The Herbicide-Resistant Palmer amaranth Management Field Day was held on Aug. 4, near Shickley, Neb. and was sponsored by the Nebraska Corn Board. Amit Jhala, assistant professor and University of Nebraska-Lincoln Extension weed management specialist, was the organizer and tour leader. Growers, crop consultants, extension educators, graduate students, industry representatives and other clientele made up the 105 people in attendance. Roch Gaussoin, UNL Department of Agronomy and Horticulture Head, started the day with a welcome address.
Palmer amaranth, a member of the pigweed (Amaranthaceae) family, is one of the most troublesome weeds in corn and soybean fields. Atrazine and HPPD-inhibiting herbicides- (Callisto, Laudis, Impact) resistant Palmer amaranth in south central Nebraska is of particular concern because of the proximity to intense seed corn production, which is heavily reliant on these herbicides for weed control.
Jhala and team members demonstrated several projects for control of herbicide-resistant Palmer amaranth in field and seed corn. These projects included efficacy, crop safety, and comparison of new herbicides in UNL’s unbiased comparison trials. Stevan Knezevic, UNL professor of integrated weed management, demonstrated projects related to dose response of palmer amaranth to atrazine and HPPD inhibitors (Callisto, Laudis, Impact). The day included a demonstration tour of the management of atrazine and HPPD inhibitors resistant Palmer amaranth in corn.
Curtis Thompson, professor of weed science at Kansas State University, was an invited speaker. He discussed Palmer amaranth identification, biology, and management in corn and soybean.
Graduate students Debalin Sarangi, Zahoor Ganie, Ethann Barnes, and Parminder Chahal demonstrated a research project on various aspects of Palmer amaranth control in field and seed corn.
The following projects were also discussed:
- Dose response of Atrazine, Callisto, Corvus, Balance Flexx applied pre-emergence to Palmer amaranth in field corn
- Tank mixing Atrazine with Callisto or Balance PRO at different rates for control of resistant Palmer amaranth
- Tank mixing Atrazine with Callisto, Laudis, or Armezone applied post-emergence for control of Palmer amaranth
- Herbicide programs for resistant Palmer amaranth control in seed corn
- Management of Palmer amaranth in
- Roundup Ready Corn
- Liberty Link Corn
- Evaluating programs of Corvus or Balance Flexx followed by DiFlexx in Roundup Ready corn
- Understanding emergence of Palmer amaranth for most effective control
- Understanding effect of tillage on Palmer amaranth emergence
- Overlapping residual herbicides for Palmer amaranth control in field corn
Irvin Schleufer, Sharon Hachtel, Caleb Wilford, Wendy Morrison, Ian Rogers, Whitney Walters, and Lyndsay Drudik provided help with registration and tour logistics. Lunch was provided followed by UNL Dairy Store’s Extension Centennial Ice Cream.