Crops Bulletin
June 30, 2015  
Issue 9                  
 
 

Prepared by

Paul Kassel

Extension Field Agronomist

 

Phone: 

(712) 262-2264

Email: [email protected] 

 

 

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. Glyphosate appears to be ineffective at waterhemp control in many area fields.

 

Flexstar, Reflex, Marvel contain fomesafen and have a 10 month crop rotation interval to corn. Fomesafen can carryover and cause injury to next years corn crop. The application of a fomesafen product on July 10 would mean a corn planting date after May 10, 2016 to comply with label guidelines.

 

Product      rate, fl. oz./a          cost/a, $              PHI

Cobra              4-12.5              6.80 - 21.50          45 days

Flexstar           12-24               7.00 - 14.00          45 days        

Flexstar GT 3.5   48                  15.00                  45 days

Marvel                 6                   10.50                  60 days

Ultra Blazer     12-24               8.40 to 16.90        50 days

- prices from an NDSU herbicide price list, Marvel at 6 oz has 9.2 oz of Flexstar.

 

Leaf burn and soybean yields.

A three-year multi-location study in Iowa and Illinois in the 1990s showed that more than 95% of the (288) postemergence herbicide applications did not reduce soybean yield regardless of the herbicide or level of soybean injury observed.

 

Significant yield loss occurred in only 3.5% of the treatments. These few instances often did not correlate to severe early-season injury and were usually associated with late herbicide applications to late-planted soybeans.

 

Check for SCN.
Check fields for soybean cyst nematode. The source of SCN resistance is limited to PI88788 with many soybean varieties. This source of resistance has lost some of its effectiveness recently. Greg Tylka has more info on this topic here.

Corn Borer.
Check conventional corn hybrids for corn borer damage. Corn borer levels have decreased in recent years. However, conventional hybrids have no protection against this insect and yield loss can occur if thresholds are exceeded. It will take about two larvae/plant to justify treatment at current costs and prices. 

 

  
 

 

 

 

Prepared by Paul Kassel, Extension Field Agronomist

Phone: (712) 262-2264, Email: [email protected]