To know the cause of the midday depression which are observed in mature tea garden immediately after the espalier pruning performed after the 1st plucking, two plots were prepared as written below and the diurnal change of photosynthesis of them was observed.
1. Upper part plot……All the leaves of the upper 10 cm layer in mature tea garden were left and the lower leaves were all removed.
2. Lower part plot……All the leaves of the upper 10 cm layer were removed and the lower leaves were all left.
The tendency of the light-photosynthetic curve of the upper part plot did not changed from that of the gardens, of which the leaves were not removed, but in the lower part plot the light saturation point and the maximum photosynthetic rate decreased and rather severe midday depression occured.
The same phenomenon was also observed on the young tea plant cultivated under, rather severely screened sun light condition.
The leaves of the lower part plot were thin-ner, larger, and had larger content of chloro-phyll than those of the upper part plot, and this result was thought to show the characteri-stics of the shade leaves.
Water content, carbohydrate content, and the degree of the stomata opening were also measured, and it was observed that the degree of the stomata opening had closer relation upon the phenomenon of midday deppression written above than other factors.

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Cross-pollinations were reciprocally carried on between diploid and tetraploid tea plants, and self-pollinations of the tetraploid were also tried (1956-1958). Since 1954, open-pollinated progenies of the tetraploid and triploids have been raised. The chromosome numbers of these progenies were determined, and several characteristics of them were investigated.
In the cross, 4x (??)×2x ( ?? ), 35% of pollinated flowers set normal fruits. The seedlings from this cross and from natural crossing of the tetraploid were all triploids. The reciprocal cross, however, gave only a few fruits with abortive seeds. The all trials of selfing of the tetraploid were unsuccessful. From the results written above, it may be suggested that tetraploid is cross-incompatible in cross 2x(??)×4x( ?? ), and show self-sterility as diploid. Seed fertility of the tetraploid was slightly lower than that of the diploids.
The distribution of chromosome numbers among the seedlings of triploid's progenies was examined. In these seedlings, euploids (2x 3x especially a number of 4x) and heteroploids were found, and the latter having very extensive variation of chromosome numbers (2n=31-63). And it was considered that these tetraploids and hyper-tetraploids were originated from unreduced n=45 gamates of the definite triploid varieties( U21, U24).
These obtained polyploids nearly resembled to the pre-examined polyploids in external morphological characteristics. In general, the growth of the heteroploids was very poor, so plant height, stem diameter and leaf size were apparently inferior to those of the euploids, but in spite of such poor growth stomata length, and thickness of leaf were proportionally correlated with the chromosome numbers.

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1. As the warm keeping effects varied with the height of cover from the tea bush surface in the frost prevention, the suitable height of cover was investigated.
2. When the straw mat was covered at the height of 30, 60, 90 cm. above the tea bush surface, the air temperature under the cover was kept warmer at any height than the open plot and especially the 60 cm. covering was kept warmest. Considering the vertical distribution of air temperature under the cover, this phenomenon was explained as follow. Under the 30 cm. covering, the straw mat was put under the inversion layer and the temperature was very lowered and the down-ward radiation was decreased and its warm keeping effect was less than the other plots, influenced by the diffusion of cold air.
While under the 90 cm. covering, the temperature gradient of inversion layer was very sharp and the air temperature on. the tea bush surface was lower than that of the 60 cm. covering. From these facts, it was thought that the flowing air entered from the outside of the cover.
3. With the same covering material, the warm keeping effect was higher and the radiation balance was less in the high covering than in the low one.
Therefore, the second test was carried out on, the influence of the flowing air upon the warm keeping effect when the height and method of covering was varied.
The air temperature under the -complete covering was kept higher under the high cover than under the low one, but in the case of the upper side covering, no differnce was observed between the air temperature under the high cover and the low one.
The horizontal distribution of air temperature under the high (120 cm.) cover was lower at the wind-ward side than .the lee-ward side. By these facts it was made clear that the warns keeping effect was influenced easily by the flowing air under high cover without side cover.

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In 1959, the experiment was designed by combining the gibberellin spraying and manuring, and each plot was given with the same treatment through all plucking seasons.
The results of experiment were as follows: the growth rate of tea shoot sprayed with gibberellin was faster, and in 1st, 2nd, and 3rd plucking seasons the amount of growth per day were 3.9, 3.9, 6.3 mm. in the sprayed plots and 2.5, 2.2, 3.5 mm. in the unsprayed plots respectively.
The number of shoot and number of leaf were not affected by gibberellin spraying, and both the sprayed and unsprayed shoot increased one leaf in 5 days in 1st season, 4 days in 2nd season and 3 days in 3rd season.
The yield and weight of shoot were larger in the sprayed plots and the former of whole shoot and of P+3L showed an increase of 8% and 5% over the unsprayed plots.
Of the chemical constituents, chlorophyll was reduced which coincided with the results of the preceding experiments, but total nitrogen, caffeine, tannin, and crude fibre contents showed no significant difference between the sprayed and the unsprayed.
The qualities of black tea made with the sprayed leaves were better than those of the unsprayed, but the increase of the plucking cycle in a year could not be expected.

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This paper reported an account of the habits of tea red spider mite, Tetranychus kanzawai KISHIDA, in the first tea season in Shizuoka-ken.
1. Habits of mite on the old leaves.
The tea red spider mite usually lived on the under side of old leaves, and their numbers increased from April to plucking season. The mite moved from lower to upper parts of tea plant, and from inner parts to plucking surface with the growth of the young leaves.
2. Habits of mite on the young leaves.
The adults and nymphs began to move towards young leaves from old ones in about 2-3 weeks before plucking, and the migration continued through the plucking period. Many numbers of mite were found. at the top and low parts of bushes during the plucking period, however, the mite more attacked lower leaves of young shoot. There was no certain relation between the number of damaged leaves and that of developed leaves. It seemed that the mite population density after plucking season was highest.
3. Dispersion of mite.
As the red spider mite spread from bush to bush by crawling, and it seemed that the wind is an important aid to its spreading. In this observation, a great numbers of adult or nymph were carried out from bushes to other parts by wind. The dispersal season was between April and June, and its number was parallel to the mite populaton density in the field.

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In order to establish the suitable manufacturing procedure of Sentya for each tea variety, the behaviour of 4 varieties Yabukita, Asatsuyu, Tamamidori and Natsumidori, in the steaming process was investigated and the results were summarized as follows:
1. In relation to the steaming period and the hardness of steamed leaf, a long steaming made the leaf more tender than a short steaming, but it was more difficult to soften the leaves of Tamarnidori and Natsumidori than Yabukita and Asatsuyu in the 2nd and 3rd crops.
2. The tea leaf kept greenish blue tint after 10 sec. steaming but with a prolonged steaming reddish tint increased in the color of leaf.
3. On the qualities of tea, the appearance of tea was good on a short steaming, and the liquor, aroma and taste were good on a long one, but in general 30-and 40-sec. steaming gave superior qualities to all varieties.
4. Concerning with the relation between steaming period and storing resistance, the longer the steaming period the less the change in qualities, and the content of V. C. showed also same tendency. It was recognized that Natsumidori was suffered from the most strong effect of steaming period on the qualities of tea after storage, and the rate of deterioration during storage was very little with regard to Asatsuyu and Yabukita.

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The influences of the washing methods of green-leaves on the decreasing degree of its radioactivity and on the qualities of tea were investigated. The results obtained were summarized as follows:
1. Radioactivity of green-leaves in the first crop was the most intensive, but it was weakened by 1/3-1/6 gradually in the second and third crops. Although about 20% of theradioactivity was reduced during the manufacturing process of tea, the decreasing rate became greater if the green-leaves were washed.
2. Concerning with the kinds of cleansers, acidic and neutral cleansers were more effective than the alkaline ones, but Dairy-BON (alkaline) was effective in the third crop. The qualities of tea washed by Lipon-F (neutral) were very good, but those washed by acidic cleansers were inferior because a part of greenleaves was changed reddish brown in color occasionally.
3. As the influence of washing on the qualities of tea, it was recognized that significant differences existed on the style and aroma in the first crop, on the color, liquor, aroma and total evaluation in the second crop, and on the aroma, taste and total evaluation in the third crop, and the qualities of tea were improved by washing the green-leaves except with the acidic cleansers.
4. There was not an obvious difference on the pH of infusion and hot water extract, so it seemed that the cleansers did not remained on the surface of tea-leaves and washing of green-leaves did not reduced the chemical components.
5. It was recognized that the decreasing of the radioactivity was remarkable in the primary heating and rolling process or secondary drying process in the case of Sentya, and Tamaryokutya and Kamairitya showed much less radioactive than the Black tea which was made by the same green-leaves as the former two.

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The changes of chemical constituents and qualities of black tea during storage were studied. Two kinds of black tea were prepared, namely one was fermented for 45 minutes, the another for 90 minutes. And these teas were stored in a factory room or in a refrigerator (3°-5°C) for one year. The following results were obtained after storage. The changes of the water content, the colour and pH of liquor were tested on every three months. The water content under room temperature varied more widely than under cooling. Though the colour of liquor was lighter under cool temperature than under room temperature, it grew more deeper with the storage.
On the pH of liquor a distinct influence was not observed by the storage.
The changes of tannin, total nitrogen, and soluble nitrogen content were tested on every six months, but all these substances did not show apparent tendency with the storage conditions.
Further, the black tea under one-year storage was tested in detail. The infusion was dialyzed through a cellophane membrane in distilled water. And the presence of saccharides and nitrogen in the non-dialyzed portion was tested, for considering whether melanoid pigment was made or not during the storage. As a result, saccharides did not present, but nitrogen a little. Polymerized tannins were contained in the following order : i. e. 90 minutes fermentation-room temperature storage, 45 minutes room temp., 90 minutes-cooling and 45 minutes cooling.
The gallic acid content was arranged in the same order.
By the paper chromatography of phenolic substances developed with phenol containing 25% water a narrow fraction on the original line was observed, and it was presumed to be polymerized tannins.
On the flavor, colour, and strength of liquor by sensory testing, all items under the room temperature storage were superior to those of under cooling storage.

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Tea seeds were sawn in sand in the dark or in the light. After germination the chemia constituents of the seedlings were compared.
Caffeine, a specific component of tea, was proved to be not contained in the root and seed, nevertheless it was contained 1.8-3 times as much in the leaf and stem grown in the dark as in the light. It was confirmed that the caffeine synthesis did not necessitate sunlight.
The nitrogenous constituents were contained most abundantly. in the leaf, and more less in the root, stem, and cotyledon in the decreasing order.
As for the composition of nitrogen fractions, one-third of nitrogen in the leaf or stem in the light, half of nitrogen in the leaf in the dark and in the root in the light, two-thirds of nitrogen in the cotyledon in the dark or light, and three-forths of nitrogen in the stem and root in the dark were in soluble form. The dark treatment generally increased the soluble nitrogen/total nitrogen ratio in the nitrogen fractions. And the caffeine-free soluble fraction was remarkably variable in the soluble nitrogen fractions.
From the calculation of the weight of each fraction per seedling, it was presumed that the amount of nitrogen in each fraction in the seedling grown in the dark was nearly equal to that of the corresponding fraction in the seed, while in the light one-tenth of the soluble nitrogen in the seed and one-third of that migrated into the seedling and transformed to the caffeine nitrogen and insoluble nitrogen respectively.
Sixteen spots of amino acids and amides except unidentified ones were detected by paper-chromatography. Theanine, a specific amide of tea, was contained in a very small amount in the seed, but after germination appeared in every part of seedling grown both in the dark and in the light, and especially occurred in the root most abundantly. Alanine, aspartic acid and arginine were also found in every part in all cases, and the former two were contained abundantly in the leaf and stem, the latter in the root respectively. Glutamine and threonine were presumed to be prevailing components and the former was found in large quantity in the stem, the latter in all parts of seedling grown in the dark. Asparagine had a trend to be contained abundantly in the dark.
As for catechins, the leaf in the light contained (-)-epigallocatechin and its gallate, (-)-epicatechin gallate. (±)-gallocatechin, gallic acid and theogallin. The former two occurred more abundantly. The light→dark treatment reduced catechins, especially (-)-epigallocatechin gallate was decreased.

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A new microdetermination of caffeine in the tea leaf by paper electrophoresis and ultraviolet absorption spectrophotometry was investigated.
The method was as follows : Moisten powdered tea (0.5g.) with a 0.5 ml. of 5% Na carbonate solution ; extract with chloroform for 2-3 hrs. in the extracting apparatus.Transfer the extract to a 25-ml. volumetric flask and make to volume with chloroform.
Subject a 0.05-0.1 ml. of the chloroform solution to paper electrophoresis (buffer solution, M/100 Na borate; voltage, 600 V.; current, 0.6-0.9 mA./cm.) for 3 hrs. After drying the paper, discriminate the position of caffeine by the aid of ultraviolet light as a dark spot. Cut the paper strip 2×3 cm. in this position and elute with hot water through a glass siphon into a 5-ml. volumetric flask and make to volume.
Transfer an aliquote of this solution into 1 cm. quartz cell and measure the absorbancy at 272.5 and 305 mμ by a spectrophotometer. Estimate the absorbancy at 272.5 mμ due to the impurities of filter paper from the correction chart. Subtract the estimated value from the absorbancy at 272.5 mμ of the sample solution to obtain a corrected absorbance value of caffeine, then determine the concentration of caffeine from the calibration curve.
This method was possible to determine as little as 10-40 μg. of caffeine in a 0.05-0.1 ml. of solution without a tedious procedure. The accuracy and time of analysis were almost the same as the semimicro method which was already reported by the authors.

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I have isolated 0.06-0.08% (0.3-0.4% on dry basis) crystal caffeine from the stamen of tea flowers.

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I have detected twelve flavonols on the paper chromatogram of the petals of tea flowers, and also isolated three of them, kaempferol, quercetin and astragalin as pure crystals.

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I have isolated kaempferol and quercetin from the stamen of tea flowers, respectively ca. 0.003% and 0.001% on the dry basis.

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The effects of saturation degree of calcium, potassium and magnesium of soil on the growth and the content of nutrient and the amount absorved by the tea seedlings were investigated by a pot experiment.
The seedlings (Yabukita variety) were planted in Makinohara plateau yellow soil having various saturation degree of Ca (2.3, 25, 50, 75, 100, 125%), K (1.2, 5, 10%), and Mg (5%)
The growth of seedlings was best in the soil containing 25% exchangeable Ca, 10% of K, 5% of Mg and observed the injury of over-liming-in the soil having more than 75% exchangeable Ca.
Increasing saturation degree of exchangeable K in the soil whose exchangeable Ca ranging from 2.3% to 75% increased the growth.
The N and P content of the tea leaves and trunks and the amount of N and P absorbed by the tea seedlings were most abundant in the soil having 25% saturation degree of exchangeable Ca, 10% of K and 5% of Mg.
Increasing saturation degree of exchangeable Ca remarkably increased the content and the amount of absorbed Ca by the tea leaves and trunks and decreased the content and the amount of Mg and Mn, and not reduced the content of K.
Increasing saturation degree of exchangeable K remarkably increased the content and the amount of absorbed K by the tea leaves and trunks and decreased the content and the amount of Ca and Mg.
The sum of cation equivalent in the tea leaves and trunks was increased with increasing the saturation degree of exchangeable Ca of soil, ; the sum of cation equivalent constancy in the tea leaves and trunks was not observed.

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In order to make clear the characteristics of Japan black teas and the content of soluble matter, tannin, nitrogen and ash of excellent Japan black teas and some imported black teas was investigated.
By this result, any distinct correlation could not be observed between the qualities of tea and the content of chemical substances, and there was not any difference on the content of chemical substances among excellent Japan and imported black teas.
But some correlations were observed between the transmittancy of colour of liquor and the sensory estimation, or the ratio of (P₂O₅+K₂O)/CaO.and the content of soluble matter and tannin.

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