June 19 , 2019   
  Issue 4

Soybean gall midge (SGM) A single adult has been found in emergence cages at the ISU NW Research Farm at Sutherland. However, adult SGM has been found in adjoining states. The SGM adults have all emerged from 2018 soybean fields. No management practices are recommended at this time.
Nitrogen Research by ISU has shown that additional N fertilizer is needed if April 1 to June 30 rainfall exceeds 16 inches. Many locations in northwest and north central Iowa have had 11 to 13 inches of rain since April 1. An additional 30 to 40 lb./a of N is recommended if rainfall exceeds or is expected to exceed 16 inches in the April 1 to June 30 time frame.
Corn rootworm. The peak corn rootworm hatch has been delayed by the cool spring and is expected next week in northern Iowa. Make plans to assess corn root injury around July 1. Fields with a history of Bt trait performance issues and continuous corn fields would be a high priority. June planted corn would be a low priority.
Black cutworm. Check June planted corn fields for black cutworm damage. Corn is susceptible to cutworm injury through the V5 stage. The threshold is 3-5% cut plants at the V2-V3 stage corn. Corn with traits Agrisure Viptera 3110, Herculex I and others will help reduce but not eliminate cutworm damage. Insecticide seed treatments - such as Cruiser, and Gaucho will help also.  

Prepared by:
  Paul Kassel- Extension Field Agronomist


Phone:  (712) 262-2264


Serving Clay, Buena Vista, Dickinson, Emmet, Hancock, Kossuth, Palo Alto, Pocahontas, Sac and Winnebago Counties



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