STRAWBERRY PRODUCTION IN JAPAN-CULTIVAR, CULTIVATING METHOD, MAIN DISEASE AND BREEDING
'Fukuba' (1899, seedling of 'General Chanzy') was a leading variety of forcing system until 1960. 'Kogyoku' (1940, 'Fairfax' line), 'Donner' (1945) and other foreign cultivars ('Victoria', 'Fairfax') were used for semi-forcing system and open culture at that time. 'Hokowase' (1960, 'Kogyuko' x 'Tahoe'), 'Donner' and 'Harunoka' (1967, 'Kurume 103' x 'Donner') were main varieties since around 1970. From 1975 to 1980 many new varieties were bred from 'Hokowase' and 'Harunoka'. Such as 'Himiko' (1975), 'Reiko' (1976), 'Meiho' (1977), 'Terunoka' (1978), 'Haruyou' (1980), 'Shizutakara' (1980). The rates of varieties (acreage) from 1984 to 1988 are shown in table 1.
Table 1. The rate of varieties (acreage %)
Variety 1984 '85 '86 '87 '88
HOKOWASE 50.4 48.4 45.6 37.3 27.2 NYOHO 1.7 4.5 6.3 20.3 35.0 TOYONOKA 1.3 7.8 7.7 12.3 18.2 REIKO 16.3 15.6 15.9 10.8 6.6 DONNER 13.6 11.6 10.8 10.6 6.8 OTHERS 16.7 12.1 13.7 8.7 6.2
Recently, Nyoho and Toyonoka have increased rapidly because of their high marketability. The acreage of Hokowase, Donner and Reiko has decreased in these few years.
'Nyoho' was bred at Tochigi Prefectural Agricultural Experiment Station in 1981. It is very vigorous, so we don't need long day treatment and Gibberellic acid spray in the forcing system, which are needed in the case of cv. 'Hokowase'. Its fruit has firmness, beautiful coloured skin and balance of sweetness and acidity. It is susceptible to anthracnose. They grow this variety in Kantou and Chubu district.
'Toyonoka' was bred at Kurume branch of National Horticultural Institute in 1983. Its fruit has firmness, sweetness and flaver. The fruit size is bigger than other varieties, but colouring of fruits isn't uniform. First and second fruits have longitudinal vallecuras.