Summer pruning is the least effective method of canopy management.

Pinching

This is the selective removal of shoot tips at the time of flowering. Usually done manually, the aims are to regularise shoot growth and improve berry set. In vigorous vines, this leads to an increase in the development of lateral shoots, and so these then have to be removed.

Trimming

Trimming is the cutting off of shoot extremities, either by hand or by machine in order to:

• Control excessive shoot growth to facilitate the passage of manpower and machinery and reduce inter-row shading and wind damage
• Reduce canopy thickness to improve the microclimate and increase spray penetration
• Encourage the onset of maturity by discouraging shoot growth, which stimulates berry development
• To look good

Trimming normally starts in July after the last tucking-in and should not be done too early or too severely.

Leaf stripping

Leaf stripping is the removal of around the fruit zone, usually between veraison & berry ripening. It is usually done by hand, but can be done by machine, the objectives are to;

• Improve canopy microclimate, thus improving fruit quality
• Improve fruit health
• Improve spray penetration
• Increases speed of manual harvesting

It is recommended to aim for 60% bunch exposure, but you should not be too severe in one pass (can take up to 70 hours/ha!).

For northern hemisphere vineyards:

• In N →S rows, start on the Eastern side and only do Western side in cool climates
• In E → W rows, start on the Northern and only do Southern side in cool climates

Crop thinning or green harvesting

This describes the removal of flowers or berries to regulate the crop. It can be essential in very young vines to help them get established. Crop thinning aims to;

• Control leaf area: fruit ratio so as to get optimum ripeness
• Conform with legal control on yields

Usually the bunches on laterals and those nearest the shoot tips are removed. If done too early (pre-veraison), vines will react by increasing the rate of berry cell division, thus increasing berry size. If done post-veraison, it will be less effective, as sugars will already have moved into the berries. Thus this is best done around the time of veraison.

Usually done by hand, it is a very laborious task that will take around 50 hours/ha. Crop thinning can be achieved by the use of a chemical spray (Ethrel C), but is not recommended as the results are unpredictable.