The Australian Wine Research Institute

Background

Most growers use a combination of different tools to achieve good weed control. Cultivation tools are some of the most common.

Disc ploughs and rotary tillers have the same working principles – an off-set disc moving soil sideways – although some disc ploughs are also hydraulically driven.

Action

Disc ploughs and rotary tillers are used to loosen soil and disturb weeds. They can also be used in combination with other tools such as finger weeders or knife weeders to improve the efficacy and speed of the operation.

Powered disc ploughs and rotary tillers are more aggressive and have a faster operating speed than draft discs and tillers. The angle of some models can be adjusted to change how aggressively they work as well as the width of the cultivated area.

Disc ploughs and rotary tillers can be used to manage weeds along the vine edge, or they can be mounted on a hydraulic tool carrier for undervine weeding.

Disc ploughs (Figure 1) mound the soil and create a straight cut which may increase the risk of erosion on sloping vineyards. In comparison, the offset position of the stars of rotary tillers (Figure 2) does not create a clean, straight cut, thereby reducing the risk of erosion on sloping vineyards.

Disc ploughs operate at a slower speed than rotary tillers – 7 km/h compared to 12 km/h. Disc ploughs are less effective at breaking up the soil and dislodging weed roots than rotary tillers, increasing the risk of the weeds being transplanted.

Advantages and disadvantages

Advantages: Disc ploughs and rotary tillers can improve the efficacy and speed of undervine mechanical weeders and provide medium-term weed control along the vine edge.

Disc ploughs and rotary tillers mounted on hydraulic tool carriers can provide medium-term undervine weed control and when fitted with sensors, cause minimal damage to vines, and require low operator skill.

Disadvantages: Cultivation tools may spread couch and kikuyu if these weeds are allowed to transplant. Repeated cultivation can damage soil structure and reduce soil carbon levels. Power-discs and tillers are more aggressive and damaging to soil structure than draft tools.

Undervine cultivation can cause reductions in vine vigour in the first two years until the vine roots adjust by moving deeper into the soil profile.

Table 1. Advantages and disadvantages of a disc plough

Ability to reduce weed competition with vines	Good
Soil disturbance caused	High
Suitability in young vineyards	Poor
Length of weed control	Good
Operating speed	Average
Operating cost	Average
Capital cost	High

Considerations

When considering which weed control tools to use, it is important to base the decision on each vineyard’s individual characteristics. Factors such as soil type and condition, slope, rainfall and water availability, weed type and pressure, vine age, vine vigour, fruit end-use targets, weather conditions, and compatibility with existing infrastructure and equipment should all be considered.

Table 2. Ease of using a disc plough or rotary tiller on different soil types

Large or excessive stones	Difficult
Stone/gravel	Moderate
Sand	Easy
Silt/loam	Easy
Clay	Moderate (can be difficult in wet or very dry soils)

Cultivation tips

• Control weeds when they are small.
• Mechanical undervine weed control is most effective in hot, dry weather with dry soils, but care is required to minimise damage to soil structure.
• Multiple passes may be required if the soils are heavily compacted.
• Using a finger weeder in combination with another cultivation tools such as a disc plough may be beneficial.
• Cultivation may be difficult in very wet or very dry conditions.