Grape Crop Load Experiment

The right crop load take years to assess and depends on so many variables such as soil, moisture, sunlight, training methods, diurnal temperature fluctuation, humidity, climate (micro and meso), nutrients etc. It really ends up being somewhat of a trial and error that one needs to go through over time.  Crop load is also related to ripening and the general idea is that if a vine is under-cropped it may hasten the ripening process as there is less fruit to ripen. On the other hand over-cropping a variety may slow the ripening process as there is more fruit to ripen. 

This year we conducted an in row trial with Leon Millot to see the how crop load affected grapes chemistry and ripening. We planned to increase the crop load by leaving addition shoots to see if the addition shoots would increase crop load without noticeably affecting the quality of the grapes for this variety.Our noramal amount of shoot is 8 per foot and on part of the row we left 12 per foot. Here are the numbers.

Leon Millot	Brix	PH
8 shoots per foot	22	3.3
12 shoots per foot	19	3.1

We saw that there was virtually no difference in production between the two pruning levels as both produced at approximately 1.5LB per linear foot having on average 2 clusters per shoot. The weight of the clusters on the vines pruned to 8 shoots per foot were averaging about 50 grams in size. We didn’t weight those that came from the vines pruned to 12 shoots per foot. However, the vines pruned to 12 shoots per linear foot in general had smaller and less well filled clusters than the clusters on the vines pruned to 8 shoots per foot. We also note that it took a bit more trellis management to train the shoots on the vines with 12 shoots per foot. It also took longer to harvest the vines with 12 shoots per foot.

The extra shoots did not translate into bigger crop but more work and poorer quality grapes. Bottom line - we won’t be doing that again, but good to know that our crop load is pretty good at 8 shoots per foot.

Also important to note is that the shoots on the vines cropped to 12 shoots per foot were generally shorter and as such won’t be as suited for use in long cane pruning next year – which is the pruning style we have been using for Leon Millot.

Angry Birds Love The Grapes

So we've never had a problem with birds until this year. Most years we don't even see any around before or during harvest but this year we had a "malfunction" with the netting. In late September, just a few days before havest, we had some nasty winds that caused some some of the netting to dislodge from its position.and several row feet of Leon Millot got exposed that we did not see untill harvest.

Pretty much every year it is the wasps that give us grief and the netting keeps them at bay but with the grapes exposed this year it brought the birds in and they pretty much cleaned the exposed grapes off the exposed vines, picking nearly every grape from each cluster. Can see in the photos the clusters stripped on the grapes;

Where the netting was still covering the grapes the birds actually worked their way several feet down the trellis and took those grapes as well or severly damaged the clusters. The amazing part was how bold the bird were during harvest. We strip the nets off the trellis as we go and the birds were comming right in close in the row or sitting on the netting on the next row over squaking - obviously angry that we were taking the grapes they'd been feasting on.

I was surprised that the bulk of the birds were Robins, at least 7 or 8 of them, as Robins don't seem to pack up like that, they seem more solitary birds. There was also a a few dark birds (almost black in colour) bit bigger than a Robin with a tuff of feathers that stands up on its head.

Lesson learned, more dilligent in deploying the nets next year.

Grape Harvest Parameters 2016

So here is the sugar concentrations for the various grape varieties that we harvested from the vineyard this year. A good year for sugars and ripeness in all the varieties relative to our location and after 8 years of data it really shows which are the standouts over time, especially the past 6 years.

The sugar readings are take in the field on harvest day and are a sampling of a few grapes from various clusters at different trellis heights and positions along the row. The sugar reading are measured in Brix and each brix will give approximately 0.56% alcohol to the wine when fermented. So for example a sugar reading of 20 brix would result in wine with alcohol concentration of about 11.2%.

We usually find that what ever reading we get in the field is often 1 brix higher once the grapes have been crushed and pressed and measured by specific gravity in the tank. So for the readings below, add 1 brix.

The table below also records, the bud break in the spring, the approximate time of flowering, the harvest date, and degree days growing (heat accumulation). Here is the table;

Grape Harvest 2016

Grape Harvest 2016

So it has been an interesting year for growing and the weather has been unusual in both that overall it was a warm year with about 1050 degree days growing celcius (+10c) over 150 frost free days and with a really early spring.  For us a really early spring is bud break 3-5 days early and this year we had about 7-10 days early for some varieties. Growth was good at the start and reds and some whites were flowering the first and second week of June in warm dry weather and had good fruit set. Some of the whites on the other hand flowered about a week later in cool wet weather and we had poor fruit set especially on the L’Acadie Blanc. We did experience some limited powdery mildew continuing on into early July and this had a minor affect on fruit set on some varieties as well.

So we picked the grapes on Oct 1^st and we had some decent numbers this year.

Reds                                                 Brix

Marechal Foch                                  20

Leon Millot                                       22

Castel                                                 23

Lucy Kuhlman                                  22

Triompe D’Alsace                             18

Colmar Precoce Noir                       22

Marquette                                         21

St. Croix                16                                                                   

Regent                                               16

Pinot Noir                                         18

Zweigelt                                            16

Marechal Foch (top) and Leon Millot (bottom) photo

Whites

Evangeline                                          22

L’Acadie Blanc                                   21

Petite Milo                                          23

Seyval Blanc                                       22

Ravat 34                                              18

Seigerrebe                                          19

Sovereign Ruby                                  18

Vandal Cliche                                     20

Siegerrebe photo