Kiwifruit vines need to be pruned in spring and summer so that sunlight is efficiently converted into high dry matter fruit, rather than excessive vegetative growth.
Your spring and summer canopy management challenge is to maintain a balance between vegetative growth and fruit production. The three key objectives at this time of year are:
• To keep good light levels on the fruiting canopy.
• To grow the best possible replacement fruiting wood to carry next year’s crop.
• To keep the canopy open to allow good spray protection.
Pruning the leader zone
Leader zone pruning improves the productivity of early canes and promotes the development of lower vigour shoots, meaning you’ll have less to prune in winter.
• Remove canes that you won’t need next season: If you have more canes growing than you need in a bay, remove excess canes keeping in mind not all canes will make it to winter and some extra canes can be left as ‘insurance’.
• Remove late growth: Canes that emerge earlier in the season are more fruitful than those that emerge late. For Gold 3 this is any growth that starts after flowering, and for Hayward and Red 19 this is canes that develop after December.
• Remove shaded cane or spurs: Wood that’s been well-exposed to sunlight will always produce more flowers and better-quality fruit than wood that’s been in shade.
• Remove canes crossing back over the leader, vertical canes, and canes from growth points high up in the canopy. These will shade the leader or be difficult to tie down in winter.
• Remove most blind shoots from the canopy while they’re still small. These are unfruitful buds that burst a little later than normal. They’re normally non-terminating and light green in colour. Some blind shoots might be retained in the leader zone if you wish to preserve the growing point for future seasons, in which case stub them. If the cane is required in the following winter to replace old growth, then consider leaving it to grow.
Tip squeezing / crushing
Commonly used to manage vegetative growth in the fruiting zone. Start early in spring, the shoot will continue to lengthen for a while after tipping. Tip squeezing reduces the need for summer pruning. Several rounds of tip squeezing may be required.
Zero-leaf Pruning
Use Zero leaf pruning on strong non-terminating fruit shoots in dense areas that aren’t required for replacement canes. These are typically in the leader zone, or at cane ends in opposing female growing systems. Multiple rounds of zero-leaf pruning can be done. Timing depends on the vigour of the canopy but completing it before the period of fruit sensitivity will minimize skin damage. Tool and pruning hygiene are important to reduce the chance of spreading Psa. Sunburn on fruit can also be an issue after zero leaf pruning.
Removing strong shoots, even if they have flowers or fruitlets, can provide a quick and effective way to dramatically reduce shading and pruning costs for the loss of a few fruit. You can do this by physically ripping out the whole shoot rather than making pruning cuts.
Cutting vigorous canes close to their base helps to reduce blow-outs and stimulates lower vigour canes to grow in their place if done early in the season.
Cut out tangles during or after zero-leaf pruning, particularly from areas that are dark or excessively dense.
Blind Shoot Removal
Remove blind shoots as soon as you can. In windy locations these shoots may be kept longer and removed after fruit set to provide some additional shelter in the canopy.
Pruning and Psa
Pruning creates an opportunity for Psa to enter the plant, you can help to reduce the risk by pruning in dry weather, applying a protectant spray immediately after pruning, especially in high-risk periods, and applying a wound dressing to large wounds.