Plantation density

This is calculated on a field of 1 hectare (100m x 100m), where plantation density =

• number of rows x number of vines in row, i.e.
• 100 (m) / alley width (m) x 100 (m) / distance between plants (m)

E.g. In a field planted at 3.0 x 1.5 m, the plantation density is = (100 / 3) x (100 / 1.5) = 33.33 x 66.67 = 2222 plants/ha.

There is little direct correlation between high density planting and quality, although high densities often increase the effective leaf surface in a vineyard. It is important that there is a balance between the vine’s root system and its canopy, and this is determined by the vigour of the cultivar, the planting density, the fertility of the soil and the training system.

The poorer the soil, the higher the root density should be to obtain the right balance. As vine vigour is low in poor soils, it is best to plant high densities. The exception to this is in low water situations, where plants need to exploit a large amount of soil. On a high potential site, low-density planting is preferable.

Example minimum legal densities for quality wines:

• Burgundy 9000
• Bordeaux 4500
• Muscadet 6500

Most high quality European vineyards are in the 5 – 10000 range.

Distance between rows

This is a compromise between different factors.
Factors that favour narrow alley widths:

• Need for high Effective Leaf Surface Area
• Reduced loss of light energy on alleys at mid-day in N->S planted vineyards
• High quality/yield requirement on low potential soils
• Improvement of canopy microclimates by windbreak action

Factors that favour wide alley widths:

• Adjacent rows can cast shade in each other’s fruiting zones: alleys should never be narrower than the heights of the row’s canopies.
• Narrow alleys require the use of specialised tractors
• Many operational costs, such as spraying & weed control are strongly influenced by total row length

Distance between plants

The correct distance between plants is that which will give a shoot density of 15 shoots/m. This is a function of the ability of the trellis system to support the vigour of the plants. Generally, the wider the alleys, the greater the distance between plants, as the plants have more vigour (they have more soil space available) and so need more trellis space.

Row orientation

Can be dictated by the:

• shape of the field
• Direction of the slope.
• Prevailing wind.

In North-South rows, maximum interception in the morning & afternoon, minimum at midday. In East-West rows, vice-versa, the maximum light is intercepted at midday. Note that in midsummer, more light is intercepted by N-S rows, but in spring and autumn, E-W rows receive more light. However, N-S has the advantage that both sides of the trellis receive the same amount of light.