| Hardy kiwi | |
|---|---|
 | |
Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Asterids |
| Order: | Ericales |
| Family: | Actinidiaceae |
| Genus: | Actinidia |
| Species: | A. arguta |
| Binomial name | |
| Actinidia arguta | |
Actinidia arguta, the hardy kiwi, is a perennial vine native to Japan, Korea, Northern China, and the Russian Far East. It produces a small kiwifruit without the hair-like fiber covering the outside, unlike most other species of the genus. [1]
The fruit is referred to as the arctic kiwi, baby kiwi, cocktail kiwi, dessert kiwi, grape kiwi, hardy kiwifruit, kiwi berry, northern kiwi, Siberian gooseberry, or Siberian kiwi, [1] and is an edible, berry- or grape-sized fruit similar to kiwifruit in taste and appearance, but is green, brownish, or purple with smooth skin, sometimes with a red blush. Often sweeter than the kiwifruit, hardy kiwifruit can be eaten whole and do not need to be peeled. Thin-walled, its exterior is smooth and leathery. [2]
Actinidia arguta was first described by Philipp Franz von Siebold and Joseph Gerhard Zuccarini in 1843 as Trochostigma argutum. [3] It was then moved to the genus Actinidia in 1867 by Friedrich Anton Wilhelm Miquel after the invalidly published suggestion by Jules Émile Planchon to move the species. [4]
The species consists of three varieties: [4]
Actinidia arguta var. giraldii was originally described by Ludwig Diels at the species rank (Actinidia giraldii) in 1905, [5] but was later reduced to a variety of A. arguta in 1972 by Vladimir Nikolaevich Voroschilov. [6] A. arguta var. hypoleuca was originally described at the species rank (Actinidia hypoleuca) by Takenoshin Nakai in 1904, [7] but reduced to a variety of A. arguta in 1980 by Siro Kitamura. [8]
Actinidia arguta had been placed in section Leiocarpae and series Lamellatae, but this current infrageneric classification is unsupported. A 2002 study of the nuclear DNA internal transcribed spacer sequence and the plastid matK gene sequence for cladistic analysis revealed the current circumscription of the sections to be polyphyletic, with A. arguta forming a clade with A. melanandra near the base of the phylogenetic tree. [4] [9]
The most popular cultivars include 'Ananasnaya', 'Geneva', 'MSU', 'Weiki', 'Jumbo Verde', and 'Rogow'. A commonly sold self-fertile hybrid is the Japanese cultivar 'Issai' (A. arguta × polygama), while the hybrid 'Ken's Red' (A. arguta × melanandra) originates from New Zealand. [10]
The fast-growing, climbing, twining vine (bine) is very hardy (hence the name hardy kiwi), and is capable of surviving slow temperature drops to −34 °C (−30 °F), although young shoots can be vulnerable to frost in the spring. [11] The vines need a frost-free growing season of about 150 days, but are not damaged by late freezes, provided that temperature changes are sufficiently gradual to allow plants to acclimate. Indeed, a period of winter chill is necessary for successful cultivation. However, rapid freezes kill off buds and split vines. The vines can also be grown in low-chill areas. [1]
While hardy kiwi may be grown directly from seeds (germination time is about one month), propagating from cuttings is also possible. Growing from seeds needs a period of cold stratification of one to two months to germinate. Hardy kiwi cuttings may be grafted directly onto established kiwifruit rootstock, or rooted themselves.
In domestic cultivation, a trellis may be used to encourage horizontal growth for easy maintenance and harvesting; however, vines grow extremely quickly and require a strong trellis for support. Each vine can grow up to 20 ft in a single season, given ideal growing conditions. [12] For commercial planting, placement is important: plants can tolerate partial shade, but yields are optimized with full sunlight. Hardy kiwi vines consume large volumes of water; therefore, they are usually grown in well-drained, acidic soils to prevent root rot. [1]
For vines to bear fruit, both male and female plants must be present to enable pollination. A male pollinator can enable six female producers to fruit. [11] Flowering typically occurs in late spring (May in the Northern Hemisphere) starting in the third year of growth. [13] If flowers become frost-burned, however, no fruit production will occur during the remainder of the year. [11]
An autumn harvest is standard among all varieties; within this, actual harvest times are highly dependent on local climate and the specific cultivar grown. [1] Each individual vine can produce up to 100 pounds of fruit per year, but average annual yield is roughly 50 lb per vine. [11] Both fruit size and total yield are highly cultivar-dependent. Fruit left to ripen on the vine has an 18 to 25% sugar content at time of harvest. [11]
Hardy kiwi vines are vulnerable to several botanical diseases, including phytophthora crown and root rot (the most serious problem), botrytis rot, and sclerotinia blight. Vines are also vulnerable to pest infestations, including root knot nematodes, two-spotted spider mites, leaf rollers, thrips, and Japanese beetles. [11] Cats can also pose a problem, as they are attracted to a catnip-like smell produced by the hardy kiwi vines. Cats have been known to destroy vines and dig up roots in search of the source of the scent. [1]
Attempts to commercialize the fruit have been historically unsuccessful due to its short shelf-life and sporadic tendencies to ripen. However, attempts are being made to bring the fruit to greater bear, and commercial production initiatives are underway on a small scale in South America, New Zealand, Europe, Canada, and the United States (in Oregon, Washington, and central Pennsylvania). [12] [14]
 Cross-sectioned and whole hardy kiwifruit (Actinidia arguta) | |
| Nutritional value per 100 g (3.5 oz) | |
|---|---|
| Energy | 322 kJ (77 kcal) |
18 g | |
| Sugars | 7.6 g |
| Dietary fiber | 3 g |
0.6 g | |
1.2 g | |
| Vitamins | Quantity %DV† |
| Vitamin C | 112% 93 mg |
| Minerals | Quantity %DV† |
| Potassium | 6% 288 mg |
| Sodium | 0% 6 mg |
| |
| †Percentages are roughly approximated using US recommendations for adults. Source: NZ KiwiBerry Growers Inc. Nutritional Value | |
Hardy kiwi can be used in jam.
In Korea, hardy kiwi is known as darae (다래). Young leaves, called darae-sun, are often consumed as namul vegetable. [15]
 |
In the Russian Far East, it is known as kishmish (the same word has a different meaning in other parts of Russia). It is a very popular seasonal fruit, usually sold at farmer's markets.
Actinidia arguta has been cultivated by hobbyists, and more recently commercially, in the northeastern United States since at least the early 1900s with no significant impact on the region's forests noted, until recently. Due to rampant overgrowth and "complete domination of mature trees" at sites in western Massachusetts and Coffin Woods, North Shore Wildlife Sanctuary in Long Island, New York, A. arguta vines of unknown genotype and provenance are now reported by groups including Mass Audubon to be invasive. [16] Whether such localized sites indicate an invasive risk for the region as a whole is controversial, given the long history of this widely distributed and cultivated species in the northeastern United States. [17] Since successful invasions of non-native species can occur gradually over time, these reported sites warrant further investigation and suggest the need for more widespread monitoring. [18]
Macrofossils of A. arguta from the early Pliocene epoch have been found in western Georgia in the Caucasus region. [19]
Kiwifruit or Chinese gooseberry is the edible berry of several species of woody vines in the genus Actinidia. The most common cultivar group of kiwifruit is oval, about the size of a large hen's egg: 5–8 centimetres in length and 4.5–5.5 cm in diameter. It has a thin, fuzzy, fibrous, tart but edible light brown skin and light green or golden flesh with rows of tiny, black, edible seeds. The fruit has a soft texture with a sweet and unique flavour.
Actinidia is a genus of woody and, with a few exceptions, dioecious plants native to temperate eastern Asia, occurring throughout most of China, Taiwan, Korea, and Japan, and extending north to southern areas of Russian Far East and south into Indochina. The genus includes shrubs growing to 6 metres tall, and vigorous, strong-growing vines, growing up to 30 m (100 ft) in tree canopies. They mostly tolerate temperatures down to around −15 °C (5 °F), and some are much hardier.
Honeysuckles are arching shrubs or twining vines in the genus Lonicera of the family Caprifoliaceae, native to northern latitudes in North America and Eurasia. Approximately 180 species of honeysuckle have been identified in both continents. Widely known species include Lonicera periclymenum, Lonicera japonica and Lonicera sempervirens. L. japonica is a highly invasive species considered a significant pest in parts of North America, Europe, South America, Australia, and Africa.
Viburnum is a genus of about 150–175 species of flowering plants in the moschatel family, Adoxaceae. Its current classification is based on molecular phylogeny. It was previously included in the honeysuckle family Caprifoliaceae.
The Juglandaceae are a plant family known as the walnut family. They are trees, or sometimes shrubs, in the order Fagales. Members of this family are native to the Americas, Eurasia, and Southeast Asia.
Lespedeza is a genus of some 45 species of flowering plants in the pea family (Fabaceae), commonly known as bush clovers or Japanese clovers (hagi). The genus is native to warm temperate to subtropical regions of eastern North America, eastern and southern Asia and Australasia.
Weigela is a genus of between six and 38 species of deciduous shrubs in the family Caprifoliaceae, growing to 1–5 m (3–15′) tall. All are natives of eastern Asia. The genus is named after the German scientist Christian Ehrenfried Weigel.
Astilbe is a genus of 18 species of rhizomatous flowering plants within the family Saxifragaceae, native to mountain ravines and woodlands in Asia and North America. Some species are known by the common names false goat's beard and false spirea.
HortResearch was a Crown Research Institute of New Zealand. The focus of research in this company was mainly in the development of new fruit varieties and other food products. It was probably most recognised for its plant breeding of various kiwifruit varieties, including new cultivars of Actinidia (genus) chinensis and arguta (species).
Actinidia deliciosa, the fuzzy kiwifruit, is a fruiting vine native to Southern China. Other species of Actinidia are also found in China and range east to Japan and north into southern areas of Russian Far East. This species grows naturally at altitudes between 600 and 2,000 m.
Euonymus fortunei, the spindle, Fortune's spindle, winter creeper or wintercreeper, is a species of flowering plant in the family Celastraceae, native to east Asia, including China, Korea, the Philippines and Japan. E. fortunei is highly invasive and damaging in the United States, causing the death of trees and forest in urban areas.
Acer rufinerve, the grey-budded snake-bark-maple, redvein maple or Honshū maple, is a species of tree in the snakebark maple group, related to Acer capillipes. It is native to mountain forests of Japan, on Honshū, Kyūshū and Shikoku.
Buxus microphylla, the Japanese box or littleleaf box, is a species of flowering plant in the box family found in Japan and Taiwan. It is a dwarf evergreen shrub or small tree growing to 1 m (3.3 ft) tall and wide.
Actinidia chinensis(Planch.), known commercially as the golden kiwifruit, is a fruiting vine, native to China. It is one of some 40 related species of the genus Actinidia, and closely related to Actinidia deliciosa, which is the source of the most common commercial kiwifruit. Fruit colour may vary from green to lime green or gold, depending on breeding.
Actinidia kolomikta, the kolomikta, miyamatatabi, super-hardy kiwi, or variegated-leaf hardy kiwi, is a species of flowering plant in the family Actinidiaceae, native to temperate mixed forests of the Russian Far East, Korea, Japan and China.
Hardy kiwi is the name of a fruit product and common name of several species of the genus Actinidia:
Talipariti is a genus of plants in the mallow family Malvaceae. It consists of 22 species, which are exclusively tropical except for one species whose range extends into temperate areas of Japan and Korea. Most authors now treat these species as part of the genus Hibiscus, in which case they form the section Hibiscus sect. Azanzae.
Zanthoxylum schinifolium, also called mastic-leaf prickly ash, is a species of flowering plant in the Rutaceae, the citrus family.
Actinidia rufa is a species of flowering plant in the Chinese gooseberry family Actinidiaceae, native to Taiwan, some of the southwestern South Korean islands, the Ryukyu Islands, and southern and south-central Japan. A large climbing shrub, it is found in mountain forests at elevations from 1,000 to 2,000 m. As a crop wild relative of kiwifruit, it is being studied for its resistance to frost and to bacterial canker of kiwifruit.