Integrated Pest & Crop Management Newsletter University of Missouri-Columbia Vol. 15, No. 5 April 15, 2005 ******************************************************************** Marketing of Grain from Corn Hybrids with the "NK603" Biotech Event By Bill Wiebold ******************************************************************** Spring may seem like an odd time to contemplate grain marketing. But, corn growers ought to consider possible marketing channels during hybrid selection and spring planting. Smart channeling of grain from some hybrids is essential to the well-being of all U.S. corn producers. Early consideration gives producers time to explore options. Marketing corn grain can be complicated if it is produced by hybrids that carry one or more biotech traits. Seed companies must provide U.S. and foreign government agencies large amounts of data on each biotech trait and any combination (stacked) of biotech traits before grain is approved for feed (animal) and food (human) purposes. The three most important government entities for US grain marketing are the United States, European Union and Japan. The National Corn Growers Association http://www.ncga.com/biotechnology/know_where/index.html provides a listing of the approval status of biotech corn events for each of these three markets. The most difficult market in which to gain approval is the European Union. Seed companies will usually market hybrids if the biotech event (or events) is approved in the United States and Japan. It is highly recommended that corn grain containing biotech events that are not approved in all three markets be carefully channeled to prevent disruption in the export market. This means that grain not approved for export to the E.U. should be used for on-farm livestock rations, sold to domestic livestock feeding channels or delivered to elevators accepting grain not yet approved for E.U. export. The American Seed Trade Association http://asta.farmprogress.com/ Web site provides information about the grain facilities accepting such hybrids. Remember that these Web sites rely on data collected from surveys and corn producers, and you should contact seed dealers and local grain buyers for the most recent information. One biotech event was recently approved by the E.U., but this approval could add to the marketing confusion if producers do not understand the details of this approval. The event, NK603, carries the trade name Roundup Ready 2, which is similar to another biotech trade name. The first glyphosate tolerant corn hybrids carried the event MonGA21 and the trade name Roundup Ready. Neither MonGA21 nor SYTGA21 (trade name GT Advantage) is accepted for import into the European Union. In addition, grain that carries the NK603 event stacked with any other biotech trait (e.g., YieldGard) cannot be imported into European Union. So, only grain from glyphosate tolerant hybrids containing NK603 as the sole biotech event can be marketed without channeling. Grain from all other glyphosate tolerant hybrids should be used on-farm or sold to faculties that are willing to accept grain not approved by the European Union. Glyphosate tolerant corn hybrids are a useful weapon in controlling problem weeds, but they should be part of an integrated crop management plan that limits the development of resistant weeds Knowledge of which biotech event is present and if it is stacked with other biotech events is essential to smart marketing. Bill Wiebold, Agronomy 573-882-0621 ******************************** Alfalfa Weevil Problem in 2005 By Wayne Bailey ******************************** Problems with alfalfa weevil larvae began in southern Missouri this past week with some fields requiring an insecticide application. The alfalfa weevil grows through 4 worm stages or instars with the smallest larvae hidden in plant growing points. During the past two weeks high numbers of small larvae have been dissected from the growing points of alfalfa plants in southern Missouri. Damage from 1st and 2nd instars is often hidden or sometimes seen as small holes in the leaflets forming plant growing points. Small larvae often are missed or may remain in the plant growing point when sampled by the bucket method. In contrast, 3rd and 4th instar larvae are readily observed and can significantly damage alfalfa plants by consumption of leaf tissue. Economic damage from alfalfa weevil throughout the southern region of the state is expected to increase during the next two weeks. Problems with this pest are expected to move northward as larvae emerge from eggs and begin feeding in central and north Missouri counties. Although larval numbers are high and some applications of insecticide have been needed, recent wet weather may initiate a fungal pathogen which can cause the alfalfa weevil larval population to collapse within a few days after they are infected. Spring weather has a strong influence on whether or not alfalfa weevil become a major problem this spring. Dry to normal conditions favor the survival of the alfalfa weevil larvae, whereas, wet conditions favor the fungal pathogen that often kill larvae. At this time producers in southern and central Missouri counties are encourage to scout for alfalfa weevil larvae in fields. Wayne Bailey Entomology 573-882-2838 or 573-864-9905 ************************************************** Herbicide Options for Bermudagrass Establishment By Kevin Bradley and Rob Kallenbach ************************************************** As the time for sprigging bermudagrass approaches in Missouri, it is important for producers to consider the impact weed infestations can have on the success of these newly established stands. Although established bermudagrass stands are often characterized by their thick, dense monocultures that outcompete most weed invaders, newly sprigged bermudagrass fields are particularly vulnerable to weed interference and competition. Plants emerging from sprigs are relatively intolerant of shading and weed competition, so severe weed infestations can result in significant stand losses. Some of the most common weeds that interfere with bermudagrass establishment include winter annual weeds like chickweed, henbit, field pennycress and early emerging summer annual grass and broadleaf weed species like common ragweed, giant foxtail and large crabgrass. Diuron is one of the only active ingredients labeled for preemergence (PRE) weed control in sprigged bermudagrass. Diuron is available in several formulations (Diuron 4L, Diuron 400, and Diuron 80) and is ironically sold under the same trade name as the active ingredient. Diuron is sold by a variety of manufacturers, including Agriliance, Helena, Drexel, MANA and Helena. Diuron may be applied PRE in sprigged bermudagrass at 0.75 to 2.25 lbs active ingredient per acre (1.5 to 4.5 pts per acre of 4 lb/gallon formulations) after planting but before bermudagrass or weed emergence. Bermudagrass injury can occur as a result of a PRE Diuron application if sprigs are planted less than two inches deep. Diuron may also be applied postemergence (POST) to sprigged bermudagrass before weeds reach about four inches in height. When applying Diuron as a POST treatment, rates should not exceed 0.75 lbs active ingredient per acre, and a non-ionic surfactant should be added to all applications. POST applications of Diuron are more likely to cause visible signs of injury to the emerged bermudagrass, but this injury is transient in nature and usually disappears after a short period of time. All Diuron treatments require a 70-day grazing restriction after application, so this should be considered before deciding to make a PRE or POST application of Diuron. Some of the key weeds that Diuron will control include large crabgrass, common lambsquarters, common ragweed and some pigweeds. Each of these species seems to be particularly troublesome at the time of bermudagrass establishment, but the opportunity to eliminate grass weeds like large crabgrass is perhaps one of the greatest benefits that Diuron offers. In one of the few research studies that has been conducted on the use of Diuron at bermudagrass establishment, Smith and Martin (1992) reported approximately 80 percent control of large crabgrass at three months after treatment with 3 pts/A of Diuron. Some 2, 4-D products are also labeled for use following bermudagrass sprigging. As there are a wide variety of products that contain 2, 4-D available, the specific label of the product in question should be consulted before applying 2, 4-D to any bermudagrass stand. Generally, the products that are labeled for use in sprigged bermudagrass can be applied at a rate of 0.5 to 1.5 lbs of 2, 4-D per acre after sprigging, but while broadleaf weeds are still small and actively growing. It is important to consider that 2, 4-D products will control most annual broadleaf weeds present at the time of application, but will not provide any appreciable degree of grass weed control. Other herbicides that might be considered later in the season include Grazon P+D, Cimarron and Cimarron Max. Grazon P+D may be applied at a maximum rate of 1.5 pts per acre but only after bermudagrass runners have reached at least six inches in length. Additionally, Cimarron and Cimarron Max can be applied to bermudagrass two months after bermudagrass establishment. Plateau (imazapic) was once utilized for the control of annual grasses in bermudagrass but is no longer available for sale over-the-counter to growers in Missouri. We have received several questions over the past few months about the potential use of Journey in bermudagrass. Journey is a new prepackaged herbicide mixture from BASF that contains the active ingredients imazapic (Plateau) and glyphosate. However, a close examination of the Journey label reveals that this product is not for use "on areas to be grazed or cut for hay." Kevin Bradley and Rob Kallenbach Agronomy /Ag Ext-Plant Sciences 573-882-4039/ 573-882-2801 ****************************************************** Foliage Diseases of Winter Wheat and Their Management By Laura Sweets ****************************************************** There have been reports of leaf rust and stripe rust on winter wheat in Arkansas for several weeks. Although I have been getting questions on the occurrence of those diseases on wheat in Missouri, I have received any actual reports of rust on wheat. However, diseased wheat samples from central Missouri and southwestern areas of the state are showing symptoms of Septoria leaf blotch. The buildup of foliage diseases prior to flowering can led to yield losses, especially if weather conditions remain favorable for disease development during and after flowering. This appears to be a year when it is important to scout wheat . elds for foliage diseases, especially if weather conditions stay warm and wet or humid. Lesions of Septoria leaf blotch begin as light yellow flecks or streaks. These flecks expand into yellow to reddish-brown, irregularly shaped blotches. Dark brown specks (fruiting bodies or pycnida of the causal fungus, Septoria tritici) may be scattered within the centers of mature lesions. Lesions may coalesce killing larger areas of leaf tissue. Stagonospora glume blotch (formerly called Septoria glume blotch) may also begin as light yellow flecks or streaks on leaves. The lesions also turn yellow to reddish brown but usually have a more oval to lens shaped appearance than those of Septoria leaf blotch. Again, the dark brown specks or fungal fruiting bodies of the causal fungus Stagonospora nodorum may be evident within the lesions. Symptoms of Stagonospora glume blotch are more common on heads than foliage of wheat. Infected heads will have dark blotches on the glumes. The initial symptoms of tan spot are small tan to brown flecks on the leaves. These expand into tan to light brown, elliptical lesions which often have yellow borders. The centers of mature tan spot lesions may have a dark brown region caused by outgrowth of the fungus. But the fungus which causes tan spot, Pyrenophora tritici-repentis, does not produce pycnidia or fruiting bodies as the Septoria fungus does. So mature tan spot lesions do not have the distinct dark brown specks scattered throughout the centers of the lesions as do Septoria leaf blotch lesions. Leaf rust lesions appear primarily on the upper leaf surfaces and leaf sheaths. Initially, lesions are small yellow to light green flecks. Eventually, leaf rust appears as small, circular to oval shaped, orange-red pustules. These pustules break open to release masses of orange-red spores of Puccinia recondita. The edges of the open pustules tend to be smooth without the tattered appearance of stem rust pustules. Heavily rusted leaves may yellow and die prematurely. Stem rust, caused by the fungus Puccinia graminis f. sp. tritici, is most common on stems and leaf sheaths of wheat plants but may develop on any of the above ground portions of the plant including both upper and lower leaf surfaces and glumes and awns. Stem rust pustules are small, oval, and reddish-brown. The ruptured pustules tend to have more ragged edges than leaf rust pustules. Frequently both leaf rust and stem rust occur on the same plant and both types of pustules may develop on an individual leaf. Stripe rust, caused by the fungus Puccinia striiformis, has become more prevalent in Missouri over the last few years. Stripe rust may develop earlier in the season than leaf rust or stem rust. The pustules of stripe rust are yellow or yellowishred and occur in obvious stripes or streaks running lengthwise on the wheat leaves. This disease is more commonly associated with cooler temperatures, especially cooler night temperatures. Powdery mildew infections begin as light-green to yellow flecks on the leaf surface. As powdery mildew develops the leaf surfaces become covered with patches of cottony white mold growth of Erysiphe graminis f. sp. tritici, the causal fungus.. These patches eventually turn a grayish white to grayish brown in color and small black fungal fruiting bodies may be visible within the patches of mildew growth. The fungi which cause most of these wheat foliage diseases survive in infested wheat residues left on the soil surface. The next growing season spores are produced during moist periods and are carried by wind currents to susceptible wheat leaves where infection may begin. Disease problems tend to be more severe when wheat is planted in fields with infested wheat residue left on the soil surface. Eventually spores that are produced in the initial lesions on plants are wind blown to other leaves or other plants causing secondary infection. Leaf rust, stem rust and stripe rust are exceptions to this simplified explanation of disease development. The rust fungi do not survive in infested residue left in a field. Rather, the rust fungi are reintroduced into this area each season when spores are carried up on air currents from the southern United States. Most of the foliage diseases of wheat are favored by warm, wet or humid weather. Frequently infection begins on the lower portion of the plant. If weather conditions are favorable for disease development, the disease may move up through the plant. Severely infected leaves may yellow and die prematurely. Yield losses tend to be highest when the . ag leaves are heavily infected. There are several fungicides that are labeled for use on wheat to control fungal foliage diseases. It is important to scout wheat fields and determine which leaf diseases are occurring as well as the level of their severity before making a decision to apply a foliar fungicide. In particular be on the lookout for Septoria leaf blotch, Stagonospora glume blotch, tan spot, leaf rust and stripe rust. When scouting fields, try to identify the disease or diseases which are present, determine the average percent of infection on a leaf and the number of leaves showing infection and determine the stage of growth of the crop. Generally, the pro. table use of foliar fungicides on wheat depends on a number of factors including varietal resistance, disease severity, effectiveness of the specific fungicides and timing of fungicide application. The greatest increases in yield are usually obtained when fungicides are applied to disease susceptible varieties with high yield potential at the early boot to head emergence growth stage when the flag leaf is in danger of severe infection. Fungicide applications are seldom beneficial if applied after flowering or after the flag leaf is already severely infected. It is also important to read the fungicide label for specific information on rates, recommended timing of application, frequency of applications, preharvest intervals and grazing restrictions. A management program for foliage diseases of wheat should include the following steps: *Plant disease free seed of varieties with resistance to diseases likely to occur in your area. *Rotate with non-host crops for one or more years. *Manage residues- if tillage system is a conservation tillage system, particular care should be given to rotation and variety selection. *Maintain good plant vigor with adequate fertility. *Control volunteer wheat. *Use foliar fungicides if warranted (see accompanying table of foliar fungicides labeled for use on winter wheat). Laura Sweets Ag Ext-Plant Sciences 573-884-7307 *************************************************** Black Cutworm Moth Catch Moderate, but Increasing By Wayne Bailey *************************************************** Black cutworm pheromone traps began capturing moths during the last week of March in central Missouri. Numbers of moths captured have increased steadily during the past few nights, but number of moths captured have not reached or exceeded the number designated as an intensive capture of moths (8 moths captured over two nights in a sticky wing trap, or 17 moths captured over one night in a Texas cone trap) Numbers or moths by county can be found on the web at (http://ipm.missouri.edu/SEMOmothtrap3.htm). As of April 11, moth numbers captured per night have approached , but not reached or exceeded the number needed to be declared an intensive capture. Once an intensive capture is achieved at a location, the date of capture is used as a "biofix" in the Missouri black cutworm predictive model. Slightly more than 300 degree days are required to accumulate from the time of a "biofix" event until larvae begin cutting corn plants. NOTE: warmer than normal temperatures can speed the development of larvae, whereas cooler than normal temperatures can slow black cutworm larval development. Damage: Third instar and smaller larvae cause small "window pane" feeding on plant leaves where they remove the chlorophyll (green) layer of tissue, but are unable to bite completely through the leaf surface. They also may notch the edge of leaves. Once larvae grow to the 4th instar stage of development they are able to cut plants at the ground surface or below ground. This type of feeding can seriously reduce plants stands to unacceptable levels. Producers are encouraged to begin scouting corn fields a few days prior to the date of predicted cutting by larvae to determine whether foliar feeding by small larvae is present. Scouting should continue every few days until plants reach the 5-leaf stage of growth. The economic threshold is based on the percent of plants cut above or below ground. Below ground cutting is more damaging as the growing point of the corn plant can be destroyed. Additional information is available in MU Guide G7112, "Black Cutworm in Missouri". Management: Several insecticides are labeled for effective management of black cutworm as "rescue" treatments. Cruiser and Poncho seed treatments give some control of black cutworm larvae with variable results found in Missouri field trials. Herculex transgenic Bt corn seed designed for control of European corn borer has produced good to excellent control of black cutworm larvae in field trials. ************************************************************************* BLACK CUTWORM LARVAL INSECTICIDE RECOMMENDATION ------------------------------------------------------------------------- Chemical Name Product Product Rate ------------------------------------------------------------------------- Permethrin *Ambush 6.4 to 12.8 oz Broadcast Apply as a Esfenvalerate *Asana XL 5.8 to 9.6 oz postemergence Cyfluthrin *Baythroid 2 0.8 to 1.6 oz rescue Bifenthrin *Capture 2EC 2.1 to 6.4 oz treatment when Bifenthrin *Fanfare 2EC 2.1 to 6.4 oz 2- 4% or more Chlorpyrifos *Lorsban 4E 1 to 2 pt of plants are Zeta-cypermethrin *Mustang Max 1.28 to 2.8 oz cut and larvae Chlorpyrifos *Nufos 4E 1 to 2 pt are present. Permethrin *Pounce 3.2EC 4 to 8 oz Gamma-cyhalothrin *Proaxis 1.92 to 3.2 oz Lambda-cyhalothrin*Warrior 1 to 2 pt Seed treatments Thiamethoxam Cruiser See label On seed Clothianidin Poncho See label On seed Transgenic seed Herculex See label On seed ------------------------------------------------------------------------- * Designates a restricted use insecticide. Read and follow all label instructions ************************************************************************* Wayne Bailey Entomology 573-882-2838 or 573-864-9905 ****************************************** Sprayer Workout: Will your pump put out? By Bill Casady ****************************************** In a year when sprayers have hit the front page along with Asian Rust, sprayers have sold like wildfire. Most sprayers come equipped with standard accessories and pumps that will handle the typical pressure and flow rate requirements of most applications. However, those specifications are not always readily apparent and there are several rules of thumb that need to be considered when selecting a pump to provide the desired output. There is some concern that sprayers equipped for low volume herbicide applications may not cut it when we attempt to supply the higher carrier rates (e.g. 20 GPA) suggested for fungicides. The most popular agricultural sprayer pumps are roller, piston, and centrifugal pumps. Centrifugal pumps are very common on farm sprayers. The centrifugal pump is a non-positive displacement pump that causes a spray solution to enter through the center of a rotating impeller. As the impeller spins, the centrifugal force causes the spray solution to be forced to the outer limits of the pump housing. This force causes a large output at low pressures or as little as zero output at high pressures. Hence, the output of a centrifugal pump is a function of the working pressure in the system. Let's determine the required specifications for a medium size sprayer. I have chosen, for the sake of example, a spray width of 60 feet, an application speed of 8 mph, and an application rate of 20 gallons per acre (GPA). Let's also choose a pressure of 40 PSI, which is the typical design operating pressure for many nozzles. Without providing the calculations in this article, the pump must deliver approximately 20 gallons per minute (GPM) to the boom at 40 PSI. The required flow rate changes by ratios of the three specifications: width, speed, rate. For example doubling speed doubles the required output. A marginal increase in speed from 8 to 10 MPH requires increasing flow rate by the ratio 10/8. In this case, the flow rate would increase by the following calculation: (20 GPM x 10/8) = 25 GPM. But that's not where the story ends. There are other flow needs that need to be tacked on to the flow rate to the boom. For example, agitation requirements for tanks using hydraulic agitation from the pump should be, as a rule of thumb, approximately 5 to 10 % of the tank capacity. Hence, a 100-gallon tank should be agitated with 5 to 10 GPM and a 400-gallon tank should be agitated with approximately 4 times those amounts or from 20 to 40 GPM. Self-cleaning line strainers also require some additional solution flow rate of approximately 6 to 8 GPM for each strainer. Each component of flow is added together to determine the actual flow rate. In this example, let's assume that we needed 20 GPM of product to the boom, that the agitation requirements are 20 GPM, and that we have a single line strainer at 8 GPM. The total flow is 48 GPM. Finally, we consider a 20% increase due to pump wear and as a factor of safety to choose a pump that is sufficient. The calculation is (48 x 1.2) or about 58 GPM. Because we selected the operating pressure to be 40 PSI, we need to select a pump that will provide 58 GPM at the selected operating pressure of 40 PSI. To do this accurately, you will need to find pump curves for the selected line of pumps. These specifications should be readily available from your pump dealer. It is worth mentioning that the additional cost for an oversized pump may be well worth the money. The additional cost is usually proportionally smaller than the additional capacity, and the extra $100 for a bigger pump is like insurance that you won't come up short handed on capacity. Be prepared for the challenges of Asian Rust. Check pump capacity to see if you might be ready to meet the challenge, and I will be more than happy to help with the calculations as you determine if your pump will 'put out' under the potentially new scenarios of Asian Rust. Bill Casady 573 882 4370 ********************************************************************** Foliar Fungicides Labeled for Use on Winter Wheat Updated April 2005 By Laura Sweets ********************************************************************** This table was prepared using current company product label books and web sites. However, label registrations can change at any time. Before using any agricultural pesticide, read and follow directions accompanying that product. Product names have been used for clarity. Reference to specific trade names does not imply endorsement by the University of Missouri; discrimination is not intended against similar products not listed. *************************************************************************** Trade Name Common Chemical Name Rate Additional Label Company and % of Active Information Ingredients --------------------------------------------------------------------------- Dithane DF mancozeb 75.00% 2.1 lbs. For control of Rainshield per acre Helminthosporium leaf Dow AgroSciences spot, leaf rust, Septoria glume blotch, Septoria leaf spot and tan spot. Dithane F-45 mancozeb 37.00% 1.6 qts. Start applications at Rainshield per acre the onset of disease or Dow AgroSciences when plants are in the tillering to jointing stage and repeat at 7- to 10-day intervals. The addition of Latron CS-7 to spray solutions will improve performance. Dithane M45 mancozeb 80.00% 2.0 lbs. Do not make more than Dow AgroSciences per acre three applications during the season. Do not apply after Feekes growth stage 10.5 or heading, but not less than 26 days of harvest. Do not graze livestock in treated area prior to harvest. Headline pyraclostrobin 23.60% 6.0 to 9.0 For control of leaf BASF fl. oz. rust, powdery mildew, per acre Septoria leaf and glume blotch, spot blotch, stem rust, stripe rust and tan spot. Headline may be applied at the onset of disease. To maximize yields in cereals it is important to protect the flag leaf. Apply Headline immediately after flag leaf emergence for optimum results. Reapply 10 to 14 days later if disease persists or weather conditions are favorable for disease development. Resistance management: To limit the potential for development of resistance, do not make more than two applications of Headline or other strobilurin fungicides per season. Apply no later than the beginning of flowering (Feekes 10.5). Do not harvest wheat hay within 14 days after last application. Kumulus DF sulfur 80.00% 6 to 15 For the control of BASF lbs. per powdery mildew. acre Apply when disease first appears and repeat as necessary or with the regularly scheduled insecticide program. Manzate 75DF mancozeb 75.00% 2.0 lbs For control of Griffin L.L.C. per acre Helminthosporium leaf spot, leaf rust, Septoria glume blotch, Septoria leaf spot and tan spot. Manzate 80WP mancozeb 80.00% 2.0 lbs Start applications at Griffin L.L.C. per acre the onset of disease or when plants are in the tillering to jointing stage and repeat at 7- to 10-day intervals. Manzate Flowablemancozeb 37.00% 1.6 qts. Do not make more than Griffin L.L.C. per acre three applications during the season. Do not apply more than 6 lbs.for 4.8 qts./acre/crop. Do not apply within 26 days of harvest. Do not graze livestock in treated areas prior to harvest. ManKocide mancozeb + 15.00% 2.0-2.5 For control of Griffin L.L.C. copper 46.10% lbs. per Helminthosporium leaf hydroxide acre spot, Septoria glume blotch and Septoria leaf spot. Make first application at early heading and follow with second spray 10 days later. Use higher rates when conditions favor disease. Do not apply within 26 days of harvest. Do not graze livestock in treated areas prior to harvest. Penncozeb 75DF mancozeb 75.00% 1.0 to 2.0 For control of Cerexagri lbs. per Helminthosporium leaf acre spot, Septoria leaf spot, Septoria glume blotch, leaf rust and tan spot. Penncozeb 80WP mancozeb 80.00% 1.0 to 2.0 Start application at Cerexagri lbs. per the onset of disease or acre when plants are in tillering to jointing stage and repeat at 7- to 10-day intervals. Do no apply more than 3 applications in one season. Do not apply more than 6.4 lbs. Penncozeb 75DF or 6.0 lbs. Penncozeb 80WP/acre/crop. Do not apply within 26 days of harvest. Do not graze livestock in treated areas prior to harvest. Do not apply after heading (around Feekes 10.5). PropiMax EC propiconazole 41.80% 4.0 fl. For control of rusts, Dow AgroSciences oz. per powdery mildew, leaf acre blight and glume Special local blotch, tan spot and needs Helminthosporium leaf registration for blights. use in Missouri extends Highest yields are application normally obtained when period to Feekes PropiMax EC is applied Growth Stage to the emerging flag 10.5. Do not leaf. PropiMax EC can apply within 40 be applied until the days of harvest. ligule of the flag leaf See SLN label has emerged (Feekes for full growth stage 8). Do not details. apply after this growth stage to avoid possible illegal residues. PropiMax EC may be applied earlier if disease symptoms appear. Do not apply more than 4.0 fl. oz. of PropiMax EC per acre per season. Do not graze or feed livestock treated wheat, barley or rye forage or cut the green crop for hay or silage. After harvest, the straw from these crops may be used for bedding or feed. Quadris azoxystrobin 22.90% 6.2 to Quadris should be Syngenta 12.3 fl. applied prior to oz. per disease development acre for from jointing to leaf rust, (Feekes 6 or Zadok’s stripe 31) up to late head rust, stem emergence (Feekes 10.5 rust, or Zadok’s 59). A crop Septoria oil concentrate leaf and adjuvant may be added glume at 1.0% v/v to optimize blotch, efficacy. and tan spot. Resistance Management: Do not make more than 7.7 to two foliar applications 10.8 fl. of Quadris or other Qol oz. per fungicides per acre per acre season. powdery mildew Do not apply until after forage stage (Feekes 6 or Zadok’s 31). Do not apply later than Feekes growth stage 10.5 (Zadok’s growth stage 59). Do not harvest treated wheat for forage. Do not apply more than 0.77 quarts product/acre/season. Do not apply within 14 days of harvest for hay. Do not apply within 45 days of harvest for grain and straw. Quilt azoxystrobin 7.00% 7.0 to 7.0 to 14.0 fl. oz. per Syngenta propiconazole 11.70% 14.0 fl. acre for early season oz. per suppression of powdery Special local acre mildew, Septoria leaf needs blotch, Stagonospora registration for glume blotch and tan use in Missouri spot. 14.0 fl. oz. per extends acre for control of application leaf diseases (rusts, period to Feekes powdery mildew, Growth Stage Septoria leaf blotch, 10.5. Do not Stagonospora glume apply within 40 blotch, tan spot). days of harvest. See SLN label Protecting the flag for full leaf is important for details. maximizing the potential yield. Highest yields are obtained when Quilt is applied when the flag leaf is 50-70% emerged. Quilt azoxystrobin 7.00% 7.0 to Applications may be Syngenta propiconazole 11.70% 14.0 fl. made no closer than a (continued) oz. per 14-day interval. Quilt acre may be applied up to Feekes growth stage 9. Do not apply more than 2 applications /A/year. Do not apply more than 20.5 fl. oz/A/season. Do not apply within 45 days of harvest for grain and straw. Do not harvest wheat for forage. Do not graze or feed livestock treated forage or cut green crop for hay or silage. Under certain environmental conditions, tankmixes of Quilt plus herbicides and/or fertilizers may cause crop injury in barley, triticale and wheat. Stratego propiconazole 11.40% 10.0 fl. For control of glume Bayer tri. oxystrobin 11.40% oz. per blotch, leaf blight, acre powdery mildew, rusts Special local and tan spot. needs registration for Begin applications usein Missouri preventively when extends conditions are application favorable for disease period to Feekes development. A second Growth Stage application (minimum 10.5. Do not interval of 14 days) apply within 40 may be made if needed. days of harvest. See SLN label Do not apply more than for full 2 applications per details. season. Do not apply Stratego after Feekes growth stage 8 (the ligule of the flag leaf emerges). Do not apply Stratego within 35 days of harvest. See label for grazing restrictions. Tilt propiconazole 41.80% 2.0 to 4.0 Early season leaf Syngenta fl. oz. disease suppression: per acre apply 2-4 fl. oz. per Special local acre for suppression of needs tan spot, Septoria and registration for powdery mildew. use in Missouri extends Leaf disease control: application apply 4 fl. oz./acre at period to Feekes first appearance of Growth Stage disease. Protecting the 10.5. Do not flag leaf is important apply within 40 for maximizing the days of harvest. yield potential. See SLN label for full Highest yields are details. normally obtained when Tilt is applied to the emerging flag leaf. Tilt can be applied until the ligule of the flag leaf emerges (Feekes Growth Stage 8). Do not apply after this growth stage to avoid possible illegal residues. Tilt may be applied earlier if disease symptoms appear. Do not apply more than 4.0 fl. oz. of Tilt per acre per season. Do not graze or feed livestock treated wheat forage or cut the green crop for hay or silage. After harvest, the straw from these crops may be used for bedding or feed. *************************************************************************** Laura Sweets, Plant Pathologist 573-884-7307 *********** Correction ************ The numbers in last week’s flea beetle article were translated in our word processing program to 900F and 1000F from the correct 90F and 100F In the flea beetle model, the potential for flea beetle damage is calculated by adding together the average daily winter temperatures for the months of December, January, and February. If the average monthly temperatures for these months is less than 90F, then the risk of economic flea beetle infestations is low. If the total is between 90F and 100F, then moderate flea beetle damage can be expected. Heavy damage is possible if the three monthly averages total 100F or more. ************************************************ Weather Data for the Week Ending April 11, 2005 By Pat Guinan ************************************************* -------------------------------------------------------------------------------- | Monthly | Growing Weekly Temperature (deg. F) |Precip (in.)|Degree Days -----------------------------|------------|------------ Ext- Ext- Depart| Depart|Accum Deprt Avg.Avg. reme reme from |Apr 1- from |since from Station County Max.Min. High Low Mean avg. |Apr 11 avg. |Apr 1 avg ------------------------------------------------------|------------|------------ Corning Atchison 71 51 78 35 61 +12 3.74 +2.75 111 +110 St. Joseph Buchanan 68 50 78 34 60 +10 2.40 +1.28 98 +91 Brunswick Chariton 73 51 83 33 62 +12 0.59 -0.51 112 +107 Albany Gentry 69 50 80 33 60 +10 2.07 +0.88 99 +97 Auxvasse Audrain * * * * * * * * * * Columbia Boone * * * * * * * * * * Sanborn Field Boone 72 53 83 37 63 +11 1.48 +0.04 124 +107 Novelty Knox 70 52 80 40 61 +12 1.51 +0.49 98 +97 Linneus Linn 70 50 80 31 60 +11 0.92 -0.05 99 +97 Monroe City Monroe 70 50 82 36 61 +10 1.15 -0.10 100 +93 Versailles Morgan 72 52 82 39 62 +9 2.03 +0.30 117 +89 Green Ridge Pettis 71 51 81 36 61 +11 1.10 -0.23 109 +105 Lamar Barton 69 52 77 42 61 +8 1.61 +0.32 101 +71 Cook Station Crawford 73 51 82 37 62 +8 1.40 +0.18 106 +71 Delta Cape 72 53 79 46 62 +8 0.94 -0.27 100 +53 Girardeau Cardwell Dunklin 71 55 81 48 62 +5 3.05 +1.44 108 +37 Clarkton Dunklin 71 54 79 47 62 +6 1.47 +0.18 103 +41 Glennonville Dunklin 71 55 78 49 62 +6 1.60 +0.34 108 +45 Charleston Mississippi 71 54 79 49 62 +8 1.47 +0.07 107 +59 Portageville- Delta Center Pemiscot 72 55 78 49 63 +7 2.05 +0.51 113 +47 Portageville- Lee Farm Pemiscot 72 55 79 48 63 +7 1.87 +0.37 116 +52 Steele Pemiscot 70 55 79 49 62 +6 2.25 +0.70 108 +46 -------------------------------------------------------------------------------- * Complete data not available for report ^Growing degree days are calculated by subtracting a 50 degree (Fahrenheit) base temperature from the average daily temperature. Thus, if the average temperature for the day is 75 degrees, then 25 growing degree days will have been accumulated. -------------------------------------------------------------------------------- Pat Guinan, Commercial Agriculture Program (573) 882-5908