CORN
Crop Observation and Recommendation Network

November 26 - December 10, 2003
C.O.R.N. 2003-39

In This Issue:

A) Water, Rots, SCN and Aphids Took Soybean Yield In 2003
B) 2003 Ohio Corn Performance Test Results Available
C) Ohio Soybean Variety Trials Available Soon
D) Corn In 2003-Where Did All The Yield Come From?
E) Regional Agronomy Meeting Series Held In December
F) Ohio No-Till Conference
G) Annual Corn Soy Conference Set For 12/11

A) Water, Rots, SCN and Aphids Took Soybean Yield In 2003 - Dorrance CORN Questions

Years in extremes: 2002 was very low in rainfall, but 2003 it seemed like fields were constantly wet. Flooding injury and root rots were among the top yield hitters this year in some fields. Fields plots at Hoyteville in NW Ohio where we intended to look at the interaction of subirrigation water levels on the expression of partial resistance to Phytophthora sojae were flooded several times this past summer. The water treatments were conventional subsurface drainage; controlled fluctuation of water and a constant water table. With the excessive amount of rain this year, the yields of conventional subsurface drainage plots averaged 44 bu/A while the plots with constant water table was 37 bu/A. Plants that had flooding injury appeared stunted, they were yellow for a short period of time and they just sat without growing. Once the plants produce additional roots - they took off, but the time was lost and this affected yield. Flooding injury occurred in pockets, or strips between the drain tiles. One of the things that left an impression on me was that plant samples shipped to me to isolate root rot pathogens - began to re-root during their trip in the mail. I would open the box and see weak, but nice white roots indicating a plant that was going to make it and not die from pathogens. For this next season - focus on improving drainage. Be aware that cultivating a wet field will only exacerbate the problem - heavy soils are a bit unforgiving and some of our problems were actually from planting in wet fields at the start.

Plant samples came in with purple, black, smelly, roots this year. Phytophthora, Pythium, Rhizoctonia and Sudden Death were all present this year. It really showed this year if your resistance package was working. In another test at Hotyville, we compared the effects of Rps genes with and with out partial resistance. Just about any Rps gene works in this one field, these varieties averaged 51 bu/A while those varieties with low levels of partial resistance (score of 6 in performance trials) yields were 34 bu/A, a 33% reduction in yield. The yield for a variety with Rps1a and no field resistance was 15 bu/A - a 70% reduction in yield. The lesson for this next year, is to choose a good variety with a combination of Rps genes and high levels of partial resistance. This resistance package will give the best protection over the greatest number of fields. Approximately 30% of the varieties entered into the performance trials this year that have high levels of partial resistance (scores of less than 4.2).

SCN -while walking fields this summer -I was absolutely amazed at the areas with SCN. Possibly you may have seen the results with the yield monitor. I was collecting samples and walking across a field the beans would be tall, trying to trip me - then I would hit a spot where they were knee high. I would dig the plants up and find the white pearls on the roots - SCN was present in high numbers. In your yield monitor - the yields would dip through this area. - I would move through this spot, sometimes the size of a car or the size of a football field or greater. SCN is taking anywhere from 5 to 50% of the yield depending on the SCN population numbers. For this next year - have a soil test of these fields. Know what your SCN populations are so you can begin to manage this beast. What we don't want to see are fields where the numbers get so high over such a large proportion of the field that it is no longer profitable to grow soybeans. Take the time to soil sample. Remember when sampling to aim for where the roots were to get a more accurate count.

Aphids were present, and impacted yields in many areas. The next question is how did these diseases, flooding injury and aphids interact. We know SDS that when SCN is present, the symptoms of SDS can be brought on 6 weeks earlier than if SDS was the only disease present. In addition, the yield loss is greater with the combination of SCN and SDS than from SCN alone. I expect that as we gain more experience with soybean aphids we will continue to learn what impact this is having and what the combination of these insects and diseases are having on Ohio's soybean yields.

B) 2003 Ohio Corn Performance Test Results Available - Thomison , Minyo, and Geyer CORN Questions

Results of the 2003 Ohio Corn Performance Test are available on-line at http://www.oardc.ohio-state.edu/corn2003/. Since assessment of hybrid performance is enhanced by using a number of test sites, farmers along Ohio's border with neighboring states may also want to consider checking results of the Purdue, Kentucky, Michigan State, Pennsylvania, and West Virginia Corn Test results. An on-line version of the 2003 Indiana corn test results is available at http://www.agry.purdue.edu/ext/variety.htm. Growers interested in results of corn hybrid silage trails should consult the Michigan State University and Pennsylvania corn hybrid tests that include silage yields. The North Central Crop Evaluation Committee web site http://www.ksu.edu/kscpt/nccec/ provides links to corn hybrid test results from state universities across the Corn Belt.

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

The Ohio Soybean Trials will be available on-line shortly. Book mark and check http://www.ag.ohio-state.edu/~perf/ periodically over the next week and these results will be available.

D) Corn In 2003-Where Did All The Yield Come From? - P. Thomison CORN Questions

As the harvest of the 2003 corn crop nears completion, one of the biggest (and most pleasant) surprise of the growing season appears to be the record high corn yields produced in many parts of Ohio. In the November crop report, USDA estimated that Ohio corn yields will average 154 bu/A in 2003, nearly 5 % greater than the previous record high of 147 Bu/A in 2000, and 75% greater than last year's dismal average yield of 88 Bu/A.

How did we obtain such high corn yields? At first glance, one might not think the weather conditions were entirely favorable for corn growth. While weather conditions especially rainfall varied considerably across Ohio, the 2003 growing season was characterized by cooler and much wetter than normal weather. During the 27-week period from early April to early Oct in much of the state, temperatures averaged below normal in 17 weeks and rainfall was above normal in 15 weeks.

The following are some of the factors that influenced corn yields in 2003. Not surprisingly, many of these involve weather in some way.

1. Timely planting: 83 percent of the corn crop was planted by May 4. This was 34 days ahead of 2002 and 20 days ahead of the five-year average. Past OSU research indicates that planting in late April through early May usually results in the highest yields.

2. Good seedbed conditions: In the 2 to 3 weeks preceding planting, rainfall was near normal to below average; temps were generally warmer than normal. Dry soil conditions allowed timely field operations and minimized soil compaction.

3. Favorable conditions for emergence and early growth. Soil conditions for most plantings in April were excellent and promoted uniform emergence and good stands.

Moderate temperatures and rainfall were favorable for growth until early May. According to USDA estimates by May 18, 72% of corn plants had emerged. This was 24 days ahead of 2002 and 10 days ahead of the five-year average.

Some growers experienced problems with emergence in corn planted at the end of April and early May because excessive rainfall in mid May resulted in saturated soil conditions which, along with cooler temperatures, inhibited seedling development and early growth. Such conditions were conducive for seedling diseases caused by primarily by Pythium and Fusarium fungi which led to stand loss and replanting in some cases. In localized areas of the state, ponding and flooding also killed or stunted corn, especially in poorly drained fields. However, cool soil temperatures prolonged corn survival in many fields subjected to flooding.

4. Crop growth was not limited by a lack of soil moisture. Rainfall was persistent throughout the growing season. Instead of turning hot and dry in June, as the weather often has in recent years following a cool, wet May, soil moisture was adequate throughout the season because of frequent rains. Above normal rainfall was especially important during grain filling (the period from silking to physiological maturity or black layer formation).

5. Cooler than average temperatures minimized stress. During most of growing season, temperatures were below normal. Cool night temperatures reduced respiration losses during grain filling. Night temperatures in the 70s and 80s result in wasteful respiration and a lower amount of dry matter accumulation in the plant. In parts of the state where rainfall was spotty in late June/early July, moderate temperatures minimized moisture stress. Cooler than normal temperatures also reduced soil nitrogen losses that can occur under warm, saturated soil conditions through denitrification.

6. No major harvest delays. Most corn hybrids planted in April and May achieved maturity with fewer GDDs than are specified by the seed company maturity ratings. This helped minimize yields losses to an earlier than normal frost Oct. 2 and 3. Although crop maturation was slower than normal, grain moisture at harvest was lower than many growers expected. Stalk lodging was negligible for the most part and did not cause major harvest delays.

7. No major disease or insect problems. Although rains were persistent through the growing season, conditions favorable for disease - extended periods of high humidity and warm temperatures - were generally absent. Disease problems including northern corn leaf blight started showing up in some fields in late August and early September. Significant disease injury was limited to especially susceptible hybrids. European corn borer injury was also observed but serious damage was not widespread.

8. Good management practices. The contribution of growers to the high yields of 2003 cannot be overlooked. The use of more effective and improved management practices involving nitrogen management, hybrid selection, crop establishment, and pest control also helped increase yields. Although the benefits of some of these cultural practices appeared to be limited last year, such practices set the stage for high yield potential under the favorable growing conditions of 2003.

E) Regional Agronomy Meeting Series Held in December - LaBarge CORN Questions

Your only chances to attend the annual series of Regional Agronomy meetings will be held at 4 sites during the week of December 15-18, 2003. Complete agenda information and CCA credits listings can be found at http://corn.osu.edu/Education/index.html

Your favorite CORN newsletter contributors will be on-hand for this fast paced industry update on current issues in corn, soybean and wheat production. Pre-registration costs are $25 and end 7 days prior to the meeting you want to attend. Registration on-site cost $30 and are dependent upon space availability, so be sure to register early. A meeting proceedings, OSU publication and lunch are included in the registration. The following sites will host the Regional Agronomy Meetings.

December 15, 2003
Knox County - Mt Vernon
Dan Emmett Conference Center
150 Howard St. Mt Vernon
Host Agent: John Barker
OSU Extension, Knox County
PO Box 1268
Mt Vernon, OH 43050-1268
740-397-0401
barker.41@osu.edu

December 16, 2003
Clinton County-Wilmington
Roberts Convention Center
123 Gano Road, Wilmington
Host Agent: Tony Nye
OSU Extension, Clinton County
111 S. Nelson, Suite 2
Wilmington, OH 45177-2099
937-382-0901
nye.1@osu.edu

December 17, 2003
Ashtabula County - Willamsfield
Williamsfield Community Center
St Rt 322 & St Rt 7
Host Agent: David Marrison
OSU Extension, Ashtabula County
39 Wall St
Jefferson, OH 44047-1137
440-576-9008
marrison.2@osu.edu

December 18, 2003
Allen County - Lima
Veterans' Memorial Civic and Convention Center, 7 Town Square
Host Agent: Curtis Young
OSU Extension, Allen County
3900 Campus Dr, Suite B
Lima, OH 45804-3596
419-222-9946
young.2@osu.edu

F) Ohio No-Till Conference - Sundermeier CORN Questions

December 9, 2003
9:30 am - 3:00 pm
Der Dutchman's , Plain City, OH on SR 42

Prepaid registrations are $20 due by December 4, with checks payable to Ohio No Till Council, c/o Jane Aycock, USDA-NRCS, 200 N. High St., Room 522, Columbus, OH 43215. At the door registrations are $25. Includes refreshments and buffet lunch.

CCA credits available

G) Annual Corn Soy Conference Set For 12/11 CORN Questions

The Corn Soy Conference is set for December 11, at the Der Dutchman in Plain City. All Ohio soybean and corn producers are invited to attend.

The Corn Soy Conference is a one-day program running from 8:30 a.m. to 3:00 p.m. Invited speakers Robert Linkhorn, CEO at Limaco; Phil Laney, American Soybean Association Country Director for China; a panel of industry personnel involved in value added opportunities for biobased products; Biodiesel and Ethanol plant representatives involved in the construction and implementation of these facilities; and the closing speaker is Eric Vaughn who will review the "state" of Washington D.C. and the effects on American Agriculture.

For reservations or more information, contact Carla at (614) 476-3100 by Friday, December 5, 2003. Registration $20/person, which includes lunch and breaks.

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.

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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.

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