Commercial sunflower crop growers have all the secrets and usually publish them to help the farmers of these crops.
You are talking about sunflower crops. Research the internet for commercial sunflower crop growers.
Even better, try to search for companies that sell commercial seed quantities.

I did that with one plant once and was amazed at how much I learned. Studying the commercial guys changed my whole way of gardening.

Lastly I would go to the books sections of Google. I often find old, free agriculture books I can read on specific topics.
IMHO

Thanks Bug Bite for the helpful information. I'll do more research as you suggested.

Hi Jeannie Marie,
I thought that I would do what I suggested to you to see if I was offbase. I searched "Commercial sunflower crop growers ". I quickly found this guide.
Good Luck,
Bob

Here is a link that might be useful: Sunflower Production

Fabulous, thank you so very much. Now if it would only stop raining here in Wisconsin so I could do some more last minute planting. Appreciate the help. Jeannie