Shigeo Harada

A Newly Registered Tea Variety “Benifuji”for Black Tea

“Benifuji ” was developed by the-Breeding Laboratory of the Tea Division, Tokai-Kinki Agricultural Experiment Station, and the registration of this variety was made in 1960.Benifuji was selected from the cross Benihomare x C 19. The superior characters of this variety are good growth both in cuttings and in young age, high yield especially when young, good tolerance to cold, and superior qualities of black tea. It is adapted to the northern distrief of black tea production in Japan because of its tolerance to cold.

Studies on the Assimilation of Carbon in Tea Plant (Part 5)

The diurnal and seasonal changes of photosynthesis of tea plant were measured in the tea garden on which some clonal tea varieties were planted.In the Y2 variety grown garden, the rate of photosynthesis increased rapidly with the increase of light intensity and decreased gradually from just before noon, so a photosynthesis curve of inclined triangular form was observed in winter.Concerning the light-photosynthesis (apparent) curve in growing season, a light saturation point was observed, but not observed in late autumn and winter.By calculating the true photsynthesis rate and also by applying 2.0 as Q10, respiration value, the light saturation point was not observed even in summer, and the photosynthesis increased every time with the increase. of light intensity.Under high air temperatures, the apparent photosynthesis decreased, but in the true photosynthesis. value such a phenomenon was not observed.The Q10 respiration value of twigs was 2.25 in summer.Examining the rate of photosynthesis of twigs, it was observed that the rate was decreased distinctly in winter.Concerning the light-photosynthesis (apparent) curve of twigs in growing season, a light saturation point was observed, but not observed in winter.Examining the annual gas exchange rate, it was observed that the accumulation of carbohydrate was proceeding even in winter, and also that the photosynthesis rate was especially large in summer and autumn in tea plant.No distinct relation between the gas exchange rate and the yield of tea leaves was observed.

The Influence of the Mother Stock Conditions on the Qualities, Rooting and Growth of the Cuttings of Tea Varieties

The influence of the conditions of the mother stocks on the qualities, rooting and growth of tea cuttings were examine, using r3 varieties. Significant differences were observed in the qualities, rooting and growth of cuttings among both treatments and varieties, and in the new shoot growth a significant interrelation was observed between treatments and varieties. The state of lateral buds of the slips seemed to have some relations on the new shoot growth.It was thought from the results of this experiment that in nursery test of varieties, rooting ability and vigour of growth should be distinguished, and generally speaking the vigour of growth is to be thought much of.As for mother stock treatments, cuttings from naturally grown (no-pruning) stock which had poorest stem and lowest N-content in leaves and stems showed poorest rooting, and cuttings from stock treated by usual method which had largest stem and highest Ncontent showed best rooting. But the growth of cuttings was best in case of down-pruned stock which had largest leaves.As for varieties, Y 3 which had lowest Ncontent in leaves showed poorest rooting, and such a tendency was observed that the larger the leaves and stems and the lower the N-content in stems, the better the growth of cuttings.The size of leaves seemed to have some relations to the growth of cuttings.Further studies must be done about the relations between the N-content of the slips and the rooting and growth of cuttings in tea.

The Effect of Oxygen Content in Soil on the Growth of the Tea Plant (Part 1)

Cutted stems of Yabvkita variety were planted in air-tight pots and air currents having 5, 8, 14 and 20% of oxygen respectively were introduced separately through the soil in these pots.The cuttings were drugged out after 24, 34 and 46 days and the formation and growth of the roots were examined.The less the oxygen content, the poorer the formation and growth of the roots.

Studies on the Rapid Tannin Test of the Tea Leaves

To test the practical applicability of the rapid tannin., test with potassium bichromate, the correlation between the tannin content and the reaction of the tea leaves to potassium bichromate was examined.No correlation was obtained, so this method is not applicable to the tannin test of the tea leaves.

On the Effect of Soil Moisture Content upon the Growth of the Tea Plants (Part 1)

Using 2 years old plants of vars. Yabukita and Miyosbi transplanted in pots, one plant per each pot, the relations between the growth and the soil moisture content were examined. The soil moisture was regulated to 30, 45, 60, 75, 90 and 105% of water capacity respectively.Concerning the top growth, 90% seemed to be most suitable and 105% the next, and with decreasing of the soil moisture, the growth became poor.But concerning the root growth, 105% Plot as well as 45% plot showed poorest growth. With increasing of the soil moisture, the area and thickness of the tea leaves became larger.Though the growth of two varieties was rather different, the effects of the soil moisture content upon their growth were almost the same between two varieties.But var Yabakita which showed vigorous growth seemed to be more susceptible to water deficit than var. Miyoshi which showed somewhat poor growth.