Crop & Pest Report

Accessibility


| Share

Clethodim on Canola and Mustards (06/16/16)

Question: I have a question on the canola and mustard application stage recommendation on clethodim labels.

Clethodim on Canola and Mustards

Question: I have a question on the canola and mustard application stage recommendation on clethodim labels. Why is the recommendation for use on canola and mustards only prior to bolting? Is the clethodim actually causing some damage at this stage or does it have to do with the MSO oil? I get this question quite often “why can’t I spray clethodim after bolting - all it does is kill grass?”

Answer: It is a common thought that POST grass herbicide are phytotoxic only to grass species but products that contain the active ingredient clethodim applied to bolting canola and mustard species are one exception. Severe stunting, injury, and yield loss can occur if clethodim is applied to mustard species after bolting begins. Tolerance of mustard plants to clethodim quickly declines once bolting begins. In NDSU field trails we have observed 60% canola injury when clethodim was applied to bolting/pre-flower canola. Why does this happen? When mustard begins to bolt the reproductive plant tissue (flowering) begins to form. The reproductive plant tissue does not have the tolerance to clethodim as vegetative tissue (rosette).

Rich Zollinger

Extension Weed Specialist

This site is supported in part by the Crop Protection and Pest Management Program [grant no. 2017-70006-27144/accession 1013592] from the USDA National Institute of Food and Agriculture. Any opinions, findings, conclusions, or recommendations expressed are those of the website author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.

USDA logo

Creative Commons License
Feel free to use and share this content, but please do so under the conditions of our Creative Commons license and our Rules for Use. Thanks.