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Volume 2004, Issue 98
Displaying 1-7 of 7 articles from this issue
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Year-round Changes in Photosynthetic Activity of Surface Leaves on Tea (Camellia sinensis L.) CanopyKunio Okano, Kiyoshi Matsuo2004 Volume 2004 Issue 98 Pages 1-9
Published: December 31, 2004
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSChanges in photosynthetic activity of growing leaves on the 1st, 2nd, 3rd and 4th flush shoots were periodically measured by an oxygen electrode in order to know the year-round fluctuation in productive ability of tea (Camellia sinensis L.)canopy. Reasons which caused a premature senescence of leaves were also investigated.
Growing leaves exhibited their maximum photosynthetic activity about 45 days after the leaf opening. In all the crop seasons, photosynthetic activity of the new leaves increased until when the buds of the next crop season sprouted, after that declined gradually and all the leaves were shed. As a result, leaves on the surface part of tea canopy were replaced in turn from the 1st to 4th flush seasons with a cycle of a little under two months. Photosyntetic avtivity of the over-wintered leaves were relativelly high, while that of the 1st and the 2nd flush shoots were lower. In autumn, the leaves on the 3rd and 4th flush shoots exhibited the highest value of photosyntesis throughout the year. Main reason for the premature senescence of tea leaves wolud not be a deterioration of light environment but an outflow of nitrogenous compounds to the growing new shoots.View full abstractDownload PDF (638K) -
Koji Uchimura, Nobuyuki Mimura2004 Volume 2004 Issue 98 Pages 11-19
Published: December 31, 2004
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSNitrogen mineralization characteristics of organic matter in a Kuroboku tea garden was analyzed by the kinetic method, and it was possible to obtain following results.
1) The nitrogen mineralization curve of organic matter in a Kuroboku tea garden suited the simple type model well, and it was possible to obtain nitrogen mineralization characteristic parameters (N-mineralization potential, mineralization rate constant, apparent activation energy).
2) The N-mineralization potential of rapeseed meal, soybean cake, meat bone meal, and fish meal in the Kuroboku tea garden was 59-89% of the total nitrogen content, and 90% of the N-mineralization potential became inorganic at 8-12 days, and the mineralization rate was more rapid than the general field soil.
3) The N-mineralization potential of offered animal manure compost was 7-39% of the total nitrogen content, and it was compared with the general field soil, and the mineralization rate was rapid in the cattle feces compost, and it was slow in the swine and poultry compost.
4) The temperature coefficient showed that the dependence on temperature of the mineralization rate differed from organic fertilizer, and it was larger in the order of:meat bone meal>rapeseed meal>fish meal>soybean cake. The integration mineralization rate in wintertime of meat bone meal and rapeseed meal was half the summertime rate.
5) The seasonally-classified nitrogen mineralization rate of each organic matter was calculated from the nitrogen mineralization characteristic parameters, and from expression time and quantity of the inorganic nitrogen, it was possible to estimate the fertilizer application time in which it was possible to raise the fertilization efficiency.
6) With this method it became possible to propose the type and fertilizer application time of the organic matter which raised the fertilization efficiency. The best time to apply spring fertilizer using rapeseed meal was from January till February. It appeared to be too late to apply spring fertilizer after March in Kagoshima Prefecture.View full abstractDownload PDF (526K) -
Takashi Mizuta, Hirofumi Nagatomo, Makoto Hattori2004 Volume 2004 Issue 98 Pages 21-32
Published: December 31, 2004
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSA feeding activity of Pseudaulacaspis pentagons (Targioni) (Hemiptera:Diaspididae) on the resistant cultivars of tea plants (Theaceae:Thea) was analyzed using the cutting stylet of female adults and a computer-based electronic monitoring system (EMS). The sap exudation through the severed stylets was observed on all tested cultivars and showed a pH of 7. 8 or higher, suggesting that the sap exuded through the severed stylet originated from the phloem and P. pentagons was a phloem feeder. The proportion of P. pentagona females of the exuding sap was significantly lower on the resistant cultivars "Hatsumomiji" and "Sayamakaori" than that on the susceptible one, "Takachiho".
Nine types of distinctive waveform (A to I) were observed by the EMS. The total times of B, C, D, and E waveforms were longer than those of the other waveforms, suggesting that these 4 waveforms associated with major feeding activities. The B waveform was shorter on the resistant cultivar "Hatsumomiji", C and E waveforms were shorter on the susceptible one, "Takachiho", and there was no difference in the duration of the D waveform between the cultivars. Wax secretion was not observed in any females of P. pentagons on the resistant cultivar "Hatsumomiji", while it was observed in almost all females on the susceptible one, "Takachiho".View full abstractDownload PDF (1837K) -
Masahiko Higuti, Shouichi Sato, Masaki Hamasaki, Seiji Shinsho, Hirosh ...2004 Volume 2004 Issue 98 Pages 33-42
Published: December 31, 2004
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSDVB/carboxen/PDMS fiber was the best for analyzing the heated aroma compounds of tea by the SPME (Solid Phase Microextraction) method with GC using a flame thermionic detector (FTD) and was better to take out the extract in the percolated liquid of the head space than in dried conditions.
In order to get enough peak area under the conditions for both strong and weak fired tea for the SPME method, twenty minutes of extraction time was needed.
Compared with the column adsorption method, the SPME method was faster, and more convenient after the process of preparation through analyzation. To analyze the nitrogenous compounds which make up the heated aroma compounds, the SPME method gave enough peak area and the peak area ratio calculated from the internal standard showed a sufficient number of peaks for analyzing the data with accuracy. Therfore, the SPME method was the most suitable method of evaluating fire temperature when analyzing aroma compounds.
Furthermore, the SPME method was efficient for analyzing the aroma compounds by using a flame ionization detector (FID).View full abstractDownload PDF (508K) -
Sawako Moriwaki, Kazumi Asai, Mari Maeda-Yamamoto2004 Volume 2004 Issue 98 Pages 43-50
Published: December 31, 2004
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSRecently, it has been increased the allergic disease like the phenomenon of immune hypersensitiveness. Mast cells play a critical role of allergy and release histamine, which is chemical mediator of allergy. Human mast cell line, HMC-1, has a great store of histamine, however, the histamine release is little. Therefore, we paid attention to histamine synthetase (histidine decarboxylase, HDC), and attempted to screen anti-allergic components in tea. HDC gene transcription level of cells was measured with RT-PCR. Among tea cultivars tested, it was shown that HDC expression of mRNA levels was decreased in 'Hatsumomiji', especially. On the other hand, tea catechines have not influenced on expression of HDC mRNA. From these results, we presumed that the lowering of the mRNA expression level is caused by the interaction of various tea components. This study suggested that this assay was useful for the screening of anti-allergic components.View full abstractDownload PDF (506K) -
Satoru Nimura2004 Volume 2004 Issue 98 Pages 51-54
Published: December 31, 2004
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSDownload PDF (249K) -
2004 Volume 2004 Issue 98 Pages 55-58
Published: December 31, 2004
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSDownload PDF (233K)
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