Crops Bulletin
 May 25, 2017   
  Issue 4  

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.

  Soybean planting date.  Soybean planting date info shows that soybean yield potential for late May  planted/replant is well over 90%. Consider replanting soybeans if populations are less than 75000 plants/acre or about 5 plants per foot of row in a 30 inch row. 
Land rolling emerged soybeans. Soybeans can be rolled after emergence. Rolling emerged soybeans can be completed any time after emergence - preferably after the unifoliate leaves have unfurled.   Land rolling emerged soybeans should occur before the V3 stage - which is about 6-inch tall soybean.
Corn replanting. Plant populations of about 10,000 to 15,000 plants would be expected to yield about 70 to 80% of normal. Corn replanted the last week of May is expected to yield about 70% of normal. A stand below 15,000 may need to be replanted. This checklist has some useful replant info.
Black cutworm. Black cutworm larvae are usually large enough to damage corn the last week of May, or 300 GDDs. We have had about 250 GDDs since black cutworm adults have arrived in northwest Iowa.
This ICM News article has an update on black cutworm in 2017.

Wet weather, soybean pre-emergence herbicide. Consider glyphosate plus Dual, Outlook or Zidua application where wet weather and soybean emergence are preventing applications of Valor, Authority, Prefix or Verdict type products. Bob Hartzler has more info here.


Prepared by Paul Kassel, Extension Field Agronomist

Phone: (712) 262-2264, Email: