Vines and wines: Art of growing healthy grapes
‘Fine wine is made in the vineyard’ is a common quote among the wine industry and the grape farmers. Although winemakers take all the credit for fine wine, the fact remains that best fruits are responsible for good wine and all great wine producers fully understand this.
The development and management of a vineyard is not hard to achieve; grapevines will grow just about anywhere and, once established, are actually quite difficult to kill. All the same, to produce a grape with the potential to make a fine wine requires a specific set of skills, knowledge and financial ability. In the case of fine wine, what you put in is what you get.
The single most important decision for a grape farmer is site selection. The special and specific characteristics of the site, mainly soil and climate, will determine the quality of the wine harvested from it. There is no getting round this simple truth.
When selecting the location, first thing to consider is how much wine you want to make. Then consider the shape of your vineyard, slope, solar radiation, frost and heat pockets, soil type, water, wind, etc. All those factors impact on grapes growth and taste.
The process of site selection is a combination of science, art and intuition. When experienced eyes see a vineyard site for the first time, they can almost taste the wine that will come from it.
Quality of vine materials is also key to a successful vineyard. The long-term productivity and quality of your vineyard depends on the quality of the vine materials you use.
Procuring the best plant materials is not an easy task, especially if you are looking for unusual clones and rootstocks. To begin with, it may be hard to tell whether a vine is healthy or not.
As with soil, what is not visible can be extremely important. In grapevines a complex of virus and fungal diseases can affect the woody parts of plants and they are often propagated and disseminated in grape nursery stock. Buy materials from certified suppliers.
To produce high quality wine grapes, a soil of modest fertility is preferable, and low to moderate pH, organic matter, and cation exchange capacity may be beneficial. Soil pH affects the ability of roots to take up soluble nutrients.
When the pH goes below 5, vines may have a problem with aluminum toxicity and phosphorus deficiency. High nitrogen levels can lead to excessive vine vigour and problems with vine balance. Knowing a field’s history can help predict its future. Was it in pasture for decades?
If so, years of manure accumulation will have had an impact on its soil chemistry. Like nitrogen, organic matter should be balanced, usually in the moderate range, from two to three per cent.
The goal is to have sufficient mineral nutrition to maintain a healthy vine, but not so much that you end up with a big vine. Seek out specific and viticulture-based recommendations for soil amendments.
There are four basic vineyard best practices that can make or break wine quality. First is shoot thinning. This involves reduction of young and tender shoots to about two per canopy foot.
This opens the canopy hence controlling yields. Second is shoot positioning. In order to have an airy open canopy, separate and tie shoots so that they are uniformly spaced. Third is leaf and lateral pulling. Just after flowering remove leaves and lateral shoots from around the clusters.
This allows for better drying and spray coverage. Forth is cluster thinning. Involves removal of young clusters to a level that will give wine concentration and terroir.
These canopy management techniques are used by the growers worldwide. It pays to learn from practising farmers. As a prospective wine grower attend viticulture seminars, workshops, field days.