TITLE:
Influence of Adjuvants on the Control of Glyphosate-Resistant Canada Fleabane and Waterhemp in Corn with Tolpyralate
AUTHORS:
Nicole M. Langdon, Nader Soltani, Alan J. Raedar, David C. Hooker, Darren E. Robinson, Peter H. Sikkema
KEYWORDS:
Biomass, Crop Injury, Density, Sensitivity, Weed Control, Yield, Amaranthus tuberculatus, Conyza canadensis L. Cronq
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.11 No.3,
March
23,
2020
ABSTRACT: Tolpyralate
is a new benzoylpyrazole herbicide for weed management in corn. It is recommended to be co-applied
with atrazine along with the adjuvants methylated seed oil concentrate (MSO)
plus an ammonium nitrogen fertilizer, such as urea ammonium nitrate (UAN). Two studies were conducted on glyphosate-resistant
(GR) Canada fleabane and GR waterhemp to determine if an additional adjuvant is
still required when tolpyralate plus atrazine are tankmixed with a commercial
glyphosate formulation (Roundup WeatherMAX®) in corn. Trials were conducted over a two-year
period (2018-19) on farms in south western Ontario with
confirmed GR populations. When co-applied with Roundup WeatherMAX®, the addition of MSO to tolpyralate + atrazine increased
control of GR waterhemp 9%; however, there was no increase in GR Canada
fleabane control from the addition of additional adjuvants. At 8 WAA, all
treatments provided > 91% and > 84% control of GR waterhemp and GR Canada fleabane,
respectively. This study concludes that the addition of Roundup WeatherMAX®
to tolpyralate plus atrazine improves the control of GR waterhemp and GR Canada
fleabane in corn.