The most sensible subject for this month’s club member letter is grapevine pruning; the paramount vineyard task every February throughout the wine growing regions of California. Choosing the optimum harvest day and how to prune vines are the two most important decisions a grapegrower can make with regard to the quality of his grapes.
Used to be (twenty years ago) that February was not necessarily the big pruning month; rather the task was spread throughout all dormant months, December – February. However, back then growers began to notice that over the years, their vines were being attacked by a fungal disease called Eutypa dieback, an ailment that doesn’t usually surface in a vine until it is ten or more years old. Imagine planting a new vineyard, waiting a few years for your first crop, enjoying just a few years of luscious growth and ample, full grape bunches before you observe the vines slowly begin to decline; in three or four years a vine can be dead.
This phenomenon became so prevalent that grower organizations began funding university research to learn more about the disease. The findings led to the reason why most vineyard pruning is now accomplished in February. It was discovered that Eutypa is spread by raindrops – ingenious Mother Nature. The fungus is common in most vineyards on the soil surface, on old vine clippings from the previous year, and even on the growing vine bark. When it rains, drops fall on the fungus, releasing spores into the air which can drift onto any new pruning cuts made on the vines. Once landing on fresh ‘wounds,’ the spores colonize and the vine is infected. If an infected cut is close to a trunk, in ten years the vine trunk is infected and it can no longer transport the nutrients it needs to survive.
In normal years, by February many rainstorms have already passed by, releasing most of the spores before there are no fresh pruning cuts to infect. The more drops that fall before you prune, the more the Eutypa’s ammunition for the season is depleted. Waiting until February to prune is now simple logic, and the best known prevention of infection.
Here on Rhinefarm, the men who do the pruning should be revered by all of us who enjoy the fruits of their February labor. Every cut they make on each vine can be reflected in your glass. A large disconnect is only natural, as they are standing up to their knees in mud on a cold, foggy morning, carefully guiding their shears to make just the right cut. We, on the other hand, are sitting at a comfortable table, a clean cloth and warm meal possibly set upon it, while the cork is pulled and the glass is filled, never giving the pruners a thought. Your pleasure can only be enhanced by reflecting on the great care of the February pruners, so let’s raise our glasses a little higher this month on their behalf.
Salud amigos,
Jim
