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Agronomic Crops Network

Ohio State University Extension


C.O.R.N. Newsletter 2008-39

Dates Covered: 
November 18, 2008 - December 2, 2008
Greg LaBarge

Trying To Make Sense of Soybean Seed and Herbicide Costs

Authors: Mark Loux

Soybean growers can choose between four types of seed/herbicide systems in 2009, and there can be substantial differences in the cost of and revenue from these systems. The systems include nonGMO, Liberty Link (LL), Roundup Ready (RR), and Roundup Ready 2 Yield (RR2Y). What we have tried to do in this article is to come up with a logical comparison between systems, based on a sound herbicide program, with the goal of helping growers select a system. As much as anything, our intent here is to show that seed and herbicide choices can greatly affect the bottom line, and the time spent making this type of comparison is time well spent.

Background Assumptions for Comparison

Seed Cost Used
This comparison uses a count of 140,000 seed per unit, since seed companies are moving toward seed counts as the basis for units, and a seeding rate of 200,000 seeds/A. Both of these figures can have a substantial effect on seed costs per acre.

Table 1. Seed cost based on herbicide resistance traits.
Herbicide Resistance Family of Seed Cost/Unit Cost/Acre
non-GMO $24 $34
Liberty Link $34 $49
Roundup Ready $37 $53
Roundup Ready 2Y $55 $78

We understand that there is a range in price for any type of seed, and there is seed available for more or less than the figures used here.

Preplant Herbicide Program Cost
Preplant herbicides should not vary much among these systems – they all typically include glyphosate or paraquat, 2,4-D ester, and a residual herbicide. This comparison uses the following for all four systems: glyphosate (0.75 lb ae/A) - $10/A; 2,4-D ester (0.5 lb/A) - $2.50/A; your choice of residual herbicide - $12; application cost - $6/A. Residual herbicide rates are often higher in nonGMO systems than in RR or LL, so we bump the cost of residual to $15/A in nonGMO. Total preplant herbicide costs: nonGMO = $34.25; LL, RR, or RR2Y = $31.25.

Postemergence Herbicide Program Cost
The cost of postemergence herbicides can vary greatly among systems. The comparison here assumes that glyphosate is still effective enough that it does not need to be supplemented with other herbicides, and this is certainly not true for all fields. We have bumped the glyphosate rate to 1.1 lbs ae/A, since this has become a standard rate for many growers. Postemergence program cost and programs are shown in Table 2 and 3, costs include product and a $6/A application cost.

Table 2. Cost of herbicides for a single postemergence application based on herbicide resistance traits.
Herbicide Resistance Trait POST Program – 1st application Cost/Acre
non-GMO Flexstar (1.3 pts/A) + grass herbicide (Select; Fusion; etc) + MSO + AMS $36.75
Liberty Link Ignite (22 oz) + AMS $16.75
Roundup Ready glyphosate (1.1 lb ae/A) + AMS $21.75
Roundup Ready 2Y glyphosate (1.1 lb ae/A) + AMS $21.75

Table 3. Cost of herbicides for two postemergence applications based on herbicide resistance traits.
Herbicide Resistance Trait POST Program – 2nd Application Cost/Acre Total Cost/Acre of POST 1 & 2
non-GMO Cobra (10 oz) + COC $21 $57.75
Liberty Link Ignite (22 oz) + AMS $16.75 $33.50
Roundup Ready glyphosate (0.75 lb ae/A) + AMS $16.75 $38.50
Roundup Ready 2Y glyphosate (0.75 lb ae/A) + AMS $16.75 $38.50

It’s probable that a second postemergence application is more likely to be needed in nonGMO soybeans than in LL or RR. Exceptions to this would occur in dense weed populations, or where the residual is used in fall instead of spring.

Putting It All Together

Table 4 is a partial budget based on only seed and herbicide cost. Gross revenue is based on a 50 bu/A yield and a soybean price of $9/bu for LL, RR, or RR2Y, or $10.40/bu for nonGMO (realizing that this underestimates the premium that some growers are getting for nonGMO). This results in gross revenue of $450 for the LL, RR, and RR2Y systems, and $520 for the nonGMO system. We are not including costs other than seed and herbicides here, since the other costs should not vary among systems. We can make the same comparison omitting application costs, but these are also consistent among systems, and omitting them does not change the relative standings. What we’re trying to come up with here are differences in revenue between systems based on seed and herbicide costs. The breakdown for each system follows (all figures on a per acre basis, and “cost” reflects seed, herbicide, and application).

Table 4. Net revenue from different herbicide programs.
Herbicide Resistance Trait Gross Revenue/A Net Revenue/A One POST application Net Revenue/A Two POST appilications
non-GMO $520 $415 $394
Liberty Link $450 $353 $336
Roundup Ready $450 $344 $327
Roundup Ready 2Y $450 $319 $302

We can complete the comparison by showing how much less the net revenue is for each system relative to the one with the highest revenue. The nonGMO system has the highest revenue here, and for a one-postemergence system the others are the following amounts lower: LL - $62; RR - $71; RR2Y - $96. For a two-postemergence system, the others are the following amounts lower than nonGMO: LL - $58; RR - $67; RR2Y - $92. It might be most appropriate to compare the one-postemergence system for the LL and RR soybeans to the two-postemergence system for nonGMO. The nonGMO revenue is still $41 to $75 higher for this comparison. It’s also possible to credit the RR2Y soybeans with a 6% higher yield (we have no idea whether this is actually the case – we’re just weed scientists). Doing so results in the RR2Y coming in about even with RR soybeans, because the higher seed price offsets the potential increase in yield.

There are many different ways to configure this comparison, which is why it’s best to run your own. There are also intangibles that need to be considered along with the numbers. Weed management is more difficult in nonGMO than in LL or RR soybeans, so there is a greater potential for increased herbicide costs or yield loss due to poor control. Fields with a history of poor weed control should not be planted to nonGMO soybeans. There is greater convenience and less risk of weed control failure in LL and RR soybeans, but our comparison shows the price of this convenience. In addition, fields where weeds have developed resistance to glyphosate can require more herbicide than indicated here. A good argument can be made for using LL soybeans in fields with a history of resistance to glyphosate and ALS inhibitors, because these can be tough populations to control with even the most comprehensive nonGMO or RR herbicide program.


Ohio 2008 Soybean Aphid Summary, 2009 Prediction Not Clear

Authors: Bruce Eisley, Andy Michel, Ron Hammond

As had been predicted, soybean aphid populations were low to non-existent this past summer in Ohio. A lack of aphids in suction traps and colonies on buckthorn in the fall of 2007 again allowed us to foresee what would happen in 2008.

What about 2009? This next summer will be hard to predict. On one hand, while soybean aphid collections in suction traps during the past summer were extremely low in neighboring states, aphid numbers went up in the fall months as expected. These higher fall collections are the initial sign of something brewing for the following summer. However, there was almost a total lack of aphid colonies on buckthorn in our state during September and October, and we have yet to find our first egg. Although most of our aphids causing economic problems will come from areas to our north, we have always found aphid colonies and eggs in the fall after a low-aphid summer, and preceding a high year. Thus, it is difficult to offer a prediction of what will happen in 2009.

At this time, we recommend reading this C.O.R.N. newsletter closely next spring and summer to see what is, or is not, happening. By following aphid development to our north, we hope to be able to give growers at least a few weeks notice if something might occur. As we figure things out, we will let you know as soon as possible.

Headline-Domark Studies In Ohio – 2008 Results and 5 Year Summary

Anne Dorrance, Christian Cruz, Dennis Mills, Dave Mangione, Gene McCluer, Rob Leeds, Todd Mangen.

Foliar fungicides were evaluated for the fifth year in on-farm studies this year in cooperation with producers in four locations: Delaware, Hardin, Mercer and Ross counties. Assistance for these trials was provided by the Top Farmers of Ohio, Ohio Seed Improvement Association, Ohio Soybean Council and North Central Soybean Association. In each location treatments were arranged in a randomized block design with four to five reps in each location. Foliar diseases were evaluated at the R2-R3, R4-5, and R7 growth stages (just before application, 2 weeks following application and at full seed. Fungicides were applied at the R3 growth stage. Yields were collected and adjusted to 13% moisture. At each location producers and/or commercial applicators applied treatments.

During 2008, only one foliar disease was present at each location and that was Septoria brown spot. This disease is caused by a fungus which infects leaves in the lower canopy. It survives on soybean residue and can be found in all soybean fields. The symptoms begin as small brown spots on the lower leaves, these will grow and the leaves will turn yellow and drop from the plant. In severe cases, on susceptible varieties, defoliation can occur as early as R5 up into the mid-canopy of the plant. Septoria levels were quite variable at all of the locations, but as in other years, both Domark and Headline reduced the severity.

In Mercer county, the field was heavily impacted by the early spring rains and Phytophthora stem rot. Phytophthora root and stem rot is caused by a water mold that infects roots when soils become saturated at anytime during the growing season. Once roots are infected, on varieties with low levels of partial resistance, stem rot will develop causing early plant death. Due to the high variability in stand in this location, we have not included the summary of this location in this summary.

Table 1. Percent leaf area affected by brown spot. Measurements were taken on 5 leaves in the lower canopy at four locations in each plot of the study.
Treatment Delaware Hardin Ross
Nontreated 7.0a 13.6a 7.6a
Domark 2.4b 6.2c 6.2a
Headline 3.5b 10b 3.8b
Means 4.3 9.9 5.9

Yields were also highly variably across three of the locations and even more interesting is that each treatment was significantly better than the others at least at one location.

o Nontreated strip was significantly better than both fungicides in Delaware.
o Domark was significantly better than nontreated but not Headline in Hardin.
o Headline was significantly better than both nontreated and Domark in Ross.

Table 2. Yields (bu/A) in on-farm evaluations of foliar fungicides in Ohio.
Treatment Delaware Hardin Ross
Nontreated 30.0a 51.1b 52.7b
Domark 28.3b 55.8a 54.1b
Headline 26.8b 53.4b 63.6a
Means 28.3 53.4 57.0

This is the third time, in the five years of this study across 31 locations that a foliar fungicide application actually recovered application costs and enhanced yield. At the Ross county location, at the R2/R3 growth stage, full flower and early pod formation, brown spot had reached 15% across the field. The lower canopy was already beginning to loose leaves. Following the fungicide application, there was one more substantial rain which was followed by a 2 to 3 week dry spell. The combination of the higher levels of brown spot, reaching into the mid-canopy combined with the additional stress of the drought may have played a role in the positive response with Headline at this location. This is highly unusual that brown spot reached the mid-canopy and may indicate that this variety is susceptible to this disease. Previous trials where Headline applications increased yields that exceeded application costs were in 2006 when Frogeye leaf spot was present at the R2 growth stage.

Yields were highly variable across all of the producers fields. Foliar disease levels should be monitored at the R2 (full flower) to determine if fungicide applications may be profitable. Frogeye leaf spot is established on a susceptible variety at levels of approximately one frogeye lesion every 25’ across four rows. For brown spot, look for substantial early defoliation but also if lesions can be found more than half way up the plant, and prices for soybeans per bushel is close to application costs, then fungicide applications may be warranted. Varieties are going to respond differently to these types of treatments, more studies are needed on how individual varieties are affected by these two foliar pathogens but to the response of the fungicides as well.


Insect/Pathology Workshop Scheduled for February 4, 2009

The Entomology and Plant Pathology Departments are offering an Insect/Pathology Workshop for CCA’s, consultants, agronomists, etc, February 4, 2009 at OARDC Wooster. Sessions will be conducted by Dr. Ron Hammond, Dr. Anne Dorrance, Dr. Pierce Paul and Dr. Andy Michel.

Topics will include:
IPM-Back to the basics
Measuring disease levels
Soybean aphid and population genetics-applications for management
Seed treatments
Insect resistance management
Frogeye, rust and plant health
Wheat scab and fungicides

4.5 CCA CEU’s are available along with applicator recertification credits of 4 hours in 2A and 0.5 hour in Core. The workshop will be held in 203 Selby Hall on the Wooster campus from 9 – 3. To register contact Dennis Mills, , 330-202-3566. There will be a $50 registration fee at the door and space is limited.

Field Crop Commercial Pesticide Applicator Recertification Conferences

Commercial pesticide applicators with field crops on their license will have an opportunity this December to earn recertification credits to renew their pesticide license. The first Field Crops Conference for Ohio Commercial Pesticide Applicators will be on December 17, 2008 in Lima at the Ohio State University Lima campus. The conference is designed to help applicators receive the state required five hours of training in one day. The conference is sponsored by Ohio State University Extension and the Ohio Department of Agriculture.

The conference will cover a variety of topics including field crop weeds, insects and disease. Other topics include seed treatment, industrial vegetation and core.

Registration information is available at the Pesticide Education Program website at or by calling (614) 292-4070.

The second Field Crops Conference for Ohio Commercial Pesticide Applicators will be at the Columbus Convention Center on February 25, 2009.

Agronomic Crops Workshops and Regional Programs

The calendar of regional agronomic educational programs and conferences can be found at Information on all meetings, including agendas and contacts can be found through this link.

This is a first posting with other events being added for 2009.

December 9
Ohio No-Till Conference
Start Time: 9:00am
County of Meeting Location: Union
Der Dutchman
Plain City
Cost: $25 before 12/2, $30 at the door

December 16
Preserving Corn and Soybean Profits with Agronomy Updates
Start Time: 9:00am
County of Meeting Location: Crawford
K of C Hall
110 S Kibler St
New Washington, OH 44854
Cost: $25

December 16
Central Ohio Agronomy Day
Start Time: 8:30 am
County of Meeting Location: Licking
OSU/COTC Newark Campus, Founders Hall
Newark, OH
Cost: varies by credits


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), Bruce Clevenger (Defiance), Wesley Haun (Logan), Steve Foster (Darke), Gary Wilson (Hancock), Marissa Mullett (Coshocton), Glen Arnold (Putnam) Mark Koenig (Sandusky), Greg LaBarge (Fulton) and Ed Lentz (Seneca).

Crop Observation and Recommendation Network

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.