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Volume 1995, Issue 81
Displaying 1-5 of 5 articles from this issue
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Kunio OKANO, Kiyoshi MATSUO, Koji CHUTANI1995 Volume 1995 Issue 81 Pages 1-8
Published: July 24, 1995
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSResponse of two-years-old tea (Camellia sinensis L.) plants to various amount of nitrogen application was analysed in order to clarify the optimum level of nitrogen nutrition in terms of growth, photosynthesis and nitrogen content in new shoots. Plants were grown in a pot containing 3.5 litre of soil under the condition of glasshouse. Defining an arbitrary unit of nitrogen application (200 mgN pot-1 year-1, corresponds to 10 kgN 10a-1 year-1) as 1 N plot, eight experimental plots (ON-12N) were prepared. As a nitrogen source, ammonium sulphate was applied to the pot with five splits in a year.
Nitrogen absorption by a plant increased in proportion to the rise of application level up to 4 N plot, above which little increase was observed. As a result, recovery rate of applied nitrogen by the plant decreased exponentially with the rise of application level. Growth of whole plant and photosynthesis of mature leaves also increased with the rise of application level up to 4 N plot, above which no further increase was detected. No significant effect of nitrogen was observed on the respiratory rate of roots among the nitrogen application level. Meanwhile, growth of first flush shoots and total nitrogen content in the shoots increased with the rise of application level up to 8 N plot.
These results indicated that the optimum level of nitrogen for the quality of new shoots was greater than that for the growth or physiological functions of tea plants. This might be one of reasons which brought about the tendency to the excess input of nitrogen fertilizer to the tea field. In the present experiment, any injury of the tea plants caused by excess nitrogen could not be detected.View full abstractDownload PDF (510K) -
Akira KAWAI1995 Volume 1995 Issue 81 Pages 9-15
Published: July 24, 1995
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSDistribution patterns in a tea shoot and in a tea field and an estimation method for the population density of Polyphagotarsonemus latus (BANKS) were examined at field and in netted house. Most mites infested on two upper developed leaves of new shoot. The rate of the mites infested on the upper leaves was higher in netted house than at field. The most numbers of mite were observed on lower surface of a leaf. The rate of the mites infested on lower surface was higher in field than at netted house. The distribution of adults, larvae or eggs were contagious both in field and at netted house. Adults and larvae were distributed as individual and eggs were distributed as colony at field, and these three stages were distributed as colony in netted house. From the distribution data obtained, a sampling method for estimating population density was proposed, i.e. two upper developed leaves should be sampled, and numbers of mite on lower surface of the leaf should be counted. The relationship between the precision of the estimation and the number of new shoots required to estimate the population density was discussed.View full abstractDownload PDF (415K) -
Yoshihiro TAGUCHI, Seiichi YONEYAMA1995 Volume 1995 Issue 81 Pages 17-23
Published: July 24, 1995
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSElectric conductivity (EC) of the soil solution was continuously monitored by an EC sensor in the tea field where various types of nitrogenous fertilizer were applied. The EC values varied depend on the types of fertilizer. Chemical fertilizer raised the EC level quickly, while mixed fertilizer, compound fertilizer and organic fertilizer increased the level gradually. No marked changes in the EC level could be detected when a powdered-born fertilizer was applied. Although rainfall largely affected the EC value of the soil solution, no abrupt change was obserbed when a controlled-releasefertilizer was used.
Based on these results, a new manuring system was constructed by the use of controlled-release fertilizer. By the new system, amount of nitrogen applied to the tea field was reduced by 21% as compared to the ordinary system. Root growth was promoted under the new system. Yield and quality of the plucked shoots were maintained at the same level as before.View full abstractDownload PDF (377K) -
Kouji SASAKI1995 Volume 1995 Issue 81 Pages 25-42
Published: July 24, 1995
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSThe main models of tea management in Saitama prefecture which consist of tea production, processing, and selling were analized and resulted as follows. A private tea farming would be suceeded by processing a large quantity of tea leaves or refining crude tea and selling. On the other hand, a cooperative tea management would be more advantageous because of the effective working of processing systemin two or three alterative labouring a day and of collecting system of fresh tea leaves in reasonable period.View full abstractDownload PDF (1018K) -
Muneyuki NAKAGAWA1995 Volume 1995 Issue 81 Pages 43-48
Published: July 24, 1995
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSMethods for analysis of natrium and ammonium ions in tea infusions with ionchromatography were examined.
Optimum ionchromatographic conditions were obtained on 2-3mM nitric acid of mobile phase, 1.4-1.5ml/min. of flow rate and 40-43°C of oven temperature to use ionexchange resin's column (Shimazu Shim-pack IC-C1), while 1mM oxalic acid solution containing 1.5mM dipicolinic acid of mobile phase, 1.0ml/min. of flow rate and 40°C of oven temperature to use chemically modified silica's column (Shimazu Shim-pack IC-C3). Under these conditions high linear relationships were observed between the concentration of natrium or ammonium ion and the peak areas in those chromatograms from 1.25 to 5.0ppm. Coefficients of variation of determined values by performing measurement six times ranged from 0.21 to 1.45% with standard solutions and from 2.93 to 8.77% with tea infusions in using IC-C1 column. While those coefficients ranged from 1.29 to 2.62% with standard solutions and from 5.17 to 10.57% with tea infusions in using IC-C3 column. Thus the precision profile of analysis was a little less in using IC-C3 than IC-C1.
There were good agreements between content of natrium or ammonium ion obtained by ionchromatography and that obtained by other analytic method i.e. atomic absorption photometry or ionmeter.View full abstractDownload PDF (264K)
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