I like this, Ken, though it may not be everyone's cup of tea. :) Nice light, exposure, and sharpness. IMO, the little white flowers on the right side compete with the sunflower for my attention. You might consider cropping or cloning them - I think a crop from the right would improve the comp as well.
I like it, too, Ken. I do think compositionally it might have been even stronger with more of the daisies on the right included to push the sunflower just a bit more to the left of the frame. It would be a minor adjustment but I think it might have made the image even stronger.
Beautiful BG. I love it when that happens in the field.