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Volume 2006, Issue 101
Displaying 1-6 of 6 articles from this issue
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Junichi Tanaka, Fumiya Taniguchi, Noriko Hirai, Satoshi Yamaguchi2006 Volume 2006 Issue 101 Pages 1-7
Published: June 30, 2006
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSUsing flow cytometry and staining by propidium iodide (PI), we estimated the genome sizes of tea (Camellia sinensis (L.) Kuntze), camellia (C. japonica L.), and their interspecific hybrids by comparing relative fluorescence density per nucleus to the values of rice (Oryza sativa), soybean (Glycine max), and wheat (Triticum aestivum), whose genome sizes are known. The genome sizes of tea and camellia were nearly equal and estimated to be 4.OG bases. Garden camellia 'Higo-Ozeki' had 1.5 times the DNA content per nucleus compared to other camellia clones. Based on chromosomal observations, size of the stoma, we conclude that 'Higo-Ozeki' is triploid.View full abstractDownload PDF (1479K) -
Koji Chutani, Yoshikazu Takewaka2006 Volume 2006 Issue 101 Pages 9-16
Published: June 30, 2006
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSTo clarify the effect of covering practice befor tea plucking, the characteristics and the constituents in new shoots of first crop of tea plants were examined with different periods and opening times of direct covering on the bush.
The longer period of direct covering brought the decrease of number of new shoots, weight of 100 new shoots, and weight of new shoots. The color of direct-covered-leaves got deeper than without covering at 3-5days after direct covering, and this result became much clearer in 10 days.
The contents of total nitrogen and free amino acids in new shoots were higher than without covering at 3-5days after direct covering, and after that, it was not influenced by the period of covering. The content of tannin in new shoots was lower than without covering at 3-5days after direct covering, and it was decreased as started to cover earlier. On the other hand, the content of neutral detergent fiber in new shoots was not influenced by direct covering.View full abstractDownload PDF (520K) -
Ryosuke Omata2006 Volume 2006 Issue 101 Pages 17-24
Published: June 30, 2006
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSI investigated the effects of spring skiffing on the densities of Tetranychus kanzawai in hedge or plucking surface of a tea field during early spring in 2005. The stages of T. kanzawai were almost adult females and eggs from 4 days before skiffing to 10 days after skiffing. The number of adult females in hedge increased rapidly from 3 days after skiffing to 10 days. The proportion of number of adult females before skiffing to 10 days after skiffing in plucking surface was 1.6, on the other hand, the proportion in hedge was 5.8. These results indicates that T. kanzawai adult females moved from branches and leaves which fell into the ground by skiffing to hedges of tea bush. I also investigated the effects of skiffing and the timing of acaricide application on the densities of T. kanzawai in hedge or plucking surface. Tea fields were subjected to one of three different treatments: acaricide spray before skiffing (plot A), acaricide spray after skiffing (plot B), or no acaricide (plot C). The densities of T. kanzawai adult female in hedge of plot A were significantly lower than those in plot B and C at 10 and 24 days after skiffing. The densities of T. kanzawai immature of plot A were significantly lower than those in plot B and C at 31 days after skiffing for the hedge and at 24 and 31 days after skiffing for the plucking surface. The rate of prevention for T. kanzawai in plot A was more than 80%, it was higher than that in plot B at 24 and 31 days after skiffing for the hedge and for the plucking surface. These results suggest that the application of acaricide before skiffing was more effective for controlling T. kanzawai than the application after skiffing.View full abstractDownload PDF (486K) -
Koji Yamashita, Yoshikimi Hayashida2006 Volume 2006 Issue 101 Pages 25-28
Published: June 30, 2006
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSEffects of several pesticides against Aleurocanthus spiniferus (Quaintance) on tea were evaluated by laboratory and field tests. Thirteen insecticides and acaricides were tested by dipping tea leaves infested with second-instar larvae. DMTP, fenpropathrin, acetamiprid, buprofezin, spiromecifen, milbemectin and tolfenpyrad produced high mortality.
Among four chemicals tested by application in a tea field, buprofezin, spiromesifen and tolfenpyrad were effective on A. spiniferus.View full abstractDownload PDF (254K) -
Yuzo Mizukami, Yusuke Sawai, Yuichi Yamaguchi2006 Volume 2006 Issue 101 Pages 29-34
Published: June 30, 2006
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSFrequency-dependent electrical impedance spectroscopy has been used to characterize the intracellular and extracellular resistances as well as the capacitance of the cell wall and cell membranes of tea leaves in the rolling process.
The extracellular resistance of the tea leaves decreased due to the electrolyte in the intracellular space leakage into the extracellular space as a result of pressurization rather than the effect of evaporation from the surface area of tea leaves during the rolling process. When the process was prolonged, the extracellular and intracellular resistances attained the same level with assumption that equalization of water advanced in the intracellular and extracellular space. The capacitance of the cell wall and cell membranes decreased due to the change of the tissue structure by pressurization. These electrical behaviors were affected by the characteristics of the materials.View full abstractDownload PDF (328K) -
2006 Volume 2006 Issue 101 Pages 35-43
Published: June 30, 2006
Released on J-STAGE: July 31, 2009
JOURNAL FREE ACCESSDownload PDF (444K)
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