Weed Technology (1998) 12, 699-706

Brett R. Miller and Rodney G. Lym (1998)
Using the rosette technique for Canada thistle (Cirsium arvense) control in row crops
Weed Technology 12 (4), 699-706
Abstract: Clopyralid applied to Canada thistle rosettes has provided better control in the following growing season than applications to bolted plants. The objectives of this research were to determine if using cultivation to prevent plants from bolting prior to herbicide application (the rosette technique) could be successfully incorporated into a row crop production system and to evaluate the effect of Canada thistle growth stage on the absorption and translocation of ¹⁴C-clopyralid. Canada thistle control 8 mo after postharvest herbicide treatment (MAFT) using the rosette technique was similar to control when using conventional in-crop plus postharvest herbicide treatments in corn and soybean. Glyphosate and clopyralid plus 2,4-D were the most consistent postharvest herbicide treatments for Canada thistle control 8 MAFT in corn and soybean. Corn yields were similar, but soybean yields were slightly lower when Canada thistle was controlled using cultivation compared to conventional herbicide treatments. ¹⁴C-clopyralid translocation to Canada thistle roots and lower shoot parts was greater when clopyralid was applied to the rosette stage than when applied to bolted Canada thistle plants. The increased translocation probably accounts for the increased Canada thistle control observed in the field. Incorporating the rosette technique into a weed management program should allow growers to control Canada thistle with less herbicide input than do standard practices.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Rodney G. Lym

Research topic(s) for pests/diseases/weeds:
control - general

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Cirsium arvense (weed)	Maize/corn (Zea mays)
	Cirsium arvense (weed)	Soybean (Glycine max)