Kiwifruit Information

The Kiwifruit is the edible fruit of a cultivar group of the woody vine Actinidia deliciosa and hybrids between this and other species in the genus Actinidia.

The most common cultivars of kiwifruit are oval, and about the size of a large hen's egg (5-8 cm long and 4.5-5.5 cm diameter). It has a fibrous, dull green-brown skin; the flesh is bright green or golden with rows of small, black, edible seeds. The texture of the fruit is soft and the flavour is sometimes described as a mix of strawberry, banana, and pineapple.

The fruit gets its name from a marketing strategy, naming it after the kiwi, the national bird of New Zealand, where the fruit was first commercially popularised in 1959 by the New Zealand fruit-and-vegetable export company Turners and Growers. Previously it was known as the Chinese gooseberry, but due to the Cold War, the Chinese label seemed unfit for popularization of the fruit in Western countries. Growers gradually adopted the name and in 1974 the kiwifruit became the official trade name.

In North America, South America and Europe, the "fruit" part of the name is usually dropped, and most people associate "kiwi" with the fruit rather than the bird.

Almost all kiwifruit in commerce belong to a few cultivars of Actinidia deliciosa: 'Hayward', 'Chico', and 'Saanichton 12'. The fruit of these cultivars are practically indistinguishable from each other.

Kiwifruit is a rich source of vitamin C. Its potassium content by weight is slightly less than that of a banana. It also contains vitamins A and E. The skin is a good source of flavonoid antioxidants. Raw kiwifruit is also rich in the protein-dissolving enzyme actinidin, (in the same family of thiol proteases as papain), which is commercially useful as a meat tenderizer but can be an allergen for some individuals. Sliced kiwifruit has long been regularly used as a garnish atop whipped cream on one of New Zealand and Australia's favourite desserts, the pavlova.

Kiwifruit can be grown in most temperate climates with adequate summer heat. Where Actinidia deliciosa is not hardy, other species can be grown as substitutes. Kiwifruit is commercially grown on sturdy support structures, as it can produce several tonnes per hectare, more than the rather weak vines can support. These are generally equipped with a watering system for irrigation and frost protection in the spring. Kiwifruit vines require vigorous pruning, similar to that of grapevines. Fruit is borne on one-year-old and older canes, but production declines as each cane ages. Canes should be pruned off and replaced after their third year. Kiwifruit plants are normally dioecious, meaning that individual plants are male or female. Only female plants bear fruit, and only when pollenized by a male plant. One male pollenizer is required for each three to eight female vines. An exception is the cultivar 'Issai', a hybrid (Actinidia arguta x rufa) from Japan, which produces perfect flowers and can self-pollinate; unfortunately it lacks vigour, is less hardy than most A. arguta forms and is not a large producer. Kiwifruit is notoriously difficult to pollinate because the flowers are not very attractive to bees. Some producers blow collected pollen over the female flowers. But generally the most successful approach is saturation pollination, where the bee populations are made so large (by placing hives in the orchards) that bees are forced to use this flower because of intense competition for all flowers within flight distance.