CORN
Crop Observation and Recommendation Network

February 11-25, 2002
C.O.R.N. 2002-3

In This Issue:

A) Soybean Seed Treatments Active Ingredients
B) Effect Of Seeding Rate On Soybean Yield
C) White Food Grade Corn: 2001 Performance

A) Soybean Seed Treatments Active Ingredients - Dennis Mills, Pat Lipps, Anne Dorrance CORN Questions

Seed treatment fungicides are useful tools to manage seed and soil borne pathogens and are highly recommended in Ohio on soybeans. However, a specific fungicide will not control all of the pathogens that may be present. Therefore seed treatment products are frequently formulated to contain more than one fungicide. It is important that agronomic crop producers know what the pathogens are in specific fields in order to choose the best fungicide or combination of fungicides for that field. In addition, the correct choice of fungicide will also limit losses due to seed-borne pathogens. The same rule applies in that specific fungicides will not effectively control all seed-borne pathogens. Refer to Extension Bulletin 639 Seed Treatment for Agronomic Crops for more detailed information concerning seed and seedling diseases affecting field crops in Ohio. (http://ohioline.osu.edu/b6339/b639_html)

The marketing of seed treatments by manufacturers may result in the same chemical being sold under several brand names and by several different companies. Using mixtures of different seed treatment fungicides is a common practice. Mixing two or more fungicides or insecticides results in a product that will control a broader spectrum of seed pathogens.

In the last C.O.R.N. newsletter (Jan 30- Feb 11, 2002) Dr. James Beuerlein presented results of field trials with several fungicide seed treatment products http://corn.osu.edu/library/articles/2001fung2.html)
The yield response to seed treatment varied with the seed treatment applied (0 to 8.4 bu/A yield increase) and with field location (average increase over untreated control 0.5 to 5.2 bu/A). These differences were caused by type and level of diseases present at each of the locations and the effectiveness of the different seed treatment products to control the diseases. Captan, Thiram, TBZ, Fludioxonil, Azoxystrobin are effective in controlling Phomopsis seed rot and seed infected by Sclerotinia. Fludioxonil, PCNB and Azoxystrobin are effective against Rhizoctonia seedling blight. Metalaxyl and Mefenoxam are effective against Phytophthora damping off, but only when used at the higher rates.

Table 1 is an incomplete listing of soybean seed treatment fungicides and their active ingredients:

B) Effect Of Seeding Rate On Soybean Yield - Jim Beuerlein CORN Questions

In 2001, we established a series of research plots at five Ohio locations to determine the effect of seeding rate on soybean yield. Two Roundup Ready varieties, Asgrow AG 2602 and Dekalb DKB 36-51, were used. The Asgrow variety had a relative maturity of 2.6, the Rps 1k Phytophthora gene and a partial resistant of 5.5. The Dekalb variety had a relative maturity of 3.7, the Rrps 1c Phytophthora gene and a partial resistance of 4.7. The seeds of both varieties were treated with fungicides (Rival, Apron) to aid in disease control.

The six seeding rates averaged over varieties, locations and replications (40 plots) produced harvest populations of 70,000; 106,000; 116,000; 125,000; 159,000; and 167,000 plants per acre. These populations equate to about 70 percent of the intended seeding rate. Yields at the 70,000 harvest population were 52.1 and 43.9 bushels per acre for AG 2602 and DK 36-51 respectively. Actual yields for the other five plant stands ranged from 64.6 to 66.3 for AG 2602 and 58.8 to 62.5 for DKB 36-51. Complete results can be found at: http://corn.osu.edu/library/articles/2001sedrate.html

For seed costing $15.00 per 50-pound unit with 2500 seed per pound and grain worth $5.00 per bushel, the most profitable seeding rate based on this data was from 155,000 to 178,000 seeds per acre. Within that range, the increased seed cost was equal to the value of the increase in yield. For seeding rates greater than 178,000, profit decreased because seed cost increased while yield decreased slightly. For seeding rates less than 155,000 seeds per acre, profit increased with increasing seeding rate, up to 155,000 seeds per acre. This data agrees well with similar data collected in numerous other studies conducted during the past 20 years.

A key point to keep in mind is that the seed used in this study was treated with fungicides to aid in stand establishment and improve the general health of the root system. The results above may not be applicable to untreated seed in planting seasons that are good for disease development.

C) White Food Grade Corn: 2001 Performance - Alan Geyer, Peter Thomison, And Rich Minyo CORN Questions

White corn is one of several specialty crops receiving greater attention by Ohio growers as an alternative to yellow dent corn. Premiums are available for white corn grown under contract. We conducted a white corn test in Ohio at the OARDC NW Branch at Hoytville in 2001 as part of a multi-state testing program coordinated by Dr. Larry Darrah, USDA-ARS and the University of Missouri. This is our fourth year of participation in these tests. Results of the 2001 Ohio trial are shown in Table 2. In 2001, 21 white corn hybrids were evaluated along with two yellow dent check hybrids. Test results provide growers with a basis for comparing the relative performance of commercial white corn hybrids and yellow corn hybrids.

Multi-state white corn yield test program results are published yearly. Data presented in the publication include food quality characteristics as well as the typical agronomic traits. For information about the food corn tests and annual field day, check the following web site: http://www.agron.missouri.edu/ars_columbia/fcpt&fd.html

For more information on specialty corns, including white corn, used in value added or identity preserved grain production check out the Ohio State University web site "Specialty Corns for Value-Added Grain Production" at: http://www.ag.ohiostate.edu/~hocorn/.

Please contact Allen Geyer (phone: 614-292-1393;e-mail: geyer.9@osu.edu)if you would like to receive a copy of "White Food Corn - 2000 Performance Tests, Spec. Rep. 540."

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 La Barge        Web Editor: Tom Rosati

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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