Interested Members of the University Community are invited to attend the Final Oral Examination for the Degree of Master of Science of Lauren Benoit of the Department of Plant Agriculture.

Tuesday, January 8th, 2019 at 2:00 pm
Crop Science Building, Room 202

Thesis Title: Control and Distribution of Herbicide Resistant Waterhemp (Amaranthus tuberculatus) in Ontario

Advisory Committee:                                    

Dr. Peter Sikkema, Advisor
Dr. Darren Robinson, Co-advisor
Dr. David Hooker    

Examination Committee:

Dr. Francois Tardif, Chair
Dr. Peter Sikkema
Dr. Darren Robinson
Dr. Clarence Swanton                                            

ABSTRACT

Field surveys were conducted in 2016, 2017 and 2018 to build on previous research. Waterhemp was located at 42 additional locations in seven Ontario counties and the province of Quebec. Greenhouse testing of populations collected between 2014 and 2017 has shown that 100% of the populations have biotypes that are resistant to Group 2 herbicides, 83% to Group 5, 87% to Group 9, and 28% to Group 14. This is the first reported case of a Group 14-resistant weed in Eastern Canada. Thirty one field studies were conducted at three locations over three years to determine the efficacy of herbicides applied preemergence (PRE), postemergence (POST), and two-pass herbicide programs for control of multiple-resistant (MR) waterhemp in corn. S-metolachlor/mesotione/bicyclopyrone/atrazine, applied PRE, controlled waterhemp 91%, 8 WAA. Mesotrione + atrazine applied POST controlled waterhemp 92%, 8 WAA. All two-pass programs provided greater than 94% control of waterhemp 12 WAA. Ontario grain farmers have access to multiple effective options for the control of MR waterhemp in corn. 

**There is a Certified Crop Advisor CEU credit available for those who attend the presentation portion of the defense**