Crops Bulletin
June 20, 2014 
Issue 5     

Prepared by

Paul Kassel

Extension Field Agronomist



(712) 262-2264




Serving Clay, Buena Vista, Dickinson, Emmet, Hancock, Kossuth, Palo Alto, Pocahontas, Sac and Winnebago Counties



The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, gender, religion, age, disability, political beliefs, sexual orientation, and marital or family status. (Not all prohibited bases apply to all programs.) Many materials can be made available in alternative formats for ADA clients. To file a complaint of discrimination, write USDA, Office of Civil Rights, Room 326-W, Whitten Building, 14th and Independence Avenue, SW, Washington, DC 20250-9410 or call 202-720-5964.

Hail Damage, Replanting: Recent hail and flooding has created widespread crop damage and potential replanting. The following are some guidelines on replanting.

  • Late June planted soybean will yield about 60 to 70% of normal.
  • Actual soybean yields may be in the 30 bu/a range.
  • Use a late group I maturity group soybean variety.
  • Corn replanted in late June for silage will yield about 7-9 ton/a of wet silage.

Corn Rootworm: There have been 483/585 soil growing degree days (GDDs) for Kanawha/Sutherland as of 6/17/14. Egg hatch (50%) occurs at 684 to 767 soil GDDs. Saturated soil conditions reduce larval survival.


Growing Degree Days: The following are GDDs for the Northwest Iowa Crop reporting district.

  • 4/22 - 6/18, 708 (-19).
  • 5/5 - 6/18, 639 (+17).

Nitrogen Losses, Management: Recent heavy rainfall will challenge nitrogen management. The following are some details from an article written by John Sawyer.

  • denitrification losses can be 4-5%/day, 60-70 lb/a total (U of IL).
  • 50 lb/a of sidedress N restored yields when denitrification occurred.
  • Nitrate loss via tile drainage ranged from 9 lb/a to 52 lb/a (ISU, ADW site).
  • Consider in-season application of 30 to 50 lb/a of additional nitrogen.

Sutherland Field Day:

The Northwest Iowa Research Farm field day will be held at the farm near Calumet on June 25 at 9:00 a.m. Speakers include Erin Hodgson - crop insects, Kurt Miene - IDOT, Joel DeJong- crop update and Paul Kassel - soybean herbicides. A noon lunch is available. There is a presentation on UAVs after lunch. 


Kanawha Field Day: The Northern Iowa Research Farm field day will be held at the farm near Kanawha on June 26 at 9:00 a.m. Speakers include Micah Smidt, John Sawyer, Mark Hanna, Angie Rieck-Hinz and Paul Kassel. A noon lunch is available.

Prepared by Paul Kassel, Extension Field Agronomist

Phone: (712) 262-2264, Email: