Comparison of fruit quality and its variation of apple "Fuji" (Malus pumila Mill. var. domestica Schneid.) between Japan and Korea

Import of apple fruit from Korea amounted to about 50 to 60 metric tons in '92 to '94. Main cultivar in Korea and Japan is 'Fuji' for its sweetness and adequate hardness of the fruit. So, it is very important to compare the quality of the fruit between Japan and Korea for the future of apple trading. We collected six carton boxes in which medium-sized fruits (32-40 fruits/box) apiece from Yochon and Taegu in Korea, and two carton boxes each from Aomori, Akita, Yamagata, Fukushima and Nagano (Nagano city and Matsukawa town) in Japan, and analyzed the fruit weight, shape, hardness, Brix, titratable acid and rate of squeeze. We had measured temperature and precipitation of the districts in fruit growth period and analyzed the influence of climatic conditions to the quality of the fruit. Mean and maximum temperature in July of Taegu and yochon, Korea were higher than Japan, and minimum temperature during June to October of Aomori was lower than other districts of both countries. Precipitation of Matsukawa during May to September was heavier than other districts of both countries, however precipitation was almost same in all districts of both countries except Matsukawa. Fruits weight of Fukushima was largest and of other districts was almost same, and difference of diameter and length of Japanese fruits were smaller than Korea. So, the fruits of Japan were more symmetric than Korean ones. However, the deference of D/L index, flesh hardness, Brix, titratable acid and rate of squeeze was not significant between Japan and Korea. Coefficient of variation (C.V.) of fruit weight, diameter, length and D/L index in Japan were remarkably smaller than Korea, however, the fresh hardness, Brix, titratable acid and rate of squeeze were not so different between Japan and Korea.