C.O.R.N. Newsletter 2006-03

Dates Covered: 
February 7, 2006 - February 21, 2006
Editor: 
Harold Watters

Application of Manure to Frozen Ground, How Should I Make the Application?

Authors: Robert Mullen

Surface application of manure to frozen or snow covered ground is a risky proposition from a water quality perspective and is discouraged by Ohio State University and State regulating agencies (NRCS, ODA, SWCD, etc.). If these applications have to be made, consider the following criteria before heading out to the field (available from NRCS Ohio Standard 633).

• Application rate for solid manure is limited to 10 wet tons/acre for manure with more than 50% moisture and 5 wet tons/acre for manure with less than 50% moisture.
• Liquid manure should not be applied at a rate higher than 5,000 gal/acre.
• Applications should be targeted to fields with at least 90% surface residue cover.
• Manure should not be applied on more than 20 contiguous acres. Contiguous areas should be separated by a break of at least 200 feet.
• Observe a 200 ft minimum setback distance from surface water sources (grassed waterways, surface drainage, streams, surface inlets, water bodies, etc).
• Application rates should not exceed future crop N needs or 250 lbs P2O5/acre. If soil test P level is excessive applications may be limited to crop P removal.
• If applying manure on fields with slopes greater than 6%, manure should be applied in alternating strips 60 to 200 feet wide and should be applied on the contour.

Additional information can be found in the NRCS Ohio Standard 633 document. Available on the Ohio NRCS website: http://www.oh.nrcs.usda.gov/technical/ohio_eFOTG.html.

Just because manure applications are targeted for regulation from a nutrient/water quality perspective do not assume that surface applications of commercial fertilizers do not present the same risk. Application of commercial nitrogen and phosphorus fertilizers can present the same risks to water quality as manure application, so utilize the same best management practices for those applications. The real difference between the two applications is the amount of nutrient applied. Manure applications typically supply more P than commercial fertilizer applications, but commercial fertilizer has a greater percentage of P that is water soluble and therefore may be considered a potential water quality threat.

Follow these rules when making any nutrient application on frozen or snow covered ground. Our goal is to maintain our ability to recycle nutrients from animal operations for crop production without representing a threat to water quality.

Wheat Growth Stage, Disease Progress, Disease Thresholds, and Fungicide Application

Authors: Pierce Paul

In a recently concluded workshop, I used Feeke’s growth stage scales overlaid with disease progress curves to explain to attendees the importance of observing disease thresholds and crop growth stages when making fungicide application decisions.

Disease thresholds are levels of disease above which some action should be taken or some event takes place. Here I am going to consider two thresholds: fungicide application threshold and yield loss threshold, and I will use Stagonospora leaf blotch as an example of a disease being controlled with a foliar fungicide. In managing Stagonospora leaf blotch on a susceptible wheat variety, 1% disease (1-2 lesions) on the leaf below the flag leaf (leaf 2) between Feekes growth stage 8 (flag leaf emergence) and 10.5.4 (flowering) is the threshold used for making foliar fungicide application. The main purpose of making fungicide applications in wheat is to keep the upper two leaves and the head healthy during the grain fill period (Feekes growth stage 8 and 10.5.4). The upper two leaves (leaf 1 - the flag leaf and leaf 2) and the head contribute most of the sugar for grain fill, so, if they are not protected, they may become severely diseased. Under favorable weather conditions, on a susceptible variety, if no fungicide is applied when the fungicide application threshold (1% disease on leaf 2) is reached, the disease may increase to levels that may lead to yield reduction. The level of disease above which yield reduction occurs is called the yield loss threshold.

An increase in the level of disease during the wheat growing season is called disease progress. A graph of the change in disease levels over time is called a disease progress curve. A typical disease progress curve for a disease like Stagonospora blotch or powdery mildew takes on an “S” shape. The time taken for the level of disease to increase (the rate of disease progress) during the growing season depends on the weather and the susceptibility of the variety planted. Hence, the shape of the disease curve may vary from one season or location to another and from one variety to another.

Examining the increase in disease levels relative to the growth stage of the wheat plant may help to explain why fungicide timing and thresholds are so important in wheat disease management. If the disease reaches the fungicide application threshold (1% disease on leaf 2) at or before head emergence (Feeke’s GS 10.1; fairly early in the season) and no fungicide is applied, the level of disease may increase and reach the yield loss threshold before grain fill is complete. This may lead to yield reduction. If, however, the disease arrives late in the growing season and only reaches the fungicide application thresholds (1% disease on leaf 2) at or after flowering (Feekes GS 10.5.4), the level of disease may increase and reach yield-reducing levels after or towards the end of the grain fill period. When disease arrives late in the season, yield reduction is less likely to occur. Hence, wheat fields planted with varieties that are susceptible to Stagonospora blotch should be SCOUTED between growth stages 8 and 10.5.4 to determine if the fungicide application threshold (1% disease on leaf 2) is reached. If the threshold is reached, fungicides should be applied soon after.

Remember, it is always better to plant resistant varieties when they are available. Fungicide application for foliar disease management in wheat is only recommended when a susceptible variety is planted, conditions are favorable for disease development, and the yield potential of the variety is high (above 60 bushels/acre) enough to pay for the cost of fungicide application.

See the complete article with figures on the Agronomic Crops website: https://agcrops.osu.edu/wheat/resources/Wheat%20growth%20stage%20_newsletter_.pdf.

Crop Production Input Outlook and Budget Scenarios for 2006

Authors: Barry Ward

Crop production input prices have increased relentlessly during 2005 as fuel and fertilizer price increases have caused already small profit margins to shrink. Unfortunately, 2006 promises more of the same as fuel and fertilizer prices continue to climb. Although these input prices are causing margins to shrink, it is imperative that farmers plan with the best possible information available.

The outlook numbers laid out in this article can be used as a starting point in creating budgets for 2006. See the entire article at:http://aede.osu.edu/programs/outlook/2005-06outlook/CropInputsOutlook.pdf.

Outlook information presented here was developed with data from the Energy Information Administration, USDA, university research, futures markets and retail sector surveys. The end of this article contains variable cost budget figures for corn and soybeans to assist readers in planning their own budgets and crop mixes for 2006. Projected corn budgets are given for conservation till and no-till corn (These base budgets assume a nitrogen price of $0.335 per pound actual N and $2.20 per gallon off-road diesel). Other scenarios include: no-till corn with higher crop chemical costs (for weed control), conservation tillage corn with higher off-road diesel price ($2.50 per gallon), and last, conservation tillage corn with lower nitrogen price ($0.30 per pound actual N) and lower off-road diesel price ($2.20 per gallon). Soybean budget numbers are provided as well.

Evaluation of Spraying Equipment for Effective Application of Fungicides to Control Asian Soybean Rust

Authors: Erdal Ozkan

We were lucky in 2005. Soybean rust did not come to Ohio. However, there is a good chance it will get here sometime in the future. If it does, we are much better prepared to fight against it now than ever before. We now have a better understanding of what type of nozzles and spray equipment may work the best when treating a field with soybean rust fungicides thanks to a study conducted jointly by Agricultural Engineers at OSU (Dr. E. Ozkan and Dr. H. Guler) and at USDA-ARS (Dr. H. Zhu and Dr. R. Derksen), and Plant pathologists at OSU (Dr. A. Dorrance and D. Mills).

Soybean rust usually shows its first symptoms in the lower parts of the plant and works itself up towards the top of the plant. So, by the time producers notice the problem in the mid to upper canopy, it may be too late to spray any fungicide. Penetrating droplets inside the canopy of a fully grown plant is a much bigger challenge for soybean producers than the challenge they face for control of weeds and insects. Therefore spraying recommendations given for controlling weeds and some insects are not applicable to spraying for rust fungicides. Unfortunately the fungicide labels fail to clearly state the spray equipment and methods that are best suited for application of rust fungicides.

Researchers in Ohio tested 9 different ways to determine which spray equipment setup would provide the best defense against soybean rust. Questions asked frequently by the soybean growers that were addressed in this study were: What is the best a) nozzle type (cone, flat-fan, low-drift, etc.), b) droplet size range (fine, medium, coarse), c) nozzle setup (twin pattern, single nozzle), and d) sprayer setup (conventional, air-assisted)? Following is a summary of this study. A detailed report is available at the following web site: https://agcrops.osu.edu/equiptill/factsheets/report_rust%20study-2005-final3.pdf.

The research was conducted in a soybean field located at ATI (Agricultural Technical Institute) of the Ohio State University / Ohio Agricultural Research and Development Center in Wooster, Ohio. The variables related to nozzles/equipment included in this study were: a conventional boom sprayer with three conventional nozzles (flat fan, cone, twin-flat fan) and a low-drift nozzle (Turbo TeeJet Duo) manufactured by Spraying Systems Co. (Wheaton, IL, USA); an air-assisted sprayer (Jacto Inc.); a pre-mixed air and liquid sprayer (AirJet); and an experimental boom sprayer called a “canopy opener” equipped with conventional XR Flat-fan nozzles. A second component of the study was to determine the effect of spray quality (fine, medium, coarse) on spray deposition and coverage using three different sizes (8002, 8004 and 8005) of XR type of a flat fan nozzle operated at different spray pressures. The application rate for all treatments was adjusted by either travel speed or flow rate to achieve 15 gal/acre, and nozzle height for all treatments was set at 12” above the top of the canopy. A control plot was added to the experiment. Each plot was 150 ft long and 15 ft wide. Each treatment was replicated 4 times. Table 1 gives detailed information on the variables included in this study.

Table 1. Nozzles, sprayers and operating conditions used in soybean rust spray tests

Sprayer Nozzle Pressure(psi) Speed(mph) Flow(gpm) SprayQuality
Air-assisted Hollowcone JA3 154 7 0.35 fine
AirJet Air& liquid pre-mixed * 7 0.35 medium
Boomsprayer XR8004 31 7 0.35 medium
Boomsprayer XR8002 42 4 0.20 fine
Boomsprayer XR8005 20 7 0.35 coarse
Boomsprayer TurboTeeJet Duo 31 7 0.35 medium
Boomsprayer TwinJet60-8004 31 7 0.35 medium
Boomsprayer Hollowcone TX-18 54 7 0.35 fine
Boomw/ canopy opener XR8004 31 7 0.35 medium
* Liquid pressure = 42 psi, air pressure = 27 psi.

Effectiveness of the variables listed above for control of soybean rust was determined using three different methods: a) spray coverage on 2” x 3” water sensitive papers, b) spray deposition on 1” x 3” sheet metal artificial targets using a spray solution mixed with a fluorescent tracer (Brilliant Sulfaflavine), and c) fungicide spray deposition on actual soybean leaves. Samples for these tests were taken at two plant heights: lower (1 ft above the ground) and middle (2 ft above the ground) parts of the canopy.

The experiment was conducted when soybeans were at R4 growth stage with a height of approximately 38 in. It was planned to conduct an evaluation of efficacy level of the fungicide for control of soybean rust.

One has to be careful in making broad conclusions based on findings from this particular study because the spray trials were conducted in a soybean field that had higher than normal canopy height and denser than normal canopy density. Therefore, under different canopy height and density conditions some of the nozzles which did not perform well may outperform other nozzles under different canopy conditions. The following list of specific conclusions emerged from this particular study.

1. When using conventional sprayers, nozzles - equipment set up that provide medium spray quality (rather than fine or coarse) tends to provide a better penetration of droplets inside canopy and better coverage.

2. Spray hitting the target from two different angles (as in the case of TwinJet nozzles) may produce better coverage if the canopy is not dense. But, in dense canopy conditions, flat-fan nozzles with single spray pattern producing medium quality spray tend to provide a better penetration of droplets inside canopy.

3. Air-assisted sprayer did a better job with penetration of droplets into canopy and spray coverage than a conventional sprayer.

4. When mechanically opening the canopy with a well-designed mechanical canopy opener, conventional boom sprayers may provide coverage and penetration nearly as good as those from air-assisted sprayers. However, the canopy opener will not be effective in reducing drift which is one more benefit achieved from air-assisted sprayers.

5. At 15 gal/acre and 7 mph, and under dense canopy conditions, flat fan nozzles provided better coverage and penetration into the canopy than the hollow cone nozzle.

 

An Update on Metolachlor Products

Authors: Mark Loux

We have written several articles for C.O.R.N. over the past two years on the generic metolachlor situation. Our assessment of this situation remains unchanged after another year of research. A recap of the important points:

- There are two forms of isomers of metolachlor produced during its manufacture; s-metolachlor and r-metolachlor. S-metolachlor apparently is more active than r-metolachlor. In other words, a given rate of s-metolachlor could provide more effective weed control or greater longevity of control compared to the same rate of r-metolachlor.

- Syngenta sells Dual II Magnum and Bicep II Magnum, which are primarily s-metolachlor. These products are available from other manufacturers with other names: Cinch and Cinch ATZ (DuPont), Charger Max and Charger Max ATZ (Agriliance), and Brawl II and Brawl II ATZ (Tenkoz). Dual II and Bicep II preceded the Magnum products, and these were roughly an equal mixture of s- and r-metolachlor. As a result of the difference in activity between Dual II and Dual II Magnum, the latter can be applied at lower rates. For example, the recommended rate on a medium soil was 1.9 lbs of active ingredient (ai) for Dual II, but is only 1.3 lbs ai for Dual II Magnum.

- A number of generic metolachlor products are available, including: Stalwart C (Sipcam Agro); Parallel and Parallel PCS (Makhteshim-Agan); and Me-Too-Lachlor and Me-Too-Lachlor II (Drexel). Here’s the catch - these all contain a roughly equal mixture of s- and r-metolachlor (similar to Dual II), but the recommended rates are about the same as Dual II Magnum. The labels for Dual II Magnum, Stalwart C, Parallel, and Me-Too-Lachlor II recommend 1.33 pints/A on a medium-textured soil, which corresponds to 1.3 lbs ai. This rate of Dual II Magnum contains primarily s-metolachlor while the others contain a roughly equal amount of both the s- and r-metolachlor. So, in theory, the generic products could be less effective or provide reduced longevity of control compared to Dual II Magnum.

- Generic metolachlor is also available in premix products with atrazine, as Stalwart Xtra (Sipcam Agro), Trizmet II (Drexel), and Parallel Plus (Makhteshim-Agan).
- Most of these products are formulated with a safener, but not necessarily the same one. Dual II Magnum, Bicep II Magnum, and Parallel/Parallel Plus contain benoxacor as the safener. Stalwart products, Me-Too-Lachlor II, and Trizmet II contain dichlormid, which is also used to safen various acetochlor products. We have not observed an increased risk of corn injury with generic metolachlor products to date.

- The atrazine premix products can vary in application rate and the amount of metolachlor and atrazine they provide for a given soil type. For a medium-textured soil with greater than 3% organic matter, product rates and amounts of active ingredient are as follows:

Bicep II Magnum/Cinch ATZ (2.1 quarts): atrazine – 1.6 lbs ai; metolachlor – 1.3 lbs ai
Stalwart Xtra (2.1 quarts): atrazine – 1.6 lbs ai; metolachlor – 1.3 lbs ai
Trizmet II (2 quarts): atrazine – 1.5 lbs ai; metolachlor – 1.2 lbs ai
Parallel Plus (2.1 quarts): atrazine – 1.5 lbs ai; metolachlor – 1.4 lbs ai

- In OSU research over the past several years, the generic metolachlor products have been similar in effectiveness and longevity of control in comparison to Dual II Magnum and Bicep II Magnum. As a result, we give all metolachlor products the same effectiveness ratings in the Weed Control Guide for Ohio and Indiana (page 39 of the 2006 edition).

The bottom line - while theory would indicate that the generic products could be less effective based on their ratio of s- and r-metolachlor, our database does not support this conclusion. However, not all manufacturers of generic metolachlor guarantee “season-long” grass control, so the generic products may not have the same level of manufacturer support in the event of performance problems, compared to Dual II Magnum and Bicep II Magnum (and Cinch/Cinch ATZ).

It’s the New (Old) Canopy

Authors: Mark Loux

We have come nearly full circle on preemergence chlorimuron-containing herbicides for soybeans with the re-introduction of Canopy, the premix of chlorimuron and metribuzin that was available prior to Canopy XL. We currently have three chlorimuron-containing herbicides that can be used preplant or preemergence in soybeans, and these include:

- Canopy EX, a premix of chlorimuron (Classic) plus tribenuron (Express), which can be applied in the fall or spring prior to soybean planting. This product must be applied at least 45 days before soybean planting, so currently its best fit is for fall treatments.

- Synchrony XP, a premix of chlorimuron (Classic) plus thifensulfuron (Harmony GT), which can be applied in the spring anytime prior to soybean emergence at rates of 1.1 to upwards of 2 oz/A. It can also be applied postemergence at lower rates, and the maximum postemergence rate depends upon whether or not the soybeans have the STS trait.

- Canopy, a premix of chlorimuron (Classic) plus metribuzin (Sencor), which can be applied in the spring anytime prior to soybean emergence.

These products all provide a relatively similar spectrum of residual control, and they all contribute to burndown of emerged weeds in a mixture with glyphosate and/or 2,4,D. Residual control from Canopy EX and Synchrony XP is due solely to the chlorimuron component, because the tribenuron and thifensulfuron provide no residual control. The metribuzin in Canopy does contribute to the residual control, but it is present at a fairly low rate (the equivalent of 2 to 4 oz of Sencor, for Canopy rates of 2.2 to 4.5 oz/A, respectively), and additional Sencor would be required to achieve substantial residual control of ALS-resistant marestail, pigweeds, or common ragweed, or much suppression of annual grasses. Canopy is most similar to Scepter and Gangster with regard to spectrum of control - see the following article for a comparison of preemergence soybean herbicides.

Comparison of Preemergence Soybean Herbicides

Authors: Mark Loux

Use of preemergence herbicides in Roundup Ready soybeans can result in more consistent control of weeds and maximize crop yields (see accompanying article on benefits of preemergence herbicides). For example, control of lambsquarters with glyphosate and Harmony GT has become more variable recently, and many preemergence (PRE) soybean herbicides effectively control this weed. Although annual grasses can be competitive with soybeans and some early-season control is desirable, we suggest that growers use PRE herbicides with activity on the broadleaf weeds that are often problematic in Roundup Ready soybeans. For this reason, PRE herbicides that control primarily grasses (metolachlor, alachlor, Outlook) are less appropriate in Roundup Ready soybeans than broadleaf herbicides such as Gangster, Scepter, Valor, Sencor, and Canopy. A quick rundown on the spectrum of control from currently available PRE soybean herbicides follows – for more information see Table 14 on page 111 of the 2006 Weed Control Guide for Ohio and Indiana. Note – control as stated here indicates that the herbicide controls the weeds for several weeks or more after application, but this does not necessarily mean season-long control of late-emerging weeds such as waterhemp or giant ragweed.

Alachlor (Lasso, Intrro, etc) – controls annual grasses, pigweeds, waterhemp, black nightshade

Boundary – controls annual grasses, pigweeds, waterhemp, black nightshade, smartweed. Can provide some suppression of common ragweed and velvetleaf.

Canopy – controls lambsquarters, velvetleaf, smartweed, pigweeds, common ragweed, and marestail. Controls or suppresses annual grasses, giant ragweed, cocklebur, morningglory. Can provide partial control of ALS-resistant common ragweed and marestail. Does not control black nightshade or ALS-resistant giant ragweed.

Domain - controls annual grasses, pigweeds, waterhemp, black nightshade, smartweed. Can provide partial control of common ragweed and velvetleaf.

FirstRate/Amplify - controls lambsquarters, velvetleaf, smartweed, pigweeds, common ragweed, marestail. Controls or suppresses giant ragweed, cocklebur, morningglory. Does not control black nightshade or ALS-resistant weeds.

Gangster - controls lambsquarters, velvetleaf, smartweed, pigweeds, common ragweed, black nightshade, and marestail. Controls or suppresses annual grasses, giant ragweed, cocklebur, and morningglory. Can provide fair to good control of ALS-resistant common ragweed. Does not control ALS-resistant giant ragweed.

Metolachlor - controls annual grasses, pigweeds, waterhemp and black nightshade.

Outlook/Propel - controls annual grasses, pigweeds, waterhemp, and black nightshade

Pendimethalin (Prowl, Pendimax, etc) - controls annual grasses, pigweeds, waterhemp, lambsquarters. Can suppress velvetleaf.

Pursuit - controls lambsquarters, velvetleaf, smartweed, pigweeds, and black nightshade. Controls or suppresses annual grasses, common and giant ragweed, cocklebur, and morningglory. Does not control ALS-resistant weeds.

Python - controls lambsquarters, velvetleaf, smartweed, pigweeds, black nightshade, and marestail. Controls or suppresses common ragweed and cocklebur. Does not control giant ragweed or ALS-resistant weeds.

Scepter – controls lambsquarters, velvetleaf, smartweed, pigweeds, common ragweed, and black nightshade. Controls or suppresses giant ragweed, cocklebur, morningglory. Can suppress annual grasses. Does not control ALS-resistant weeds.

Sencor – controls lambsquarters, smartweed, pigweeds, waterhemp, and marestail. Partial control of common ragweed and velvetleaf. Can suppress annual grasses. Does not control black nightshade, cocklebur, giant ragweed, or morningglory.

Synchrony XP - controls lambsquarters, velvetleaf, smartweed, pigweeds, common ragweed, and marestail. Controls or suppresses giant ragweed, cocklebur, and morningglory. Does not control black nightshade or ALS-resistant weeds.

Valor/Encompass - controls lambsquarters, smartweed, pigweeds, waterhemp, black nightshade, and marestail. Fair to good control of common ragweed and velvetleaf. Can suppress annual grasses. Does not control cocklebur, giant ragweed, or morningglory.

The Multiple Advantages of Preemergence Herbicides

Authors: Mark Loux

Postemergence herbicides, and especially glyphosate, have become the primary component of herbicide programs in soybeans. This is likely to occur in corn as well, due to the current and projected increase in use of Roundup Ready corn. Total postemergence herbicide programs can be difficult to effectively manage, and when not properly implemented, can result in crop yield loss and reduced control. Total postemergence programs also tend to place the most pressure on the weed population to evolve herbicide resistance, which ultimately reduces herbicide utility.

A planned preemergence (PRE) plus postemergence (POST) approach to weed management in corn and soybean results in more consistently effective weed control and maximizes crop yield, compared to an approach consisting of only POST herbicides. This applies to Roundup Ready as well as conventional corn and soybeans. In the PRE plus POST approach, the PRE herbicide controls or suppresses weeds for a number of weeks after application, which reduces both the size and number of weeds present at the time of POST herbicide application. This tends to allow for the most effective POST herbicide activity and also introduces flexibility in the POST application window. The benefits of a PRE plus POST approach include the following:

1) A reduction in the effect of weeds on crop establishment and growth during the early part of the growing season, and less risk of yield loss when POST herbicide applications are later than optimum. So what is the optimum timing? University research shows that, in the absence of PRE herbicides, the optimum POST application timing in soybeans is when weeds are no more than 6 inches tall, and in corn when weeds are no more than 4 inches tall. There is a common misconception among some users of Roundup Ready soybeans that yield has been maximized as long as weeds are eventually controlled, but our research data says otherwise. Growers who routinely apply glyphosate when weeds are more than 8 inches tall most likely suffer occasional crop yield loss, even when weeds are adequately controlled. Applying this same mismanagement of glyphosate in Roundup Ready corn will result in even more frequent yield loss due to the increased sensitivity of corn to early-season weed interference. Residual control of weeds from PRE herbicides prevents yield loss due to delayed POST applications.

2) More consistent control of weeds that emerge continuously during the early part of the growing season, or late-emerging weeds. Weeds that fit this description include waterhemp, giant ragweed, black nightshade, burcucumber, shattercane, annual grasses and lambsquarters (sometimes). A single early POST application of glyphosate or other herbicide is likely to be subjected to later reinfestation by these weeds. Early-season control of these weeds from PRE herbicides allows a delay in POST application timing, which results in more effective control of late-emerging weeds.

3) More consistent control of weeds that POST herbicides struggle to control well. These are weeds that respond inconsistently to POST herbicides, or for which environment, size, or age can reduce POST herbicide activity. Examples include waterhemp, lambsquarters, giant ragweed, and morningglory. In this case, the PRE herbicides can control the weed for the entire growing season (lambsquarters, for example), or provide enough control or suppression so that surviving weeds are small and more easily controlled by POST herbicides.

4) More effective control of perennial weeds. Glyphosate and other herbicides with activity on perennials can be most effective when perennials are somewhat advanced in size and growth stage. The use of PRE herbicides can allow delayed application of POST herbicides, which is more likely to correspond to the appropriate perennial growth stage.

5) Finally, while the advantages are more long-term, a PRE plus POST approach accomplishes the following with regard to resistance management: a) it allows for the use of herbicides with several different modes of action within the same season, and b) it reduces the number of weeds present at the time of POST application. The net result of these two effects is a reduction in selection pressure, so that glyphosate or other POST herbicides are not the sole means of weed control.

We recognize that PRE herbicides can appear to be an added expense to Roundup Ready systems, and some growers believe them to be unnecessary. However, we believe that growers fully recuperate the cost of PRE herbicides in Roundup Ready systems, or other systems where POST herbicides are a major component of the weed management program. This occurs through the increased effectiveness of control and fewer instances where a second POST application is required, and the reduction in risk and preservation of maximum yield that occurs due to reduction in early-season weed competition. No less important, but less obvious in the short term, is the reduction in selection pressure for herbicide resistance, which is necessary to preserve the utility of glyphosate and other POST herbicides.

Agronomy Guide 14th Edition Available

Authors: Greg LaBarge

Almost everyday we refer our crop producers to the OSU Agronomy Guide. This publication was updated last year and became available again late summer. This has been an excellent crop production information resource for over 20 years. Stop by your OSU Extension office to get an updated copy. It is also available as a downloaded file from our OhioLine web resources: http://ohioline.osu.edu/b472/index.html.

Farming Tips for 2006 Program - March 6th

A program targeted to Darke and Mercer County crops and livestock producers will be held March 6th from 9:45AM to 3:15PM at the North Star American Legion hall – located on the west side of SR127 and south of the North Star-Ft Loramie Road intersection. Producers in west central Ohio and eastern Indiana are invited to attend.

The program includes a morning joint session with speakers Don Breece talking about the Economics of Corn - Soybean Production, Robert Mullen to discuss Nitrogen Management and Dennis Mills with an update on 2006 Soybean Rust Issues. Lunch is provided at noon and afterward there will be two concurrent sessions on crop production and manure handling issues.

The cost for the program is $15 if you register by March 1st, or $20 after that date. Register with the Darke County Extension office by calling 937 548-5215 or by email dark@postoffice.ag.ohio-state.edu or Steve Foster foster.99@osu.edu. Pesticide recertification credits will be available for Core and Category 1.

Crop Profit Program February 21, 7PM

Authors: Harold Watters

The next program in the Crop Profit series from your Agronomic Crops Team will be February 21st at 7PM and held by many of your local OSU County Extension offices. Below is the agenda for the Crop Profit broadcast via IP video, additional details and locations can be found at the website: http://cropprofit.osu.edu.

From concerns about spraying fungicides for Asian soybean rust to resolutions for high nitrogen prices, this should be a good program for all crop producers in Ohio. Please plan to attend your nearest site for this important spring preparation program. Use of the streaming video process brings state extension specialists to your local offices. There will be opportunity for questions as well.

Start Time 7:00

7:03 Research update on nozzle selection for disease control, Erdal Ozkan

7:20 Preserving our Weed Control Tools by Managing Resistance, Mark Loux

7:50 Managing Insect Resistance and Soybean Insect Update, Ron Hammond

8:20 Economic Recommendations for Nitrogen, Robert Mullen

8:50 Questions and wrap up

9:00 End Time

Locations:
Union County Agricultural Center
18000 St.Rt. 4 Suite E
Marysville

OSU Extension-Morrow County
871 W Marion Road
Mt. Gilead

Champaign County Community Center
1512 South US 68
Urbana

OSU Extension
117 E. Mansfield Street
Bucyrus

Clinton County Extension Community Room
111 S. Nelson Ave
Wilmington

Miami County Extension Office
201 W. Main St.
Troy

OSU Extension
810 Fair Road
Sidney

Ashland County Agriculture and Family Center (downstairs meeting room)
804 US Hwy 250 East
Ashland

OSU Extension, Auglaize County
208 S. Blackhoof Street
Wapakoneta

Allen County Extension Office
3900 Campus Drive
Lima

Hancock Co. Ext. Office
7868 CR 140
Findlay

OSU Extension, Darke County Office
603 Wagner Ave.
Greenville

Putnam County Extension Office
219 S. Oak Street
Ottawa

OSU Extension
2000 Countryside Drive
Fremont

Stark County Extension Office
2650 Richville Drive SE
Massillon

Van Wert County Extension Office
1055 South Washington
Van Wert

Lorain Co. Ag. Center
42110 Russia Road
Elyria

Robert Fulton Ag Center
8770 St Rt 108
Wauseon

OSU Extension Williams
1122 W High St
Bryan

Ashtabula County Extension Office
39 Wall Street
Jefferson

Archive Issue Contributors: 

Pierce Paul and Dennis Mills (Plant Pathology), Peter Thomison (Corn Production), Mark Loux and Jeff Stachler (Weed Science), Robert Mullen and Maurice Watson (Soil Fertility), Erdal Ozkan (Ag Engineering), and Ron Hammond (Entomology). Extension Agents: Dusty Sonnenberg (Henry), Steve Foster (Darke), Roger Bender (Shelby), Gary Wilson (Hancock), Howard Siegrist (Licking), Harold Watters (Champaign), Keith Diedrick (Wayne), Bruce Clevenger (Defiance), Glen Arnold (Putnam) and Greg LaBarge (Fulton)

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.