The plantation framework will not only establish the positioning of the strains, but also, with the use of different densities, we can directly influence the quality of the grapes produced.
The number of vines per hectare is a very important parameter in the design of a plantation. The cost of the plantation and its profitability (both in kg and in grape qualities) are directly related to the density of the plantation.
Direct effects on wine at different planting densities.
Trials carried out by GENCAT, with the
Cabernet Sauvignon variety , with densities of 2000, 3000 and 4000 vines per Ha have shown the following results:
1. Production: There are considerable differences between the production of the different plots at different densities. The highest productions are observed in the density of 3000 vines / Ha and the lowest in the densities of 2000 vines / Ha. The density of 2000 vines / Ha obtained a lower productive performance and a greater irregularity in the quality parameters of the wine. The average bunch weight is higher in the density of 3000 vines / Ha. The density of 3000 strains / Ha has achieved the best balance between production and qualitative parameters.
2. Probable alcoholic strength: Higher densities tend to be higher than lower ones.
3. Total acidity : The lowest total acidity corresponded to the density of 3000 vines / Ha and the highest acidity to the densities of 2000 vines / Ha.
4. pH: The variations in pH are very small and are not statistically representative. The trend is to show a faster maturation rate at higher densities.
5. Polyphenols: In the density of 2000 strains / Ha there was greater variability than in that of 3000 strains / Ha where the content was more regular.
6. Anthocyanins: They follow the same pattern as polyphenols, their content is more regular in the density of 3000 strains / Ha.
7. The production / vigor balance reached its optimum point between the densities of 3000 and 4000 strains / Ha. The density of 4000 vines / Ha achieved slight advantages in some quality parameters of the wines.
Reflections:
In general, there is a correlation between production and sugar rate , the higher the production, the more sugars decrease.
But other factors, such as physiological balances and climate, are more decisive and sometimes yield and quality are not incompatible, as can be seen in the following table where quality increases when planting density rises.
|
Strains / Ha |
2500 |
5000 |
7500 |
10 000 |
| Production |
(hl/ha) |
61,9 |
60,4 |
88,8 |
102,1 |
| Probable grades |
|
10,9 |
11,10 |
11,10 |
11,3 |
| Total acidity |
(g H2SO4 |
6,45 |
6,45 |
6,15 |
5,70 |
| Anthocyanins |
(mg/l) |
890 |
970 |
1036 |
1120 |
| Tannins |
(g/l) |
3,95 |
4,10 |
4,20 |
4,60 |
Plantation density tests in Médoc 1979 (Dumartin, Boniface, Ducasse, Barrrière, Cordeau, Pradier)
Conclusions:
Some studies on the influence of planting density show that the distance between the vines has no effect on the production and quality of the wine .
But, on the contrary, the width of the streets can have repercussions in the development of the plant and in the quality.
It is actually the leaf area that is important. When the distance between the vines decreases, the space is occupied by the vegetation, but when the width of the streets decreases, it has to be compensated by increasing the height of the foliar cover to preserve an equivalent foliar surface.
The optimal amount of illuminated leaf surface is between 1 and 1.4 m2 per kg of grape produced.
