Integrated Pest and Crop Management Newsletter Vol. 17, No. 5 April 12, 2007 ********************************************************************** Wind Information and Resources By Ray Massey and Pat Guinan Over the years, the University of Missouri Commercial Agriculture Program has continually added to its weather resources. The network of weather stations currently numbers 25. Horizon Point is delivering site specific, customized weather information via e-mail to subscribers. BERM and AFOSITE are two interactive Websites that integrate site-specific weather information to assist farmers in understanding how to manage their land. In discussions, producers have repeatedly asked for more windrelated weather information. They relate to us the importance of wind for short term activities such as spraying and for long term investment decisions such as where to locate an animal feeding facility. We have organized several new wind products at http://agebb.missouri.edu/weather/windroses. Two of the new products are highlighted below. Windroses are the most recent weather products developed by the Commercial Agriculture Program to aid in management decisions. A windrose is a graphical presentation of the average hourly speed and direction of wind at a particular location. The windrose for Novelty is shown below. It consists of 16 petals that indicate the percent of time that a wind is blowing from that direction. For example the largest petal is the one for wind blowing from the south-southwest and indicates that about 11 percent of the time wind is blowing from that direction. By looking at the windrose, you can quickly see that the prevailing wind direction is from the south and southwest. The petals of the windrose also are composed of different colors that represent the percent of time that a wind from that direction is within a specified speed range. The petal for a south wind indicates that about 3 percent of the time the wind is between 1-5 mph; 6 percent of the time it is between 5- 10 mph and 2 percent of the time it is between 10-15 mph. The average windspeed is reported as 5.99 mph. The windroses located on the web are produced in color and contain information about the sources of data. Some windroses use National Weather Service (NWS) data, reporting speed at 30 feet above the ground, while other windroses use the MU Agricultural Weather Station data, reporting speed at 10 feet above the ground. Wind speeds are slower at when measured closer to the ground due to frictional effects. If you use a windrose that relies on NWS data understand that the speed might be greater than you would expect because they are reporting speeds at 30 feet above the ground. Another representation of the average hourly wind data is a chart showing the average wind speed for each hour of the day during 4 months when wind information most affects land activities such as spraying. The Novelty average wind speed graph shows a consistent rise in wind speed starting at about 9:00 a.m., peaking at 4:00 p.m. and reducing until 9:00 p.m. at which time it remains fairly consistent until shortly after sunrise the next morning. The graph shows 4 lines, one each for April, May, June and July. April’s wind speed is greater than May’s wind speed by about 1 mph. July has the lowest average wind speed during this 4-month period. The hourly average wind speed reveals how diffi cult it is to find a good time to spray pesticides so that they don’t drift. For a NWS forecast of wind speeds at your farm (specific latitude and longitude) subscribe to Horizon Point (http://agebb.missouri.edu/horizonpoint) and specify that you want to receive the wind forecasts. These forecasts give predicted wind speed at three hour increments for the next 60 hours. Using these to plan when the wind might be favorable for your specific field activities could contribute in your management decisions. Ray Massey and Pat Guinan MasseyR@missouri.edu GuinanP@missouri.edu ********************************************************************** Alfalfa Weevil and Freezing Temperatures By Wayne Bailey Numerous questions have been received concerning whether alfalfa weevil larvae survived recent freezing temperatures. Although larval survival in fields can vary, historically alfalfa weevil larvae have survived similar cold weather in the past. In 1987, freezing weather during April froze alfalfa plants to the ground in many regions of Missouri. Alfalfa weevil larvae survived the freezing temperatures to cause severe damage to the recovering crop by feeding on the new, emerging alfalfa tillers. In many of the fields where the larvae were not treated with an insecticide either before or after the freeze event, weeds became a problem due to lack of competition from the recovering alfalfa plants. Will this happen in 2007? I believe the alfalfa weevil have survived in most fields and will probably cause problems by feeding on new alfalfa tillers. The exception will be in those fields where the pathogenic fungus (Zoophthora phytonomi) has infected larvae due to recent rainfall. Typically, healthy alfalfa weevil larvae are light green to lime green in color. When they become infected by the fungal pathogen, then develop a yellow color, stop feeding, and die within 3- 4 days. Infestations by this pathogen often cause the collapse of the entire alfalfa weevil larval population in the field within about a week. Is the fungal pathogen going to control the surviving alfalfa weevil larval population in 2007? The potential for the expression of this pathogen in the alfalfa weevil population is high in areas of the state where rainfall occurred on a several day period. However, alfalfa producers are encouraged to scout individual fields to determine larval survivorship following the freezing temperatures and whether the surviving larvae are infected by the fungal pathogen. In those fields where the alfalfa was frozen back to ground level, larvae can be found in plant residue on the ground and at the crown of the plant in areas where new tillers are developing. In fields not frozen back to the soil surface, small larvae will be found in surviving plant terminals and larger larvae on leaf foliage. Harvesting of the alfalfa crop will help reduce larval numbers, but producers are encouraged to check for surviving larvae in plant residues and on the plant crowns. Most insecticides need temperatures above 50 degrees to cause larval mortality within 1-2 days post application. Cool weather will slow this response and should be considered when scouting alfalfa fields. ##################################################################################### #Recommended Insecticides for Larval Alfalfa Weevil Management - 2007 # #Insect Pest # # # #Alfalfa Chemical Common Rate of Formulated Rate of Active # #weevil name name Material Ingredient (a.i.)# #Larvae: # # Beta-cyfluthrin *Baythroid XL 1.6 to 2.8 0.0125 to 0.022 # # fl oz/acre lb a.i./acre # # Carbofuran *Furadan 4F 1/2 to 2 0.25 to 1 # # pts/acre lb/acre # # Chlorpyrifos 4E *Lorsban 4E 1 to 2 0.5 to 1 # # pts/acre lb/acre # # *numerous see specific see specific # # products labels labels # # Methyl Parathion *Chemnova 1 pt/acre 0.5 lb a.i./acre # # Methyl 4EC # # Gamma-cyhalothrin *Proaxis 2.56 to 3.84 0.02 to 0.03 # # fl oz/acre lb a.i./acre # # Phosmet Imidan see speciic see specific # # labels labels # # Zeta-cypermethrin *Mustang Max 2.24 to 4.0 0.014 to 0.025 # # fl oz/acre lb a.i./acre # # Carbaryl Sevin 4F 1.5 qts/acre 1.5 lb a.i./acre # # Carbaryl Sevin XLR Plus 1.5 qts/acre 1.5 lb a.i./acre # # Lambda-cyhalothrin *Warrior 2.56 to 3.84 0.02 to 0.03 # # fl oz/acre lb a.i./acre # # *Numerous see speciic see specific # # products labels labels # # # #Read and follow all label direction, precautions, and restrictions. # #* Designated a restricted use product. # ##################################################################################### Wayne Bailey, 573-864-9905 BaileyW@missouri.edu ********************************************************************** Domark 230ME Fungicide Receives Section 3 Registration By Laura Sweets Domark 230ME Fungicide (tetraconazole) is one of the fungicides which has had a section 18 quarantine label for use if there is a threat of soybean rust. Under the section 18 label Domark 230ME Fungicide could only be used on soybeans if there was a threat of soybean rust. The Environmental Protection Agency has just sent out notification that A section 3 registration has now been established for this use of tetraconazole on soybeans, and although the emergency exemption for Missouri will not expire until November 10, 2007, the new registration can be used by growers in lieu of the currently approved section 18 labeling. End users that have un-used stocks under the section 18 are encouraged to follow the use directions and terms carried on the newly stamped section 3 label. The new section 3 registration, covers control and/or suppression of certain diseases in soybean including Asian soybean rust, Cercospora blight, frogeye leaf spot, Sclerotinia white mold, powdery mildew, Septoria brown spot and anthracnose. The following restriction and limitations are listed on the label: 1. Do not apply Domark after soybean growth stage R5 (beginning seed). 2. Do not make more than two (2) applications of Domark to soybeans per year. 3. Do not apply more than 10 fl. oz. (0.150 lb at tetraconazole) of Domark per acre per season. 4. Do not graze or feed soybean forage or hay to livestock. 5. A restricted entry interval (REI) of 12 hours is to be followed. 6. Chemigation: Do not apply Domark through any type of irrigation system. 7. Do not harvest immature soybeans for consumption once plants are treated with Domark. 8. Do not use on vegetable soybean varieties grown for their immature pods. See section 3 label for further information on the use of Domark 230ME fungicide on soybean. Laura Sweets 573-864-7307 SweetsL@missouri.edu ********************************************************************** Weather Data for the Week Ending April 10, 2007 By Pat Guinan -------------------------------------------------------------------------------- | Monthly | Growing Weekly Temperature (deg. F) |Precip (in.)|Degree Days^ -----------------------------|------------|------------ Ext- Ext- Depart| Depart|Accum Depart Avg.Avg. reme reme from |Apr 1 from |since from Station County Max.Min. High Low Mean avg. |Apr 10 avg |Apr 1 avg. ------------------------------------------------------|------------|------------ Corning Atchison 42 24 47 17 33 -16 | 1.21 +0.29 | 20 +19 St. Joseph Buchanan 41 25 45 18 33 -17 | 0.52 -0.43 | 21 +16 Brunswick Chariton 44 25 52 18 34 -16 | 0.70 -0.18 | 28 +21 Albany Gentry 43 24 50 18 33 -16 | 0.54 -0.46 | 15 +13 Auxvasse Audrain 45 26 54 18 35 -15 | 1.02 +0.04 | 32 +26 Columbia Boone 44 26 52 19 35 -17 | 1.27 +0.10 | 33 +16 Sanborn Field Boone 45 28 52 20 36 -16 | 1.01 -0.16 | 37 +17 Williamsburg Callaway 44 27 53 20 35 -15 | 1.96 +0.90 | 35 +28 Novelty Knox 44 25 56 18 33 -16 | 1.62 +0.79 | 20 +18 Linneus Linn 44 24 55 16 33 -16 | 0.50 -0.26 | 22 +20 Monroe City Monroe 44 26 56 19 34 -17 | 1.61 +0.64 | 27 +20 Versailles Morgon 45 27 51 19 36 -17 | 0.83 -0.53 | 40 +10 Green Ridge Pettis 44 26 51 19 35 -15 | 0.74 -0.33 | 34 +29 Lamar Barton 46 30 55 22 37 -16 | 0.24 -0.82 | 40 +9 Cook Station Crawford 47 25 56 17 36 -17 | 0.69 -0.34 | 39 +7 Alley Spring Shannon 52 24 59 14 38 -15 | 0.61 -0.43 | 34 +8 Round Spring Shannon 50 26 57 16 38 -15 | 0.59 -0.45 | 34 +8 Delta Cape | | Girardeau 51 29 60 20 40 -14 | 0.47 -0.67 | 40 -3 Cardwell Dunklin 53 34 58 27 44 -13 | 0.66 -0.93 | 48 -18 Clarkton Dunklin 52 31 59 24 42 -14 | 0.73 -0.53 | 45 -13 Glennonville Dunklin 52 32 58 26 42 -14 | 1.15 -0.06 | 48 -12 Charleston Mississippi 51 31 62 26 41 -13 | 0.69 -0.64 | 48 -1 Portageville- | | Delta Center Pemiscot 52 34 60 27 43 -13 | 0.67 -0.79 | 53 -10 Portageville- | | Lee Farm Pemiscot 53 33 61 27 43 -14 | 0.52 -0.92 | 55 -7 Steele Pemiscot 54 34 60 26 44 -12 | 0.67 -0.79 | 53 -6 -------------------------------------------------------------------------------- ^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 GuinanP@missouri.edu