INSECTS. A Little More Information About the Bulletin

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1 A Little More Information About the Bulletin For issue no. 1 of the Bulletin, I wrote an article describing the new look and new features associated with the Bulletin, pest management and crop development information for Illinois. I failed to indicate, however, that new features will be added to the Web site over time. We do not expect the Bulletin to remain static. Rather, the publication and its associated features will evolve over time. So, again, I invite you to offer suggestions for additional information or improvements so that we can continually enhance the manner in which we deliver information. FOR IMMEDIATE RELEASE No. 2 / April 2, 2004 Executive editor: Kevin Steffey, Extension Entomologist Available on the Web at For subscription information, phone , or acesnews@uiuc.edu Copyright 2004, Board of Trustees, University of Illinois Also in This Issue Let s Talk Grubs, 14 Start Thinking About Alfalfa Weevils, 15 New Product for Insect Control, 15 National Road Map for IPM: Will Corn and Soybean Producers Use It? 16 North Central Branch Meeting, Entomological Society of America, 17 Announcing the New Field Crop Scouting Manual, 17 and more... As I have written in past issues of the Pest Management & Crop Development Bulletin, Extension specialists in almost all other states publish weekly newsletters throughout the growing season. Although much of the information is state specific, information from other states can be highly instructive. We have referred to the articles of colleagues in nearby states many times in our own articles. So, as a service to you, we have included the URLs of other states newsletters on the Bulletin Web site. From the home page, click on the Resources tab to move to the IPM Resources page. From there, you can click on the newsletter of your choice. Look for additional resources to be added in the future. Kevin Steffey INSECTS Continuing Information About Moth Captures Because Mike Gray, Kelly Cook, and I will have been at the annual meeting of the North Central Branch of the Entomological Society of America through Wednesday, March 31, which was the due date for articles for the Bulletin, we could not present the most current information about moth captures here. However, as I have mentioned many, many times before, Ron Hines, senior research specialist at the University of Illinois Dixon Springs Agricultural Center, monitors several traps for moths during the growing season. To obtain the most current information, refer to The Hines Report on the IPM Web site at The moth captures may be interesting during the week of March 29, given the extensive storm front that passed through during the weekend of March 27. During the week of March 15, Ron informed me, he captured one armyworm moth in a trap in Massac County on March 16. He also has captured a few more black cutworms since the time of his last report. As of March 26, six black cutworm moths had been caught in each trap at the Jefferson County and St. Clair County locations. The traps at these locations are monitored by Ron Krausz (St. Clair County site, Southern Illinois University Belleville Research Center), Ed Billingsley (Jefferson County site, Rend Lake College), and Alan Mosler (Southern FS). Ron Hines also communicates with a specialist in Princeton, Kentucky, who monitors moth traps in the spring. Two armyworm moths have been captured at that site thus far one on March 18 and one on March 23 and they captured one black cutworm moth on March

2 In the near future, we will add a slide set that Ron Hines has developed to help identify moths. The nice thing about Ron s slides is that the insects in the photographs are not pretty they look exactly as they would if you pulled them off a sticky trap or out of a bucket. Other identification aids usually show moths that have been beautifully pinned, with their wings spread. These specimens make for nice photos, but they often don t resemble the beatup insects you find in traps. I will make you aware when Ron s identification aid is available. I second the request for submitting information made by Kelly Cook in her article Insect Monitoring Network in issue no. 1 of the Bulletin. The information you submit can be used by many others who rely on the Bulletin for the most current information about the development of insect pests. If you are monitoring traps for any insects, we invite you to send us your information at your convenience. Thanks in advance for your cooperation. Kevin Steffey Let s Talk Grubs Grubs are a topic that continues to grow each year. Over the past couple of years, grubs and grub damages have been at the tip of many farmers tongues. Each year we receive reports of injured seedling corn and replanting of severely injured parts of fields. In Illinois, primarily two types of white grubs cause damage to seedling corn: true white grubs and annual white grubs. The so-called true white grubs, or Phyllophaga white grubs, have three-year lifecycles. The southern masked chafer, Cyclocephala lurida, and the Japanese beetle, Popillia japonica, are the two most common annual white grubs found in corn in Illinois. Phyllophaga white grubs may cause considerable damage to cornfields. Hosts for the adults of these grubs include ash, elm, poplar, and willow trees. The risk of infestation of Phyllophaga white grubs is greatest near those adult food sources, and thus their injury is probably not widespread. That fact, in conjunction with research that tells us that the southern masked chafer rarely causes economic injury to corn or soybeans, leads us to believe that most of the grub damage in Illinois has been caused by Japanese beetle grubs. Japanese beetle grubs lay eggs in the soil in mid- to late summer. Larvae hatch and feed through the fall until temperatures begin to fall. They then descend in the soil (about 15 to 18 inches deep) until temperatures begin to warm again. The grubs feed primarily on organic matter but will feed on corn roots, especially when organic matter is not readily available. The lifecycle of Phyllophaga grubs is different from that of the annual white grubs. May or June beetles, the adults of Phyllophaga white grubs, also lay eggs in mid- to late summer. The larvae then hatch and molt once before descending in the soil and becoming dormant over the winter. As temperatures rise in the spring, they move toward the soil surface to feed on plant roots, including corn and soybeans. They will feed throughout the summer. They pass a second winter in the soil and feed once again on plant roots in the spring. Problems associated with Phyllophaga white grubs are noticed more this second spring because the grubs are full grown and consume more root tissue. When they finish feeding, the grubs pupate, and adults emerge in midsummer. Both types of grubs cause similar injury to corn plants. Grubs feed on root hairs of seedling corn plants. This affects the uptake of water and nutrients (phosphorus), causing the plant to wilt and stems and leaves to turn purple. Stand loss may occur in severely infested fields when injured plants die. Early-planted corn may be more susceptible to grub injury because grubs feed early in the spring. 14 It is very difficult to anticipate the occurrence of injury caused by white grubs. While most Phyllophaga problems occur near adult food sources, there has not been a telltale indicator for where Japanese beetle grub damage may occur. Both types of grubs are found in the soil in late summer, but few people look for them. In the spring, watch for white grubs during tillage operations, which bring the grubs to the soil surface, where they are visible (especially to birds that follow you through the field!). Identifying what grub species is present in the field is very important; Phyllophaga or Japanese beetle grubs may cause damage to corn seedlings, while Cyclocephala grubs will not likely cause economic damage. To identify white grubs, you need to examine the rastor pattern the pattern of small hairs and spines on the underside of the last abdominal segment (Figure 1). Different species of grubs have different rastor patterns. The Japanese beetle has an arrangement of hairs that form a V-shaped pattern (Figure 2a). These lines of hairs usually form a V that is distinct in the center of the pattern. The Cyclocephala grub has no distinct pattern of hairs on its rastor (Figure 2b). The Phyllophaga grub has hairs on its center arranged in nearly parallel rows, resembling an open zipper (Figure 2c). If Japanese beetle grubs or Phyllophaga grubs are found, a soil insecticide or seed treatment might be justi- Figure 1. Location of raster on a white grub. (Illustration modified from the 2000 Corn and Soybean Field Guide, Publication ID-179, Purdue University Cooperative Extension Service, West Lafayette, Indiana.)

3 fied, especially if corn is planted early. Table 1 lists insecticides registered for control of white grubs in corn. As you re in the field this spring, please pass on any observations. We ll continue our research efforts to provide you with more information regarding these insects. Kelly Cook Start Thinking About Alfalfa Weevils It s once again that time of year the snows have melted, temperatures are on the rise, and spring is on its way! But so are the alfalfa weevils. As degree-days start to accumulate, the watch for alfalfa weevils begins. Larval hatch from eggs is expected to occur after the accumulation of 300 degree-days from January 1. Alfalfa fields in southern Illinois will soon be experiencing larval hatch. Accumulated degree-days are shown in Table 2. View statewide maps and the most current degree-day accumulations at locations near you with our degreeday calculator at degreedays/. First instars can be found in the folded terminal leaves. Initial injury caused by the larvae appears as pinholes in the leaf terminals. As larvae continue to develop and increase in size, damage also increases. Alfalfa weevil larvae have a green body with a prominent white stripe down the center of the back. When the larvae reach about the third instar, they begin skeletonizing the leaves. If temperatures continue as they are, alfalfa weevil hatch will be well under way in the southern third of the state by mid-april. Here are some tips for scouting for alfalfa weevil larvae. Be sure to look for them and the symptoms of their feeding injury throughout the field, not just along the edges. Look at field areas that may warm up early, such as south-facing slopes or areas of lighter soil. The best way to count larvae is to snap a stem off at ground level and place it top down into a white bucket. We recommend walking in a U-shaped Figure 2. White grub raster patterns: (a) Japanese beetle, (b) Cyclocephala grub, and (c) Phyllophaga grub. (Grub illustration modified from the 2000 Corn and Soybean Field Guide, Publication ID-179, Purdue University Cooperative Extension Service, West Lafayette, Indiana.) Table 1. Soil insecticides and seed treatments suggested for the control of white grubs in corn. Amount of product per Insecticide acre Placement Aztec 2.1%G* 6.7 oz/1,000 ft row Band, furrow Aztec 4.67G* 3 oz/1,000 ft row Band, furrow Capture 2EC* 0.15 to 0.3 oz/1,000 ft row Band, furrow Capture 2EC* 3 to 4 oz BC-PPI Counter CR* 6 oz/1,000 ft row Band, furrow Empower* 3.2 to 8 oz/1,000 ft row Band, furrow Force 3G* 4 to 5 oz/1,000 ft row Furrow Fortress 2.5G* 6 to 7.5 oz/1,000 ft row Furrow Fortress 5G* 3 to 3.75 oz/1,000 ft row Furrow Lorsban 4E* 4 pt BC-PPI Lorsban 15G 12 oz/1,000 ft row Furrow Regent 4SC* 0.24 oz/1,000 ft row Furrow Thimet 20G* 6 oz/1,000 ft row Band Warrior* 0.66 oz/1,000 ft row Band Cruiser See product label. On seed Poncho See product label. On seed ProShield with Force ST See product label. On seed *Restricted use pesticide. Table 2. Accumulated and projected degree-day totals, base 48 F, from January 1. Degree-days, base 48 F, through March 25 pattern through the field, collecting stems at random locations. After collecting 30 stems, you can beat them, a few at a time, against the sides of the bucket to dislodge the larvae. Sample plant heights throughout the field, or randomly select a sample of 10 of the stems to measure the height. Projected degreedays, base 48 F, through April 1 Location Dixon Springs Brownstown Champaign Monmouth DeKalb Projected degreedays, base 48 F, through April 8 Please keep us posted on alfalfa weevil activity in your area. Kelly Cook New Product for Insect Control American Vanguard Corporation (AMVAC) has received a registration 15

4 for a pyrethroid insecticide for control of insects in corn and cotton and on some vegetables and fruits. The active ingredient (bifenthrin) for their product, Discipline 2EC, is the same active ingredient for Capture 2EC, manufactured and marketed by FMC Corporation. The list of insects in corn controlled by Discipline 2EC is the same list that appears on the label of Capture 2EC. Among the insects on the Discipline 2EC label troublesome for Illinois corn producers are aphids, armyworms, corn rootworm adults, cutworms, European corn borer, flea beetle, grasshoppers, Japanese beetle adults, southern corn leaf beetle, southwestern corn borer, and stalk borer. The rates of application for Discipline 2EC are 2.1 to 6.4 fluid ounces of product per acre, depending on the target insect. Please consult the label for additional information, including precautions and restrictions. The label can be viewed on AMVAC s Web site at Click on Labels & MSDS, then select Discipline 2EC from the Select product menu. Kevin Steffey National Road Map for IPM: Will Corn and Soybean Producers Use It? Fourteen years ago, I presented a paper at the 1990 Illinois Crop Protection Workshop titled Integrated Pest Management in Illinois: A Look at the Last 15 years and into the 1990s. It seems appropriate that I now pause and reflect on the last 15 years, and offer some thoughts regarding the future of IPM efforts in this state. As I pointed out in the 1990 paper, the first organized Extension IPM project in Illinois started in 1972, with a pilot scouting initiative in Boone County. This first IPM thrust was almost exclusively devoted to scouting for insects and using rudimentary economic thresholds. Within Boone County, 115 cornfields were enrolled in this pilot program, which included a total of 4,268 acres. The following information was collected for each cornfield: (1) field histories were obtained; (2) plant stands were taken; (3) European corn borer whorl feeding was measured; (4) corn rootworm larval counts were obtained; (5) levels of corn leaf aphids were assessed; and (6) records were kept on the abundance of predators, parasites, and diseased insects. The costs incurred during this coordinated scouting program, including total labor, travel, and subsistence allowances, were estimated to be 50 cents per acre! Pete Petty, Illinois first Extension entomologist, thought that costs could be reduced over time: If we continue this pilot program, further refinements may reduce the per-acre cost. In 1973, the University of Illinois College of Agriculture began to receive annual federal support to conduct IPM educational programs. That support continues to this day. Over time, primarily due to inflation, support in our land-grant institutions for IPM Extension programs has eroded. For the most recent federal fiscal year, IPM extension programs in all 50 states have seen their budgets reduced by 10%. I hope that these funds will be restored in the 2005 budget cycle. Will political support for IPM educational programs continue to diminish? In August 2001, the U.S. General Accounting Office (GAO) issued the report Agricultural Pesticides Management Improvements Needed to Further Promote Integrated Pest Management (IPM). This document was compiled in response to Senator Patrick Leahy s request that the status of IPM adoption in U.S. agriculture be accurately assessed. In 1993, in response to the Clinton administration, the USDA established a goal of 75% implementation of IPM practices on the nation s crop acres. This 1993 initiative has continued to receive mixed reviews. On pages 11 and 12 of the GAO Report (GAO Agricultural Pesticides), sharp criticism is leveled at the agricultural establishment for the continued escalation of pesticide use: Although some IPM practices have resulted in significant reductions in pesticide use, 16 nationwide use of chemical pesticides in agriculture has not declined since the beginning of the IPM Initiative. Chemical pesticide use in agriculture which accounts for about threefourths of all pesticides used in the United States has increased from about 900 million pounds in 1992 to about 940 million pounds in 2000, according to EPA, even as total cropland has decreased. However, data on total pesticide use aggregates relatively benign pesticides, such as sulfur and mineral oil, with more risky chemical pesticides, including organophosphates, carbamates, and probable or possible carcinogens. This subset of pesticides which has been identified by the EPA as posing the greatest risk to human health is suspected of causing neurological damage, cancer, and other adverse human health effects. There is a silver lining to this cloud. The GAO report also indicates that use of the riskiest subset of pesticides decreased from 455 million pounds of active ingredient in 1992 to about 390 million pounds in Despite this reduction, these products categorized as risky still represent more than 40% of the pesticides that producers continue to use. In partial response to the GAO report, a national road map for IPM was presented and published in the Proceedings of the 4th National IPM Symposium, held in Indianapolis, Indiana, April 8 to 10, Three broad national IPM goals were articulated: (1) improve the economic benefits related to the adoption of IPM practices, (2) reduce potential human health risks from pests and the use of IPM practices, and (3) minimize adverse environmental effects from pests and the use of IPM practices. General performance measures were listed for each goal. Will corn and soybean producers find the very general directions of the IPM road map useful? In reality, I realize most producers have never heard of the map. How will it be perceived by the agribusiness sector? Will the IPM road map influence IPM educational programs led by scientists within our

5 land-grant institutions? There are no easy answers to these questions. In 1990, W. A. Allen and E. G. Rajotte published a paper in the Annual Review of Entomology titled The Changing Role of Extension Entomology in the IPM Era. They surveyed extension entomologists who were members of the Entomological Society of America and were active from 1972 to More than 200 responses were received. These extension entomologists believed that synthetic pesticides would play a less critical role in IPM decision-making in the future (defined as 1989 through 2000). They (71.4% of respondents) also believed that scouting and the use of economic thresholds would be very important throughout the 1990s. It appears that they underestimated the future importance and continued use of pesticides and overestimated the adoption of scouting practices and use of thresholds in a field crop setting. If you disagree, ponder these questions: What percentage of soybeans grown in Illinois are scouted for the western corn rootworm variant in order to make more-informed soil insecticide decisions on first-year corn? What percentage of continuous corn acres in Illinois are scouted for corn rootworms in order to make soil insecticide use decisions? What percentage of corn acres in Illinois will be treated with systemic insecticidal seed treatments this spring for secondary soil insects without any scouting input? For corn rootworms? Will interest continue to build for the registration and use of systemic insecticidal seed treatments for soybeans to reduce potential bean leaf beetle and soybean aphid infestations despite the sporadic nature of these insect pests? How much concern exists regarding the potential for substantial numbers of acres of corn and soybean to be treated in the future with insecticidal seed treatments that have the same mode of action? Should insecticide resistance management protocols be developed and recommended for the nicotinioid insecticides? If your answers to these questions make you feel somewhat uncomfortable with respect to the progress we ve made regarding the adoption of scouting and use of thresholds since the University of Illinois pilot scouting program in the early 1970s, you re not alone. If pesticide use remains at current levels on corn and soybean acres and the adoption of scouting practices and use of economic thresholds continue to lag, will federal support of IPM continue to erode? As urban population centers increase in political importance, will federal support swing in favor of those programs that focus on alternative agriculture practices such as organic food production? Time will tell. Mike Gray North Central Branch Meeting, Entomological Society of America Among many entomologists in the Midwest, one of the year s most highly anticipated events is the annual meeting of the North Central Branch of the Entomological Society of America (ESA). The 2004 meeting was just held in Kansas City, Missouri, March 28 through 31. Illinois own Dr. Rob Wiedenmann, a biological control research specialist with the Illinois Natural History Survey, is this year s president. Mike Gray, Kelly Cook, and I (regular contributors to the Bulletin) had to write our articles for issue no. 2 of the Bulletin during the week of March 22, well in advance of the March 31 deadline, because we all attended the meeting, along with our students, Sue Ratcliffe and Ron Estes. We learned quite a bit about insect pests of field crops that we should be able to use throughout the growing season. 17 Presentations about the following insect pests and insect management topics were made by research and extension entomologists at the meeting: bean leaf beetle, biological control, Bt corn (including resistance management and effects on nontarget organisms), corn earworm, European corn borer, insecticidal seed treatments, Japanese beetle, multicolored Asian lady beetle, potato leafhopper, soybean aphid, and western corn rootworm (variant and otherwise). Symposia presented included the following: New Products and Technologies for the Future Established and Emerging Insect Pests of Oil Crops in the North Central Region Western Corn Rootworms on the Move: What Have We Learned Since the Mid-1990s? Evaluating the Risks of Genetically Modified Plants to Natural Enemies: Learning from Transgenic Bt Crops We always learn a great deal from both the formal presentations and informal hallway conversations, and we intend to share what we have learned with you, with hopes of enhancing insect management strategies in Illinois. Kevin Steffey PLANT DISEASES Announcing the New Field Crop Scouting Manual The new edition of the Field Crop Scouting Manual is on the shelf, ready for you to order. The manual is appropriate for field crop scouting across the Midwest. This fifth edition has 10% more content than the prior edition and 30% more color. Each chapter has been revised and updated to give you the most current information on scouting for significant pests in Illinois and the Midwest, thanks to our University of Illinois Extension specialists and educators and the ITCS publishing staff. The printed manual is $55 and the CD is $55, or order both for $99. Order Field Crop Scouting Manual x880d online at www. PublicationsPlus.uiuc.edu (directly at

6 shopsite/x880d.html); call ; or return the order form on page 23. Interested in a bulk order? Call Ken McPheeters at (217) for a special price. Suzanne Bissonnette Efficient Scouting Eight Simple Rules One thing is for sure: The pest situation in Illinois and the Midwest is never static. Each year brings new challenges. Last season, when many of you were inundated with new pest situations, did you know how to make treatment decisions about them? Did you know the latest techniques for soybean aphid scouting, or when you should do something about those pesky Japanese beetles or soybean cyst nematodes? Were you confident in your field identifications of pests and beneficial organisms? Were those diseases out there or environmental problems? Spring is here, and with the new growing season it s a sure thing that new and old pests will make themselves known. You will be able to informatively respond to developing pest situations by scouting. Scouting gives you the information you need about pest identification and population growth to make environmentally sound management decisions for your clients or your own fields. Extension Educator Matt Montgomery and I presented a session at the 2004 Illinois Crop Protection Technology Conference on field crop scouting. What can a crop scout do to become more efficient? The following summary from that session of eight simple rules will help you scout more efficiently. Rule 1: Correctly identify the causal agent. This rule is really the cornerstone of any good integrated pest management program. If you don t take the time to determine the identity of the causal agent, you are wasting your time and possibly the producer s money. Incorrectly identifying or lacking identification of a causal agent in the field may lead to unnecessary use of pesticides, missed pest management opportunities, elimination of beneficial organisms, or worse. An example of how this simple rule can benefit the producer pertains to earlyseason cutworm observations. If observed cutworms are black cutworms, an insecticide may well benefit the producer, depending on the percentage of the plants clipped and other factors. However, if the cutworms observed are dingy cutworms, an insecticide will likely not benefit the producer. Dingy cutworms are often leaf feeders and thus tend to cause non-economic injury to seedling corn. An insecticide application to a dingy cutworm infested field often results in unnecessary expenditure by the producer. Rule 2: Understand how the environment influences a problem. The development of pest problems can be greatly influenced by environmental conditions. For example, insects such as the corn flea beetle cause more problems following mild winters when the overwintering adults survive at fairly high levels. Rule 3: Keep up with the latest. Resources and time are limited for all involved in agriculture, and the efficient crop scout will be the one who stays apprised of the latest pest developments and plans activities accordingly. The Field Crop Scouting Manual and periodicals represent one means by which to accomplish this feat. The Bulletin, pest management bulletins from other states, company pest bulletins, and local newsletters can provide the bird s-eye view of the current pest situation. Human resources can supply especially valuable information. Clients, co-workers, and others with even a basic understanding of possible field pests can provide many eyes and ears to the crop scout, alerting you to missed pest developments, accelerating problems, and true non-issues. Add some eyes and ears south of your territory, and you gain a virtual crystal ball. Since some pest problems will progress south to north, friends down south can warn crop scouts of problems that might be coming their way in the next few weeks. 18 Rule 4: Remember that beans can be tough stuff. Soybean leaves can take a lot of punishment. Enough said. Rule 5: Know what structures/stages you should be looking for during each crop growth stage. Following this rule requires that you know about pest life cycles and how a particular pest matures and reproduces. References such as the Field Crop Scouting Manual and the Bulletin will help tremendously. Rule 6: Take more than a glance. Crop scouts are often tempted to quickly glance at the end rows of a field when making pest management decisions. However, making a good decision requires that one take a good survey of the actual situation in the field. Is the pest problem limited to a few localized areas? If so, a quick survey may provide an exaggerated view of the actual situation as you stumble into a hot spot. Likewise, a quick survey can cause you to miss a real problem if you happen to examine one of a field s few relatively healthy areas. A 2003 example of this phenomenon relates to Japanese beetle management in eastern Sangamon County. Initial quick observations of field edges showed very intense pressure from this silk-clipping pest, but additional more-intense observations showed that many of those infestations were confined to the end rows. Fertilization was inhibited in the end rows in these cases, but the interior regions of the field established kernel before beetles could inhibit that process. Producers who choose to quickly examine fields in 2004 for Japanese beetle may overestimate or underestimate the impact of this pest. Only a good, thorough survey into the field will provide an accurate picture for decision making. Rule 7: Recognize what nature can do for you. You need to be able to recognize beneficial insect species as well as pay attention to changing local weather conditions that may be unfavorable for disease or insect development. Rule 8: When possible, catch it early. This one is straightforward.

7 Maintain a regular scouting schedule so that increases or decreases in pest populations can be quickly realized. Our general recommendation of scouting a field every 7 to 10 days has everything to do with the typical lifecycles of our common field crop pests in Illinois and nothing to do with how many miles we think you should be putting on your vehicle. Suzanne Bissonnette and Matt Montgomery WEEDS Early-Season Weed Identification References There are very few weed identification sources that focus on earlyseason weeds. One of these, A Pocket Identification Guide of Early-Season Weed Species, is available from Extension specialists at the University of Illinois. This little flipbook contains color images from various growth stages and describes key characteristics for identification of 19 weed species, such as purple deadnettle, henbit, cressleaf groundsel, and buttercup. The pocket guide is available for $3 (plus shipping and handling) and can be ordered by clicking on Pocket Identification Guide to Early-Season Weed Species at and filling out the form. Early Spring Weeds of No-Till Crop Production, a North Central Region publication, focuses on identifying and managing vegetation commonly found in no-till fields. It is an excellent guide to help identify those hard-to-identify weed problems in no-till fields, such as winter annuals and biennials. The 22-page guide contains more than 130 color photographs of both vegetative and reproductive stages of 45 weeds common to field crops across much of the Midwest. It also contains a taxonomic key to aid in identification and a table listing the sensitivity of various species to selected herbicides. The guide is available from University of Missouri, Extension Publications, 2800 Maguire Road, Columbia, MO ( ). Cost of this publication is $3 (plus shipping and handling). Dawn Nordby and Aaron Hager Corn and Soybean Herbicide Premixes Herbicide premixes can often be confusing with respect to components, product equivalents, application rates, and so on. Table 3 lists many of the corn herbicide premixes used in Illinois, while Table 4 is a similar list of soybean herbicide premixes. Let s examine the information in these tables in a little more detail. The first column lists the commercial, or trade, name of the herbicide and its formulation. The trade name is the one most familiar to folks. Another list of names (arguably less familiar than the trade names) appears in column 2; these are the common names for each herbicide component of a premix. For example, in Table 3, we see that Axiom (trade name) 68DF (formulation) is composed of the active ingredients flufenacet (common name) and metribuzin (common name). Common names are useful because they always refer to the same active ingredient; trade names don t always. Think back a few years to a herbicide with the trade name Option; this product contained the active ingredient fenoxaprop (common name) and was used for postemergence control of grass species in soybean. The Option (trade name) herbicide now on the market contains foramsulfuron (common name) and is used for postemergence control of grass species in corn. Needless to say, you do not want to apply fenoxaprop to corn or foramsulfuron to soybeans hence the benefit of knowing herbicide common names. Column 2 also provides the amount of active ingredient or acid equivalent of each 19 component per gallon or pound of formulated product. Column 3 lists an application rate for each premix. We tried to select application rates representative for Illinois, but you may want to select a different rate and redo the calculations in columns 4 and 5. Column 4 indicates how much of each active ingredient is applied at the rate listed in column 3. Going back to the example of Axiom, we see that 19 ounces of Axiom provides lb flufenacet active ingredient and lb metribuzin active ingredient. Note here that while rates of commercial products are usually expressed in ounces, pounds, pints, quarts, and so on of product per acre, active ingredients are usually expressed in units of pounds of active ingredient or acid equivalent per acre. Finally, the last column lists product equivalents for each premix component when applied at the rate listed in column 3. So the 19-ounce rate of Axiom provides the same amount of flufenacet and metribuzin that is contained in ounces of Define 60DF and 3.45 ounces of Sencor 75DF, respectively. The application rates in the tables are meant to be used for reference; for some of these herbicides application rates will vary depending on soil texture, organic matter, weed species size, and other factors. Always consult the respective herbicide label for appropriate application rates. If you are interested in a rate different from that listed for a particular herbicide, it s relatively simple to do the calculations for your rate of choice. We ll work through an example. The application rate of Harness Xtra 5.6L listed in Table 3 is 2.5 quarts per acre. Instead of 2.5 quarts, you want to know how much acetochlor and atrazine are applied at a 2-quart rate of Harness Xtra 5.6L.

8 Table 3. Corn herbicide premixes. Herbicide Accent Gold 83.8WDG Axiom 68DF Basis 75WDG Basis Gold 89.46WDG Bicep II Magnum 5.5L Cinch ATZ Bicep Lite II Magnum 6L Cinch ATZ Lite Buctril + atrazine 3L Bullet 4CS Components (ai/gal or lb) clopyralid = lb ae flumetsulam = lb nicosulfuron = lb rimsulfuron = lb flufenacet = lb metribuzin = lb rimsulfuron = 0.50 lb thifensulfuron = 0.25 lb rimsulfuron = lb nicosulfuron = lb atrazine = lb S-metolachlor = 2.4 lb atrazine = 3.1 lb S-metolachlor = 3.33 lb atrazine = 2.67 lb If you apply/ acre You have applied (ai) Product equivalents 2.9 oz clopyralid = lb ae flumetsulam = lb nicosulfuron = lb rimsulfuron = lb 19 oz flufenacet = lb metribuzin = lb 0.33 oz rimsulfuron = 0.01 lb thifensulfuron = lb 14 oz rimsulfuron = lb nicosulfuron = lb atrazine = lb 2.1 qt S-metolachlor = 1.26 lb atrazine = 1.63 lb 1.5 qt S-metolachlor = 1.2 lb atrazine = 1.00 lb Stinger 3S = 4 fl oz Python 80WDG = 0.69 oz Accent 75DF = 0.25 oz rimsulfuron = lb ai Define 60DF = oz Sencor 75DF = 3.45 oz rimsulfuron = 0.01 lb ai Harmony GT 75DF = 0.11 oz rimsulfuron = lb ai Accent 75DF = 0.25 oz AAtrex 90DF = lb Dual II Magnum 7.64E = 1.32 pt AAtrex 4L = 3.26 pt Dual II Magnum 7.64E = 1.31 pt AAtrex 4L = 2 pt bromoxynil = 1.0 lb atrazine = 2.0 lb 2 pt bromoxynil = 0.25 lb atrazine = 0.5 lb Buctril 2E = 1 pt AAtrex 4L = 1 pt alachlor = 2.5 lb 4 qt alachlor = 2.5 lb Micro-Tech 4CS = 2.5 qt atrazine = 1.5 lb atrazine = 1.5 lb AAtrex 4L = 1.5 qt Camix 3.67L S-metolachlor = 3.34 lb 2.4 qt S-metolachlor = 2.0 lb Dual II Magnum 7.64EC = 2 pt mesotrione = 0.33 lb mesotrione = lb Callisto 4SC = 6.34 fl oz Celebrity Plus diflufenzopyr = 0.17 lb ae 4.7 oz diflufenzopyr = lb ae diflufenzopyr = lb ae 70WDG dicamba = lb ae dicamba = lb ae Clarity 4S = 3.98 fl oz nicosulfuron = lb nicosulfuron = lb Accent 75DF = 0.66 oz Degree Xtra acetochlor = 2.7 lb 3 qt acetochlor = lb Degree 3.8CS = 2.13 qt 4.04CS atrazine = 1.34 lb atrazine = 1.00 lb AAtrex 4L = 1 qt Distinct 70WDG diflufenzopyr = 0.20 lb ae 4 oz diflufenzopyr = 0.05 lb ae diflufenzopyr = 0.05 lb ae dicamba = 0.50 lb ae dicamba = lb ae Clarity 4S = 4 fl oz DoublePlay 7E acetochlor = 1.4 lb 5 pt acetochlor = lb Surpass 6.4E = 1.1 pt EPTC = 5.6 lb EPTC = 3.5 lb Eradicane 6.7E = 4.2 pt Epic 58WDG flufenacet = 0.48 lb 12 oz flufenacet = 0.36 lb Define 60DF = 9.6 oz isoxaflutole = 0.10 lb isoxaflutole = lb Balance 75WDG = 1.6 oz Equip 32WDG foramsulfuron = 0.30 lb 1.5 oz foramsulfuron = lb Option 35WDG = 1.28 oz iodosulfuron = 0.02 lb iodosulfuron = lb iodosulfuron = lb ai Expert 4.88L S-metolachlor = 1.74 lb 3 qt S-metolachlor = 1.31 lb Dual II Magnum 7.64EC = 1.37 pt atrazine = 2.14 lb atrazine = 1.61 lb AAtrex 4L = 3.21 pt glyphosate = 0.74 lb ae glyphosate = 0.56 lb ae Glyphosate 3L = 1.48 pt Field Master 4.06S FulTime 4CS G-Max Lite 5L Guardsman Max 5L Harness Xtra 6L Harness Xtra 5.6L Hornet WDG 68.5WDG Keystone 5.25L Keystone LA 5.5L acetochlor = 2.0 lb atrazine = 1.5 lb glyphosate = 0.56 lb ae acetochlor = 2.4 lb atrazine = 1.6 lb dimethenamid-p = 2.25 lb atrazine = 2.75 lb dimethenamid-p = 1.7 lb atrazine = 3.3 lb acetochlor = 4.3 lb atrazine = 1.7 lb acetochlor = 3.1 lb atrazine = 2.5 lb clopyralid = 0.50 lb ae flumetsulam = lb acetochlor = 3 lb atrazine = 2.25 lb acetochlor = 4 lb atrazine = 1.5 lb 4 qt acetochlor = 2.0 lb atrazine = 1.5 lb glyphosate = 0.56 lb ae 4 qt acetochlor = 2.4 lb atrazine = 1.6 lb 3 pt dimethenamid-p = atrazine = pt dimethenamid-p = 0.85 lb atrazine = 1.65 lb 2 qt acetochlor = 2.15 lb atrazine = 0.85 lb 2.5 qt acetochlor = 1.94 lb atrazine = 1.56 lb 3 oz clopyralid = lb ae flumetsulam = lb 3 qt acetochlor = 2.25 lb atrazine = 1.69 lb 2 qt acetochlor = 2 lb atrazine = 0.75 lb Harness 7E = 2.29 pt AAtrex 4L = 3 pt Roundup Ultra 3L = 1.5 pt TopNotch 3.2CS = 3 qt AAtrex 4L = 1.6 qt Outlook 6EC = 18 fl oz AAtrex 4L = 2 pt Outlook 6EC = 18.1 fl oz AAtrex 4L = 3.3 pt Harness 7E = 2.46 pt AAtrex 4L = 1.7 pt Harness 7E = 2.21 pt AAtrex 4L = 3.13 pt Stinger 3S = 4 fl oz Python 80WDG = 0.69 oz Surpass 6.4EC = 2.81 pt AAtrex 4L = 3.38 pt Surpass 6.4EC = 2.5 pt AAtrex 4L = 1.5 pt 20

9 Table 3. Corn herbicide premixes (cont.). Herbicide Laddok S-12 5L Liberty ATZ 4.3SC Lightning 70DG Lumax 3.95L Marksman 3.2L NorthStar 47.4WDG ReadyMaster ATZ 4SC Shotgun 3.25F Spirit 57WDG Steadfast 75WDG Yukon 67.5WDG Components (ai/gal or lb) bentazon = 2.5 lb atrazine = 2.5 lb glufosinate = 1 lb atrazine = 3.3 lb imazethapyr = lb imazapyr = lb S-metolachlor = 2.68 lb mesotrione = lb atrazine = 1 lb dicamba = 1.1 lb ae atrazine = 2.1 lb primisulfuron = lb dicamba = lb ae atrazine = 2 lb glyphosate = 1.5 lb ae atrazine = 2.25 lb 2,4-D = 1 lb ae prosulfuron = lb primisulfuron = lb nicosulfuron = 0.5 lb rimsulfuron = 0.25 lb halosulfuron = lb dicamba = 0.50 lb ae If you apply/ acre You have applied (ai) Product equivalents 1.67 pt bentazon = 0.52 lb Basagran 4S = 1 pt atrazine = 0.52 lb AAtrex 4L = 1 pt 40 fl oz glufosinate = lb Liberty 1.67L = 24 fl oz atrazine = 1.03 lb AAtrex 4L = 2.06 pt 1.28 oz imazethapyr = lb Pursuit 70DG = 0.96 oz imazapyr = lb 3 qt S-metolachlor = 2.01 lb mesotrione = lb atrazine = 0.75 lb 3 pt dicamba = lb ae atrazine = lb 5 oz primisulfuron = lb dicamba = lb ae 2 qt atrazine = 1 lb glyphosate = 0.75 lb ae 2 pt atrazine = 0.56 lb 2,4-D = 0.25 lb ae 1 oz prosulfuron = lb primisulfuron = lb 0.75 oz nicosulfuron = lb rimsulfruon = lb 4 oz halosulfuron = 0.03 lb dicamba = lb ae Arsenal 2AS = fl oz Dual II Mangum 7.64EC = 2.1 pt Callisto 4SC = 6.4 fl oz AAtrex 4L = 1.5 pt Banvel 4S = pt AAtrex 4L = 1.56 pt Beacon 75WDG = 0.50 oz Banvel 4S = 4 fl oz AAtrex 4L = 2 pt Roundup 3L = 2 pt AAtrex 4L = 1.13 pt Salvo 5E = 0.4 pt Peak 57WDG = 0.25 oz Beacon 75WDG = 0.57 oz Accent 75DF = 0.5 oz rimsulfuron = lb ai Permit 75WSG = 0.67 oz Banvel 4S = 4 fl oz First, convert 2 quarts to gallons: 2 quarts 1 gallon x acre 4 quarts = 0.5 gallon Next, we can calculate how much acetochlor and atrazine active ingredient are contained in 0.5 gallon of Harness Xtra 5.6L. 0.5 gallon 3.1 lb ai acetochlor x acre gallon = 1.55 lb ai acetochlor per acre 0.5 gallon 2.5 ai atrazine x acre gallon = 1.25 lb ai atrazine per acre Finally, we can also determine product equivalents based on these active ingredient amounts: 1.55 lb ai acetochlor 1 gallon Harness 8 pints x x acre 7 lb ai gallon = 1.77 pints Harness 7E 1.25 lb ai atrazine 1 gallon AAtrex 8 pints x x = 2.5 pints AAtrex 4L acre 4 lb ai gallon Aaron Hager and Dawn Nordby 21

10 Table 4. Soybean herbicide premixes. Components (ai/gal Herbicide or lb) Axiom 68DF flufenacet = lb metribuzin = lb Backdraft SL imazaquin = 0.15 lb 1.35L glyphosate = lb ae Boundary 7.8EC S-metolachlor = 6.3 lb metribuzin = 1.5 lb Boundary 6.5EC S-metolachlor = 5.25 lb metribuzin = 1.25 lb Canopy 75DG chlorimuron = lb metribuzin = lb Canopy XL sulfentrazone = lb 56.3DG chlorimuron = lb Conclude Xact bentazon = 2.67 lb B&G acifluorfen = 1.33 lb Co-Pack sethoxydim = 2 lb Domain 60DF flufenacet = 0.24 lb metribuzin = 0.36 lb Extreme 2.17L imazethapyr = 0.17 lb glyphosate = lb ae Fusion 2.56EC fluazifop = 2 lb fenoxaprop = 0.56 lb Gangster V&FR flumioxazin = 0.51 lb Co-Pack cloransulam = 0.84 lb Gauntlet Co-Pack sulfentrazone = 0.75 lb cloransulam = 0.84 lb Pursuit Plus imazethapyr = 0.2 lb 2.9EC pendimethalin = 2.7 lb Rezult B&G Co- bentazon = 5 lb Pack sethoxydim = 1 lb Storm 4S bentazon = 2.67 lb Synchrony STS 42DF acifluorfen = 1.33 lb chlorimuron = lb thifensulfuron = lb If you apply/acre You have applied (ai) Product equivalents 13 oz flufenacet = lb Define 60DF = oz metribuzin = lb Sencor 75DF = 2.36 oz 2.5 qt imazaquin = lb Scepter 70DG = 2.14 oz glyphosate = lb ae Roundup 3L = 1.47 pt 2 pt S-metolachlor = 1.57 lb Dual Magnum 7.62E = 1.65 pt metribuzin = lb Sencor 75DF = 8 oz 2.4 pt S-metolachlor = 1.57 lb Dual Magnum 7.62E = 1.65 pt metribuzin = lb Sencor 75DF = 8 oz 6 oz chlorimuron = lb Classic 25DF = 2.56 oz metribuzin = 0.24 lb Sencor 75DF = 5.14 oz 6.8 oz sulfentrazone = lb Authority 75DF = 4.25 oz chlorimuron = 0.04 lb Classic 25DF = 2.56 oz 1.5 pt (B) + bentazon = 0.5 lb Basagran 4S = 1 pt 1.5 pt (G) acifluorfen = 0.25 lb Blazer 2S = 1 pt sethoxydim = lb Poast 1.5E = 2 pt 10 oz flufenacet = 0.15 lb Define 60DF = 4 oz metribuzin = lb Sencor 75DF = 4.8 oz 3 pt imazethapyr =0.063 lb Pursuit 2AS = 4 fl oz glyphosate = lb ae Roundup 3L = 1.47 pt 8 fl oz fluazifop = lb Fusilade DX 2E = 8 fl oz fenoxaprop = lb Puma 1EC = 4.48 fl oz 2 oz (V) + flumioxazin = lb Valor 51WDG = 2 oz 0.6 oz (FR) cloransulam = FirstRate 84WDG = 0.6 oz 5.33 oz sulfentrazone = 0.25 lb Authority 75DF = 5.33 oz oz cloransulam = lb FirstRate 84WDG = 0.6 oz 2.5 pt imazethapyr = lb Pursuit 2AS = 4 fl oz pendimethalin = 0.84 lb Prowl 3.3EC = 2 pt 1.6 pt (B) + bentazon = 1.0 lb Basagran 4S = 2 pt 1.6 pt (G) sethoxydim = 0.20 lb Poast Plus 1E = 1.6 pt 1.5 pt bentazon = 0.5 lb Basagran 4S = 1 pt acifluorfen = 0.25 lb 0.5 oz chlorimuron = 0.01 lb thifensulfuron = lb Blazer 2S = 1 pt Classic 25DF = 0.64 oz Harmony GT 75DF = oz REGIONAL REPORTS Northern Illinois Some fieldwork occurred prior to the middle of the week of March 22. Precipitation at that time and continuing through the past week has stopped most field activity. Tasks that did occur focused on dry fertilizer application, nitrogen application on wheat, and limited alfalfa and oat seeding. Alfalfa and wheat appear to have survived the winter very well. Jim Morrison, Extension educator, reported wheat in the Rockford Freeport area at Feekes stages 3 and 4, and alfalfa height at 2 to 3 inches. Southern Illinois Widespread thunderstorms during the past week have brought fieldwork to a halt. Prior to the rain, field operations had included anhydrous ammonia applications and some seed bed preparation. Along with the rain, these storms brought this year s first intense captures of black cutworm moths. Ron Hines, at the Dixon Springs Agricultural Center, reports intense black cutworm moth captures in Pulaski and St. Clair counties, with projected cutting dates around the last week of April. Most of the wheat acreage has had nitrogen applied and appears to be in excellent condition. Wheat growth stage ranges from Feekes 5 to 6, depending on location and planting date. If Harmony hasn t been applied yet, it needs to be applied very soon. Winter annual weeds are becoming more obvious, with henbit and purple deadnettle beginning to bloom in fields that did not have fall herbicide applications made. West-Central Illinois Some corn was planted on March 18 to 20, but heavy rains and cold weather have stopped all fieldwork since then. Tillage equipment and planters are hooked up and will be in the fields as soon as weather conditions permit. With the recent rains, wheat and alfalfa fields have greened up consider- 22

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12 U of I Extension Newsletter Service University of Illinois at Urbana-Champaign 528 Bevier Hall, MC S. Goodwin Avenue Urbana, IL ably. Almost all nitrogen has been applied to wheat, and some Harmony for garlic control has also been applied in the southern part of the region. Alfalfa plant height measurements will begin in a couple of weeks and will be recorded on the PEAQ Web site. Check the Web site to determine when first harvest should begin. Black cutworm moth traps have been distributed around the region, and intense capture numbers will be reported in future issues of the Bulletin. Contributing Authors Suzanne Bissonnette Champaign Extension Center, (217) Kelly Cook (kcook8@uiuc.edu), Extension Entomology, (217) Mike Gray (megray@uiuc.edu), Extension Entomology, (217) Aaron Hager (hager@uiuc.edu), Extension Weed Science, (217) Dawn Nordby (dnordby@uiuc.edu), Extension Weed Science, (217) Kevin Steffey (ksteffey@uiuc.edu), Extension Entomology, (217) Published by University of Illinois Extension and Information Technology and Communication Services, College of Agricultural, Consumer and Environmental Sciences, University of Illinois. Editor: Erin Cler; formatter: Virginia Cuppernell. Copyright 2004, Board of Trustees, University of Illinois Helping You Put Knowledge to Work University of Illinois U.S. Department of Agriculture Local Extension Councils Cooperating University of Illinois Extension provides equal opportunities in programs and employment. 24