Crops Bulletin
July 10, 2014 
     Issue 7       
 
 

Prepared by

Paul Kassel

Extension Field Agronomist

 

Phone: 

(712) 262-2264

Email: kassel@iastate.edu 

 

 

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.

Waterhemp: Some waterhemp have survived glyphosate applications in some area fields. The following are some options to control larger waterhemp.

 

Products that contain fomesafen (Flexstar, Reflex, Marvel, etc.) have a 10 month crop rotation to corn. Fomesafen can carryover and damage next years corn crop if dry weather persists after application. The application of a fomesafen product on July 10 would mean a corn planting date after May 10, 2015 to comply with label guidelines.

 

Product       Rate, fl. oz./a          Cost/a, $              PHI

Cobra                6-12.5                 9.40-19.50         45 days

 

Flexstar             8-24                   8.75-26.25          45 days        

Ultra Blazer        8-24                   5.60-16.80          50 days

 

Cost is based on an NDSU price list and the range of costs is based on the rate/acre.

 

Weed control results with these products will be improved with the use of flat fan nozzles, 10-20 GPA and boom pressures of 40 PSI or greater. The use of crop oil concentrates versus nonionic surfactant will provide better weed control but also increase the amount of soybean leaf burn.

 

Herbicides to Tank Mix with Glyphosate: The following are tank mix partners for soybean and some of the benefits of those products.

  • FirstRate can be added to assist in the control of cocklebur, sunflower, giant ragweed, velvetleaf, and Venice mallow. There is a 9 month rotation restriction to corn and the PHI is 65 days.
  • Harmony SG/generic thifensulfuron can be added to assist in the control of velvetleaf, lambsquarter. The PHI is 60 days.
  • Classic can be added to assist in the control of velvetleaf, sunflower, giant and common ragweed. The PHI is 60 days.
  • Cadet can be added to assist in the control of velvetleaf. The PHI is 60 days.

 

Added Nitrogen for Corn: Cornfields that are stressed from lack of drainage/excess moisture may respond to added nitrogen. Fields or areas with the best chance of a profitable response to added N are those where height and growth stage are similar to non N-stressed corn but have a general yellow color. Corn that is several growth stages behind corn in better drained areas has limited yield potential.

 

Prepared by Paul Kassel, Extension Field Agronomist

Phone: (712) 262-2264, Email: kassel@iastate.edu