re: Weed control in sunflowers

White Bear is right. Treflan won't have much of an effect if it isn't incorporated.

Looks like we have a rain coming to the TX-LA-MS area on Thur afternoon or Friday. If you have time I would go back and spray a mix of Dual and Spartan. If you can't find the Spartan, use a stiff rate of Dual. A rain helps to activate it.

Then once the sunflowers emerge and are about 8-12" tall you can come back over the top with Select (the generic is Volunteer) for grass control.

If you planted Clearfield sunflowers then you can come over the top with Imazamox (Imox is the generic) at the same time as your Select

That's about all you can do. Other than fertilize.

The other thing you could do is cultivate with a field cultivator if you have a high plant population