No abstract

We investigated radiocesium distribution in tea plants (Camellia sinensis L. var. sinensis) of Saitama Prefecture, located approximately 200-250 km away from Tokyo Electric Power Company's Fukushima Daiichi nuclear power plant. In 2012, more than 2500 samples of tea plants were analyzed. We found differences in radiocesium concentration among tea plant cultivars, which appeared to be attributable mainly to the leaf morphology and depth of the leaf layer in tea plants. Furthermore, the radiocesium concentration in the first tea crop showed a strong correlation with that in spring skiffing.

New extremely late budding green tea cultivar 'Okuharuka' with cold resistance has been bred at the Green Tea Laboratory of Saitama Prefectural Agriculture and Forestry Research Center. 'Okuharuka' was selected from seedlings crossed between Saitama20 and Saitama7 in 1975. Local adaptability, tolerance to bark split frost injury, and blister blight were tested at 14 prefectural tea experiment stations from 2002 to 2011. As a result, it was registered as 'Okuharuka' in 2013. The shape of the cultivar is spread type, and the growth is vigorous. The plucking time of the first crop of the cultivar is 6 days later than that of 'Yabukita'. The yield of 1st and 2nd crop is more than that of 'Yabukita'. 'Okuharuka' has resistance to cold drought damage and bark split frost injury. However, it has slightly weak resistance to gray blight and blister blight. The green tea quality of 'Okuharuka' with the aroma like preservedcherry-leaves and rich good taste is better than that of 'Yabukita'. The level of the aroma like preserved-cherryleaves is enhanced in less steamed processing. 'Okuharuka' is suitable for northern tea producing area and cool semi-mountainous areas for its cold resistance. Key words：new green tea cultivar, Okuharuka, cold resistance, extremely late budding green tea cultivar, cherry-leaves-like aroma