[in Japanese]

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There are a considerable number of literatures on the growth of tea roots, but little work on the estimation of their physiological activity has been reported. The enzymatic activity of tea roots, therefore, was evaluated by determining the oxidizing and reducing-power of tissue with a-naphthyl-amine (a-NA) or TTC (2, 3, 5-triphenyl tetrazolium chloride).
Some experimental results on the roots of flooded tea plants were also obtained by using this method.
A highly significant correlation (r=+0.899) between the TTC reductive activity and the a-NA oxidative one was found when the fleshy roots were used. However, the former was far more striking in its reaction than the latter. The TTC reduction method can be recommended for the determination of the physiological activity of tea roots.
Since the root systems of tea plants consist of a large number of roots of various developmental stages like other woody plants, a careful attention should be paid to obtain uniform samples of rootlets in the examination of their physiological activity. The TTC reducing-power of fleshy roots of a tea variety varied slightly with its plant age and growing place.
The physiological activity of tea roots grown under flooding conditions decreased significantly with the increase of flooding days.
It is concluded that the above-mentioned method may be an excellent means to estimate roughly the activity of tea roots grown under various conditions.

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After some laboratory experiments, it was found that thiophanate-methyl (Topsin-M) and benomyl (Benlate) were effective on black rot of tea.

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1. Pieces of infected tea root of white root rot were dipped in water solutions of thiophanate-methyl (Topsin-M, ingredient 70%) and benomyl (Benlate, ingredient 50%) for 24 hr. Mycelium growth of the causal fungus from treated roots was nearly inhibited at concentrations higher than 1 : 5000 dilution in both fungicides.
2. Water solutions of Topsin-M (diluted 1 : 700) and Benlate (diluted 1:1000) were irrigated into soil at the rate of 40 ?? /m² and throughoutly mixed. Mycelium growth from infected roots collected from the treated soils was reduced to the same degree as chloropicrin treatment which was set up as the control.
3. Infected young plants of tea were dipped in the 2 fungicides (the same solutions stated in 2) for 24 hr and replanted. After 6 or 12 monthes, it was found that the dipping treatment markedly inhibited the development of rhizomorpha of the causal fungus around the root.
4. From the results of these experiments, it was concluded that the soil treatment of these 2 fungicides and dipping infected plant in the solutions of them were both effective for control of the disease.

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[in Japanese]

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An investigation was made on the relation between score of sensuous test and inorganic components of 32 samples of tea which were drawn from both upper group which consisted of 50 ones and lower group which consisted of 50 ones, each group was elected from 150 ones which were displayed for Nara prefectural tea exhibition in 1973, and the results may be summed up as follows.
1) In the upper group, the negative correlation between total nitrogen content and score of taste was observed at the level of 5%.
2) For calcium content, the negative correlations were observed with score of taste, aroma and inner-quality at the level of 5%. In the lower group, the positive correlation was observed between calcium content and score of the color of liquor.
3) In the lower group, the negative correlation was observed between manganese content and score of aroma. The quality was found distinctly inferior in the content of more than 2, 000 ppm of manganese.
4) For iron content, the negative correlation was observed with score of the color of liquor and total score of inner-quality at the level of 5%. In the upper group, the negative correlation was observed between iron content and score of taste.
5) The positive correlation was observed between iron content and menganese content at the level of 5%.

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1. The tea which grew normally but absorbed luxurious manganese was found in the tea production area originated from syenite (Fushiogami Yamazoe-mura and Hachibuse-cho Nara city in Nara prefecture).
2. An investigation was made on chemical properties of tea soil and results were as follows. The tea soil originated from syenite contained remarkably large amount of easy reductional manganese. The amount of manganese in old tea leaves was proportional to that of easy reductional manganese of tea soil.
3. The amount of manganese of old tea leaves in the area of syenite was maximum in July and then decreased. In the area of granite and dacite, it increased gradually from March and remained evenly from June to September and then decreased gradually. As for other inorgantc components, the amount of calcium of old leaves in the area of syenite was smaller than that in the area of granite. Potacium showed the same tendency.
The amount of manganese of new leaves was always larger in the area of syenite than that in other areas.

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