Vine Cycle and Vineyard Activities

I've already used the following illustration in a blog I wrote called Vine Growth where I summarize when the various parts of the grapevine are growing. But, it is still a very good reference to have about all of the activities that the grape vine is undergoing once budbreak occurs.
This illustration is from Ronald Jackson's Wine Science: Principles and Applications, and shows the growth rate of various organs of ‘Colombar’ grapevines grown in South Africa throughout the season.¹

One of the things that can be gleaned from this illustration is that it takes about 200 days from budbreak to harvest. This is a guideline.
From another one of my favorite online articles, Ed Hellman's Grapevine Structure and Function, I extracted this timeline and kept information about our varieties beginning with our very first very small harvest of Chenin Blanc in 2015.

One thing that can be gleaned by keeping a log like that shown above is the number of days from budbreak to harvest. We now have six data points!

Varietal	Budbreak	Harvest	Number of Days
Chenin Blanc	May 8, 2015	September 22, 2015	137
Chenin Blanc	April 26, 2016	September 26, 2016	156
Auxerrois	April 30, 2017	September 21, 2017	144
Chenin Blanc	April 30, 2017	October 7, 2017	160
Chardonnay	April 30, 2017	September 23, 2017	146

Since the data points above are for very young plants, they serve only as a rough guideline. This year, we hope to have a better understanding of how to ripen a vineyard that is at 85% replanted capacity, with vines in their fourth leaf. We're hoping for Mother Nature's full cooperation!
References:
1. Jackson, Ronald S., Wine Science: Principles and Applications, Third Edition, Elsevier, Academic Press, 2008, pg. 109.
2. Ed Hellman, Grapevine Structure and Function.