The 4X sorghum is slow coming out of the flag leaf. The part that is out is blooming, but it is a tiny part. This is true on all 3 plants with any part of a head out of a flag leaf. I guess this i9s just a variety trait. Don't know yet. I went for a ride in the country looking for Johnson grass heads that should be right for pollen tomorrow. Noticed 2 ecotypes of J grass. Those down near the river are much bigger, and the heads much bigger. Though not more flowers. Those on the upland are smaller. I plan to use both in pollinating the 4X sorghum.
On some plants, the seeds on the top head aren't ripe yet, but the head coming from a branch on the second node down in about to bloom. I hadn't noticed that before.