| dc.description.abstract | Field experiments were conducted at five Northern Midwest locations to evaluate
one and two pass herbicide programs developed for weed control in Optimum GAT
(Glyphosate Acetolactate Synthase Tolerant) corn (Zea mays L.). All treatments provided
greater than 95% control of grass and broadleafweed species 14 days after application
(DAA) and greater than 80% control 28 DAA. There were no statistical differences in
weed control 14 and 28 DAA between one and two pass herbicide treatments.
Field experiments were conducted at three North Dakota locations to evaluate the
growth and yield of hard red spring wheat (Triticum aestivum L.), field corn, dry bean
(Phaseolus vulgaris L.), canola (Brassica napus L.), sunflower (Helianthus annuus L.),
and sugar beet (Beta vulgaris L.) one year after chlorimuron-ethyl was applied to soils with
different pH. Chlorimuron treatments at Valley City (soil pH< 6.2) and Reynolds (soil pH
> 8.3) caused 18 to 86% canola injury 28 days after emergence (DAE). All treatments at
these locations delayed canola flowering 2 to 7 days compared to the control. Pinto bean
yield at Reynolds was reduced from the control by 25% at 11.6 g ha- 1 and 34% at 17.5 g
ha- 1
• Chlorimuron applied at 11.6 g ha- 1 and 17.5 g ha- 1 at Alice (soil pH 6.2 to 7.8)
resulted in 21 to 26% corn injury 28 DAE, but yield was unaffected. Sugar beet yield at
Alice and Reynolds was reduced from the control by 43 to 86% at 11.6 and 17.5 g ha- 1.
These data confirmed that low rates of chlorimuron can injure canola and sugar beet one
year after application. These data also suggest that minor injury may occur to pinto bean, hard red spring wheat, and com when 5.8 g ha- 1 or less of chlorimuron is applied the
previous year; however, yield should not be significantly impacted.
Field experiments were conducted near Mapleton and Casselton, North Dakota, to
evaluate the enhancement of glyphosate plus rimsulfuron, tribenuron methyl, and
mesotrione (Trigate™) and glyphosate plus chlorimuron ethyl, tribenuron methyl, and
thifensulfuron methyl (Freestyle™) from adjuvants of different classes on flax (Linum
usitatissimum L.), quinoa (Chenopodium quinoa Willd.), tame buckwheat (Fagopyrum
esculentum Moench.), and conventional com. Adjuvants containing ammonium sulfate
(AMS) or an AMS replacement provided greater enhancement of glyphosate plus
Trigate™ and glyphosate plus Freestyle™ on flax and com compared to oil-based
adjuvants. The enhancement of these herbicides on quinoa and tame buckwheat appeared
to be somewhat similar for oil-based adjuvants compared to AMS-based adjuvants. Cut
Rate and ET 4000 adjuvants provided little to no enhancement of these herbicides on flax
and quinoa. The addition of Class Act NG to glyphosate plus Trigate™ or glyphosate plus
Freestyle™ provided 68 to 94% control on species tested 28 DAA.
Greenhouse experiments were conducted to evaluate the effect of pH on the
e ffit eacy o fTn.g ateT M an d FreestyleT M on common lambsquarters (Chenopodr.n m album L.)
and velvetleaf (Abutilon theophrasti Medik. ). Adjusting the pH of the spray solution did
not appear to influence the efficacy of Trigate™ and Freestyle™ herbicides on common
lambsquarters. Control ofvelvetleaf was greater and dry weights were lower compared to
other pH treatments for glyphosate plus Freestyle™ applied when the pH was raised to 9
and lowered to 2; however, this pattern was not observed with glyphosate plus Trigate™ or
with Trigate™ and Freestyle™ applied alone. | en_US |
