Thanks for the reply. I didn't think there was much interest in this topic based on the number of responses. I did send an e-mail to the manufacturer of Sevin and ask the question of them. The response:
<font color="blue"> Yes, SEVIN and Roundup can be used in a tank mix situation effectively. As
always, verify any further specifics in regards to tank mixing with both
product labels to ensure best results.
Please call the number listed below if you have additional questions.
Thank you for your inquiry,
Bayer Crop Science
Customer Interaction Center
1-866-992--2937
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