GRAPE BUD ANALYSIS
NEWSLETTER
NOVEMBER 2010
FEAR AND GREED
Some say the growing of grapes runs on the basis of balancing fear and greed.
On the greed side the grower wants to get as much tonnage as possible. This is because pounds or boxes of grapes, gallons of juice to the buyer translates into more dollars in the pocket of the grower.
The fear side of the equation recognizes that “over cropping” the vine may mean problems with berry color or sugar. Thus deficiencies in the quality side of the equation may adversely impact the growers income as well.
The cooler than normal summer of 2010 can and did exacerbate these balancing issues. In the San Joaquin Valley there was a proliferation of plastic covering of late season grapes that was partially in response to lateness of the season. I am sure the fog bank that existed along the north coast for much of the summer also had adverse impact on the ripening of wine grapes grown closer to the Pacific Ocean.
Will the summer of 2011 be a repeat of the coolness of 2010 ? This is difficult to ascertain at this date.
But Grape Bud Analysis can help the properly determine the potential crop on their grape vines and with that knowledge they can tailor their pruning practices to appropriately.
The best and cheapest time to alter crop load for 2011 is with winter pruning.
Over Cropping:
By “over cropping” I mean setting too large of a crop that the vines cannot mature in a normal season.
If you “over crop” a vineyard by the time you realizeyou have too many grape bunches it is expensive and perhaps too late to recapture the energy in the bunches that have to fall to the ground.
Remember the grape vine is not a net positive photosyntheizer until bloom time. It is running on energy and nutrients stored from last year for much of the early spring.
If you “over crop” the energy that went into growing a rachis, flowers and perhaps young berries is lost once the excess bunches are cut and dropped to the ground. In the cooler grape growing regions of California plant energy is at a premium.
Under Cropping:
If you leave too few bunches on the vines you not only under utilize your vineyard but you risk creating excess growth of the canes and canopy. This excess growth can hinder Mildew and other disease control (getting the sprays into a dense canopy to the bunches is difficult) as well as color development.
Quality Parameters:
The grape berries need to mature to satisfy your buyers. Too many grapes in a vineyard can lead to problems with sugar (brix) and acid levels as well as berry color.
Late Season Harvest in 2010:
The major root growth period for grape vines occurs after harvest. In 2010 many fields were harvested late and thus the root growth was less or in the case of very late harvest non-existent as the soil temperatures cooled to where root growth was minimal. This root growth is vital for storing energy for the following spring.
Late harvest means the plant stored less energy for the early growth in 2011. That means your canopy for 2011 might be less than optimal. It takes leaf canopy cover to make a good grape crop. If you will be short on canopy in 2011 you may need to adjust your crop expectations.
For assistance with Grape Bud Analysis to help with all of these scenarios.
Contact
California Ag Supply
Call Tom at 559-281-5411
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