May 7, 2007
Time to Scout for Cutworms
With the early corn emergence and past warm temperatures, cutworm damage may appear earlier than normal this year A network of pheromone traps across Iowa indicated that a significant flight of black cutworm moths occurred in southern Benton county on April 6. This does not necessarily indicate that we will have a problem with cutworms, but does tell us when to start scouting for corn cutting. Based on degree days accumulated, cutting could begin this weekend in that area. Moth flights were later in the rest of the state. Most years black cutworms are not a problem, but it’s prudent to take some time and monitor fields until they reach V5 (5 leaves fully emerged from the whorl). An insecticide treatment is recommended if 2-3% of the plants are cut and the cutworms are less than ¾ inch long. When cutworms reach 1 inch long, 5% cutting is the threshold. An article showing predicted cutting dates for the rest of the state will appear next week in the ICM News. For a past article on black cutworm management, with pictures on how to distinguish between black and dingy cutworms see http://www.ipm.iastate.edu/ipm/icm/2005/5-16-2005/cutworm.html.
The growing point on corn is below the soil surface until the corn is about a foot tall, so even if we get some frost this weekend, it should not be detrimental to emerged corn. The cold spell could have more of an effect on corn that was more recently planted and is in the process of germinating and emerging. Cold weather during this time can “disorient” the growing seedling and result in reduced vigor, and also increases the risk of seedling diseases. Roger Elmore and Lori Abendroth have a nice article on this at http://www.extension.iastate.edu/CropNews/2010/0505elmoreabendroth.htm.
FOR YOUR CALENDAR
SPRING FIELD DAY & SPECIAL SESSION FOR CCAs
SE IA RESEARCH FARM – CRAWFORDSVILLE
The Spring Field Day of the Southeast Research and Demonstration Farm (Crawfordsville) will be on the afternoon of Thursday, June 24, 2010 at the farm. Certified Crop Advisor (CCA) credits will be available. The field day will feature Erin Hodgson on new advances in soybean aphid management, Matt Helmers on Tile Drainage Research results, Emily Heaton, on Miscanthus and other Cellulosic Ethanol Crops, and Johns Sawyer on Nitrogen Management and Cover Crops. In addition, Certified Crop Advisors can obtain additional hours of credit (including soil and water) by attending a special session in the morning followed by the afternoon tour. Soil drainage will be featured in this special session. More details 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.
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