|LINDENMEYER, BRADLEY - Colorado State University|
|NISSEN, SCOTT - Colorado State University|
|WESTRA, PHILIP - Colorado State University|
|BRUNK, GALEN - Colorado State University|
Submitted to: Weed Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/24/2012
Publication Date: 1/1/2013
Citation: Lindenmeyer, B., Nissen, S., Westra, P., Shaner, D.L., Brunk, G. 2013. Aminocyclopyrachlor absorption, translocation and metabolism in field 1 bindweed (convolulus arvensis). Weed Science. 61(1):63-67.
Interpretive Summary: Field bindweed is a noxious weed that is very difficult to control. Aminocyclopyrachlor is a new herbicide that has very good efficacy on field bindweed. This research examined the behavior of aminocyclopyrachlor in field bindweed. The results show that this herbicide is easily absorbed by field bindweed and rapidly translocates throughout the plant. Aminocyclopyrachlor has greater translocation to the underground plant structures than other herbicides and this movement, along with limited metabolic breakdown of the herbicide, accounts for the excellent activity on field bindweed.
Technical Abstract: Field bindweed (Convolvulus arvensis L.) is extremely susceptible to aminocyclopyrachlor compared to other weed species. Laboratory studies were conducted to determine if absorption, translocation, and metabolism of aminocyclopyrachlor in field bindweed differs from other, less susceptible species. Field bindweed plants were treated with 3.3 kBq 14C-aminocyclopyrachlor by spotting a single leaf mid-way up the stem with 10 µL of herbicide solution. Plants were then harvested at set intervals over 192 hours after treatment (HAT). Aminocyclopyrachlor absorption reached a maximum of 48.3% of the applied radioactivity by 48 HAT. A translocation pattern of herbicide movement from the treated leaf into other plant tissues emerged, revealing a nearly equal aminocyclopyrachlor distribution between the treated leaf, aboveground tissue, and belowground tissue of 13, 14, and 14% of the applied radioactivity by 192 HAT. Over the time-course, no soluble aminocyclopyrachlor metabolites were observed, but there was an increase in radioactivity recovered in the fraction bound to a non-soluble fraction. These results suggest that aminocyclopyrachlor has greater translocation to belowground plant tissue in field bindweed compared with results from other studies with other herbicides and other weed species, which could explain the increased level of control observed in the field. The lack of soluble metabolites also suggests that very little metabolism occurred over the time course of the experiment.