Sunday, October 7, 2012

2012 Grape Harvest

We had a very interesting year this year starting out with a normal May and bud break around the 18-20th of May.  We had lots of moisture throughout May and June, way above average and probably about 12 inches by early July.

June was cold though, way below normal and stunted the vines so that the flowering didn`t happen until nearly the middle of July.  Most varieties were in mid-bloom stages by about the 12th-13th of July, which is about 5-7 days later than normal.  just as the vines were flowering we experienced record breaking heat and had 9 days of 35-37c heat, and the month was the second warmest July we have recorded at 20.3c average.  It appears that the extreme temperatures during flowering caused some stress to the vines at this delicate stage and the flower clusters on all varieties did not have good berry set. 

August was the warmest August we`ve recorded yet at 19.6c average and no rain fall at all and we had a few days in the 37c range.  September was also warmer than normal at 14.6c average but we had a 8 day stretch in mid month of 26-30c temperatures which helped with the ripening.  It finally rained on the 8th and 9th of September and we received about 1.5-2 inches, which was enough to help out the heat stressed vines and just in time.

We harvested on October 3, as we had a -3.5c frost and that ended the season.  Canes on most varieties had hardened off quite well by then.

The grapes were few by volume but the juice chemistry numbers were better than expected (see Grape Harvest Data pages).  Some of the highlights were the Leon Millot that read 19.7 brix in the vineyard and when crushed the juice was 20.5 brix and 3.1ph.  The Petite Millot also stood out and is consistently putting up good numbers, this year at 19.5 brix in the field and 20 brix after crush.  The Colmar Precoce Noir also ripened to 20 brix in the filed and 21 brix after crush and was very ripe.

We made some changes in the vineyard this year, one we went to a more conventional netting that is black and has virtually no shading effect.  The netting we had been using was white and had approximtely 12-16% shading.  While relatively small shading effect, the accumulation over a week or a month could reduce the ripening of the grapes.  The other change that proved very important was the early September removal of the large ponderosa pine that was on the south west corner of the vine (see previous blog).  While the shading effect of the tree  was held to only the south west corner of the vineyard during May-August, by September the sun is low enough in the sky that the tree eventually shades parts of the entire vineyard over much of the day.  It appears that removing the tree changed the heat accumulation for the month dramatically.  If we compare the heat accumulation over the last 5 years for Kelowna and our vineyard, historically on average we have accumulated about 20 DDG (10c base) less than Kelowna in September.  However, without the tree and shading we were only 4 DDG less than Kelowna for the month - that is a dramatic change for us.

We also learned this year that while the mid row cover crop of clover is helping generate plant matter and nutrients for the soil and vines, it draws too much moisture from the soil that is desperately needed by the vines - especially in the droughty periods.  For our sandy soil and dry land farming practices we will be reducing the width of the between row cover to just a few feet wide in years to come.