Various Stages of Dormancy

We were asked by our vineyard consultant to spray lime sulfur on our dormant vines to control overwintering diseases that could be in our vineyard. He stressed that the buds should be in their closed state because application of lime sulfur to a bud that is in the budburst stage can burn the nascent leaves. We were seeing all different stages of dormant buds which prompted me to look at more photos of grape buds in their dormant stage. I found a really good research paper on the internet: Adoption of a system for identifying grapevine growth stages, authored by B. G. Coombe. In this research paper, I found detailed descriptions of the various stages of vine phenology based on the Eichhorn Lorenz system. I took photos of our Chenin blanc buds and put it against the silhouettes provided in the paper and came up with the following:

At the moment, approximately 3% (or about 200 out of 6804 vines) of our buds are at stage 5 which is the "rosette of leaf tips visible" stage. Interestingly, most of these vines are located at the south end of the vineyard and it doesn't matter which variety it is i.e. Auxerrois, Chenin blanc or Chardonnay. It appears, however, that our Chenin blanc are the most advanced and our Auxerrois are the laggards.
References:
1. B. G. Coombe, Adoption of a system for identifying grapevine growth stages, Australian Journal of Grape and Wine Research 1, 100-110, 1995.