Today, Surecrop and City Park pecan cultivars were just starting to expand their buds (photo above). At this point in bud development, you really can't see any difference in bud break appearance between the protandrous and protogynous cultivars.
The buds on Major and Kanza trees had vegetative buds that had expanded to the point you can see leaves about ready to unfurl (photo above). At this point in bud development, the difference between the protandrous Major and protogynous Kanza is readily apparent. Major has pushed out catkins while the catkins on Kanza are still not visible.
Faith and Lakota trees had leaves that were well developed (photo above). At this point, the protandrous Faith cultivar had well developed catkins while the catkins on the protogynous Lakota cultivar were just starting to emerge from their bud scale coverings.
As your trees break bud this spring, you might want to check out this phenomenon on your pecan trees.