C.O.R.N. Newsletter 2008-40

Dates Covered: 
December 1, 2008 - December 16, 2008
Editor: 
Greg LaBarge

2008 Ohio Corn Performance Test: An Overview

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

In 2008, 242 corn hybrids representing 33 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.

Environmental conditions varied greatly across Ohio during the 2008 growing season, especially with regard to the amount and distribution of precipitation. At most test sites, rainfall from planting through the mid to late vegetative stages of corn development was above normal. It was the wettest June on record in many areas of Ohio. Excessively wet soils in May and June limited early season root development and resulted in shallow root systems. Dry weather conditions persisted from the late vegetative stages through maturity at most sites. Water deficits were especially severe in the Northwestern region especially at the Hoytville test site. At other test sites, water stress was limited by timely rains and adequate soil moisture. On September 14, record high winds associated with hurricane Ike caused severe root and stalk lodging at the test sites in SW/WC region and at the Hoytville test site in NW region. Slower than normal crop development in parts of northern Ohio contributed to higher than normal harvest grain moisture at the Beloit and Bucyrus test sites. Disease and insect pests were not a significant factor at most test sites. However, the western corn rootworm variant was observed for the first time in the hybrid performance trial at S. Charleston (which followed soybean) and caused considerable root lodging among hybrids without the Bt rootworm resistance trait.

Although growing conditions were drier than normal during the grain fill period and stalk and root lodging was greater than normal, excellent yields were recorded at several test sites. Yields, averaged across hybrid entries, exceeded 200 bu/A at S. Charleston, Washington C.H. and Greenville in the SW/WC region, Bucyrus in the NC/NE region, and Coshocton.

Tables 1 and 2 provide an overview of 2008 hybrid performance in the early maturity and full season hybrid trials by region. Complete results are available online at: http://www.oardc.ohio-state.edu/corntrials/ and https://agcrops.osu.edu/~perf/ .
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 2008 Ohio Corn Performance Test.
Region Entries Grain Yield(Bu/A) Moisture(%) Lodging (%) Emergence(%) Final Stand(plants/A) Test Wt.(lbs/bu)
SW/WC 51 235 15.8 25 95 31000 58.6
  range (201-258) (13.8-18.5) (3-82) (90-98) (28500-34100) (56.0-62.9)
NW 69 159 17.3 33 96 32900 58.3
  range (142-183) (14.8-21.3) (3-73) (88-98) (27600-41000) (55.0-62.5)
NE/NC 56 193 19.7 14 96 31400 56.4
  range (175-212) (14.8-24.2) (2-58) (88-99) (25900-40000) (52.0-60.1)


Table 2. A regional overview of the full season 2008 Ohio Corn Performance Test.
Region Entries Grain Yield(Bu/A) Moisture(%) Lodging (%) Emergence(%) Final Stand(plants/A) Test Wt.(lbs/bu)
SW/WC 67 230 17.1 31 95 31400 57.9
  range (201-250) (14.7-20.1) (3-92) (88-98) (26600-36400) (54.1-60.7)
NW 87 156 18.7 41 96 32200 56.9
  range (125-177) (16.2-22.8) (14-65) (89-100) (28400-36800) (53.4-61.3)
NE/NC 56 193 23.2 10 96 31200 53.8
  range (156-212) (18.8-28.3) (1-78) (92-99) (27200-36800) (50.1-58.5)

 

Have Triple and Quad Stacks Become the New “Conventional” Hybrids?

Authors: Allen Geyer, Rich Minyo, Peter Thomison

“Traited” hybrids (i.e hybrids with transgenic traits for Bt insect resistance and herbicide tolerance) now dominate the Ohio Corn Performance Test (OCPT) and more than 71% of the entries are triple or quad stacks (contain three or four transgenic traits). In the 2002 test, less than 15% of the hybrid entries were traited. In 2007, over 80% of the entries were traited. This year over 92% of the entries were traited. Of these traited hybrids, 172 hybrids are triple or quad stacks, 27 are double stacks, 23 contain a single trait. This trend in the Ohio Corn Performance Test reflects the increasing adoption of transgenic hybrids by farmers in Ohio. As recently as 2005, less than 20% of corn acreage in the state was planted to transgenic corn hybrids. However, this year the USDA-Economic Research Service (http://www.ers.usda.gov/data/biotechcrops/ ) estimates that two thirds of the state’s corn acreage was planted to transgenic corn hybrids (37% of total acreage planted to stacked trait hybrids, 17% to herbicide tolerant hybrids, and 12% to some type of Bt hybrid). Many corn agronomists in the past used the term “conventional” to characterize hybrids without transgenic traits (non-GMO). However, if conventional also implies commonly grown corn hybrids, it’s no longer applicable to non-transgenic hybrids.

In the OCPT summary of hybrids evaluated in western Ohio (five test sites), seven of the top ten yielding hybrids are triple or quad stacks and one contains a single trait (Bt corn borer resistance). However, non-transgenic hybrids with high yield potential are available and two of the top ten hybrids are non-transgenic. Stacked traits don’t ensure high yields. Of the bottom ten hybrids, eight are triple stacks.

2008 Ohio Corn Performance Test results are now available online at:
http://www.oardc.ohio-state.edu/corntrials/.

Key Steps in Corn Hybrid Selection

Authors: Peter Thomison

One of the most important management decisions a corn grower makes each year is the selection of corn hybrids for spring planting. During the past 40 to 50 years, there has been continuous improvement in the genetics of corn hybrids which has contributed to steady increases in grain yield potential ranging from 0.7 to 2.6% per year. To stay competitive growers must introduce new hybrids to their acreage on a regular basis.

Growers should choose hybrids best suited to their farm operation. Corn acreage, previous crop, soil type, tillage practices, desired harvest moisture, and pest problems determine needs for such traits as drydown, insect and disease resistance, early plant vigor, plant height, etc. End uses of corn should also be considered - is corn to be used for grain or silage? Is it to be sold directly to the elevator as shelled grain or used on the farm? Are there premiums available at nearby elevators or from end users for identity-preserved (IP) specialty corns such as food grade or non-GMO corn? Capacity to harvest, dry and store grain also needs consideration.

The following are some steps to follow in choosing hybrids that are best suited to various production systems.

STEP 1. Select hybrids with maturity ratings appropriate for your geographic area or circumstances. Corn for grain should reach physiological maturity or "black layer" (maximum kernel dry weight) one to two weeks before the first killing frost in the fall. Use days-to-maturity and growing degree day (GDD) ratings along with harvest grain moisture data from performance trials to determine differences in hybrid maturity. Because fossil fuel prices have risen significantly, corn producers should give careful attention to moisture differences between hybrids when evaluating grain yield. Grain drying represents a major portion of the energy requirement for corn production. It may be preferable to select short to mid season hybrids than full season hybrids for grain, especially if planting is delayed until late May. Results of the 2008 Ohio Corn Performance Test results indicate that the average yields of hybrids entries in the early maturity test were similar to those in the late maturity test but that the average grain moisture of hybrid entries in the early test was 1.5 to 3.5 percentage points lower than those in the full season test.

STEP 2. Choose hybrids that have produced consistently high yields across a number of locations. The 2008 Ohio Corn Performance Test indicates that hybrids of similar maturity varied in yield potential by as much as 60 bu/A depending on test site. Choosing a hybrid simply because it’s a “triple stack” or “quad stack” or possesses appealing cosmetic traits, like big “flex” ears, will not ensure high yields; instead, look for yield consistency across environments. Hybrids will perform differently, based on region, soils and environmental conditions, and growers should not rely solely on one hybrid characteristic or transgenic traits to make their product selection. Just as was the case for conventional (non-traited) hybrids in the past, there is considerable variation in yield potential for hybrids with transgenic traits.

The 2008 Ohio Corn Performance Tests revealed that stacked trait hybrids not only produced the highest grain yields in the trials but also the lowest. Several non-transgenic hybrids suitable for non-GMO grain production produced yields that were not significantly different from the highest yielding triple/quad stack entries.

When planting fields where corn rootworm (RW) and European corn borer (ECB) are likely to be problems (in the case of RW - continuous corn, presence of the rootworm variant, and in the case of ECB - very late plantings), Bt traits offer outstanding protection and may mitigate the impact of other stress conditions.

STEP 3. Plant hybrids with good standability to minimize stalk lodging. This is particularly important in areas where stalk rots are perennial problems, or where field drying is anticipated. In 2008, severe lodging was present in many corn fields in western Ohio due in large part to the high winds associated with hurricane Ike on Sept. 14. However, severe water stress in July and August in parts of Ohio may have also predisposed the crop to stalk rots. Major differences in lodging were evident among hybrid entries in the 2008 Corn Performance Test with % plant lodging ranging from less than 5% to over 90% at certain test sites.

If a grower has his own drying facilities and is prepared to harvest at relatively high moisture levels (>25%), then standability and fast drydown rates may be somewhat less critical as selection criteria. There are some hybrids that have outstanding yield potential but are more prone to lodging problems under certain environmental conditions after they reach harvest maturity.

Traits associated with improved hybrid standability include resistance to stalk rot and leaf blights, genetic stalk strength (a thick stalk rind), short plant height and ear placement, and high "staygreen" potential. Staygreen refers to a hybrid's potential to stay healthy late into the growing season, after reaching maturity, and should not be confused with late maturity. European corn borer (ECB) Bt resistance minimizes ECB stalk injury that can promote stalk rot in corn. However, the Bt trait is not a substitute for good stalk quality and tolerance to stalk rots. Bt rootworm resistance can significantly limit root lodging caused by western and northern corn rootworm and thereby minimize yield losses where rootworm pressure is heavy.

STEP 4. Select hybrids with resistance and/or tolerance to stalk rots, foliar diseases, and ear rots. Consult the Ohio Field Crops Diseases web page online at http://www.oardc.ohio-state.edu/ohiofieldcropdisease/ for the most common disease problems of corn in Ohio. In recent years, several diseases have adversely affected the corn crop - including northern corn leaf blight, Stewart’s bacterial leaf blight, and diplodia ear rot. Corn growers should obtain information from their seed dealer on hybrid reactions to specific diseases that have caused problems or that have occurred locally.

STEP 5. Never purchase a hybrid without consulting performance data. Results of state, company, and county hybrid replicated performance trials should be reviewed before purchasing hybrids. Because weather conditions are unpredictable, the most reliable way to select superior hybrids is to consider performance during the last year and the previous year over as wide a range of locations and climatic conditions as possible. However, multi-year data for hybrids is becoming increasing difficult to obtain.

In the 2008 Ohio Corn Performance Test only 14% of the hybrid entries had been entered in the test for two years and only 6% of the entries for three year. Therefore, if limited to single year data, it’s important to try to evaluate a hybrid’s performance across a range of different growing conditions, for example compare the hybrid’s performance at test sites where rainfall was adequate with those where rainfall was limited and stress conditions may have occurred.

To assess a hybrid’s yield in 2008 averaged across multiple Ohio test sites look at the “Combined regional summary of hybrid performance” tables. These tables and other results for the 2008 Ohio Corn Performance Trial are available online at https://agcrops.osu.edu/~perf/ Since assessment of a hybrid performance is enhanced by using a number of test sites, corn growers farming along our borders with neighboring states should check results of the Purdue, Kentucky, Michigan State, Pennsylvania, and West Virginia Corn Test results. The University Crop Testing Alliance web site (http://www.agry.purdue.edu/pcpp/UCTA/index.html) provides links to corn hybrid test results from state universities across the Corn Belt.

New Herbicide Update

Authors: Mark Loux

Brief descriptions are provided here for a number of herbicides that have were approved for use over the past year or so. Some of these were available for use in 2008, and all are in the new edition of the “Weed Control Guide for Ohio and Indiana”, OSU Extension Bulletin 789. This publication should be available in county offices later this month, and can also be purchased by calling the OSU Extension Publications office at 614-292-1607, or online at http://estore.osu-extension.org/.

Laudis (Bayer) is applied postemergence to corn for control of broadleaf and certain small annual grass weeds. The active ingredient is tembotrione, which is an HPPD inhibitor, the same site of action as Callisto. Spectrum of broadleaf weed control is also similar to Callisto. Laudis is most effective when applied in combination with atrazine (0.5 lbs ai/A), and can be weak on ragweeds in the absence of atrazine. Apply with MSO plus UAN or AMS. Laudis can be applied to seed corn, popcorn, and sweet corn, but users should check with seed supplier for hybrid and inbred tolerance information before use. Laudis can be applied up to the V8 stage of field corn and popcorn, and the V7 stage of sweet corn.

Resolve Q (DuPont) is labeled for postemergence application in corn, and a primary intended use appears to be mixing with glyphosate in glyphosate-resistant corn. Resolve Q is a premix of rimsulfuron (Resolve), thifensulfuron (Harmony), and isoxadifen, a safener that reduces risk of injury and broadens the window of application. Rimsulfuron, can provide several weeks of control of annual grasses, lambsquarters, pigweeds, and smartweed.

Cadet (FMC) is labeled for postemergence application to corn or soybeans. The active ingredient, fluthiacet-methyl, is a non-translocated PPO inhibitor. Cadet has a fairly narrow spectrum of activity. It can control or suppress a few small broadleaf weeds when applied at the high rate (0.9 oz/A), including lambsquarters, pigweeds, black nightshade, and annual morningglory. Cadet can be applied to field corn, popcorn, seed corn, and sweet corn from the 2-collar stage up to 48 inches tall.

Ignite 280SL (Bayer) replaces Liberty in Liberty Link crops. The standard use rate for Ignite is 22 oz/A. In Liberty Link corn and soybeans, Ignite is most effective when applied following a preemergence application of a broad-spectrum residual herbicide. Most effective control in corn occurs when Ignite is applied with atrazine. Ignite can be applied from corn emergence through the V5 stage. Apply in a minimum spray volume of 15 gpa, using nozzles that produce primarily medium-sized droplets (250 to 350 microns).

Authority First (FMC) and Sonic (Dow AgroSciences) are trade names for the same premix product, which contains cloransulam (FirstRate) and sulfentrazone (Spartan/Authority). These products, for preplant or preemergence use in soybeans, provide control or partial control of many broadleaf weeds, but will not control ALS-resistant common or giant ragweed. The addition of these products to glyphosate or glyphosate plus 2,4-D ester can improve control of emerged weeds in preplant burndown treatments, but to a lesser extent than Envive or Valor XLT. However, Authority First and Sonic can be used at any soil pH, whereas only the lowest rates of Valor XLT and Envive can be used where soil pH is higher than 6.8 or 7.0.

Authority Assist (FMC) is a premix of sulfentrazone (Spartan) plus imazethapyr (Pursuit) for preplant/preemergence use in soybeans. Authority Assist controls a number of broadleaf weeds in soybeans, and can suppress annual grasses also. It may be one of the better preemergence products for control/suppression of annual morningglory, but it has limited activity on common ragweed (and no control of ALS-resistant ragweeds) and cocklebur, and will not control giant ragweed.

Envive (DuPont) is a premix of chlorimuron (Classic), thifensulfuron (Harmony GT), and flumioxazin (Valor) for preplant or preemergence use in soybeans. Envive is similar to Valor XLT in burndown activity and residual control it provides, although the addition of thifensulfuron may improve control of emerged wild garlic. Both products have worked well in combination with glyphosate, or glyphosate and 2,4-D ester, in burndown treatments. Envive provides residual control or partial control of most broadleaf weeds, with the exception of ALS-resistant giant ragweed.

Spartan Advance (FMC) is a premix of sulfentrazone (Spartan) and glyphosate for preplant/preemergence use in soybeans. Spartan provides residual control of lambsquarters, nightshade, pigweeds, waterhemp, and smartweed, and partial control of velvetleaf, morningglory, and yellow nutsedge. Spartan Charge is a premix of sulfentrazone and carfentrazone (Aim), for preplant/preemergence use in soybeans also. Sulfentrazone and carfentrazone have some potential to reduce the activity of glyphosate (antagonism), and 2,4-D ester should be added to Spartan Advance, or mixtures of Spartan Charge with glpyhosate, to reduce the risk of antagonism.

Valor XLT (Valent) is a premix of chlorimuron (Classic) and flumioxazin (Valor) for preplant or preemergence use in soybeans. Valor XLT is similar to Envive in burndown activity and residual control it provides. Both products have worked well in combination with glyphosate, or glyphosate and 2,4-D ester, in burndown treatments. Valor XLT provides residual control or partial control of most broadleaf weeds, with the exception of ALS-resistant giant ragweed.

Finesse(DuPont) can be applied to wheat for postemergence control of annual bluegrass and a number of winter annual broadleaf weeds. Finesse is a premix of chlorsulfuron and metsulfuron methyl, two long-residual sulfonylurea herbicides (ALS inhibitors). Wheat should be in at least the 1-leaf stage at the time of application. Finesse should generally be applied in the fall for most effective grass control, and to minimize recrop problems. STS soybeans can be planted 6 months after application, but this extends to 18 months for corn or non-STS soybeans.

Huskie (Bayer) controls many winter and summer annual broadleaf weeds in wheat, oats, and other small grains. Huskie is a premix of bromoxynil and pyrasulfotole, which is an HPPD inhibitor (same site of action as Callisto). Appy in fall or spring after crop reaches the 1-leaf stage, up to flag leaf emergence.

Orion (Syngenta) controls winter and summer annual weeds in wheat, oats, and other small grains. Orion is a premix of MCPA and florasulam, which is an ALS inhibitor. Apply when weeds are in the seedling stage, and the crop is in the 3-leaf to joint stage.

Chateau (Valent) is the same formulation as Valor SX (active ingredient – flumioxazin), but is labeled for crops other than corn and soybeans. Chateau can be applied to established alfalfa for residual control of lambsquarters, pigweeds, nightshade, and a number of winter annual weeds. Apply when the alfalfa has no more than 6 inches of growth. Chateau does not control emerged weeds.

Milestone (Dow AgroSciences) contains aminopyralid, a growth regulator herbicide for use in grass pastures, and CRP and non-crop areas. Milestone controls musk, bull, and Canada thistle, and a number of other broadleaf weeds, but has little activity on brushy and woody species. Aminopyralid is also available as a premix with 2,4-D, Forefront. The addition of 2,4-D broadens the spectrum considerably to control many broadleaf weed species in pastures and non-crop areas.

2008 Soybean Performance Trials

Authors: Jim Beuerlein

A pdf document with the 2008 Ohio Soybean Performance Trial results can be found at: https://agcrops.osu.edu/soybean/documents/2008 ohio soybean performance trials.pdf. The 2008 Soybean Performance Trials are to be posted on-line. Those interested should check the link at: http://corn.osu.edu/~perf/ for availability.

Central Ohio Agronomy Day

Authors: Howard Siegrist

Elwynn Taylor, Iowa State University’s Climatologist and Bryan Young, Agronomist with Southern Illinois University will be two of the featured speakers at the December 16th Central Ohio Agronomy Day in Newark, Ohio. Taylor will present two talks including “One Hundred Years of Climate Change” and “Crop and Weather Outlook for 2009”.

Dr. Young will share two presentations including “Managing Troublesome and Glyphosate Resistant Weeds with Tank Mixes” and “Application Technology and Adjuvants that Increase Spray Efficiency”. The program will run from 8:30 a.m. until 3:15 p.m. at the Newark Campus of Ohio State University Newark and Central Ohio Technical College.

Other speakers will include Dr. Larry Brown, OSU Agricultural Engineer, Dennis Mills, OSU Plant Pathology Specialist and Dr. Ron Hammond, OSU Extension Entomologist.

Pre-registration is $25.00 for the basic program and lunch. Pesticide credits have an additional cost. Reservations for the basic program are $30.00 at the door.

The complete program and registration form can be secured by logging on to: http://licking.osu.edu or contacting the Licking County Extension office at 740-670-5315. Up to seven hours of continuing education credits through the certified crop advisor are available at the event. Three hours of commercial pesticide credits are also potentially available.

A listing of all agronomy programs being offered statewide December through March can be found at:https://agcrops.osu.edu/calendar/. A variety of programs topics, times and dates are available with new dates being added. Be sure to check this site often in the next month so you do not miss a program close to you.

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), Tim Fine (Miami), Wesley Haun (Logan), Steve Foster (Darke), Gary Wilson (Hancock), Howard Siegrist (Licking), Glen Arnold (Putnam) Mark Koenig (Sandusky), Greg LaBarge (Fulton), Les Ober (Geauga) and Mike Gastier (Huron).

About the C.O.R.N. Newsletter

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.