September 10, 2009
Although soybean aphids are still present in many fields, nearly all fields are at or beyond R6 (full seed size), so insecticide applications aren’t likely to pay. I’ve noticed that Japanese beetles have disappeared from some fields now, so hopefully they are done for the season. One insect that is more widespread than usual this year is the green stink bug. I know of at least one field in the area that was sprayed for this pest, although it is unusual for this pest to cause enough damage to justify an insecticide. It is a more common pest in Brazil. You can see a picture of the adult and nymph green stink bug in this ICM article http://www.ipm.iastate.edu/ipm/icm/2001/9-17-2001/stinkbugs.html.
This is the one of the worst years I’ve seen for Soybean Sudden Death Syndrome (SDS), which will likely keep the yields down somewhat. It is easy to see where there is extra soil compaction or poor drainage in fields. Fields with SDS should be tested for Soybean Cyst Nematode (SCN), if they haven’t already. Most fields with SDS also are infested with SCN. The sample submission form and instructions for taking the sample are in PD-32 “Plant Nematode Sample Submission Form” which is available at Iowa State University Extension offices or can be downloaded from http://www.extension.iastate.edu/Publications/PD32.pdf.
This has also been a bad year for white mold. It is best to harvest the worst infested fields last, or clean the combine after harvesting the infested fields to try to prevent its spread. One possible long term treatment for white mold is to use the biological insecticide “Contans WG.” It is composed of natural fungi that colonize the white mold fungus. A good time to apply the product is after harvesting the diseased crop so it has plenty of time to establish before the soybeans are planted again in the field. This University of Wisconsin publication contains some good information on white mold management, including biological control: http://www.plantpath.wisc.edu/soyhealth/pdf/whitemold_06.pdf.
Soybean rust has spread some in the southern states, but it looks like Iowa has escaped for another year. Rust development can be monitored at the following USDA web site: http://sbr.ipmpipe.org/cgi-bin/sbr/public.cgi
FOR YOUR CALENDAR
Advances in Precision Ag Expo
ISU SE Iowa Research & Demonstration Farm – Crawfordsville
10:30 a.m. - 4:30 p.m.
Come see the latest in precision ag technology, including RTK guidance systems, auto-steer, automatic shut-off planters, strip-tilling and planting on the contour using RTK guidance. The expo will feature field demonstrations and industry exhibits on the latest technology and crop producers will have a chance to participate in ride and drive activities. Companies involved in the demonstrations and exhibits include Ag Leader Technology, AutoFarm, Brokaw Supply, CASE IH, Crop Tech Services Elder Implement, Eldon C. Stutsman, Heartland Ag, HTS Precision Ag, Kinze, J.J. Nichting Co., John Deere, Leica Mojo, Monsanto, New Holland, Pioneer Hi-Bred, Plank Equipment, and Topcon. The EXPO is free to SE IA Association members or $15 for nonmembers (5-year memberships available for $25). The entrance fee includes lunch. A brochure for the EXPO is available here http://www.extension.iastate.edu/Pages/eccrops/09apaebrochure.pdf.
Special Session for CCAs at Precision Ag EXPO
CCAs can earn up to 5 CCA credits (2.5 in soil and water) by attending a special session from 9:00-11:00 a.m. on Making Strip Till Work in Eastern Iowa followed by the Precision Ag EXPO on Sept. 17. There will be hands-on training on adjusting tillage and planter equipment, and a discussion on how auto steer and RTK technology have helped to make strip till a more viable option on eastern Iowa hills. There is a $50 fee for credit (or $15 without credit). Fee includes entrance to the EXPO and lunch. Please send me an e-mail if you plan to attend this session.
If you have any questions, please feel free to contact the Iowa State University Extension Office.
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