In New Zealand in 2007, just under 12,000 hectares were planted in kiwifruit. By far the greatest concentration of orchards is in the Bay of Plenty, especially near Te Puke. Smaller concentrations are in the Northland, Auckland, Gisborne and Nelson regions.
Kiwifruit vines are fairly hardy and grow in a wide range of temperatures, but to produce satisfactory fruit they need:
- well-drained, fertile soils
- shelter from the wind
- adequate moisture year-round
- protection from autumn and spring frosts.
The deep, yellow-brown loams of the Bay of Plenty are well-drained, but need regular nitrogen, phosphorus and potassium once the vines begin cropping. Orchards are usually fertilised in spring and early summer with 200 kilograms of nitrogen, 55 kilograms of phosphorus and 100–150 kilograms of potassium per hectare.
Wind is a major limiting factor in establishing a kiwifruit orchard and growing high-quality fruit. Young and flowering shoots are easily damaged, and most orchards need protection from New Zealand’s persistent winds. In the 1970s and 1980s growers planted shelter belts of fast-growing trees, but increasingly they are building artificial windbreaks using polythene fabric.
On the drier East Coast, where annual rainfall is less than 1,000 millimetres, kiwifruit orchards need irrigation in summer. Elsewhere, young vines usually benefit from irrigation.
In winter, kiwifruit vines are leafless and dormant, and can withstand frosts to -10°C. But in spring and autumn, plants are vulnerable to frost damage. Growers use water sprinklers and wind machines to protect their crop if frosts are forecast.
Kiwifruit is grown in orchards that are almost exclusively devoted to the one fruit. This differs from other countries, where kiwifruit is grown along with a number of other fruits.
The average New Zealand orchard is small compared with overseas competitors. In 2006, there were 3,077 kiwifruit growers registered with Zespri. Two-thirds had orchards smaller than 5 hectares.
Vines are grown and trained on supports – either a pergola or T-bar – both of which were designed in New Zealand, but have been adopted as the global industry standard. Vines need to be pruned, otherwise they become a tangle of unproductive, leafy shoots.
The vines are planted out in rows some 3–5 metres apart, depending on the type of support, and with a spacing of 5–6 metres between plants in a row. To ensure pollination, male plants are distributed through the orchard, with male to female plant ratios around 1:5.
Kiwifruit arrived in New Zealand without any of its associated pests, and for the first decades of its cultivation was virtually pest-free. But as the area of vines increased, leafroller caterpillars, scale insects and mites began to attack. Various species of leafroller feed on the leaves and scar the fruit, with the brownheaded leafroller (Ctenopseustis obliquana) the most common. Greedy scale insect (Hemiberlesia rapax) sucks the sap of young plants and can infest the fruit. Kiwifruit with signs of greedy scale are not accepted for export.
Root rots can develop from infection by Phytophthora soil fungi, especially on poorly drained sites. The native bootlace fungus Armillaria novaezelandiae spreads to kiwifruit from infected dead tree stumps or buried wood and causes fatal infections. In humid climates, grey mould Botrytis cinerea rot infects flowers and young fruit.
The bacterium Pseudomonas syringae pv. actinidiae (Psa) arrived in New Zealand on Chinese kiwifruit pollen. First discovered in local vines in November 2010, it had a widespread and severe impact on the local industry, costing several hundred farmers hundreds of millions of dollars.