Crops Bulletin
June 5, 2012
Issue 4 


Prepared by

Paul Kassel

Extension Field Agronomist



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.




Weed control in larger corn. The following is some selected information for weed control in larger sized corn.


Product            Corn Size/Stage     Notes on Weed Control

Callisto + Atrazine    V8, or 30 inch           up to 10-inch lambsquarter                                                                            or waterhemp    


Capreno                     V5                               up to 6 inch lambsquarter   

                                                                           and waterhemp    


Glyphosate                V8, up to 30 inch       rates are weed size  


Halex GT                    V8


Impact                        drops if needed         6 inch lambsquarter,  



Laudis                        up to V8                      6 inch lambsquarter,  

                                                                             waterhemp, velvetleaf  

Liberty                        up to V7                       4-6 inch weeds


Status                         V10, or 36 inch          3-4 inch weeds  


Surestart                    11 inch corn


Nitrogen tests.   The late spring nitrogen test (LSNT) can be useful to confirm nitrogen (N) levels or nitrogen needs. Fields that have had manure with questionable N content, or fields where N rates were less than planned may be good candidates for the LSNT.


Corn Rootworm hatch. Warm early season soil temps raised questions on the date of corn rootworm hatch. However, since soil temps in April and May were more normal, rootworm hatch will be about normal - or about June 6. Therefore corn rootworm damage is not expected to be any less or more than previous years.  


ISU Research Farm Field days. 

-          June 26, Northern Iowa, Kanawha, 9:00 to 1:00.

-          June 27, Northwest Iowa, Sutherland, 9:00 to 1:00.

Prepared by Paul Kassel, Extension Field Agronomist

Phone: (712) 262-2264, Email: