C.O.R.N. Newsletter 2007-39

Dates Covered: 
November 21, 2007 - December 5, 2007
Greg La Barge

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2007 Ohio Corn Performance Trials – Results and Observations

Authors: David Lohnes, Bert Bishop, Allen Geyer, Rich Minyo, Peter Thomison

Results of the 2007 Ohio Corn Performance Test results are now available online at http://www.oardc.ohio-state.edu/corntrials/.

In 2007, 237 corn hybrids representing 35 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 Coshocton, an area with high gray leaf spot incidence. 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.

Grain yields of hybrid entries were outstanding despite what appeared to be a less than ideal growing season. Test sites averaged more than 200 bu/A except for Hoytville, which averaged 180 and 182 for the early and full season trials, respectively.

Environmental conditions varied greatly across trial locations during the 2007 growing season, especially with regard to the amount and distribution of precipitation. Temperatures were above normal and rainfall below normal at planting. These warm, dry conditions promoted crop establishment and probably deeper root development.

Warm, dry weather persisted through maturity at the test locations near S. Charleston and Washington CH in SW Ohio. However, drought stress damage was averted by timely rains. Rainfall deficits at the other test sites were alleviated by above average rainfall in August. Rainfall accumulation was 7 to 8 inches above normal at NW test sites and 1 to 2 above normal at NE sites. These above normal August rains coincided with grain fill and contributed to high grain yields. Hot, dry conditions in September and October resulted in rapid grain dry down and unusually low grain moisture at harvest at several locations. Despite periods of drought stress, stalk quality was excellent and stalk lodging negligible across locations. Disease and insect pests were not a significant factor at test sites.

“Traited” hybrids (i.e hybrids with Bt insect resistance and herbicide resisitance) now dominate the Ohio Corn Performance Test and close to half the entries are triple or quad stacks. In 2002 less than 15% of the hybrid entries were traited. In 2006, 59% were traited, and this year, 84% of the 237 entries are traited. Of these, 114 hybrids are triple or quad stacks, 46 are double stacks, 44 contain a single trait. Overall triple stack hybrids generated the highest yields. In the OCPT regional summary (see the table showing performance of hybrids entered in the three regions, i.e. 9 test sites), eight of the top ten yielding hybrids are triple stacks, one is a double stack, and one contains a single trait. However, stacked traits did not necessarily ensure the highest yields. Of the bottom ten hybrids, nine are triple stacks and one is a double stack.

Tables 1 and 2 provide an overview of 2007 hybrid performance in the early maturity and full season hybrid trials by region. Averages for grain yield and other measures of agronomic performance are indicated for each region. In addition, the range in test sites averages is shown in parentheses.

Table 1. A regional overview of the early maturity 2007 Ohio Corn Performance Test.
Region Entries Grain Yield(Bu/A) Moisture(%) Lodging(%) Emergence(%) Final Stand(plants/A) Test Wt.(lbs/bu)
SW/WC 51 222 17.7 0 94 30300 58.5
    (201-242) (16.1-19.1) (0-1) (87-97) (27400-34200) (55.7-62.2)
NW 66 201 17.7 1 94 30900 59.4
    (176-219) (15.8-20.1) (0-9) (82-98) (26200-35600) (56.4-62.2)
NE/NC 56 230 20.3 1 95 31000 55.4
    (204-254) (18.1-23.0) (0-5) (85-99) (27000-34600) (52.3-58.9)

Table 2. A regional overview of the full season 2007 Ohio Corn Performance Test.
Region Entries Grain Yield(Bu/A) Moisture(%) Lodging(%) Emergence(%) Final Stand(plants/A) Test Wt.(lbs/bu)
SW/WC 72 220 18.7 0 95 30300 58.4
    (186-241) (17.3-22.6) (0-1) (88-98) (23000-33600) (55.0-60.4)
NW 87 203 18.8 1 95 30800 58.7
    (181-225) (17.3-21.6) (0-5) (80-99) (24500-34000) (56.0-61.5)
NE/NC 56 237 23.3 0 96 30300 53.9
    (215-261) (21.0-26.0) (0-2) (84-99) (25500-34600) (51.6-56.9)


Update on Spraying Aphids for Barley Yellow Dwarf Virus

Authors: Andy Michel, Bruce Eisley, Pierce Paul, Ron Hammond

We have been receiving reports of aphid spraying on wheat for control of barley yellow dwarf virus (BYDV). It is questionable whether cost-effective control of BYDV is possible by aphid spraying, especially at this time of year. For a general discussion on this topic, we would refer growers back to the article in the C.O.R.N. newsletter from Oct 15-21, 2007-35.

However, the main question at this time is: if a decision is made to spray an insecticide for control of BYDV, are we past the date when it would be effective? Recommendations from southern states where BYDV is more common and spraying for aphids is a frequent practice suggest that insecticide application should be between the 2-leaf stage and tillering, or about 30 days following emergence. In many fields in Ohio, we are already beyond this time period, especially in fields planted before the Hessian fly free date which are most likely to see an increase in BYDV incidence. And although it takes very few aphids to warrant treatment, the threshold being about 2 aphids per linear ft, even this level of aphids is seldom seen throughout the entire field.

Remember that BYDV management should be done from an IPM perspective: 1) plant varieties less susceptible to BYDV; 2) delay planting until after the Hessian fly safe date to avoid early fall infections; 3) balanced fertility; and 4) controlling volunteer wheat, barley, and oats (for more on BYDV, visit the field crops disease website at http://www.oardc.ohio-state.edu/ohiofieldcropdisease/wheat/byd.htm).

Western Corn Rootworms in Soybeans-Final Summary

Authors: Bruce Eisley, Curtis Young, Ron Hammond

There have been several requests concerning the status of the western corn rootworm variant in Ohio. The article at: http://entomology.osu.edu/ag/fycr/07fycr.htm has information showing the counties that were sampled in 2007, the number of westerns collected in each field and a map showing the counties with the highest western counts.

Central Ohio Agronomy Day

Authors: Howard Siegrist

The Central Ohio Agronomy Day is slated for Tuesday, December 18, 2007. This year's event will be held at the Newark Campus of The Ohio State University and Central Ohio Technical College in Newark, Ohio. The program will offer 6 1/2 hours of continuing education credits for certified crop advisors. Program offerings will include Fertilizer Application Accuracy and Precision Farming with Planter Units and Spray Nozzles presented by Dr. Scott Shearer of the University of Kentucky; Soil Tilth; Enhancing Water Holding Capacity and Capillary Action in Soils by Dr. Jerry Hatfield of the National Soil Tilth Lab in Iowa; as well as a look by a hydrologist at 2007 weather and a peak at what kind of 2008 growing season weather may be in store; Value Added Output Traits in Soybeans; Optimizing your Fertilizer Dollar; Weed Resistance and Disease Management in More Valuable Corn and Soybean Crops.

Registration is $25.00 in advance or $30.00 at the door. One half hour of private and commercial pesticide credit will be available at $3.00 for private and $15.00 for commercial license holders.

Additional information may be secured by phoning the Licking County Extension office at 740-670-5315 or accessing the brochure with registration form at: http://licking.osu.edu/agriculture .

Brown and Yellow Discoloration of Wheat Plants

Authors: Jim Beuerlein, Dennis Mills, Pierce Paul

Reports have been coming in over the past two weeks regarding the appearance of yellowish-brown discolored strips or areas in wheat fields. From the information we have gathered, it seems to be more weather- than disease-related. It is not uncommon for leaves to start becoming discolored at this time of year as temperatures drop. It may be more pronounced this year because of the lush growth of the wheat. In general, sick-looking plants seem to be more uniformly distributed across field in some counties, which is another indication of an abiotic or weather-related stress. Some reports state that the pattern is more common in areas with soybean residue and discoloration is more predominant on the older leaves in early-planted fields. This may be the result of differences in microclimate (pockets of moisture and temperature) in different areas of the field. The increased damage where residue is heavy may be due to the fact that residue retarding the flow of heat from the ground, leading to colder air just above the residue and thus more tissue damage from cold air.

Had it been a problem associated with a soil-borne pathogen (Pythium for example) sick plants would have occurred in patches and not widely distributed across fields. For seed-borne pathogens, we would expect that all fields planted from that lot of seeds to show symptoms. Based on conversations with extension educators and observations made in the laboratory, the root system and crown of the affected plants are healthy, whitish-cream, not discolored as you would expect when a root rot pathogen is involved.

Overall, the wheat crop looks very good across most of the state, with excellent stands and tiller development going into the winter. For those fields with yellowish-brown stripes or areas, growers should pull a few tillers from areas with symptoms, remove the lowers leaves, and examine the base of the stem and root system for discoloration. If the roots and crowns of the affect plants remain healthy and white, the plants should survive the winter.

Upcoming Agronomy Programs

The Ohio Agronomic Crops Team Calendar is a good place to keep track of educational events across the state of Ohio. The calendar page can be found at:https://agcrops.osu.edu/calendar/

Many events for the winter season are already listed while others will be added shortly.

Soybean rust was found to the North, Ontario Canada

Authors: Anne Dorrance

As many of you may have seen, Ontario reported a soybean rust find last Friday (www.sbrusa.net). The sample was actually collected on October 16th, the result of widespread spore deposition that was predicted to have occurred on the first week of October. This again was a rare find, a few leaves left in a plot on some plants- and in the 1 pustule in 60 leaves type of scenario. In Ohio, by mid-October, when pustules would have developed from this same predicted spore deposition, only a few samples came in, mainly because few leaves were left in the whole state-- and those were negative - A lot of our beans were already harvested by this time.

The primary question now is it possible that rust may have developed in Ohio? I think based on the models - in October, the spores would have landed on the dirt or on the stray soybean that still had leaves, but were soon lost due to maturity. The benefit of findings like these from Ontario is that it helps build the models for future years on spore deposition. This will give us better information in the future on where to increase our scouting efforts throughout the state to look for soybean rust even when few plants are left to examine!

The sentinel plot system is scheduled to continue next year during 2008. Funding for this is provided in Ohio primarily from soybean check-off funds from United Soybean Board, North Central Soybean Plant Health Initiative, Ohio Soybean Council as well as USDA.

Ohio Soybean Performance Trials Available

The Ohio Soybean Performance Trials can be found at: http://www.oardc.ohio-state.edu/soy2007/

Archive Issue Contributors: 

State Specialists: Ann Dorrance, Pierce Paul and Dennis Mills (Plant Pathology), Ron Hammond and Andy Michel (Entomology), Jim Beuerlein (Soybean & Small Grain Production)and Peter Thomison (Corn Production). Extension Educators: Harold Watters (Champaign), Howard Siegrist (Licking), Roger Bender (Shelby), Glen Arnold (Putnam), Wes Haun (Logan), Steve Foster (Darke), Jonah Johnson (Clark), Greg LaBarge (Fulton), Bruce Clevenger (Defiance), Mike Gastier (Huron) and Mark Koenig (Sandusky).

About the C.O.R.N. Newsletter

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.