5) Varieties of sweetpotatoes and their characteristics

<Recent varieties bred by Ministry of Agriculture, Forestry and Fisheries>

[Sunny Red] (Norin No. 51, 1998) [Kyukei No. 79] x [Benikomachi]

• Long and spindle-shaped with deep-orange flesh.
• Resistant to root-knot nematode, but somewhat susceptible to black rot.
• Suitable for food processing and powder production. Produces beautiful deep-orange colored bread, pasta, and confectionery.

[Harukogane] (Norin No. 50, 1998) [Kanto No. 79] x [Beniazuma]

• Long and spindle-shaped with good appearance. Skin is deep reddish purple; flesh is yellow.
• Taste is equal to Beniazuma (standard table variety), but with higher yield.
• Susceptible to root-knot nematode and fusarium wilt (stem rot), so must avoid growing in infested areas.
• Suitable for growing in Okinawa for the local fresh market.

[J-Red] (Norin No. 49, 1997) [Shiroyutaka] x [86J-6]

• Short and spindle-shaped with superior appearance compared to Benihayato. Skin is deep red; flesh is deep orange.
• Resistant to root-knot nematode, somewhat resistant to against root-lesion nematode, somewhat weak against black rot.
• Suitable for food processing, especially beverage production. Raw juice expressed from storage root soon changes color, but has low carrot smell and superior taste.

[Elegant Summer] (Norin No. 48, 1996) [Kanto No. 99] x [Kyushu No. 92]

• Its leaf petioles are edible, making it a potentially marketable summer vegetable. Leaf petioles are much longer, thicker and more regular than those of conventional varieties; green with good appearance and quality.
• The yield of leaf petioles per plant is far higher than that of other varieties. Excellent-tasting whether boiled or fried.

[Ayamurasaki] (Norin No. 47, 1995) [Kyushu No. 109] x [Satsumahikari]

• World's first variety developed especially for pigment extraction. Developed jointly by the Ministry of Agriculture, Forestry and Fisheries and the private sector.
• Skin is deep purplish red; flesh is deep purple. Long and spindle shaped, has better yields than "Yamakawamurasaki," and high anthocyanin content.
• Expected to be used for pigment production and processing.

[Beniotome] (Norin No. 43, 1990) [Kyushu No. 88] x [Kyukei 7674-2]

• Good taste and uniform shape and size; suitable for roasting.
• Resistant to root-knot nematode, somewhat resistant to black rot. Stores well.
• Easy to cultivate; can be grown even by nonprofessionals with relative ease.

[Satsumahikari] (Norin No. 40, 1987) [Kyushu No. 84] x [Kyushu No. 88]

• A completely new type - does not become sweet whether boiled, baked, or steamed.
• Suitable for use with a wide range of flavorings, adapted for making ice cream, sherbet, and salad. Expected to become used for croquettes as well.

[Benihayato] (Norin No. 37, 1985) [Centennial] x [Kyushu No. 66]

• Flesh is clear orange in color. Contains high levels of carotene, which converts to vitamin A.
• Suitable for a wide range of use such as ice cream, sherbet, cookies, salad, and tempura. Development of other uses such as pigment production is expected.

<Varieties bred by MAFF before 1985>

[Norin No. 1]

• 1942: The first variety bred by the Ministry of Agriculture, Forestry and Fisheries. [Genki] x [Shichifuku]
• Features reddish-brown skin and a round shape, superior appearance. The flesh is light yellow and starchy.
• Sprouts can be prepared easily. High-yielding and tasty.
• Highly evaluated for making roast sweetpotatoes.

[Norin No. 2]

• 1942: Bred in Kagoshima Prefecture. [Yoshida] x [Okinawa No. 100]
• Skin is yellowish white, and the flesh is light yellow and moderately starchy. Easy to cultivate and high yielding. Medium taste.
• Excellent choice for warm climates; for fresh consumption and starch production.

[Kokei No. 14]

• 1945: Bred in Kochi Prefecture. [Nancy Hall] x [Siam]
• Red skin; flesh is yellowish white and starchy.
• Early tuberization, high yielding, and tasty. Widely cultivated nationwide for the fresh market. There are many mutations of this variety named after the district where they are grown, skin color, or so on: "Kokei," "Kotobuki," "Tosabeni," "Benisatsuma," "Benikokei," "Shinkokei," "Nishiki," "Narutokintoki," "Chibabeni," and so on.

[Tamayutaka] Norin No. 22

• 1958: [Kanto No. 33] x [Kuroshirazu]
• Skin is yellowish white and each end is a light purplish-red. The flesh is yellowish white and is moderately starchy. Taste is medium. Short and spindle shaped, with slightly lower starch content than "Norin No. 1." Adapted to various cultivation conditions; can be easily cultivated.
• Typical variety grown in the Kanto area for producing steamed, dried slices as a snack item.

[Koganesengan] Norin No. 31

• 1966: [Kakei 7-120] x [L-4-5]
• Skin is yellowish brown, and the flesh is light yellow and starchy.
• High-yielding variety, greatly exceeds both "Norin No. 1" and "Norin No. 2" in yield and starch content. Small starch particles help give good texture and taste when eaten.
• Used primarily for starch-related products, but with considerable household consumption.

[Benikomachi] Norin No. 33

• Skin is clear red, and if cultivated skillfully, has a good shape.
• Rated as tastier than "Kokei No. 14" or "Beniaka."
• Storage roots are irregular and susceptible to Fusarium wilt (stem rot), so cultivation is difficult. Main production area is Chiba Prefecture.

[Minamiyutaka ] Norin No. 34

• The first variety bred incorporating the germplasm of a wild species closely related to sweetpotato.
• Tuberization continues until the end of its growth period, making it very high-yielding in warm districts.
• With high resistance to nematodes, good storability, and easy-cultivating properties, well suited for use in starch-related products.

[Beniazuma] Norin No. 36

• Storage roots thicken rapidly and yields are high; excessive length and shape deformities can be a problem, however.
• Very sweet and delicious; popular in the fresh market.
• Skin is a pretty, deep red; flesh is clear yellow.

<Traditional and other varieties >

[Genji]

• Also known as "Santokuimo" or "Genki."
• Skin is light reddish-brown; flesh is yellowish white, and extremely starchy.
• Highest starch content of any traditional variety.
• Short and spindle shaped. Storage root bulks late; suitable for warm districts, but not for cool or cold areas.

[Taihaku]

• Was widely cultivated in the Kanto area.
• Skin is clear red; flesh is white and moist. Long and spindle shaped, with a strong, sweet taste and good flavor.
• Sprouts are difficult to raise, and has lintolerant to drought; difficult to cultivate.

[Oiran]

• Foliage is slightly thick.
• Skin is purplish red with a tinge of brown; flesh is white, with purple pigmentation in the center. The flesh is somewhat moist. Starch content is low, yields are relatively high.

[Shichifuku]

• Skin is yellowish white. The flesh is yellow and slightly mealy at harvest, but quickly becomes moist.
• Short and spindle shaped - nearly flat. Sweet and tasty, with medium starch content.
• Suitable for dry areas.

[Yamakawa murasaki]

• Origin unclear. Skin is a deep purplish-red; flesh is purple. Short and spindle shaped.
• Unsuitable for the fresh market. However, due to its bright purple flesh, suitable for processing into food pigments, paste, flakes, ice cream, candies, and so on.
• Unsuitable for fertile land or black soils, but can be cultivated relatively easily in rather infertile or dry soils.

[Beniaka]

• 1898: Obtained as a result of a natural mutation, and discovered by Ichi Yamada, Saitama Prefecture. A leading variety from the private sector, it has remained popular for a century.
• Thin and long, with bright reddish skin. When cultivated using ordinary methods, yields are low and sizes irregular.
• Cooks quickly by steaming while retaining its good taste; most suitable for making kinton (sweetened mashed sweetpotato) and tempura.
• Also known as "Kintoki." Produced mainly in Chiba Prefecture.

[Okinawa No. 100]

• 1934: Bred in Okinawa Prefecture. [Shichifuku] x [Choshu]
• Skin is light red; flesh is light yellow and moist, with root surface grooves.
• In Okinawa, yields well under early cultivation, and tastes notably good. In other areas, easy to cultivate and yields well, but has poor taste. Cultivated for starch production and feed.

[Gokokuimo (Kokei No. 4)]

• 1943: Bred in Mie Prefecture for the patriotic purpose of assisting the nation's recovery from an energy crisis (was used to produce alcohol as a petroleum substitute). [Genki] x [Shichifuku]
• Skin is a yellowish light brown; shape is round with excellent appearance. Flesh is yellowish white and starchy, and taste is medium.
• Vines grow well, and sprouts can be raised with ease. Highly tolerant to drought.