@article{oai:repository.naro.go.jp:00001826,
 author = {山田, 昌彦 and YAMADA, Masahiko and 山根, 弘康 and YAMANE, Hiroyasu and 佐藤, 明彦 and SATO, Akihiko and 岩波, 宏 and IWANAMI, Hiroshi and 平川, 信之 and HIRAKAWA, Nobuyuki and 吉永, 勝一 and YOSHINAGA, Katsuichi and 小澤, 俊治 and OZAWA, Toshiharu and 中島, 育子 and NAKAJIMA, Ikuko},
 journal = {果樹研究所研究報告, Bulletin of the National Institute of Fruit Tree Science},
 month = {Mar},
 note = {Soshu' is a pollination constant non-astringent (PCNA) type of Japanese persimmon (Diospyros kaki Thunb.) cultivar released by the Persimmon and Grape Research Center (presently the Department of Grape and Persimmon Research) of the National Institute of Fruit Tree Science (NIFTS), Akitsu, Hiroshima, Japan, in the year 2000. The fruit is distinguished by its very early ripening time, no cracking habit at calyx end, red skin color and excellent eating quality. 'Soshu' resulted from the cross 'Izu'×'109-27' made in 1988. '109-27' is a PCNA selection from the cross 'Okitsu-2'×'Okitsu-17'. 'Okitsu-2' and 'Okitsu-17' are PCNA selections from crossing 'Fuyu'×'Okugosho' and 'Okugosho'×'Fukurogosho', respectively. 'Soshu' was primarily selected at NIFTS, Akitsu in 1994, designated as 'Kaki Akitsu-13', and had been tested at 29 locations in 28 prefectures under the Fifth Persimmon Regional Trial initiated in 1996. The 'Soshu' fruit ripens in late September to early October (the same time as that of 'Nishimurawase'), and is flat-shaped, weighing on an average of 250 g (slightly less than the fruit of 'Matsumotowase-Fuyu') at NIFTS, Akitsu. The fruit shape is unlikely to be uniform. The skin is reddish-orange at harvest time, having a value of 6 to 7 on the color chart for 'Fuyu' (Yamazaki and Suzuki, 1980, Bull. Fruit Tree Res. Stn. A7:19-44), more reddish than that of 'Tonewase', a leading early-ripening astringent cultivar. The flesh is moderately fine and juicy. Soluble solids content in juice averages 15.9% and is comparable to that of 'Izu'. The fruit is PCNA, in which the deastringency in fruit occurs naturally and stably on the tree, irrespectively of the number of seeds contained in fruit when the tree is grown in warm areas. 'Soshu' can be commercially grown in 'Fuyu' and 'Matsumotowase-Fuyu' production area. Fruit cracking at the calyx end, which is a serious physiological disorder in 'Izu' and 'Matsumotowase-Fuyu', does not occur in 'Soshu'. Fruit cracking at the stylar end occurs rarely, except for very small size of cracking that does not affect its marketablity. The occurrence of skin blackening, a physiological disorder, averaged 20% in the regional trial, which was comparable to that of 'Nishimurawase'. The shelf life of 'Soshu' averaged 12 days at ambient temperature in the regional trial, which was longer than that of 'Izu' and shorter than that of 'Matsumotowase-Fuyu'. The tree is moderately vigorous but less vigorous than 'Fuyu'. It is intermediate between upright and spreading in shape. It produces no male flower but easily produces many female flowers every year. The trees treated with flower thinning show slight physiological fruit dropping in early fruit-developmental stage in June and July, which is higher than that of 'Fuyu'. Planting pollinizer trees is needed to promote pollination for stable fruit production. 'Zenjimaru' is suitable as the pollinizer in terms of flowering time, male flower quantity, pollen quantity, and pollen activity. Fruit dropping in late fruit-developmental stage in August and September is very rare in 'Soshu'. Anthracnose resistance in 'Soshu' is less than that of 'Fuyu'. Thrips attacks are rare.},
 pages = {53--66},
 title = {カキ新品種 '早秋'},
 volume = {3},
 year = {2004},
 yomi = {ヤマダ, マサヒコ and ヤマネ, ヒロヤス and サトウ, アキヒコ and イワナミ, ヒロシ and ヒラカワ, ノブユキ and ヨシナガ, カツイチ and オザワ, トシハル and ナカジマ, イクコ}
}