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Volume 2000, Issue 88
Displaying 1-12 of 12 articles from this issue
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Yukio KOSUGI2000 Volume 2000 Issue 88 Pages 1-8
Published: March 31, 2000
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSInfluence of injury by Tea Green Leafhopper, E. onukii on browning of the leaf vein and growth of new shoots of tea plants was investigated.
By the infestation of a middle-stage nymph for one day, the color of veins became brown. And after infestation for 4 days, veins had became brown in all shoots. However the number of shoots with the brown veins was lower by one female infestation than by a nymph one. By the infestation of a middle-stage nymph or a female, the brown veins was appeared from at the upper site of shoot to at the lower site.
Stippling at the midrib were appeared by infestation of either a middle-stage nymph or a female for one day. And stippling of the leaf had been appeared more at the second and third leaves than the top leaf on the shoot. There was a significant correlation between the ratio of shoots with brown veins and the length of plucked new shoots, but not the weight of plucked new shoots.View full abstractDownload PDF (409K) -
Takayuki NAKANO, Kiyoshi MATSUO2000 Volume 2000 Issue 88 Pages 9-24
Published: March 31, 2000
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSIn almost cases of past frost disasters for tea (Camellia sinensis L.) field, a partial damage has been observed. Especially, frost injuries used to concentrate only on an east side of the arc-shaped canopy surface for tea bushes planted with the direction from north to south. In this research, the difference of frost tolerance for buds and new shoots between the east and the west side of an arc-shaped canopy surface, effects of freezing temperature and melting method were investigated. Adding analysis of the canopy surface temperature on cold nights, it was observed as follows ;
1. Freezing tolerance level of buds and new shoots depended on their growth stage. Their injured and dead rate after the freezing treatment increased as they grew. However, . buds and new shoots picked up from the east side of the canopy surface generally showed only a little decline in the freezing tolerance than that from the west side.
2. On each growing stage, injured and dead rate of tea buds and new shoots were increased at lower temperature and at longer treatment time. They were influenced by the difference of only 1°C at a critical temperature.
3. In the past meteological data since 1992 to 1997 at Makinohara AMeDAS, which established in the area of Shizuoka tea experiment station in 1988 by Japanese Meteological Agency, almost freezing night occurred in the atmospheric pressure distri-bution of which is low at east and high at west around Japanese land. In such a case, winds used to breeze from west to east.
4 . The leaf temperature of the canopy surface was lower at an opposite side of a wind direction. As most patterns of cold night, the wind from west to east rise the leaf temperature of the west side. In this experiment, the maximum difference was over 2°C.
It was concluded that the different leaf temperature between east and west and declination of freezing tolerance induce the partial frost injury on the east side of arc-shaped canopy surface.View full abstractDownload PDF (3849K) -
Tadakazu TAKEO, Yoshitaka KIMURA, Toshirou NAKAJIMA, Tamio KAWAMURA2000 Volume 2000 Issue 88 Pages 25-30
Published: March 31, 2000
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSThe differeces on fired green tea flavor were compared between the standard firing (S) by pan-direct-heating and the modified firing (M) combined pan-direct-heating and far-infrared ray radiation.
On the S-firing, a part of green tea was overheated on pan surface and over-roasting aroma was produced localy. On the M-firing with two heating sources, the temperature of pan surface was fixed lower than that of S-firing. Then, the over-heating of tea on pan surface was averted. Therefore, the M-fired tea showed milder and more fragrant flavor than that of the S-fired tea.
The energy consumptions on firing were about same between the both firings. And the temperature-control of teas during firing process was easier on the M-firing than that of the S-firing.View full abstractDownload PDF (309K) -
Masakazu SHIWA, Kiyoo YOSHIZAWA, Masatomo ITO2000 Volume 2000 Issue 88 Pages 31-38
Published: March 31, 2000
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSCoated urea fertilizer 120days type and 40days type labelled with 15N-nitrogen were examined in order to clarify dissolution of them and absorption of tea plants with time. Coated urea fertilizer 120days type was applied to potted plants (1/2000a) on the end of Aumnst and 40davs tvne was annlied on the end of February.
Nitrogen of coated urea fertilizer 120days type dissolved out 70% until November, and it kept up dissolution until next August for one year. Absorption percentage of tea plants was 20% on November, it was relatively low in comparison with urea without coating, after that however it increased gradually, and absorption of tea plants was verified on next August. On one side nitrogen of coated urea fertilizer 40days type dissolved out 50% until the first flush season on May, and it kept up dissolution until the second flush season on July for 100days. Absorption percentage of tea plants was low of 9% on the first flush season, after that however it increased notably until the second flush season. And then absorption of tea plants was not verified.
These results suggested that, as coated urea fertilizer kept up dissolution over an extended period of time, the rate of fertilizer application and the times of application in autumn and summer could be reduced. However, it was difficult to secure efficiency of coated urea fertilizer in low soil temperature. Moreover spring-applied nitrogen contributed to the build up of the first flush shoots considerably, and was also distributed to it. So it was considered that the coated urea fertilizer was required to use with readily available fertilizer. In addition it was suggested that the amount of roots increased in the space between hedges, because coated urea fertilizer reduced burning of roots.View full abstractDownload PDF (479K) -
Masaki TSUJI2000 Volume 2000 Issue 88 Pages 39-44
Published: March 31, 2000
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSIn order to establish a method of quality evaluation with leaf thickness of raw material leaf of Tencha, leaf thickness of tea shoot was measured and the characteristic was examined. Furthermore, leaf weight and leaf area of tea shoot was measured and the appropriate measurement position of leaf thickness of tea shoot in natural shape bush formation was examined.
1. The appropriate measurement part of leaf thickness in a leaf was the center part of leaf blade, which was surrounded by lateral vein.
2. Elder leaf of new shoot was thicker than younger leaf.
3. In the same order of upper three leaves in a new shoot, the leaf thickness was approximately similar regardless of the shoot order and the growth degree of the branch.
4. As a result of measurement of leaf weight and leaf area, final Tencha crude tea was mainly composed of the third leaf.
5. In conclusion, the third leaf was the most suitable for evaluating material quality as Tencha.View full abstractDownload PDF (357K) -
Katsunori KOHATA, Youichi YAMASHITA, Hideki HORIE, Yuji YAMAUCHI2000 Volume 2000 Issue 88 Pages 45-48
Published: March 31, 2000
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSThere are three methods for the measurement of converting percentage of chlorophyll to pheophytin in green tea leaves. Characteristics of these methods were investigated. For the first method reported originally, the converting percentage is obtained colorimetrically using the empirical calculating equation. This has merits of simplification and lower running expense, while it has demerits of lower accuracy and applicability. The second method which improved the first one also has a demerit of lower applicability, nevertheless it is more excellent in the other comparative points. The third method, in which the converting percentage is calculated based on the individual pigment contents obtained by HPLC, has merits of high accuracy, reproducibility and applicability, while it has demerits of using the expensive apparatus and high-price standard pigments. These results suggest that the second method is the best from a standpoint of wide-spread utilities.View full abstractDownload PDF (208K) -
Akira SAKAMOTO, Hironari SUGIYAMA, Muneyuki NAKAGAWA, Isao TOMITA, Har ...2000 Volume 2000 Issue 88 Pages 49-55
Published: March 31, 2000
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESS1) Analytical conditions for the nitrate nitrogen contents of Sen-cha were examined using ion-chromatographic method with anion exchange column (either Shim-pack IC-A3 or Hitachi 2740). CV (n=7) and the recovery of the nitrate nitrogen added to Sen-cha infusions were 5.6% and 102.3% respectively, in the average of 7 ro 6 determinations.
2) The nitrate nitrogen contents in 18 commercally available Sen-cha leaves and their infusions prepared in usual drinking manner were 6.2-22.0mg/kg (13.0mg/kg in average) and 0.1-0.4mg/ 9 (0.3mg/l in average) respectively. These levels of nitrate nitrogen were far below than that allowed for drinking water (10.0mg/l as nitrate and nitrite nitrogen).View full abstractDownload PDF (364K) -
Influences of the Paper Pot Length and Container Setting Position on the Rooting PatternsYoriyuki NAKAMURA2000 Volume 2000 Issue 88 Pages 57-65
Published: March 31, 2000
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSInfluences of the paper pot length, the setting position of the container and the environment of the intervening space between the bottom of the container and the ground surface on the rooting patterns of tea cuttings were investigated using paper pot set within a holding container.
1) When the holding container was set above the ground surface, the root of cuttings only developed inside the pot irrespective of the paper pot length (10-20cm).
2) A distance of more than 3cm between the holding container and ground surface was necessary for the development of roots only within the pot. If the holding container was set on the ground surface or on the nursery bed, roots developed and grew out of paper pot.
3) Conditions of darkness and high humidity in the intervening space between the holding container and ground surface, stimulated the roots to jut and grow out from bottom of paper pot.View full abstractDownload PDF (1181K) -
Akira KAWAI2000 Volume 2000 Issue 88 Pages 67-77
Published: March 31, 2000
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSThe varietal differences of tea plant to the infestation of Tetranychus kanzawai KISHIDA was examined in 1994, 1995 and 1997 using 39 varieties planted in the tea field of NIVOT. Since populations on each varieties reached the peak at the different day, varietal difference in the density at each day did not represent the varietal differences to the infestation. Since there was significant positive correlation between the peak and cumulative densities in each variety (r=0.956, N=39, p<0.01), the peak density represents the varietal differences to the infestation. There was the great varietal difference in the infestation. The infestation was the maximum on the variety 'Yabukita', and was also high on the natural crossing varieties of 'Yabukita'. The infestation on Japanese varieties is high, and that on assam hybrid and varieties introduced from China is low. Though significant correlation could not be found between the survival of female adults and the infestation in the field in each variety, there was significant positive correlation between the number of eggs oviposit-ed and the infestation in the field in each variety (r=0.805, N=39, p<0.01). The difference in the number of eggs oviposited strongly affects the varietal difference in the infestation.View full abstractDownload PDF (610K) -
Hideki HORIE, Yusaku YAMASAKI, Youichi YAMASHITA, Yuji YAMAUCHI, Katsu ...2000 Volume 2000 Issue 88 Pages 79-85
Published: March 31, 2000
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSDownload PDF (391K) -
Hideki HORIE2000 Volume 2000 Issue 88 Pages 87-93
Published: March 31, 2000
Released on J-STAGE: December 03, 2009
JOURNAL FREE ACCESSDownload PDF (419K) -
2000 Volume 2000 Issue 88 Pages 95-98
Published: March 31, 2000
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSDownload PDF (225K)
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