Wheat Research

Weed management in wheat
Dr. Peter Sikkema, University of Guelph; Ridgetown Campus

Through 21 field experiments in 2008 at the Huron Research Station and the University of Guelph Ridgetown Campus, much has been revealed about weed management in winter wheat. The goal of these experiments was to determine the most effective weed control strategies where weed control is maximized, crop injury is minimized and crop yield
is maximized.

ROUNDUP TANKMIXES
Through this research it has been found that the tankmix of Roundup plus Amitrol has no negative effect on winter wheat yield or height and results in minimal (one percent or less) visible crop injury.

The tankmix of Roundup plus Distinct resulted in up to four percent visible crop injury. In addition, there was no negative effect on winter wheat height but yields were decreased one, four, nine and seven bushels per acre when the tankmix was applied 14, seven and one day before seeding and immediately after seeding, respectively.

Also discovered was that the tankmix of Roundup plus Classic resulted in up to five percent visible crop injury in the fall and 23 percent visible crop injury the following spring. Winter wheat height was reduced as much as eight centimeters. Additionally, winter wheat yield was decreased 21, 20, 24 and 30 bushels per acre when the tankmix was applied 14, seven and one day before seeding and immediately after seeding, respectively.

TOLERANCE OF KIXOR
Four studies have been completed on the tolerance of winter wheat to Kixor (saflufenacil - BAS 800) at 25, 50, 100 and 200 gallons per hectare applied pre-plant, pre-emergence and post-emergence in the fall.

The pre-plant application resulted in minimal visible crop injury with up to three percent visible injury observed in the fall and one percent the following spring. The pre-emergence application resulted in up to six percent visible injury observed in the fall and two percent the following spring.

Kixor applied post-emergence without an adjuvant resulted in up to 16 percent visible crop injury in the fall which decreased to less than 2 percent when evaluated the following spring.

Kixor applied post-emergence with an adjuvant resulted in up to 36 percent visible crop injury in the fall which decreased to less than five percent when evaluated the following spring. There was no decrease in winter wheat height or yield (plus or minus five percent) with the application of Kixor.

FUNGICIDE TANKMIXES
Four experiments were established to determine the tolerance of winter wheat to herbicide (Buctril M, Estaprop, Refine Extra + MCPA amine or Infinity) plus fungicide (Tilt, Headline, Folicur, Stratego or Quilt) tankmixes. The tankmixes of Buctril M, Estaprop, Refine Extra plus MCPA amine or Infinity plus the above fungicides did not result in any visible crop injury and there was no decrease in winter wheat height or yield.

Generally, the addition of a fungicide to a herbicide did not affect weed control in winter wheat. However, of the 144 evaluations there were eight combinations that resulted in a slight decrease in weed control and there were two tankmixes where the weed control was increased. These preliminary findings will have to be confirmed in future studies. There was no effect of the herbicide plus fungicide tankmixes on winter wheat height or yield.