Integrated Pest and Crop Management Newsletter Vol. 17, No. 3 March 16, 2007 More Roundup Ready© Corn? What Should We Prepare For? By Kevin Bradley If you have heard anything over the past several months, you’ve heard that we are going to be planting more corn this year in Missouri and throughout the U. S. And not only more corn, but according to all the predictions I’ve heard, more Roundup Ready© corn. According to USDA statistics, last year we planted 21 percent of our corn acreage in Missouri with herbicide tolerant varieties. This does not mean that all of this 21 percent was Roundup Ready©, but certainly the vast majority of acres were. This figure, 21 percent, is for some reason much lower in our state compared to any state that borders us. In some of our neighboring states, there was twice this level of adoption of herbicide tolerant (and presumable Roundup Ready©) corn last year. To be honest, I’m not sure why our numbers have stayed this low. Regardless, just about every seed company that I have listened to over the winter meeting season has predicted that our Roundup Ready© corn acres are going to increase as they have each year over the past several years. Five years from now, I’ve heard some predictions that we will be planting 75 percent or more of the corn acreage in the United States with Roundup Ready© or other glyphosate-tolerant varieties. I don’t know if these predictions will come true or not, but it is clear that each year we have been planting more Roundup Ready© corn in Missouri. So, the following are some general weed management considerations for you to think about as you head into the planting season and consider what type of corn variety and herbicide program you are going to choose. First, if you are moving towards more Roundup Ready© corn, you have to consider what weed management program will fit you the best in this system, just as you would if you were planting a conventional corn variety. I don’t think it will be wise for growers to conduct weed management practices in Roundup Ready© corn as it has been and is currently being done in Roundup Ready© soybeans. Why? Because the research clearly indicates that corn is much more susceptible to early season yield loss than soybeans, and that we can’t stand to wait to remove the weeds until they are 6-inches or more tall. By this time, significant corn yield losses will already have occurred. There’s no question that glyphosate will be a good postemergence herbicide option for use in Roundup Ready© corn, but our research has shown that the "safest" programs are two-pass programs that consist of a preemergence followed by a postemergence herbicide. Before I came to Missouri, Dr. Bill Johnson had looked over many years of research and over 2,000 treatment observations that had been conducted here in this state and found that in 12 out of 13 years, a two-pass program consisting of a preemergence herbicide followed by a postemergence herbicide provided the best overall weed control in July. In only one out of 13 years did a one-pass total postemergence program provide better weed control than the other programs, and a one-pass preemergence program never provided better weed control than the other programs evaluated. This kind of historical analysis paints a very clear picture for me. In fact, I found this data so interesting that I decided to conduct a similar exercise and look at what the response to corn yield would be under these different kinds of programs. Understand that these are not comparisons of specific herbicide treatments and trade names, but rather are comparisons of different program approaches. I was able to make a fair comparison of three different program approaches in 29 trials that have been conducted in Missouri over the past five years. What I found was that in 19 out of the 29 trials where these comparisons could be made (65 percent of the time), highest corn yields were obtained with a two-pass program consisting of a preemergence herbicide followed by a postemergence herbicide. In 8 out of the 29 trials (28 percent of the time), a one-pass postemergence program that also contained a residual herbicide provided highest corn yields, whereas in 2 out of the 29 trials (7 percent of the time) a one-pass preemergence herbicide program provided highest corn yields. Collectively, what all of this indicates to me is that depending on the year, environment, soil type, and weed spectrum that you have, either of these program approaches might work for you, but year-in and year-out, the two-pass preemergence followed by postemergence herbicide program should provide the highest levels of weed control and highest corn yields. In other words, the two-pass program is "safer" than the other programs. In some ways, it becomes an issue of how much risk you are willing to take and these results indicate that the least risk will occur with a two-pass program. Another important thing to consider at this time of the year is what your crop rotation and herbicide programs are going to be not only this year but over the next several years. From the perspective of preventing and/or managing resistant weeds, we have got to do more of this than has been done in the past. More than likely, if you are planting soybeans, you are planting Roundup Ready© soybeans and treating with glyphosate at least once per season. And why wouldn’t you? It is a very effective, economical program. If we start planting more Roundup Ready© corn, then many fields will be in a Roundup Ready© corn- Roundup Ready© soybean rotation where glyphosate will be utilized as the primary, if not only, postemergence herbicide. This will greatly increase the likelihood of selecting for a glyphosateresistant weed, even in a corn-soybean rotation, because we are still spraying the same herbicide (glyphosate) in the same place over time. The best way to decrease the likelihood of resistant weed development under these scenarios is to break up the cycle with a herbicide that acts at an alternate site of action. One way to accomplish this is to stay with conventional herbicides in a conventional corn-Roundup Ready© soybean rotation. To my knowledge, no glyphosate-resistant weeds have been selected for in this kind of crop rotation and herbicide system. Another way to reduce the likelihood of selecting for glyphosate-resistant weeds is to apply preemergence herbicides in Roundup Ready© corn. As discussed previously, I consider this almost a necessity in order to protect corn yields and hope we will not move away from this practice as we plant more and more Roundup Ready© corn. Alternative postemergence herbicides is another consideration, but for the most part if a grower has paid the tech fee associated with the Roundup Ready© technology, then more than likely the grower is going to use glyphosate as the postemergence herbicide of choice. One last way to decrease the likelihood of glyphosate-resistant weed development is to apply herbicides other than glyphosate in Roundup Ready© soybeans, which will be the focus of another article in the next few weeks. Kevin Bradley BradleyKe@missouri.edu ******** Take Steps Now to Manage Soybean Cyst Nematode By Allen Wrather Here is the situation: Soybean cyst nematode (SCN) is the worst pest of soybeans in the USA, and the situation isn’t getting any better. This nematode suppressed soybean production in the USA about 123 million bushels during 2006, and the valued at $804.6 million. Fortunately, University of Missouri scientists have developed several highyielding soybean varieties resistant to SCN that are adapted for planting in Missouri and learned that crop rotation is a great SCN management tool. But soybean farmers must take steps to protect their crop against SCN. The first step toward protecting soybean against SCN is to test the soil for it. University of Missouri Extension Regional Agronomists have information about taking and submitting soil samples for SCN analysis, and more information is available at the University of Missouri Website http://soilplantlab.missouri.edu/nematode. March is a great time of the year to collect samples for SCN analysis because the results will be available in early April so farmers can make SCN management plans if necessary. If SCN is present, soybean farmers should take steps to protect their crop. Crop rotation is a great SCN control because nematode numbers drop during years when crops such as corn, grain sorghum, or cotton are planted. The number of years these crops should be planted before planting soybean again will depend on the number of SCN in the soil. Soybean farmers should be cautious when selecting SCN resistant. University of Missouri scientists recently surveyed Missouri for SCN and learned that races one, two, three, four and five were present, but races one and three were most common in the central and north part of the state, and races two and four were found in the south part. Information about soybean variety resistance to SCN is available at the University of Missouri Variety Testing Website, http://agebb.missouri.edu/cropperf/vartest. At this Site, visitors should click on "2006 Soybean Test Results," then in the next window click on "Characteristics of Varieties," then select the soybean seed company name and click on submit. This source provides information about varieties tested during 2006 and the source of SCN resistance used to develop each variety. The Missouri soybean farmer checkoff managed by the Missouri Soybean Merchandising Council funded much of the research by University of Missouri scientists to develop SCN resistant varieties and determine that crop rotation is a great SCN tool. More information about SCN management is available at the University of Missouri Extension offi ces. Additional information is available at, Soybean Cyst Nematode: Diagnosis and Management, http://muextension.missouri.edu/explore/agguides/crops/g04450.htm, and in, Soybean Cyst Nematode Management Guide, http://planthealth.info/scnguide/. Following these suggested procedures will give soybean farmers a better chance of producing a profitable soybean crop in 2007. Allen Wrather, Professor University of Missouri-Delta Center WratherJ@missouri.edu ******** Missouri Soil Testing Association Approval Program and Listing of Missouri State Approved Labs By Manjula V. Nathan The Missouri Soil Testing Association (MSTA) Approval Program is designed to assure that results provided by participating public and private labs serving the citizens of Missouri agree with allowable statistical limits. This is accomplished by evaluating the soil testing laboratories in their performance through interlaboratory sample exchanges and a statistical evaluation of the analytical data. Based on this premise, soil test results from MSTA approved labs will be accepted by the U.S. Department of Agriculture, Farm Service Agency (FSA) and Department of Natural Resources and Conservation Services (NRCS) in federally assisted cost share programs and nutrient management plans in the state of Missouri. Beginning in 1999, MSTA combined its efforts with the North American Proficiency Testing Program (NAPT). The NAPT coordinator sends soil test data from quarterly sample exchanges of the labs participating in MSTA program to the state coordinator. The MU Soil Testing Lab director serves as the state program coordinator and performs statistical analysis of the data as specified in the MSTA program. If a lab's results fall within the allowable limits, the lab will be placed on the Farm Service Agency's (FSA) list of approved labs. A lab that is not approved may re-apply after six months. Approval procedures for MSTA labs The labs that wish to participate in the MSTA program should send a formal written request to the director of the University of Missouri Soil Testing Laboratory. They also need to request the NAPT coordinator to include their lab to the Missouri State Certification list and sign the Missouri release form giving authorization to send test results to the MSTA program coordinator. Participating labs must use procedures of the Missouri Soil Testing Program in current use as described in the University of Missouri-Columbia Extension Guide #923 (August, 1983) entitled, Soil Testing in Missouri. An updated version of this guide is available on the MU Soil and Plant Testing Lab's Website at: http://soilplantlab.missouri.edu/soil/soilprocedures.htm. The lab will be approved for routine soil tests: * Bray-IP * ammonium acetate extractable K, Ca, and Mg * Organic matter * pH in 0.01 M CaCl2 * Neutralizable acidity (using the Modified Woodruff Buffer test) The MSTA coordinator will receive results of the quarterly sample exchanges from the NAPT program coordinator on the recommended tests and do the statistical evaluation. Approval criteria for MSTA labs The MSTA program uses the median and median absolute deviation (MAD) as used by the NAPT program as robust estimations of central values and variances of all data sets. This statistical approach is less sensitive to influence of extreme values (outliers) than the mean and standard deviation. The MSTA summary report lists the median and MAD values and the lab data. If the lab's data falls outside the range of +2.5x MAD (it is marked as Low or High) and considered to be out of the allowable limit. If the lab data falls outside the limits of +3.5x MAD they are marked as outliers. Test results of 75 percent of the samples must fall within the above allowable limits for each test. Upon meeting these criteria a letter will be sent to FSA to add the requesting lab to the list of approved labs in Missouri. If a lab fails the lab director may discuss with the MU Soil Testing Lab director ways to solve problems at the expense of the requesting lab. List of MSTA Approved labs Georgia Waters Agricultural Laboratories, Inc., 257 Newton Highway, PO Box 382 Camilla, GA 31730 Illinois Alvey Labs, 1511 East Main St., Belleville, IL 62221 Ingram's Soil Testing Lab, RR2 Box 309, 7 Oaks Farm, Athens, IL 62613 Mowers Testing, 117 East Main St., Toulon, IL 61483-0518 Indiana A&L Great Lakes Laboratory, Inc., 3505 Conestoga Drive, Fort Wayne, IN 46808 Iowa A&L Heartland Laboratory, Inc., 111 Linn St., PO Box 455, Atlantic City, IA 50022 Ag Source Belmond Labs, 1245 Highway 69 N, Belmond, IA 50421 Kentucky Waters Agricultural Laboratories, Inc., 2101 Old Calhoun Road, Owensboro, KY 42301 Missouri Custom Lab, 204 C St., Golden City, MO 64748 Delta Soil Testing Lab, University of Missouri, PO Box 160, Portageville, MO 63873 MU Soil and Plant Testing Lab, University of Missouri, 23 Mumford Hall, Columbia, MO 65211 Perry Agricultural Lab, PO Box 418, State Highway 54 East, Bowling Green, MO 63334 Nebraska Midwest Laboratories, Inc, 13611 B St., Omaha, NE 68144-3693 Ward Laboratories, PO Box 788, Kearney, NE 68848 Ohio Brookside Lab Inc., 308 S. Main St., New Knoxville, OH 45871 Spectrum Analytical, PO Box 639, Washington Court House, OH 43160 Tennessee A&L Analytical Laboratories Inc., 2790 Whitten Hall, Memphis, TN 38133 Note: Approval of soil analysis does not imply approval of fertilizer and limestone recommendations. Manjula V. Nathan, Director, MU Soil Testing and Plant Diagnostic Service Laboratories NathanM@missouri.edu ******** MU Soil Testing and Plant Analysis Lab in Columbia Offers Manure Testing By Manjula V. Nathan The University of Missouri Soil & Plant Testing Laboratory in Columbia now provides manure analysis to clients. Manure is a valuable source of nutrients for crops and improves soil productivity. Manure testing is necessary to make optimum use of manure while protecting water resources. Manure analysis is strongly recommended to help farmers know the value of manure applied to their crops in place of commercial fertilizer. Using manure in place of commercial fertilizer often results in increased crop yields, but accurate analysis of the manure is crucial. The analysis techniques offered at the MU Columbia lab are designed for accuracy and rapid turn-around of results to our clientele. You can submit samples direct to the lab. The samples should be accompanied by a duly filled sample information form that can be obtained by contacting the lab, or via the lab’s Website http://soilplantlab.missouri.edu/soil. Soil and Plant Testing Laboratory University of Missouri-Columbia 23 Mumford Hall Columbia, MO 65211 Tel: 573-882-0623 Fax: 573-884-4288 Email: soiltestingservices@missouri.edu Web: http://soilplantlab.missouri.edu/soil The lab offers Soil Testing, Plant Analysis, Manure, Compost, Greenhouse Media, Water Testing and Special Tests. Tests offered and fees Complete manure analysis (Total nitrogen, phosphorus, potassium, ammonium-nitrogen, pH, electrical conductivity and percent moisture) $ 40.00. Total nutrients analysis (Nitrogen, phosphorus, potassium and percent moisture $22.00. For additional tests and fees refer to the sample information form or visit the lab’s Website at: http://soilplantlab.missouri.edu/soil Guidelines for submitting samples Obtaining a representative manure sample from each storage area is critical to getting accurate test results. The basic guideline is to collect multiple samples, mix them together and make a composite sample. Submit at least one pint of the material to the lab for analysis. Taking a representative sample Obtain samples from at least 10 different places and/or depths to make the composite sample. In the case of poultry litter, sample to the bottom of the litter. If possible, agitate the liquids before collecting the sample. Submitting dry samples Submit one quart of dry manure in a Ziploc bag, squeeze excess air from the bag and seal it. Complete the manure testing sample information form and make sure to write your sample number or ID on the bag and mail it to the lab. Submitting wet samples Submit one pint of liquid manure in a plastic container. Do not fill the container. Make sure to leave at least one third free space and tighten the cap securely. Complete the manure testing sample information form and write your sample number or ID on the container with permanent ink and mail it to the lab. Each sample submitted to our lab should be accompanied by a sample information form. When submitting a sample to the lab the sample information form should be filled out accurately and completely. Include a check for the amount due payable to "MU Soil Testing." Turnaround time for samples is five to seven working days after samples are received by the lab. So plan ahead and submit samples in time. Manjula V. Nathan, Director, MU Soil Testing and Plant Diagnostic Service Laboratories NathanM@missouri.edu ******** Native Plant Sale at Bradford Farm This first native plant sale at Bradford will be featuring local Missouri native plant and seed producers, demonstrations and seminars including raingarden installation, gardening in diffi cult areas, spring wildflowers, nature books for sale, and a special bird watch tour will take place from 7 to 9am- Please RSVP if you plan to attend the bird watch tour by calling Nadia at 573-884-7945. For directions, visit: http://aes.missouri.edu/bradford/index.stm or call Thresa Chism or Tim Reinbott at 573-884-7945. Date: 14 April 2007 Time: 9 a.m. - noon Location: Bradford Research and Extension Center ******** Sprayer Calibration’s Link to Energy Conservation and Production By Bill Casady What holds 1000 gallons of fuel, 100,000 gallons of water and special materials with a value of $75,000 that protect your crop from competition by other species? The answer is that this is your sprayer in a two-pass program covering 2,500 acres. Put your own estimates to these figures, but no matter how you report the inputs, spraying accounts for a significant chunk of a crop budget with a very important purpose. What’s on the line? The answer is ‘the effi ciency of a field to convert soil resources and sunlight to what could be an energy crop’. Controlling weeds could be compared to cleaning the surface of a giant solar collector. Weeds also tie up valuable resources in the soil including water and nutrients. With so much on the line, uniform and precise placement of crop protection materials is a critical aspect of farming. The window of opportunity for good weed control is short and there is only room for the most effi cient and precise application of herbicides to get the job done right. Many are familiar with statistics on spraying and the potential payback of sprayer calibration on the front page of the March issue of Successful Farming ‘The $1,875-per-hour payback’. Sprayer calibration has the potential to save not only materials, but the energy used to create them, as well as the bottom line. Sprayer calibration also has the potential to improve the effi ciency of energy production when the crops we grow are used to produce ethanol or biodiesel. When sprayer calibration improves weed control, then calibration increases the energy balance for ethanol or biodiesel production. Proper calibration techniques are very important for accurate calibration. Details are available in MU publication G1270 on the University of Missouri extension Website at http://muextension.missouri.edu/explore/agguides/agengin/g01270.htm. Sprayer configuration and nozzle selection and maintenance should also be considered when performing sprayer calibration. It matters little how well other components are functioning if nozzles have not been properly selected or if they become worn or partially plugged. Replace old nozzles and carefully inspect individual spray patterns and flow rates to ensure that each nozzle is performing properly. As you protect sprayer performance through calibration, remember also to protect yourself and nearby vegetation by wearing personal protective equipment PPE) and by spraying only when conditions are right. Have a safe and productive and energy effi cient 2007. Bill Casady 573 882-4370 CasadyW@missouri.edu ******** Weather Data for the Week Ending March 11, 2007 By Pat Guinan -------------------------------------------------------------------------------- | Monthly | Growing Weekly Temperature (deg. F) |Precip (in.)|Degree Days^ -----------------------------|------------|------------ Ext- Ext- Depart| Depart|Accum Depart Avg.Avg. reme reme from |Mar 1 from |since from Station County Max.Min. High Low Mean avg. |Mar 11 avg |Apr 1 avg. ------------------------------------------------------|------------|------------ Corning Atchison 54 29 65 24 41 +6 | 0.38 -0.39 | * * St. Joseph Buchanan 57 30 62 23 43 +5 | 0.57 -0.16 | * * Brunswick Chariton 57 30 62 26 42 +4 | 1.04 +0.29 | * * Albany Gentry 54 27 64 21 40 +3 | 0.83 -0.01 | * * Auxvasse Audrain 57 31 63 24 43 +5 | 0.83 +0.02 | * * Columbia Boone 58 32 63 25 44 +4 | 1.13 +0.30 | * * Sanborn Field Boone 58 34 63 27 45 +5 | 1.18 +0.34 | * * Williamsburg Callaway 57 31 62 24 43 +5 | 1.01 +0.20 | * * Novelty Knox 51 28 62 23 39 +1 | 1.08 +0.21 | * * Linneus Linn 55 28 63 22 41 +4 | 0.63 -0.07 | * * Monroe City Monroe 52 28 63 24 39 0 | 0.79 -0.06 | * * Versailles Morgon 61 35 66 29 48 +6 | 0.74 -0.17 | * * Green Ridge Pettis 61 33 66 27 47 +9 | 1.21 +0.30 | * * Lamar Barton 63 39 68 29 50 +8 | 1.28 +0.12 | * * Cook Station Crawford 65 30 71 21 47 +4 | 0.10 -0.88 | * * Alley Spring Shannon 69 27 76 18 47 +5 | 0.17 -0.82 | * * Round Spring Shannon 68 28 73 18 46 +4 | 0.16 -0.83 | * * Delta Cape | | Girardeau 65 34 74 26 48 +4 | 0.51 -0.63 | * * Cardwell Dunklin 68 38 74 32 53 +7 | 0.07 -1.62 | * * Clarkton Dunklin 66 36 74 31 51 +6 | 0.12 -1.23 | * * Glennonville Dunklin 66 37 75 30 51 +6 | 0.02 -1.28 | * * Charleston Mississippi 65 36 73 30 50 +6 | 0.28 -1.00 | * * Portageville- | | Delta Center Pemiscot 67 39 74 31 52 +7 | 0.12 -1.38 | * * Portageville- | | Lee Farm Pemiscot 68 39 75 31 53 +8 | 0.18 -1.32 | * * Steele Pemiscot 69 38 74 30 53 +7 | 0.19 -1.48 | * * -------------------------------------------------------------------------------- * Complete data not available for report ^Growing degree days are calculated by subtracting a 50 degree (Fahrenheit) base temperature from the average daily temperature. Thus, if the average temperature for the day is 75 degrees, then 25 growing degree days will have been accumulated. -------------------------------------------------------------------------------- Pat Guinan, Commercial Agriculture Program (573) 882-5908