No, they are planted, and normally harvested. The photo shows the field of cut sunflower plants.....
This is the first time i ever saw sunflowers planted on state land. Years ago i was able to kill a couple of whitetail on state land that was planted with corn. The producer explained to me that the agreement with the state, was he seeded, and fertilized, and irrigated the crop, then left 1/3 of the corn uncut. What the agreement is here, i don't know.
What it looked like to me was all of the sunflower plants are cut, but there seemed to be areas in the field where the heads had all the seeds still attached, and there seemed to be areas where the heads had no seeds.
No whitetail have been in the sunflowers yet, but i have seen mule deer out there twice. The closest i was able to get to the deer was 300 yard, so i wouldn't have had much chance with my muzzle loader. Have seen Sharptail grouse, and the coyote, but no whitetail. Chances of killing a whitetail seem bleak.