Crops Bulletin
 June 8, 2017   
  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.

Corn development.  Corn in many area cornfields has developed to the V6 stage or beyond. The V6 stage of corn is a milestone of sorts for the corn plant.

-The growing point is now above the soil surface
-The nodal root system is now the dominant root system.
-The ear shoot has formed although microscopic in size.
-The rows of kernels on the ear will be determined by V7.
-The current dry weather will accentuate growth differences where root growth is restricted.
Nitrogen losses 2017.  The current dry weather is favorable to minimize N losses. Various methods can be used to estimate N losses. One indicator of N losses occurs when rainfall exceeds 15.5 inches from April 1 to June 30.

Rainfall amounts for much of northwest/north central Iowa is around 8 inches for the April 1 to June 30 time frame. Monthly rainfall amounts can be viewed on the Mesonet

Late Spring Nitrogen Test (LSNT).   The LSNT can be useful to confirm nitrogen (N) levels or N 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.

A new publication provides updated info on the LSNT. The basics on the test and interpretations are the same. Tables for manure and prior alfalfa crop are clarified. Additional text was added explaining various aspects of the test.

Growing Degree Days. The following are GDDs for Spencer with 3 different planting dates. Use the Useful to Usable website to view GDDS for your location.
Planting date            GDDS            departure
April 11                       567                  -2
April 24                       478                  -14
May 10                       375                  +14
Accumulation of GDDs is about 30 to 40 above normal since June 1.

Wind history. This   website is handy to access info on wind speed and direction for a particular day or time frame.

Prepared by Paul Kassel, Extension Field Agronomist

Phone: (712) 262-2264, Email: