Chagyo Kenkyu Hokoku (Tea Research Journal)
Online ISSN : 1883-941X
Print ISSN : 0366-6190
ISSN-L : 0366-6190
Volume 1968, Issue 29
Displaying 1-11 of 11 articles from this issue
  • An Evaluation of the Frost Injury by Measuring the Electric Conductivity of Exosmosis of Tea Leaves
    Tadayuki TOYAO, Kiyoshi KATSUO, Saneyuki KAYUMI
    1968 Volume 1968 Issue 29 Pages 1-5
    Published: March 31, 1968
    Released on J-STAGE: February 05, 2010
    JOURNAL FREE ACCESS
    To determine the frost hardiness of the tea plant, evaluations of the frost injury by measuring the electric conductivity of exosmosis of frozen leaves were investigated.
    Approximately 3g. of frozen leaves is infused in 150 ml. distilled water at 20°C for 20 hours, after which period the electric conductivity (μÖ/cm2) of the liquid is measured (denote by A), and unfrozen control sample is also measured (B). To determine the amount of electrolytes diffused from the completely killed leaves, sample is infused in boiling water and the electric conductivity of the liquid is measured (C).
    With regard to the above values, the following model equations are postulated
    A=α(1-β)e+βe
    B=βe
    C=e
    where α is the percentage of the frost injury, showing a reasonable approximation of the percent of tissue destroyed by the freezing treatment, and Q is the percentage of diffused electrolytes of uninjured leaves, and e is the amount of electrolytes which diffused from the completely killed leaves.
    Thus the degree of frost injury can be estimated by the equation :
    α=A-B/C-B×100
    Various clones were tested for frost hardiness in midwinter using this method, consequently it was presented that the value of α was nearly corresponded with the visual observations on the frost injury. The above correspondence, however, was not so consistent, because the visual observations might be fluctuated in cases of too severe or too slight demage to leaves by the artificial freezing treatment, and in cases of using the injured or discoloured samples. The value of (A-B) should be useful for a substitute value of the degree of frost injury.
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  • On the Effects of the Concentration and Opportunity of the Leafspray by Some Growth Regulators
    Shirô SUGII, Yoshimitsu YANASE
    1968 Volume 1968 Issue 29 Pages 6-20
    Published: March 31, 1968
    Released on J-STAGE: July 31, 2009
    JOURNAL FREE ACCESS
    To extend the plucking period, some growth regulators namely MCP, MCPP, etc. were tested to hasten or late the plucking time.
    Some of these growth regulators were judged to be suitable to retard the sprouting of tea bud and delay the plucking time.
    The good time of spraying in the first season was one or two weeks before sprouting stage, and was from soon after plucking time to one week before sprouting in the second or third season.
    The following concentrations of these growth regulators were available, 100-1000 ppm. of MCP ; 500-2000 ppm. of MCPP ; 100-1000 ppm. of RD-7693 ; and 100-500 ppm. of MDBA and the higher concentration, the later sprouting. And too high concentration often brought about some leaf injury.
    So the plucking time can be delayed one or two weeks by some chemicals.
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  • Shinsuke SAKAI
    1968 Volume 1968 Issue 29 Pages 21-27
    Published: March 31, 1968
    Released on J-STAGE: February 05, 2010
    JOURNAL FREE ACCESS
    As a substitute for the fractionation method for the determination of tea plant carbohydrate, the Weinmann method of estimating the “total available carbohydrate” was investigated.
    Take a 0.3 gram sample and 20 ml. of distilled water into a flask, heat for % hour on a boiling water-bath to gelatinize starch. Pipette 20 ml. of buffer solution of pH 4.45 and 20 ml. of takadiastase solution into a flask. Stopper the flask tightly and incubate for 44 hours at 37 to 38°C.
    After digesting, nearly neutralize, pipette 2 ml. of basic lead acetate, shake, and allow precipitate the protein, tannin and etc. in the digest solution. Filter quantitatively into a 100 ml. standard flask containing 800 mg. of powderd potassium oxalate, and make to volume.
    Filter and hydrolyze a 2.5 ml. of the cxtract solution with 0.25 ml.of hydrochloric acid (specific gravity 1.103) for % hour on a boiling water-bath. Cool and neutralize, and determine the reducing power of the extract by the Hanes method. Results are calculated as glucose, and reported as “total available carbohydrate”.
    When the selection of a sort of Takadiastase was suitable for tea plant digestion, it was not recognized the retardation of digestion by the tea tannin.
    Results obtained with this new method were higher than the combined amounts of total sugars and starch by the fractionation method. However, the correlation coefficient of the data between the fractionation method and the new method was +0.908.
    The variation coefficients of the determination were 3.6 to 5.0%. A comparison of the variation coefficicnt between the fractionation method and the new method showed that the latter had lower accuracy than the former. But, a considerable number of determinations can be completed with this method in a relatively short time, making 72 determinations per week.
    The Weinmann method is simple and suitable for a large-scale analysis of the available carbohydrate in tea plant.
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  • Kenjirô IKEGAYA, Shigeo HIRAMINE
    1968 Volume 1968 Issue 29 Pages 27-31
    Published: March 31, 1968
    Released on J-STAGE: July 31, 2009
    JOURNAL FREE ACCESS
    The effect of supplied dolomite in tea field on absorption of phosphorus by tea plant was examined in field experiment (soil : "Kuroboku" derived from diruvial and tea variety: Yabuki ta) .
    Radioactive (32P) monocalcium phosphate (4.32mCi, P2O5 12g. per bush) was fertilized in three plots (0kg, 100kg. and 300kg. dolomite/10a.) on 30 th May 1967.
    The new leaves were cropped in 2nd season (21st June) and 3rd season (31st July).
    The radioactivity and the total phosphorus content of tea leaves were determined with ordinary method.
    The percentage of supplied phosphorus content to total phosphorus content was calculated.
    The available phosphorus content and the transformation of radio and nonradioactive phosphates in each soil were investigated.
    The results were summarized as follows :
    The yield of new leaves was most in 100kg./10a. dolomite plot and least in without dolomite plot.
    The phosphorus content of new leaves increased by fertilizing of dolomite in tea soil.
    Increasing amount of fertilized dolomite decreased the percentage of supplied phosphorus content to total phosphorus content in the new leaves.
    The available phosphorus content of tea soil increased with increasing amount of fertilized dolomite,
    The iron-bound phosphorus increased and alminum-bound phorphorus decreased by sup-plying of 300 kg./10a. dolomite.
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  • Occurrence of Abnormal Tea Leaf with Increasing Supply of Nickel or Manganese
    Yoshirô MUKASA, Shigeru OGAWA
    1968 Volume 1968 Issue 29 Pages 32-36
    Published: March 31, 1968
    Released on J-STAGE: July 31, 2009
    JOURNAL FREE ACCESS
    The tea plants were planted in pots filled with the field soil of the Shizuoka Tea Experiment Station and were supplied with excessive amounts of nickel and manganese to detect the toxic symptoms due to these elements.
    1. The tea plant developed striped chlorotic leaves when supplied with 5 ppm. of Ni, and died with 50 ppm. of Ni.
    A diffused chlorosis was observed on the leaves when supplied with 1 g. of MnO per pot.
    2. There was a tendency that the striped chlorosis due to excessive nickel was detected in summer and the diffused chlorosis due to excessive manganese was detected in the fall. In winter, the striped chlorotic leaves produced brown spots, and sometimes the brown part of leaves died.
    3. Zinc content was poor in the striped chlorotic leaves.
    4. The soil which produced the striped chlorotic leaves contained richer exchangeable Ni, and that produced the diffused chlorotic leaves contained richer exchangeable Mn and water-soluble Mn.
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  • Fungi Isolated from Affected Tea Roots
    Susumu HIROKAWA, Shigeo TAKAYA
    1968 Volume 1968 Issue 29 Pages 37-47
    Published: March 31, 1968
    Released on J-STAGE: July 31, 2009
    JOURNAL FREE ACCESS
    The depression of tea plants which principally due to root rot and some of them pro gress to death has been occurring in many tea cultivated areas in Japan. As the first step to reveal the causes of these disorders of tea plant, an evaluation of microbial factor as the causal agent of root rot was made.
    Isolation frequency of fungi from diseased tea roots (most of them was rootlet) was in order of Fusarium spp., Cylindrocarpon spp., and Pythium-like fungi. Rhizoctonia sp. and Verticillium sp. were also isolated occationally.
    More than 120 isolates of those fungi were tested their pathogenicity against the cut off tea rootlet in laboratory. Thirteen of the 15 Pythium, 15 of the 17 Cylindrocarpon, 15 of the 42 Fusarium, 4 of the 6 Rhizoctonia and 15 of the 40 isolates of unidentified fungi demonstrated moreor less pathogenicity. Isolates of Pythium, Cylindrocarpon and Fusarium which were found to have the strongest pathogenicities were heavy-innoculated to tea seedlings grown in pot.
    Each isolate also demonstrated pathogenicity in the experiments and Pythium (P-4) was the strongest.
    From these results, it was estimated that the microbial factor could be pointed out as a cause of the root rot and might be partially account for the root rots actually occurring in tea fields.
    Though fungal colony and morphology of mycelium of Pythium-like fungi were characteristics of Pythiutn species, the organ such as zoospore or zoo sporangium was not found and the fungi remained unidentified. Most
    Cylindrocarpon isolates were thought to belong to C. radicicola and a Fusariunt isolate which showed the strongest pathogenicity to F. solani.
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  • Kôzô FURUYA, Gengorô IWAHORI, Shinzô TANAKA
    1968 Volume 1968 Issue 29 Pages 47-56
    Published: March 31, 1968
    Released on J-STAGE: July 31, 2009
    JOURNAL FREE ACCESS
    In frozen storage of steamed tea leaves, it is necessary to maintain the storage temperature at about -20°C or lower. Above this temperature the steamed tea leaves cannot keep freshness for long time of 30-90 days.
    Tea, manufactured with stored leaves for 90 days at -20°C, had no evident difference in the qualities compared with standard one, manufactured with fresh leaves.
    But, some damages were found on their tissues in these frozen leaves and these damages seemed to occur with slow freezing of air flow at -20°C.
    These damages occurred usualy in parenchyma of stem of shoots, rarely in main nerve and none in leaf blade tissue.
    The occurrence of these damages was avoided with rapid freezing by immersing the leaves into 50% gricerin water solution at -20°C or liquid nitrogen.
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  • Muneyuki NAKAGAWA
    1968 Volume 1968 Issue 29 Pages 57-61
    Published: March 31, 1968
    Released on J-STAGE: July 31, 2009
    JOURNAL FREE ACCESS
    The nature and the origin of major polyphenols in Hôji-cha were elucidated from the effects of heating on individual flavanols by using paper-chromatographic technique. Furthermore the direction of thermal transformation of each flavanol and the quantitative variation of major products and original flavanols were shown. The heating of flavanol solution resulted in epimerization, polymerization and decomposition, though the aspect of change was different with the kind of flavanol and thermal condition. Thus it was revealed that (-)-catechin, (-)- gallocatechin, gallic acid, phloroglucinol and two thermal products from flavanol gallates occurred characteristically in Hôji-cha.
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  • Variation of the Enzyme Activity Concerning the Maturity, Position of Leaf, Season, Year and Clone
    Isao ÔTA, Norio NAKATA, Kôsei WADA
    1968 Volume 1968 Issue 29 Pages 62-68
    Published: March 31, 1968
    Released on J-STAGE: July 31, 2009
    JOURNAL FREE ACCESS
    The variation of polyphenol oxidase activity in the tea leaves was examined, concerning maturity, position of leaf on the shoot, plucking season, year and clone.
    The enzyme activity, indicated by the oxygen uptake (μl) per 10 mg of acetone powder(I) showed a decreasing tendency with the development of shoot. The specific activity indicated by the oxygen uptake (μl) per mg of acetone-insoluble N (II) of the clones Benihomare and Benitachiwase showed an increasing tendency with the development of shoot. But the variation was slight up to about 50% of debiraki-do in every clone.
    The first leaf of shoot had a highest enzyme activity (I) and the fourth leaf had a low activity. The stem had a very higher specific activity than the leaves.
    Among the clones, ANAN 1671 and Hatsu-momiji had low activities while Benihomare, Benikaori and Indo had high ones in every year.
    The enzyme activity (I) in the leaves of the second season was higher than that in the other two seasons, but the specific activity (II) of the third season was as same as the second.
    Correlations between the enzyme activities (I, II) and the qualities of black tea made by the Raikai method were observed all the year round but not in each plucking season.
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  • Kiyoshi IWASA
    1968 Volume 1968 Issue 29 Pages 68-74
    Published: March 31, 1968
    Released on J-STAGE: July 31, 2009
    JOURNAL FREE ACCESS
    The influence of shading culture on the catechin composition in the tea leaves was examined.
    During the developing period of the tea shoots, the tea plants were covered with several sheets of black net for 8-13 days. The light intensity under the shade was reduced to 1.6-6.4 percent of the open field. The shoots were plucked at different intervals from the shaded and the unshaded plots and subjected to the estimation of each catechin fraction.
    As a result of shading, the yield of the plucked leaves and the content of total catechins decreased, however, a uniform tendency of decreasing in catechin content was not observed with each catechin fraction. The decreasing of the contents of (-) epicatechin and (-) epigallocatechin was characteristic of variation by shading. A significant difference of gallate content between the shaded and the unshaded shoots was not observed. In consequence, the tea shoots grown under the shade were rich in the proportion of (-) epigallo catechin gallate. After removal of the shade, a remarkable restoration of catechin content occurred quickly.
    It seems that the results mentioned above involve a suggestion of the possible pathway of catechin formation in the tea leaves.
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  • Yutaka HOMURA, Aogu NAKAYAMA, Hideya AONO, Tsuneo MATSUOKA, Yoshimistu ...
    1968 Volume 1968 Issue 29 Pages 75-162
    Published: March 31, 1968
    Released on J-STAGE: July 31, 2009
    JOURNAL FREE ACCESS
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