extension Office soon.

D) 2003 Ohio Forage Performance Trials Available - Sulc and McCormick CORN Questions

The 2003 Ohio Forage Performance Trials Report is available on-line at http://www.ag.ohio-state.edu/~perf/ and is being printed in a special insert of Ohio's Country Journal along with the Corn and Soybean Performance Trials. It will also be available soon in hardcopy at county Extension offices. The report summarizes performance results from 9 trials planted at three Ohio locations, including more than 39 commercial alfalfa varieties, 13 red clover varieties, 11 tall fescue varieties, and 13 orchardgrass varieties. See how the first commercial hybrid alfalfa (HybriForce-400) is stacking up against other new alfalfa varieties under Ohio conditions. Consider the newest potato leafhopper resistant alfalfa varieties that can reduce losses caused by this troublesome pest. Find red clover varieties that have persisted and performed well into the fourth year, which is certainly amazing! Evaluate the yield performance of endophyte-free tall fescue varieties as well as a new tall fescue variety with the novel animal-friendly endophyte (MAX Q). From the Forage Performance web page, be linked to forage variety performance information across the nation.

E) Fungicide Yield Response In Wheat Depends On Disease Risk - Lipps CORN Questions

Fungicides have been available for use to control leaf diseases of wheat in Ohio since the mid 1980s. There use has been limited to less than about 10% of the wheat acres annually due to various reasons. During epidemic years more wheat growers could benefit from applying fungicides, but in low disease years fungicide applications would not be economic. Yield response to fungicide application is directly dependent on the amount of disease in the field and the susceptibility of the variety to that disease. In Ohio, the most important yield reducing leaf diseases include powdery mildew, Stagonospora leaf and glume blotch and leaf rust. Of these, Stagonospora leaf and glume blotch is most common statewide and powdery mildew is most common in the northeast, east central and south central parts of the state. Most years leaf rust is detected in the state after flowering of the crop and is usually considered too late to cause significant yield loss. Yield losses are greatest when the upper two leaves of the plants become diseased at or before heading of the wheat crop. When this happens, yield losses can be as high as 25 to 30%.

Fungicide efficacy studies have been conducted on wheat in Ohio for over 15 years. We have learned a lot about what works and what does not work. We do know that varieties susceptible to disease are more at risk for disease losses than resistant and moderately resistant varieties and that the amount of disease that occurs in the field varies with year or environmental conditions. During the past few years we have conducted fungicide trials at Wooster in north east Ohio and Hoytville in north west Ohio, two locations with very different environmental conditions. The environment at Wooster in May and early June, during the time when diseases develop rapidly, is characterized as having mild temperatures (50-70 oF) and long periods of high relative humidity (above 90% RH), frequently lasting into the late morning or early afternoon. On the other hand, the environment at Hoytville generally has slightly cooler temperatures than Wooster (usually only a degree or so) and the relative humidity drops quite quickly after daybreak in part due to persistent wind that blows nearly every day during this time period.

Wooster is a location where diseases occur at epidemic levels nearly each year. The high relative humidity and frequent rain showers promote the development of powdery mildew and Stagonospora leaf blotch by mid to late May. In contrast, powdery mildew rarely spreads to the upper leaves of plants at Hoytville, but is usually confined to the lower most leaves of the plants. Stagonospora requires at least 13 hours of leaf wetness for its spores to germinate and infect the leaves, a time period requirement that is not met as frequently at Hoytville as it is at Wooster. Therefore, the differences in weather conditions between the two locations dictate what diseases are important and the degree of their severity.

From 1998 to 2003, fungicide trials were conducted using the same varieties and fungicides at Wooster during each of the six years and at Hoytville during five of the years. At Wooster, fungicide application onto susceptible varieties resulted in a significant increase in yield over the untreated control plots each year, with an average yield response of 11.6 bu/A across all six years. The story was very different at Hoytville where plots treated with a fungicide had higher yields than the untreated plots only during two out of the five years. The average yearly yield increase for the fungicide application was only 1.4 bu/A. In the two years that had a significant yield response, the fungicide treated plots out-yielded the untreated plots by 4.3 and 5.5 bu/A. The obvious reason for the lack of a yield response during three of five years at Hoytville was the overall low level of disease in the field.

When deciding to apply a fungicide growers should consider the susceptibility of the variety to disease, the amount of disease in the field, the weather conditions, the yield potential of the field and the price of wheat. Fields should always be scouted before applying a fungicide to determine if the upper two leaves are in danger of becoming severely diseased before flowering of the crop. If the disease does not spread to the upper two leaves then there will likely be no significant yield response. For more information on using fungicides on wheat and to see symptoms of the important diseases go to the Ohio Field Crop Disease web site (www.oardc.ohio-state.edu/ohiofieldcropdisease/) and click on 'wheat' or view OSU Extension Bulletin 785 'Wheat Disease Management in Ohio' on Ohioline at http://ohioline.osu.edu/b785/index.html.

F) Advanced Crop Management Workshop For CCA's and Other Ag Professionals CORN Questions

Why wait until the end of your cycle to get your CCA continuing education hours? Start early next year by participating in Ohio State University's Advanced Crop Management Workshop for CCA's and other Ag Professionals. Unlike other programs, this workshop is designed to deepen and expand your knowledge in the four subject areas of the CCA program.

Pat Lipps and Anne Dorrance will take you to their greenhouse and demonstrate how plant pathogens affect crop production. Mark Loux and Jeff Stachler will have seedling weeds for hands-on activities as well as a discussion on the latest tools for weed management. Participants will work with crop numbers and solve management problems with Jim Beuerlein. Soil phosphorus dynamics including soil and plant interactions, strengths and weaknesses of phosphorus soil tests from Don Eckert. Larry Brown will discuss how soil properties affect soil drainage in Ohio and Norm Widman will review soil erosion and methods to evaluate fields for erosion potential. Learn how to properly design an on-farm field experiment or better yet, understand statistics of field research with Steve St. Martin.

These and other topics will give the CCA 3 hours of soil and water management, 2 hours of nutrient management, 3 hours of crop management and 3 hours of integrated pest management. This workshop will be held on the Ohio Agricultural and Research Development Center main campus in Wooster. Dates and times are February 11 (10:00-6:00 pm) through February 12 (8:00-noon).Cost of workshop will be $150 which includes educational materials for participants, food and refreshments. Class size will be limited to allow more interaction between faculty and participants. Workshop details are currently being finalized and registration details will be in flyers and future C.O.R.N. newsletters after the first of the year. Contact Ed Lentz at lentz.38@osu.edu or by phone (419-422-6106) for more information.

Readers can subscribe electronically to this newsletter by sending an e-mail message to: corn-out-on@postoffice.ag.ohio-state.edu. A successful subscription message will receive by an automatic reply from the listserv. Contact your local Ohio State University Extension Office or e-mail labarge.1@osu.edu if you have problems subscribing.

Past versions of C.O.R.N. can be found on the World Wide Web at: http:/www.ag.ohio-state.edu/~corn/archive/

C.O.R.N. is a summary of crop observations, related information, and appropriate recommendations for Ohio Crop Producers and Industry. C.O.R.N. is produced by the Ohio State University Extension Agronomy Team, State Specialists at The Ohio State University and Ohio Agricultural Research and Development Center. C.O.R.N. Questions are directed to State Specialists, Extension Associates, and Agents associated with Ohio State University Extension and the Ohio Agricultural Research and Development Center at The Ohio State University.

Editor: Greg LaBarge        Web Editor: Nathan Watermeier

Information presented above and where trade names are used, they are supplied with the understanding that no discrimination is intended and no endorsement 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.

All educational programs conducted by Ohio State University Extension are available to clientele on a nondiscriminatory basis without regard to race, color, creed, religion, sexual orientation, national origin, gender, age, disability or Vietnam-era veteran status.

Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, Keith L. Smith, Director, Ohio State University Extension.

TDD # 1 (800) 589-8292 (Ohio only) or (614) 292-1868

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