July 20, 2009
High numbers of potato leafhoppers continue to be found in some hay fields. Be sure to use a sweep net to monitor potato leafhopper numbers and treat if numbers exceed the threshold. For more information on managing potato leafhopper, see pages 107 - 110 of the June 21, 1999 Iowa State University Integrated Crop Management Newsletter or http://www.extension.iastate.edu/Pages/eccrops/potatoleafhopper.html. Remember, waiting to see hopperburn is waiting too long as substantial losses have already occurred by that time. Be careful to not confuse leaf diseases with hopperburn.
Many hay fields now have evident leaf diseases, most commonly common leaf spot and “lepto” leaf spot. Fields in third year alfalfa have greater disease risk than first and second year alfalfa fields because the pathogens build up over time. There are differences in disease tolerance between varieties. Because many of the hay nutrients are in the leaves and because severe leaf disease can cause defoliation, if the disease level is high, early cutting generally is recommended so that defoliation can be avoided. Cutting as early as mid-bud stage may be necessary when the disease is severe.
Rotation Resistant Western Corn Rootworms
As you know, rotation resistant western corn rootworms have been confirmed throughout the counties I cover, and levels above threshold were confirmed in the area from northeastern Muscatine County through Scott County and into Clinton County in 2006. The Illinois and Indiana experience with this pest is that it starts out very spotty, so a cart blanc use of rootworm management in first year corn is not yet warranted. Rather, soybean fields that will be planted to corn in 2009 should be monitored for western corn rootworm adult activity beginning in the last week of July and continuing through the first three weeks of August using the Trece Pherocon AM yellow sticky traps. Follow the protocol developed by the University of Illinois, which can be found at http://www.ipm.uiuc.edu/fieldcrops/insects/western_corn_rootworm/wcr.pdf. The traps can be ordered from:
Great Lakes IPM
10220 Church Road NE
Vestaburg, Michigan 48891
100 Countryside Drive
PO Box 270
Belleville, Wisconsin 53508
The time is fast approaching or upon us when final decisions about applying foliar fungicides to corn will be made. Alison Robertson, ISU Extension Plant Pathologist, wrote an excellent article on the subject, which can be viewed at http://www.extension.iastate.edu/CropNews/2008/0703Robertson.htm.
X.B. Yang, ISU Extension Plant Pathologist, addresses soybean fungicide application issues at http://www.extension.iastate.edu/CropNews/2008/0708xbyang.htm.
CORN & SOYBEAN
Japanese Beetles were reported on ornamentals in Scott County some time ago, and reports og them in agronomic fields have come in from areas with a previous history of Japanese Beetles. The adults have a metallic green head and pronotum (neck region) and reddish bronze wing covers with a row of white hair tufts along the abdomen. There is a single generation in the Midwest, with beetles living for 30 – 45 days. Beetle feeding tends to occur from late June to early September, with the heaviest defoliation in July and August.
In soybean, the economic threshold for the beetles is the general leaf defoliation threshold used for other pests. During the reproductive stages of soybeans, the threshold for considering an insecticide treatment is if greater than 20% of the leaf area is gone due to feeding. However, the high price of soybean may lower the threshold slightly. But remember that most people tend to overestimate defoliation. If it looks like 20% defoliation, most likely it’s only 10%. The pictures in the following article can help in estimating percent defoliation: http://www.ipm.iastate.edu/ipm/icm/2002/7-29-2002/soydefoliation.html.
In corn, Japanese Beetle adults feed on leaves, tassels, silks, and pollen and are capable of interfering with pollination If silks are being clipped to within 0.5 inch of the end of the ear and pollination has not yet occurred, consider and insecticidal treatment.
For more information and insecticides labeled for Japanese beetles see the July 28, 2003 ICM Newsletter at http://www.ipm.iastate.edu/ipm/icm/2003/7-28-2003/japanesebeetle.html.
FOR YOUR CALENDAR
Upper Midwest Manure Handling Expo
July 22, 2009
The Upper Midwest Manure Handling Expo is scheduled for July 22 at the Central Iowa Expo site between Ames and Boone. The theme of the expo, SET for Fall, will focus on safety, efficiency and technology. This expo will be a great opportunity to see many different kinds of liquid and dry manure application equipment. The expo will include educational sessions, exhibitors, and 19 field demonstrations as well as a spill response demonstration. There is no fee to attend the expo, however parking is $5 per vehicle. A complete list of expo activities and maps can be accessed at: http://www.ag.iastate.edu/wastemgmt/expo_home.htm
Illinois Forage Expo
Meier Farms, 205 N Dakota Road, Ridott, IL
Friday, July 31, 2009 9 AM to 4 PM
Directions From the West: Exit US Rt 20 at RT 75 (Freeport/Dakota) exit. Go south (right) ¾ mile on Route 75. Go east (left) 2 miles on River Road, turn right on Dakota Road 1/2 mile.
Equipment Field Demonstrations
times subject to change
9:00 AM — 10:00 AM Mowing & Tedding
10:00 AM —11:00 AM Raking
10:30 AM Baleage
11:00 AM — Noon Chopping
1:00 PM Chopping
2:00 PM — 4:00 PM Baling
10:00 AM Autosteer in Forage Systems
Jay Solomon, U of I Extension
10:20 AM Dollars & Cents of Alfalfa Production
Jim Endress, U of I Extension
10:40 AM Managing Risk with Hay Insurance
11:00 AM Nutrient Management Planning & How EQIP Can Help
USDA NRCS Staff
11:20 AM Forages & Today’s Milk Price
Dr. Mike Hutjens, U of I Extension
Industry and Equipment Exhibits
Crop Management and Diagnostic Clinics
August-September – Ames
The Field Extension Education Laboratory is a 43-acre teaching and demonstration facility dedicated to providing a hands-on learning experience for crop production professionals. The demonstration plots are used to show a wide range of management problems, solutions, and diagnostic challenges. “We make the mistakes on these plots so you won't in the future!” The clinics and programs are taught by Iowa State University staff and faculty and invited specialists from other institutions and industry. Modern, air-conditioned classroom facilities complement the in-field sessions, all of which are within walking distance. Current open programs for this summer include the following:
Aug 25-27, Iowa Drainage School
September 2, Alfalfa Production Clinic
September 3, Corn Disease Diagnostics and Management
September 15, Soil Management Clinic
For other Agribusiness Education program information, check out the Homepage at: http://www.aep.iastate.edu/homepage.html
Advances in Precision Ag Field Day
ISU SE Iowa Research & Demonstration Farm – Crawfordsville
See the latest in precision agriculture technology, including RTK guidance systems, auto-steer, automatic shut-off planters, and sprayers. As details emerge, they will be posted at http://www.extension.iastate.edu/Pages/eccrops/meetserc.html.
If you have any questions, please feel free to contact the Iowa State University Extension Office.
Nondiscrimination Statement and Information Disclosures