Capfall

The first year that we had flowering in our vineyard, I took many pictures of the process. I was so intrigued! Pictures are one thing but what is actually going on is quite remarkable.¹

• 3 to 4 days before bloom, the petals (calyptra) is easily detached from the flower
• Petals turn a pale yellow green
• The disks (discus) begins to swell
• On the morning of bloom, the rising temperature and the drying air desiccate the upper, less supplied part of the petals sticking together at their tips
• The tension developed between the outer, dry and inner, turgid cell layers first detaches one of the petals
• At 20- to 30-second intervals, the next petals separate
• The abscission (natural detachment portion) is helped by the swollen discs (lower and upper discs or nectaries)
• The filaments elongate, the petals separate from the base of the flower, to lift upward, thereby releasing the stamens
• Capfall, or the shedding of the calyptra has been achieved!

Reference:
1. M. Carmo Vasconcelos, Marc Greven, Chris S. Winefield, Mike C.T. Trought, and Victoria Raw1, The Flowering Process of Vitis vinifera: A Review, Am. J. Enol. Vitic. 60:4 (2009).

Bloom and Fruitset

On June 12th, I wrote a blog called Stages of Flowering and predicted that flowering would be on July 6th. Well, while we were nipping and tucking our Cabernet Sauvignon, my husband looked over to the Chardonnay and saw that some of our plants were flowering! That was way back on June 19th!
Why is knowing the date of flowering important? With the data that we have been tracking, we believe that between flowering and harvest, in our vineyard, it is approximately 90 days. If flowering came on July 6th, that puts harvest around October 4th.
We have come to learn that our Chardonnay is always the first to bloom (also called anthesis), but we were surprised to see that our Cabernet Franc was also in bloom! On June 21st, here is where our vineyard stood with respect to percentage flowering:

Variety	% Bloom on June 21
Chardonnay	50%
Cabernet Franc	40%
Auxerrois	40%
Chenin Blanc	10%
Cabernet Sauvignon	Not in bloom yet

It is very interesting to have visitors in the vineyard during bloom because many believe that the pre-bloom flowers are already the young grapes.

Superficially, the two stages do look remarkably alike, but on closer inspection, there is a discernible difference. The pre-bloom grape buds have ridges that are formed by the presence of the calyptra or flower cap which are actually the petals of the grape flower.
Since flowering is a full 2 weeks earlier than what I thought, our harvest should be more like the end of September, Mother Nature willing!

Rethinking Our Vineyard Trellis

This year, we have been spending an inordinate amount of time with shoot positioning. We believe that one of the problems that is causing us to spend so much time with shoot positioning is that the distance between the fruiting wire and the first set of catchwires is 12-inches.

When we were first contemplating how to construct our trellis system, one of the sources that we consulted, along with the many books that we have was the online reference Vineyard Trellis Construction, a very practical guide put together by Dr. Paul Domoto of Iowa State University, Viticulture Extension.
One illustration which was helpful in determining where to put our catchwires was this:

Our Manwerkes linepost has slots every 4-inches apart so that initially dictated our catch wire spacing. We decided on fixed catch wires instead of movable catch wires, so our three sets of catch wires are spaced 12-inches apart. When we didn't have a full vineyard, tucking in our growing vines was not such a huge task. Now that we are almost up to repopulating our vineyard, this has become a time-consuming task.
So, what is our solution? Our plan after this growing season is over is to raise the fruiting wire one notch on the Manwerkes line post. Raising the fruiting wire will shorten the distance between the first set of fixed catch wires to 8-inches.
Grapevines grow quickly after budbreak. The photo below shows grapevines two weeks after budbreak. Our thinking is that by raising our fruiting wire, most of the growing shoots will grow through the first catch wires, putting them on the right trajectory to grow vertically through the remaining catch wires.

Canopy Management: Nip and Tuck

Our friends have been helping us in the vineyard since spring and one of the tasks that we are doing is called shoot thinning and positioning. I like to refer to this as nip and tuck. We began in May with the task of disbudding, which is the removal of buds from positions along the cane that are too close together or not turning upward toward the sunlight.
May disbudding activities:
During May, we did the first pass of disbudding approximately 6,000 vines which took 4 days.
The second pass occurred from May 23 to May 31st. During this pass, we were once again disbudding shoots that were growing toward the ground and also shoots that were too close together. We are doing this to divert energy into the remaining growing shoots and also to open up the canopy so that we can get a good amount of air flow to prevent the occurrence of fungal diseases.

Some of our vines were farther along and we were pruning shoots and whenever possible, saving 4 shoots to serve as next year's canes.

June nip and tuck activities:
During the first weeks in June, we had cool weather and rain so the shoots jumped up. Some of our vines have decided that they have so much energy that they would send out their secondary and tertiary buds, necessitating us to implement nipping as well as tucking procedures. Our friends came to give us a hand at the task.:

This work continues unabated!