No. 1 May 10, 2007
Inside this Issue... Here’s a summary of the releases and new labels: 1) Latitiude (Gustafson LLC; active ingredients: 25% Updates for the 2007 Insect Management Guide ...... 1 imidacloprid, 14% carboxin, 1% metalaxyl) for protection Time to Scout for Cutworms in All Field Crops!...... 2 of seeds and seedlings of field corn, sweet corn, popcorn 2007 Section 18 ...... 2 and sorghum against seed corn beetles, seed corn maggots, and wireworms as well as seedling diseases caused by Grasshoppers Active in Pastures / Rangelands ...... 3 Pythium and Phizoctonia. Apply as a seed treatment in the Managing Soybean Aphid Short Course Videos ...... 4 planter box prior to planting. Delayed Corn Planting - 2007 ...... 5 2) Mustang Max (FMC Corporation, active ingredient: New Extension Plant Pathologist Joins NDSU ...... 5 zeta-cypermethrin) has a new label that includes Two Products Receive Section 18 Registration ...... 5 sunflowers, canola, potatoes, alfalfa, and grass grown for seed, forage or hay. For sunflower, Mustang Max label Correction - Potato Leak Control...... 5 includes seed weevils, sunflower beetles, stem weevil and Proline Registered for Dry Beans, Canola, and others . . 6 other major sunflower insect pests. For canola, label 2006 NDSU Small Grain Fungicide Results Available . 6 includes flea beetles, grasshoppers, cutworms, and New Fungicide Registrations for Wheat and Barley . . . 6 Lepidopterous insect pests. Major insect pests of potato that are on label are cutworms, leafhoppers, aphids, and Label Information for the above Fungicides ...... 6 Colorado potato beetle. Please see label for other crops. Corn Following Wheat - Disease Risks...... 6 3) Capture LFR (FMC Corporation; active ingredient: Wheat Following Corn - Scab Risk ...... 6 bifenthrin) ) has a new label that includes at-plant uses for Sugarbeet Crop Update ...... 7 dry beans and potatoes for control of grubs, seed corn maggots, and wireworms. This is good news because Projections for 2007 Sugarbeet Crop ...... 7 producers have been looking for an alternative to control Buyer Beware...... 7 wireworm in potatoes and dry beans. Capture LFR will Nitrogen Rates for Corn...... 7 directly mix into liquid fertilizer for controlling insects at- Sign up for
1 North Dakota State University CROP & PEST REPORT May 10, 2007
TIME TO SCOUT FOR CUTWORMS IN ALL Cutworm control involves the use of postemergence FIELD CROPS! foliar insecticides applied as a rescue treatments. Early season cutworm activity has been reported in Insecticide application is recommended in evening hours winter wheat in the southern tier and in canola in the north when cutworms are active. Treat if cutworms exceed the central regions of North Dakota. There are many different threshold and are 1-inch or less in length. Cutworms species of cutworms. When soil temperatures are above larger than 1-inch are mature and likely to pupate (cease 40F, cutworms will become active. Cutworms damage feeding) before causing significant crop damage. Field plants by chewing and/or cutting the plant in the early crops with preventative treatments applied at or before stages of crop development. Generally, cutworms destroy planting (seed treatments) have given erratic control (only more of the plant then they eat. Their numbers vary suppression), especially when cutworm numbers are high. greatly from year to year and when numerous may destroy Also, most fields do not have a cutworm problem every 50-75% of a crop! Cutworms feed at night and hide in year so preventative treatments are unnecessary. soil during the day. Cutworm feeding activity usually Insecticides applied at planting time may be advisable if extends from May through the end of June and young replanting is necessary due to cutworm problems and emerging plants are the most susceptible stage of crop cutworms are 1-inch or less in length. Wet soil conditions development. will also improve insecticide efficacy, as cutworm fed near the soil surface in these conditions. Please see “2007 North Dakota Field Crop Insect Management Guide” for list of insecticides available on different field crops.
2007 SECTION 18: TWO PESTICIDES ARE NOW AVAILABLE TO PROTECT THE STATE’S $23 MILLION HONEY CROP FROM VARROA MITES AND SMALL HIVE BEETLES The U.S. Environmental Protection Agency approved North Dakota’s request for Section 18 exemptions for Checkmite+ Bee Hive Pest Control Strips to control small hive beetles and Hivastan to manage varroa mites. Both small hive beetles and varroa mites can be devastating to beekeepers and can completely kill all bees Cutworm (photo courtesy Clemson University - USDA Cooperative Ext. Slide Series, www.forestryimages.org) in a hive if left uncontrolled. The exemption for Hivastan was needed because the resistance of varroa mites to Scout fields once a week beginning with plant many previously-effective insecticides is widespread. emergence. Once plants are larger, little additional injury Both exemptions allow use of the products inside will occur, for example, 6-leaf stage corn minimizes beehives. The use directions for both products prohibit cutworm injury. Look for symptoms of leaf feeding use inside hives during honey flow. The exemptions (holes) and/or cut plants at several locations in each field. expire Feb. 1, 2008. Hivastan is manufactured by Pay special attention to poorly drained areas or places Wellmark International; Check-Mite Strips are where weeds were present before planting. If cut plants manufactured by Bayer HealthCare Animal Health are found, examine the soil around injured plants for Division. North Dakota is the nation’s leading honey- cutworms. producing state. In 2006, the state produced 25.9 million Economic thresholds vary depending on the field crop: pounds or 17 percent of the nation’s honey crop. For labels, see ND Department of Agriculture website below: • Canola – 1 per square foot • Small grains – 4 to 5 cutworms per square foot http://agdepartment.com/Programs/Plant/Section18Exemp • Corn – 3 to 6% of the plants cut and small larvae less tions.html than 1-inch present • Soybeans / Dry beans – 1 or more larvae per three feet of row or 20% of plants cut • Sunflower – 1 per square foot or 25-30% of plants cut • Alfalfa – 4 to 5 or more per square foot (new stands – only 2/sq ft) • Lentils – 2 to 3 cutworms per square meter (Canada) • Peas – 2 to 3 cutworms per square meter (Canada) Early detection is critical for effective control.
2 North Dakota State University CROP & PEST REPORT May 10, 2007
GRASSHOPPERS ACTIVE IN PASTURES / RANGELANDS Decrease when . . . The recent rains have improved the forage situation in • Warm early spring pastures and rangelands. High population of rangeland premature hatch grasshoppers have been observed emerging in the North IF get a cold snap - poor development Central Region of North Dakota. Rangeland grasshopper • Hot period in early spring . . . species that are economically important in North Dakota promotes hatching include whitewhiskered, bigheaded (see photograph), . . . following by cloudy, wet weather migratory, Dawson’s, to name a few. favors the occurrence of disease • Cool summer and early fall delays the maturity of the grasshoppers shortens the time for egg laying
Increase when . . . • Cool, wet weather in early spring prevents premature hatch insures adequate food supply • Warm and dry in late spring promotes uniform hatching time good weather conditions for feeding • Hot summer with adequate rainfall provides good food supply low incidence of disease • Late fall Big-headed grasshopper (photo by G. Fauske, NDSU) long egg laying period Figure 1. Effects of weather on grasshopper populations See ND Grasshopper website.
www.ndsu.nodak.edu/entomology/hopper/orthoptera_home.htm Grasshopper activity and feeding begins as temperatures in their micro-habitat rise above 65-70F. Grasshoppers cause defoliation by directly feeding on the Cool-season grasses such as needlegrasses, wheatgrasses, leaf and stem tissues and cutting off leaves or stems. and bluegrasses begin growth before most grasshoppers High populations of grasshoppers in pastures or rangeland become active, and grow most rapidly when air can damage the plant crowns and grass plant may die temperatures are 65-75F. By the time infestation of under drought conditions. Rangeland grasshoppers rarely grasshoppers begin to heavily defoliate plants, cool- feed on field crops, except during years of very high season grasses have completed their growth and recharged populations, with the exception of migratory energy reserves needed for spring growth next year. grasshoppers. Most of the rangeland grasshoppers Warm-season grasses such as bluestems, grama grasses, overwinter as partial grown nymphs whereas most field and buffalograss do not begin growth until May-June and crop grasshoppers overwinter as eggs. As a result, the grow most rapidly when temperatures are 85-95F. rangeland species emerge earlier and as ‘large’ Consequently, grasshoppers are most likely to damage grasshopper nymphs, which usually become adults by the warm-season grasses because they don't complete their end of May or early June. growth until late summer. Grasshoppers are cool-blooded and profoundly Economic thresholds for grasshopper densities in affected by temperature and relative humidity in their pasture or rangeland vary from eight to 40 grasshoppers micro-environment. Warm temperatures can speed up per square yard. A program developed by USDA-APHIS grasshopper development where as cool temperatures called “Hopper” can be used to determine the threshold in retard all development. Increasing the time required for individual situations depending on the cost of the grasshoppers to mature generally increase juvenile insecticide, and projected forage yield and value. Please mortality, which reduces defoliation and the number of see website: eggs produced for next year’s grasshopper population. http://www.sidney.ars.usda.gov/grasshopper/Support/index.htm See Figure 1 for the effects of weather on grasshopper populations. For monitoring, one can count the number of grasshoppers hopping away from a visually delineated square yard or square foot areas as the scout slowly walks towards the marked area. However, the standard 15-inch sweep net is the most reliable and easiest method. Four 180-degree sweep equals a square yard and the number of
3 North Dakota State University CROP & PEST REPORT May 10, 2007
grasshoppers can be counted. MANAGING SOYBEAN APHID SHORT COURSE If grasshopper populations are above action VIDEOS AVAILABLE ONLINE thresholds, insecticides can be applied as a foliar spray or If you missed the short course “Managing Soybean bait. An early application to grasshopper hatching areas is Aphids in 2007: How Will Biological Control recommended to reduce high populations while Contribute?” that was held on March 6, 2007, videos grasshoppers are in early nymphal stages (young (audio recordings synchronized with PowerPoint grasshopper nymphs are easier to control). Insecticides presentations) are now accessible from the North Central registered for use on pastures or rangeland for grazing or IPM Center Web site: cut hay include: malathion, zeta-cypermethrin (Mustang Max), dimilin (insect growth regulator) and carbaryl http://www.ncipmc.org/teleconference/soybean2007/videos/ (Sevin). See “2007 North Dakota Field Crop Insect Management Guide” or label for rates. Always read The following topics were discussed during the short labels thoroughly before using any insecticide, and course and are available as separate video: observe safety, pre-harvest intervals and grazing restrictions. Insecticide baits, once the most popular • History and biology of the soybean aphid - David control method, have been replaced by foliar insecticide Voegtlin, Illinois Natural History Survey, sprays. However, baits are still used occasionally in some Champaign, Illinois circumstance on rangeland with short, dry vegetation. • Review of the situation with soybean aphids in the Carbaryl (Sevin) 5% bait is available. Some grasshopper Midwest - David Ragsdale, University of Minnesota, species do not feed on baits so control may be limited. St. Paul Attractiveness of bait affects efficacy and is reduced by • Biological control of soybean aphids: What is it, and rain and heavy dew. what do we have to work with in the Midwest - Bob Research at the University of Wyoming has O'Neil, Purdue University, West Lafayette, Indiana demonstrated the effectiveness of a new grasshopper • The players: Predators, parasitoids, and pathogens-- control strategy in rangeland called RAATs (Reduced Dan Mahr, University of Wisconsin, Madison; Kelley Agent/Area Treatment). The most effective insecticide Tilmon, South Dakota State University, Brookings used with this method is Sevin XLR (ultra low volume, • Practices to conserve and use natural enemies in aerial application) or dimilin. Sevin XLR is applied at soybean aphid IPM - Matt O'Neal, Iowa State half the recommended rate (8 fl oz per acre) instead of the University, Ames full rate (16 fl oz per acre). In addition, only 50% of the • Introducing new natural enemies into the U.S. - Bob area is treated leaving every other spray strip untreated. O'Neil This methods cuts control costs and lowers the • Foreign exploration - Kim Hoelmer, USDA-ARS, populations of grasshoppers in rangeland. Grasshopper Newark, Delaware control in the RAATs area lags behind control in full rate • Host specificity testing - George Heimpel, University areas; however, in six days after treatment both treatments of Minnesota, St. Paul showed the same level of control. The reasons for this • Studies with non-target aphids - Cory Straub and dramatic control are believed to be due to grasshopper Claudio Gratton, University of Wisconsin, Madison movement into the treated strips while the insecticide is • Preparing for soybean aphids in 2007: Management still effective, and to the preservation of natural enemies guidelines, and the potential for biological control - in the untreated strips. • Chris DiFonzo, Michigan State University, East More information a grasshopper control on pasture or Lansing; Marlin Rice, Iowa State University, Ames rangeland is available at the following website: The short course was sponsored by the North Central http://www.sidney.ars.usda.gov/grasshopper/ Soybean Research Program.
Janet Knodel Extension Entomologist [email protected]
4 North Dakota State University CROP & PEST REPORT May 10, 2007
NEW EXTENSION PLANT PATHOLOGIST JOINS DELAYED CORN PLANTING - 2007 NDSU The rains of last week effectively stopped all planting Before I begin composing articles, giving talks, and in North Dakota and in the wetter regions of the state, interacting with people throughout the state, I wanted to planting will likely be delayed a week or more. introduce myself. My name is Sam Markell, and I joined Furthermore, fields or areas of fields that had been planted the plant pathology department at NDSU on April 16. I that have had standing water for more than three of four have the same responsibilities as my predecessor, Carl days will almost certainly need to be replanted. The Bradley, which includes diseases of broadleaf crops. question on many growers’ minds is, how late can I plant I am originally a Minnesota native, but received a corn and at what point do I need to switch to an earlier B.S. degree in biology and M.S. degree in plant pathology maturing hybrid or consider growing a different crop? at NDSU. In February, I finished a Ph.D. in plant For ND, the optimum period for planting corn is early pathology at the University of Arkansas. My reasearch May. In most years there is little or no yield reduction if projects focused on Fusarium head blight (FHB) and planting is delayed to May 20th, particularly in the stripe rust of wheat, but I have been involved with southern half of the state, so stay with your full season soybean and canola diseases as well. I am happy to be hybrid until the last week of May. For plantings during home! I look forward to meeting and working with the last week in May or first week in June, consider people in the state, and providing information on growing hybrids that are 5 days earlier in relative management of plant diseases. maturity. After the first week in June you should consider growing another crop. When considering late plantings of corn, review your crop insurance contract, as planting date TWO PRODUCTS RECEIVE SECTION 18 can affect your coverage. Late planted corn has the REGISTRATION FOR LENTIL SEED ability to “catch-up” to a limited extent by hastening its TREATMENT development. Nevertheless, a challenge with late planted Two seed treatment products received a Section 18 corn in ND is dealing with the extra grain moisture at registration on March 6 for use on lentil to control harvest. Most years limited field drying occurs after Ascochyta blight. The products are LSP Flowable (Bayer November 1st, so excessive moisture after that date must product) and Mertect 340 (Syngenta product). LSP be removed with artificial drying. With all of the extra Flowable is to be applied between 1.7 - 3.0 fl oz/cwt, acres of corn in ND this year, drying facilities will likely while Mertect 340 is to be applied at 1.05-1.85 fl oz/cwt. be inadequate, so be conservative with the relative Thiabendazole is the active ingredient in both products. maturity of the hybrids that you plant late, particularly if The Section 18 labels are good from Feb. 21 - June 1, you do not have your own drier. 2007. Label information on these two section 18 products At what point does it make sense to switch from corn may be found at: to soybeans as the optimum planting date for soybeans is later in May than corn? If you have applied all or most of http://agdepartment.com/Programs/Plant/PesticideRegProg.html the nitrogen fertilizer that was required for your corn crop, given the high price of fertilizer this year, switching to soybeans may not be a viable option. Furthermore, high CORRECTION - POTATO LEAK CONTROL nitrate levels can accentuate the iron chlorosis problem in The published NDSU 2007 Fungicide Guide (PP- soybeans. 622) indicated that Pythium leak of potato may be Although planting date influences yield, do not rush controlled with the use of sodium, potassium or out and plant when the field is too wet. Poor and uneven ammonium phosphites. Dr. Neil Gudmestad, NDSU stands that are associated with “mudding it in” will Dept. of Plant Pathology, has indicated that these negatively impact yields more than planting the crop a phosphite products, when used alone, have no efficacy on few days later. Pythium leak.
Joel Ransom Extension Agronomist for Cereal Crops [email protected]
5 North Dakota State University CROP & PEST REPORT May 10, 2007
PROLINE REGISTERED FOR DRY BEANS, Tebuconazole is to be applied at 4 fl oz/acre at early CANOLA, PULSE CROPS AND OTHER CROPS flowering for wheat and full head emergence in barley. The Bayer CropScience fungicide “Proline 480 SC” The Section 18 labels do not specify use of an adjuvant, has been granted Section 3 full-registration for use on but NDSU testing with these products indicates they canola, chickpea, lentils, dry peas, dry beans, crambe, and perform better when a non-ionic surfactant is added. field mustard. Proline is a triazole (prothiconazole) B. Proline Sec. 3 Registration: A Section 3 full fungicide, FRAC group 3, and has broad activity against registration was granted on 4/16/2007 for the use of different fungal pathogens. According to the label, Proline 480 SC fungicide on wheat and barley in ND. Proline can be used to control Ascochyta blight of lentils The registrant is Bayer CropScience. Proline is a triazole and chickpea, Sclerotinia stem blight of canola, white (prothioconazole) fungicide with a wide spectrum of mold of dry peas and beans, and Sclerotinia stem rot of activity. field mustard, crambe, and other crops. The Proline is to be applied at 4.3-5.7 fl oz/acre for recommended rate for control of diseases listed above is suppression of Fusarium head blight (FHB). (NDSU has 4.3-5.7 fl oz/acre. For more information on timing and not tested any rate lower than 5 fl oz/acre) For leaf disease rate of applications refer to the Proline 480 SC label. control, the Proline label recommends 2.8-4.3 fl oz/acre for barley and 4.3 - 5.7 fl oz/acre for wheat. NDSU’s Sam Markell testing of this product has always included a non-ionic Ext. Plant Pathologist surfactant in the tank mix. [email protected]
LABEL INFORMATION FOR THE ABOVE COMPILATION OF 2006 NDSU SMALL GRAIN FUNGICIDES can be found at the ND Dept. of FUNGICIDE RESULTS AVAILABLE Agriculture’s Web site at: A compilation of NDSU associated 2006 small grain fungicide trials may be found through the NDSU http://agdepartment.com/Programs/Plant/PesticideRegProg.html Extension Plant Pathology web site, at the following link:
http://www.ag.ndsu.nodak.edu/extplantpath/Fungicide%2 CORN FOLLOWING WHEAT - DISEASE RISKS 0Field%20Trials.pdf A few questions have been asked about the disease risk associated with planting corn after wheat. The primary These results were was provided by Extension state risk is the potential for seedling blight from Fusarium and area specialists and Experiment station agronomists graminearum or from a few other fungal species. My across ND, and represent fungicide work done on spring recommendation would be to use a seed treatment for wheat, durum wheat, barley and winter wheat during the control of seedling blights in corn. Fortunately, most corn 2006 growing season. Small grain disease pressure was seed purchased already is treated with one of the several very low across most sites in 2006, but some differences fungicides that will control seedling blights. among fungicide treatments were noted.
NEW FUNGICIDE REGISTRATIONS FOR WHEAT WHEAT FOLLOWING CORN - SCAB RISK AND BARLEY FOR 2007 Over 1100 wheat fields were surveyed statewide in 2006 A. Sec. 18 for tebuconazole: A Section 18 emergency for diseases and insects. Only 2.5% of these wheat fields exemption was granted on 4/18/2007 for use of were planted into corn ground. However, by 2008, with tebuconazole on wheat (including durum) and barley for the increased corn acreage in ND, there is the big suppression of Fusarium head blight in 2007. The possibility of this percentage going higher. The risk of exemption runs until Sept. 1, 2007. The products Fusarium head blight (scab) goes up for wheat and barley registered for use in ND under this Section 18 exemption if the crop is planted into corn ground. The scab fungus include: often inhabits corn stalks and overwinters very well in Trade Name of Tebuconazole Company those stalks. The fungus also produces many more spores on corn stalk residue than on wheat or barley residue. Folicur 3.6F Bayer CropScience Any grower planting wheat or barley into corn ground Orius 3.6F Makhteshim will have to take extra precautions, using a variety with Muscle 3.6F Sipcam the best resistance available and using an appropriate fungicide treatment if conditions favor the disease. Embrace 3.6L Agriliance Tebuzol 3.6F UPI Marcia McMullen Ext. Plant Pathologist TebuStar 3.6L Albaugh [email protected]
6 North Dakota State University CROP & PEST REPORT May 10, 2007
SUGARBEET CROP UPDATE Sugarbeet growers in North Dakota and Minnesota are off to a good start in their sugarbeet planting. American Crystal Sugar Company growers have completed planting just over 90% of their acreage. Wetter conditions in the Hillsboro and Moorhead factory districts have delayed planting in those districts. Minn- Dak BUYER BEWARE Farmers Cooperative growers have completed about 75% Although the State of North Dakota has laws on the of their planting. Growers in the west and southwest books that help screen farmers from products with areas of the Minn-Dak district have been hampered by questionable benefits, the laws have several loopholes. wet soil conditions early in the season and had significant Basically, if a product sounds too good to be true, it is. amounts of rainfall last week. Southern Minnesota Beet Fertilizers with special almost magical qualities are Sugar Cooperative growers have completed planting over especially prominent this season. Unusual fertilizer 90% of their acres. products are registered based on their guaranteed analysis, The sugarbeet crop should be off to a good start since then the “magic” is added to the marketing later. The the warm soils and adequate moisture will accelerate following are important questions to ask when evaluating germination and emergence. It would be useful to have a a product- cover crop to protect seedlings especially on soils that Can I see the data from unbiased, non-company ‘blows’. Barley and oats at half a bushel per acre are related research? widely used as cover crops. The cover crop should be Was any of the research done locally or regionally? killed when sugarbeets are in the three to four leaf stage. If there is no data from unbiased, non-company related research, or the research was done far away, be extremely skeptical of any testimonials, or company-led PROJECTIONS FOR 2007 SUGARBEET CROP research that you see. Not all unusual products are without Total sugarbeet acreage in the US for 2007 is value. Some have demonstrated efficacy in certain projected at about 1.367 million acres; a slight reduction situations. Check the research results to see how often from 2006 because of the bumper crop last year. yield or quality improvements have been recorded. Check American Crystal Sugar Company will plant about to see if improvements are related to certain soils or 498,000 acres, Minn- Dak will plant 109,000 acres, and conditions. If your farms fit into the model of when the Southern Minnesota Beet Sugar Cooperative will plant product works best, then perhaps this product might 111,000 acres. Growers in Western North Dakota will improve your bottom line as well. plant about 15,000 acres for the processing plant in Finally, when testing a product on your farm, don’t Sidney, Montana. This means that North Dakota and “test” it on 5,000 acres. Test it on a few strips across the Minnesota will plant a total of 760,140 acres of sugarbeet field and be prepared to evaluate the results using a yield which is about 54% of the US sugarbeet acreage. monitor (preferred) or weigh wagon at season’s end. A Growers will be continue their efforts at improving satellite image of the farm prior to heading/tasselling can efficiency by properly preparing seed beds, using starter also show differences in a field from the strip application fertilizer, using adequate seeding rate to start with a good of product. plant stand and timely application of herbicides for In the end, the law can only protect buyers to a point. effective weed control to give their crop a good The phrase “buyer beware” has never been more foundation. applicable than this planting season.
Mohamed Khan Extension Sugarbeet Specialist NITROGEN RATES FOR CORN 701-231-8596 Nitrogen recommendations across the corn-belt have been changed radically during the past two years based on a reevaluation of hundreds of site-years of corn nitrogen rate trials from Minnesota to Ohio. The recommendations were changed due to the inability of formulas like 1.2 X Yield Goal to predict the economic optimal nitrogen fertilizer rate. Several common themes were observed from compiling the data across these states. One theme was that the rate of N necessary to optimize N rate in a poor-growing year was similar to the optimal N rate in a good year. Another observation was that the northern states (MN, WI) tended to have higher relative check (0 N) yields than more southern states (IA, IL). Based on these observations and data analysis with N
7 North Dakota State University CROP & PEST REPORT May 10, 2007
costs we have today, N recommendations have been decoupled to yield goal in several states, including MN. One rate is used for corn following corn, and a rate, usually 30-40 lb/a lower is used for corn following soybean. In NW MN, using a percentage of the residual nitrate determined with a 2-foot soil test is subtracted from the table N rate for the soil. In North Dakota, our corn N-rate database comes SIGN UP FOR
8 North Dakota State University CROP & PEST REPORT May 10, 2007
AERIAL APPLICATION OF HERBICIDES ACETOCHLOR LABEL REVISION ALLOWING Recent rains have delayed herbicide applications and MORE CROP ROTATIONS have created a greater interest in aerial application. It was Acetochlor is being re-registered through EPA and, suggested that we point out a source to quickly determine when complete, one of the results will be an increase in if a herbicide can be applied aerially. Certain product the number of crops that can be planted the year following listings in the North Dakota Weed Guide show the application. Currently, the only crops that can planted the following icon: year following acetochlor is corn, soybean, wheat, and sorghum. Many people are asking when the acetochlor (Harness, Surpass, others) labels will be revised to allow crop rotation to most crops grown in North Dakota and If the herbicide listing has this symbol it means that Minnesota. no aerial application is allowed. If there is no symbol in the listing then aerial application is allowed. There are It has not happened yet. only a few herbicides where aerial application is not allowed. The following is a short list of herbicides that are Dow (Surpass) and Monsanto (Harness) registration restricted from aerial application: people anticipate it will be soon. When EPA does approve Far-Go, Buckle, acetochlor, Balance Pro, Permit, of these follow crops I will get a message out on Camix, Lumax, Python, linuron, and Crossbow.
once they are found outside of quarantined areas. Unfortunately, eradication of EAB appears to be a losing battle as the high cost and difficulty in detecting the beetle early before it spreads has hindered this effort.
EMERALD ASH BORER UPDATE Exotic (non-native) tree pests are among the greatest threats to forest and shade trees of North America. The emerald ash borer (EAB) is a devastating insect pest of ash trees that has drawn regional and national attention in recent years. Native to eastern Asia, the insect was first discovered near Detroit MI in 2002. Scientists believe that it was unintentionally brought into the U.S. through infested ash crating or pallets. Since its initial discovery, the insect has been found in southeast Michigan, adjacent Ontario (Canada), and several counties in Ohio, Indiana, and Maryland. Two new infestations were detected near Emerald Ash Borer adult (D. Cappaert, MI St. Univ.) Chicago, IL in 2006. The damage caused by this pest has been astonishing. If the EAB becomes established in North Dakota, the Unlike native ash-boring beetles that only kill weakened impacts will be overwhelming. Green ash is one of the and dying trees, EAB attacks all ash trees regardless of most abundant species in the North Dakota’s forests and their vigor, size, or age. Nearly 25 million ash trees have woodlands. Similarly, ash species and cultivated varieties been destroyed by the insect to date. are some of the most common within the state’s Quarantines have been imposed in infested areas to community forests and rural tree plantings. The cost of restrict the interstate movement of regulated materials and removing dead ash trees would be a huge financial burden prevent the spread of the insect to un-infested areas. to city governments. The loss of ash within riparian Materials regulated by the quarantines include firewood, forests would negatively impact water quality and wildlife nursery stock, green lumber, and other living or dead ash habitat. In addition, the loss of ash within the state’s material. In addition, eradication efforts have been farmstead and field windbreaks would have a considerable employed to eliminate the insect from new infestations effect on rural residents.
9 North Dakota State University CROP & PEST REPORT May 10, 2007
The insect’s rate of natural spread is relatively In addition, North Dakotans are encouraged to slow as adult beetles can only fly about 1 mile. incorporate diversify into tree plantings. There has been Although this rate of spread suggests that the beetle an over-reliance on the use of ash over the past 2 decades will not reach the Plains States for many years, the and now there is an overabundance of ash in our rate of spread is increased substantially by human communities and rural tree plantings. As such, these activities. Human activities that augment the EAB’s plantings are at risk to EAB. As a rule, diverse tree spread include: 1) movement of ash firewood from plantings are more resilient to damaging factors (including infested areas to un-infested areas and 2) shipment of climate, insects, diseases, etc…). Tree species selection infested nursery stock and low-grade packing material should not hinge on substituting one single species for from infested areas to un-infested areas. another, but rather, diversifying the overall species The insect completes the juvenile portion its life cycle composition of the planting. That is, don’t put all your beneath the bark of ash trees and logs. Often, infested eggs in one basket. trees and logs may show no obvious external symptoms of Lastly, stay current with the status of this pest. The infestation. When infested material is moved to a new emerald ash borer website (www.emeraldashborer.info) is location, the adult insect emerges and seeks new ash trees the best location to find current information about EAB. to attack. Consequently, a shipment of infested ash trees arriving in North Dakota or a person bringing a load of Michael Kangas infested firewood into the state could introduce the pest at Forest Health Specialist any time. The nursery industry has been cooperative with North Dakota State Forest Service the restrictions placed on the shipment of ash plant [email protected] material and few North Dakota nurseries receive ash from states near the quarantined areas. The transport of firewood by campers, sports persons, and firewood dealers has emerged as the most important spread of EAB as the regulation and enforcement of this mode of spread have been limited. Although the EAB is still several states away, all North Dakotans must take action now to help prevent the spread of this beetle into the state. Adequate techniques to SUBMITTING SAMPLES TO THE NDSU PLANT manage this pest are currently lacking and the sole cost- DIAGNOSTIC LAB effective choice is to remove and destroy infested trees. County extension agents have been learning to use a Therefore prevention of its arrival into the state is the only new database to submit sample information and images realistic option. If its arrival can be delayed for one or for samples submitted to the NDSU Plant Diagnostic Lab. more decades, the tools needed to manage this pest Using this database, samples from anywhere in the state effectively might exist and some of North Dakota’s ash can be checked into the NDSU Plant Diagnostic Lab right resource will be spared. All citizens can help stop the from the county offices. Information and images can be spread of this insect into our state. If someone you know uploaded directly into the database, ultimately saving time is planning a trip to North Dakota, tell them to leave their and hopefully leading to faster turnaround times for firewood at home and only use local firewood sources. diagnoses. County agents are encouraged to use this system, although it is not required. The NDSU Plant Diagnostic Lab generally examines samples on a ‘first-come-first-serve’ basis, but certain samples (such as suspected high risk pests/pathogens and samples where a timely diagnosis is required for appropriate treatment) must take priority. For more information on how to submit samples to the NDSU Plant Diagnostic Lab, please see the following website, http://www.ag.ndsu.nodak.edu/diaglab/, where you can obtain a lab form and tips on submitting good quality samples. Before submitting a sample to the NDSU Plant Diagnostic Lab, please first consider using your local county extension agent or other local expertise. A nominal fee of $15 for North Dakota residents ($25 for non- residents) helps offset the cost of lab supplies and for technical support. Emerald Ash Borer galleries (Art Wagner, APHIS-PPQ)
10 North Dakota State University CROP & PEST REPORT May 10, 2007
UPDATE FROM THE NDSU PLANT According to Kangas, the damage (see photograph) DIAGNOSTIC LAB has only been observed on Bur Oak in North Dakota, and From January 1 to May 3, 2007, the NDSU Plant not yet found on additional hosts (elms, cherry). Diagnostic Lab has received at least the following Kangas further encourages homeowners to continue samples: to consider using Bur Oak, since it is “a long-lived, drought-tolerant, cold-hardy species that is well adapted Sample Category Number for the northern plains,” and it is unknown if this new pest Seed Health/Phytosanitary 299 is an outbreak or part of a normal periodic event. Woody ornamental (evergreen) 7 Chemical controls are not recommended at this time, Field Crop 5 since efficacy is not known. Rather, pruning out affected Woody ornamental (deciduous) 4 limbs may be helpful. Severely infested trees should be Turf 3 removed. Older trees reportedly are not severely affected Soil – SCN extraction 1 by this suspected pest. Natural predators of this pest include birds (woodpeckers) and carpenter ants. Plant/Mushroom ID 1 Maintaining tree vigor is always advised, since stressed Insect ID 1 trees are more attractive to these types of beetles. Miscellaneous – drain tile 1 Total 322
Among the woody ornamental evergreens, winter injury or other environmental stress was the most common diagnosis, followed by possible root injury (mechanical or chemical). Root injury or soil-applied herbicide injury was suspected in at least two spruce situations. Spider mite injury was observed on at least 2 samples, but the spruce spider mite was only observed on one sample. Such mite injury probably occurred in prior years, and it was secondary to the primary problems faced by those particular samples. No needle cast disease has been diagnosed yet this season. It has been a drier and warmer April, which does not favor disease development. So, hopefully needle cast will not be a problem in 2007. Cytospora canker has been diagnosed on at least two spruce samples this year, based on symptoms alone (dead limbs, excessive sap production, no obvious mechanical A twig of Bur Oak infested with pupae of an wounds). A diagnosis for Cytospora canker is much more unidentified borer beetle; the shredded bark results reliable if the fungal fruiting bodies are detected, but this from woodpeckers seeking the tasty but damaging usually requires submission of the entire limb (all the way insect pests. back to the trunk of the tree), and for obvious reasons, this Kasia Kinzer is often deemed impractical by the homeowner. NDSU Plant Diagnostic Lab e-mail: [email protected] Telephone: 701-231-7854 A BUR OAK PEST PREVIOUSLY UNKNOWN TO NORTH DAKOTA A borer beetle has been detected on at least two bur oak samples that have come to the lab. Several other samples have been submitted to Michael Kangas (Forest Health Specialist, North Dakota Forest Service) and others. The identity of this borer beetle has not yet been confirmed. NDSU entomologists are currently processing the samples. Per Kangas, this pest has been observed “on young bur oak trees in several locations of eastern North Dakota as of 4/16/07.” Species identification depends on observing the adult beetles. The species is suspected to be the living beech borer (Goes pulverulentus), but emphasis must be made that this is a tentative identification and it cannot be confirmed until the adults emerge.
11 North Dakota State University CROP & PEST REPORT May 10, 2007
South-Central ND Southwest ND
The geographic area covered by this report includes a Rainfall this past weekend kept producers out of the field northern border of Eddy County to Sheridan County for at least the first couple of days of this week and southward to Emmons County through Sargent County. probably will keep them out of some fields for at least two During the past week (May 1-7), most of the region more days. Rainfall totals at the NDAWN sites in received a ‘million-dollar rain’, ranging from 0.7 to 2.2 southwest North Dakota for the week ranged from 0.71 inches, based on NDAWN (North Dakota Agricultural inches at Mott to 1.95 inches at Watford City. Reports of Weather Network). However, Barnes, LaMoure, Ransom, heavier rainfall of up to 2.25 inches at other locations Dickey and Sargent counties received rainfall ranging up have been received. This was a well timed precipitation to 4 to 8 inches. event for getting spring seeded crops off to a good start. Prior to this past weekend’s rain, early no-till seeded Winter wheat fields generally have adequate plant density wheat and barley were beginning to emerge. Precipitation and are actively tillering. during the time period of November through March was Alfalfa appears in good condition. Seeding of spring nearly an inch less than normal. Early April snow at wheat and barley acres will essentially be complete by Dickinson and showers during the remaining part of that May 12. Fields seeded in April are in the 1- to 2-leaf stage month brought April’s precipitation to within 0.01 of an of growth. As of May 8, 25 to 50 percent of corn acres inch of normal or 1.42 inches. , Where soils were bare have been planted. This week’s planting emphasis will be from tillage, extreme wind last week caused severe on corn as soil conditions allow planting to resume. erosion exposing seed in some areas of the field and Soybean planting also will begin this week. burying seed deeper in other parts of the field.
Greg Endres Winter wheat growth is excellent but there is some Area Extension Specialist/Cropping Systems concern about early season tan spot on the crop. Early NDSU Carrington Research Extension Center seed spring wheat, barley, canola and corn that was [email protected] seeded at the end of April has emerged. Soil temperatures have been favorable for germination and emergence. Alfalfa development is progressing well with plant height at about 4 to 8 inches.
Cutworms were found in winter and spring wheat fields this past week in the Beach and Dickinson area but not at economically damaging levels. This past fall the cutworm moth trap network caught a few months as they migrated to fields to lay eggs. However, trap catches indicated a medium or high risk for injury from this pest for this spring. However, since trap locations are few and far between there is always a possibility that last fall that moths could have avoided the traps and found a home to lay eggs in your field. Be sure to scout areas where crop stand appears to be diminishing or slow to emerge. Additional information on the cutworm trap survey can be found at http://www.cutworm.org. Click on Maps.
Roger Ashley Area Extension Specialist/Cropping Systems Dickinson Research Extension Center Email: [email protected]
12 North Dakota State University CROP & PEST REPORT May 10, 2007
13 North Dakota State University CROP & PEST REPORT May 10, 2007
14 North Dakota State University CROP & PEST REPORT May 10, 2007
F. Adnan Akyüz, Ph.D. Assistant Professor of Climatology North Dakota State Climatologist http://www.ndsu.edu/ndsco/
15 North Dakota State University CROP & PEST REPORT Extension Entomology Hultz Hall 202 Fargo, ND 58105-5346
Janet Knodel, Co-Editor Soils Entomology 231-8881 phone 231-7582 phone 231-7861 fax 231-8557 fax
Sam Markle, Co-Editor Weeds Plant Pathology 231-7972 phone 231-8866 phone 231-8474 fax 231-7851 fax
Plant Sciences Ag Engineering 231-7972 phone 231-7236 phone 231-8474 fax 231-1008 fax
Helping You Put Knowledge To Work The information given herein is for educational purposes only. References to a commercial product or trade name is made with the understanding that no discrimination is intended and no endorsement by the North Dakota Extension Service is implied.
NDSU Extension Service, North Dakota State University of Agriculture and Applied Science, and the U.S. Department of Agriculture cooperating. Duane Hauck, Director, Fargo, North Dakota. Distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914. We offer our programs and facilities to all persons regardless of race, color, national origin, sex, handicap, age, Vietnam era veterans status, or sexual orientation; and are an equal opportunity employer. This publication will be made available in alternative formats for people with disabilities upon request (701) 231-7881.
NDSU Crop and Pest Report http://www.ag.ndsu.nodak.edu/aginfo/entomology/ndsucpr/index.htm