I'm a little late to the party as I see many more posts since I started writing this, but just thought I'd throw these thoughts out there. Very interesting topic!
I think there are just too many variables involved to try to take a large number of them into account without it being a huge undertaking. My thought would be to try and get maximum and minimum branch and bud counts under “realistic” conditions, which I suspect is the original idea behind a daylily branch count.
By realistic I mean throwing out only the extremes. For example, exceptionally poor conditions like growing them during extreme drought or in Siberia, or exceptionally good conditions like a season where everything must have been perfect and the plant produced 6 branches instead of 3 or 4 every other season. Otherwise anyone living in a “normal” populated area, with half-way “normal” growing conditions, would submit branch and bud counts. By eliminating extremes the data should be fairly representative of what a majority of the plants will be grown under.
If these realistic maximum and minimum values result in a branch count description of, say, 3-4, I think that would probably be sufficient for most people. However, a branch description of 2-6 might leave people wanting to know more.
It would be more work, potentially a lot more work, but of course additional information about the growing conditions could be attached to the performance data. This could be limited to a few key values such as cold climate zone of the area, overall moisture conditions for the growing season, and cooling degree days for the season. (Soil nutrient conditions, especially nitrogen, would also be critical but nearly impossible to get values for). This data may then enable a more specific association between growing conditions and large differences in the maximum and the minimum performance of the plant.
The value of collecting this additional data to generate this correlation would depend on the number of daylilies that have a relatively large variation in their branch and bud counts, and the difficulty in collecting and working with the additional data.
