Douglas,
How many acres are we talking about here?
Jogee was saying the other day that Tiffleaf3 won't produce much seed and suggested Tiffseed, I believe. I think he has also said that Tiffseed is a much shorter variety, so that is really going to knock down on the tonnage of hay. Compared to Tiffleaf3, that is.
I'm with you on killing off the fescue and weeds this fall and planting something like oats or wheat for a spring hay crop. Depending on the kinds of weeds involved, they may already be done for the season by then though. I think my RoundUp was $10 an acre, at 1 quart per acre of chemical. Plus surfactant which was another few buck per acre. I sprayed myself. You should have time to spray for weeds again, in the spring before you cut it for hay. Gonna have to get at them at them as soon as they are big enough to spray though, to allow the 2,4,D to breakdown in time to broadcast or drill the millet.
Depending on your cultivation, chemical, fertilizer and seed costs, it might not be such a bad deal to go halves on the hay crops. He might need to pay some or give you a larger share of the hay. The kicker is still going to be having ripe seedheads for the doves, I believe. How much seed Tiffleaf3 makes may not be the issue, time to produce ripe seedheads in time for dove hunting will be. Our season starts September 1, here in Missouri.
Assuming you guys are ahead of us, lets say you can plant in early May. First cutting will be possible around early to mid to late June, depending on how high you let it get. That should allow enough time for two more cuttings before September 1. So, that part of the plan would work out. It isn't going to stop growing though, until frost kills it. Hmmmm. Let me back up on that statement a minute and puzzle out loud here a bit. OK, only two cuttings and then let it go to seed. But then that last cutting won't be very nutritious hay, since the food value goes in the tank once seedheads form. Hmmmm. Thought I was on to something there but it seems maybe not. I'm at a stumbling block here. I can't get past that last part of the timing vs: quality hay issue and how to allow seedheads for the doves. I would be more inclined to plant strips of sunflowers or something in the millet and just treat my millet as a hay crop. Sunflowers for the dove hunting and the best hay I could grow. How does that notion strike you?
Best I can do for now. Some of these other millet guys that use it for dove hunting need to wade in.