Weed Control in Sunflowers

By Grant Woods,

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Grant,

For the past two years, I have unsuccessfully attempted to grow sunflowers (for birds).  The area was tilled, and then subsequently sprayed with glyphosate two and four weeks from the original tilling.  When I planted the sunflowers, there wasn’t a weed (or grass) to be seen.  As the sunflowers grew, so did the weeds — to the point that the sunflowers simply could not compete to grow tall and produce.

Do you have any suggestions?  One thought I had was to spray the area with a pre-emergent (pendimethalin?) after the sunflowers emerge from the ground.  Is this sound logic?

Barry

Barry,

I haven’t used Pendimethalin to control weeds in sunflowers.  However, I checked the label and it states…

“In sunflowers, groundnuts, kidney and dry beans and soybeans PENDIMETHALIN 500 EC must always be mechanically incorporated before seeding and within 5 days of application.  Best results will be obtained if incorporation is carried out within 24 hours of application.”

I always attempt to follow the instructions in a herbicide label exactly for the best results and to prevent damage to a crop.

Growing Deer together,

Grant