OK - here is where I saw it - http://www.midislanddahlia.com/Learning/Planting/LongSproutTuber/index.html

I just wonder if it CAN be planted with that whitish sprout? Will it green up the way amaryllis or lily shoots do when they come via mail order with premature sprouting?

Here is a link that might be useful: Dahlia Sprout

Why not try the best of both worlds: plant it with the white shoot on- yes, it should green up if it stays in tact. And the bonus: if it happens to break off, eyes will likely resprout from that same location, the shoot will disintegrate into compost and you will still have your dahlia.

I've inadvertently broken off sprouts and in a few days you can find the bulging pink or yellow eye forming right where the other fell off, or to the side. I don't know of any reason NOT to plant the white shoot, other than its frailty.

Thank you Poochella! That is exactly what I wanted to know!