Chagyo Kenkyu Hokoku (Tea Research Journal)
Online ISSN : 1883-941X
Print ISSN : 0366-6190
ISSN-L : 0366-6190
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Volume 2009, Issue 108
No.108
Displaying 1-16 of 16 articles from this issue
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Original Articles
  • Behavior of a Resistant Factor against White Peach Scale (Pseudaulacaspis pentagona Targioni-Tozzeti) on Tea Trees Grafted Using a Combination of Resistant and Susceptible Varieties
    Sakae Kubota
    2009 Volume 2009 Issue 108 Pages 108_1-108_6
    Published: December 31, 2009
    Released on J-STAGE: June 12, 2012
    DOIhttps://doi.org/10.5979/cha.2009.108_1
    JOURNAL FREE ACCESS
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    The development of Pseudaulacaspis pentagona females on grafted tea trees was examined using a combination of two grafting categories-tea variety (resistant vs. susceptible) and graftpart (scion vs. stock)-in order to clarify the behavior of a resistant factor against this organism. P. pentagona females exhibited better growth on the susceptible variety than on the resistant variety, regardless of the plant part on which they grew. Conversely, those individuals that grew on the resistant variety exhibited poorer growth than those on the susceptible variety, with the exception of individuals growing on the graft union. It is suggested that the resistant factor influencing the growth of P. pentagona is probably not transported through either the phloem or the xylem in tea trees.
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  • Occurrence of the Tea Tortrix Complex and their Parasitoids in Pesticide-Free Tea Fields in Shizuoka Prefecture, Japan
    Chikara Ishijima, Yasushi Sato, Makoto Ohtaishi
    2009 Volume 2009 Issue 108 Pages 108_7-108_18
    Published: December 31, 2009
    Released on J-STAGE: June 12, 2012
    DOIhttps://doi.org/10.5979/cha.2009.108_7
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    The occurrence of the tea tortrix complex and its parasitoids in pesticide-free tea fields from 2006 to 2008 was investigated by using light traps and sticky suction traps, respectively, in order to examine the interaction between them. The numbers of both Adoxophyes honmai Yasuda and Homona magnanima Diakonoff trapped by light traps were observed to decrease from 2006 to 2008, and the rate of decrease in the case of the former was higher than that in the case of the latter.
    The most numerous parasitoids trapped by suction sticky trap were Trichogramma spp., followed by Apanteles adoxophyesi Minamikawa. Ascogaster reticulata Watanabe and Bracon adoxophyesi Minamikawa were found to be trapped rarely. Although the numbers of both Trichogramma spp. and A. adoxophyesi trapped by sticky suction traps between 2006 and 2007 were observed not to be different, the numbers of them drastically decreased in 2008. The numbers of A. reticulata and B. adoxophyesi were observed to decrease from 2006 to 2008. Particularly in 2008, they were found to be trapped rarely.
    We also compared seasonal changes in the numbers of tea tor trix complex with Trichogramma spp. and A. adoxophyesi. As a result, the number of trapped Trichogramma spp. adults reached a peak 10 to 28 days (average : 19.9 days) and 2 to 25 days (average : 15.7 days) after the peak in the number of A. honmai and H. magnanima adult females, respectively. The number of trapped A. adoxophyesi adults reached a peak 2 to 48 days (average : 26.1 days) and 1 to 39 days (average : 21.8 days) after the peak in the number of A. honmai and H. magnanima adult females, respectively. In addition, a comparison of the seasonal changes in the number of tea tortrix complex with the number of parasitoids suggested that parasitoids increased after late July the period in which eggs and larvae of tea tortrix complex are found in tea fields with great frequency. Judging from these results, the application of pesticides should be minimized or selective pesticides should be used after late July to conserve the parasitoids and serve as biological control agents.
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  • Effect of nitrogen fertilizers on composition of catechins in shoots of tea cultivars
    Akiko Matsunaga, Tetsuji Saba, Atsushi Nesumi
    2009 Volume 2009 Issue 108 Pages 108_19-108_27
    Published: December 31, 2009
    Released on J-STAGE: June 12, 2012
    DOIhttps://doi.org/10.5979/cha.2009.108_19
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    A field experiment was conducted using 14 cultivars to evaluate the effects of different application rates of nitrogen fertilizers on catechins composition in tea shoots. Tea plants were planted in 2000 at Kanaya Tea Research Station of National Institute of Vegetable and Tea Science. They were treated with ammonium nitrate fertilizers applied at annual rates of 200, 400 and 600kg /ha. Tea shoots were plucked in 2005, 2007 and 2008. The concentrations of epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECG), and epigallocatechin gallate (EGCG) in shoots of the first and second harvest seasons were determined by HPLC. In the concentration of each catechin in shoots of the first harvest season, there were significant differences at the 1% level between nitrogen fertilization treatments, cultivars and harvest years. Reduction of nitrogen application resulted in increase in the concentrations of EC, EGC, ECG and EGCG in the shoots of the first harvest season. Apparent increases of concentrations of EC, EGC, ECG, and EGCG were observed with 200kg /ha nitrate fertilization. The concentrations of catechins of the second harvest season were higher than those of the first harvest season. The interaction between cultivars and nitrogen application levels was very small and not significant at the 1% level in the concentrations of catechins in each harvest season.
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  • Actual State of Residue Accumulated by Skiffing and Pruning in Space between Hedges of Tea Field and the Effect of It on Behavior of Applied Fertilizer Nitrogen in Soil
    Masakazu Shiwa, Eiji Nishino, Yoshihiko Wada, Kazuhiro Nakagami, Yoshi ...
    2009 Volume 2009 Issue 108 Pages 108_29-108_38
    Published: December 31, 2009
    Released on J-STAGE: June 12, 2012
    DOIhttps://doi.org/10.5979/cha.2009.108_29
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    A large quantity of pruned shoots had accumulated in space between hedges by light trimming of canopy after second crop every year, and it was feared that its state influenced the environment of space between hedges. So twenty tea fields in Shiga prefecture were examined in order to investigate actual state of residue accumulated by skiffing and pruning in space between hedges , and a tea field was examined in order to clarify the behavior of applied fertilizer nitrogen in soil under it.
    In the actual state investigation, depth of accumulated residue, weight of it and questionnare to cultivators were examined. In the behavior of applied fertilizer nitrogen under accumulated residue coated urea fertilizer 40days type was examined until 80days after fertilizer application.
    Depth of accumulated residue was 10-20cm in many tea fields, and its avarage was 12.8cm. Average of accumulated residue weight was 31430kg/ha, and its amount of nitrogen was 867kg/ha. Coated urea fertilizer applied on accumulated residue could not reach to soil, so it was mixed into accumulated residue. But its dissolution rate was the same as it was mixed into soil. Every time amount of anmonium nitrogen in the soil removed accumulated residue was much more than one of the soil under it. On the other hand amount of nitrate nitrogen in the soil removed accumulated residue did not differ much from one of the soil under it.
    These results suggested two possibility of that, applied nitrogen was fixed by accumulated residue, or applied nitrogen denitrificated in accumulated residue or rather shallow soil. In either case as fertilizer nitrogen was applied on accumulated residue, its loss increased, or nitrogen could not increase in soil appropriately.
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  • Post-fermented green tea with yeast and effects on suppression of glucose absorption in rats
    Yuko Watanabe, Toshiki Matsuura, Kiyoshi Hayakawa, Hiroshi Ueno
    2009 Volume 2009 Issue 108 Pages 108_39-108_49
    Published: December 31, 2009
    Released on J-STAGE: June 12, 2012
    DOIhttps://doi.org/10.5979/cha.2009.108_39
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    The unsterilized tea leaves were fermented by Saccharomyces cerevisiae which is widely used for food production. The growth of S. cerevisiae and other bacteria were monitored with different concentrations of sucrose and water. Under the condition of 5% sucrose and 28% water, the optimum growth of S. cerevisiae was observed while the growth of other bacteria was suppressed. The levels of catechins and bitterness were decreased after the fermentation.
    The inhibitory effects of the fermented and unfermented tea suspensions and extracts on intestinal absorption of glucose were examined in rats using portal cannulae. No differences in the glucose absorption levels as well as the inhibitory effects were observed between the fermented and unfermented tea when they were administered as the form of suspension. However, the glucose absorption was clearly suppressed and the inhibitory effects were sustained longer for the fermented tea than the unfermented tea when administered as the extracts. Our results suggest that the intestinal glucose absorption can be inhibited and the inhibitory effects may be sustained by drinking the fermented tea. The low levels of EGCg and ECg in the fermented tea extract also indicate that the presence of water soluble components produced by the fermentation process may have a effect on lowering the blood glucose level. These observations suggest that the fermented tea has health-promoting benefits.
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Technical Reports
  • Effect of only organic fertilizer application to use much during winter and spring on yield and quality of green tea
    Nobuyuki Miura, Koji Uchimura, Takahisa Nakamura, Mitsuaki Karasuyama, ...
    2009 Volume 2009 Issue 108 Pages 108_51-108_59
    Published: December 31, 2009
    Released on J-STAGE: June 12, 2012
    DOIhttps://doi.org/10.5979/cha.2009.108_51
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    As an attempt to support organic tea cultivation, we examined the effects of the application of only organic fertilizer on green tea. Our findings are described below.
    We compared the routine method wherein a combination of chemical and organic fertilizers is applied with a method wherein only an organic fertilizer is applied; this method involves a liberal use of the organic fertilizer from winter to spring, and the fertilizer was applied at an annual amount of 50 kgN/10a. The organic fertilizer method had almost no influence on yield, but the quality of the 1st, 2nd, and 3rd crops of green tea deteriorated during the 1st and 2nd years. However, in the 3rd and 4th years, the crop yield and quality was the same as that with the combined fertilizer method. On the basis of this primary result, it was thought that an increase in the protein-like organic nitrogen (neutral phosphate buffer-extractable organic nitrogen, PEON) concentration in the soil leads to an increase in nitrogen absorption by the tea plants.
    Moreover, the use of the organic fer tilizer method also led to an increase in the concentration of actinomycetes and bacteria in the soil. However, with the application of the meat and bone meal, one should carefully consider the increase of phosphoric acid and calcium in the soil.
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