The growing season
The kiwifruit year starts after the previous season’s harvest, when the vines drop their leaves and enter winter dormancy. Growers prune fruited and surplus canes. Dormancy lasts until late August, when buds begin to swell. Budbreak, shoot growth and flowering occur in spring. The timing and extent of these depends on how cold winter was – chillier winters usually lead to more profuse flowering. However, prolonged freezing temperatures in winter, and spring and autumn frosts, can harm kiwifruit production.
Pollination and fruiting
In early summer, flowers are pollinated and thinned. Kiwifruit are not self-pollinating, so part of each orchard must be devoted to male vines unless pollen is brought in for artificial pollination. Unlike most other fruits, kiwifruit need high levels of pollination (about 13,000 pollen grains per stigma compared to only 12 grains for apple flowers). Growers either place numerous honey-bee hives in the orchards temporarily, or artificially pollinate the flowers.
As well as being New Zealand’s most important horticultural crop, kiwifruit has also become one of its problem weeds. Silvereye birds feed on ripe fruit and spread the seed to bush margins, where the vines grow and smother stands of native bush. Most wild kiwifruit is in the Bay of Plenty, but it has also been found in Canterbury and south Westland – quite distant from kiwifruit orchards.
Throughout summer the main tasks are to remove damaged or misshapen fruit, prune excessive vine growth to maintain fruit health, and control pests and diseases.
Historically, kiwifruit harvesting was timed using a Brix test to determine the amount of sugar in the fruit. Orchardists now also use dry matter and colour tests to ensure harvested fruit has the desired eating qualities. Most fruit is picked in May. Since the mid-1990s, fruit from some early-maturing orchards has been picked for early shipments under the KiwiStart programme.
Fruit is picked by hand and put into bags, which when full are emptied into large wooden bins.
Packing and storing
The bins are taken to packhouses, where most of the kiwifruit is graded, packed into trays then placed in a cool store. A small proportion of fruit is kept in bins for cool storage, or in some cases storage in a controlled atmosphere, and is packed later.
Kiwifruit is sold from April to the end of December, with supplies taken out of cool storage near the end of the season.