Japanese Journal of Tropical Agriculture
Online ISSN : 2185-0259
Print ISSN : 0021-5260
ISSN-L : 0021-5260
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Volume 32, Issue 1
Displaying 1-10 of 10 articles from this issue
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  • Elongation Ability of Deepwater Rice Varieties from Different Land Levels of Bangladesh
    Quazi Rezaul ISLAM, Jun INOUYE
    1988 Volume 32 Issue 1 Pages 1-5
    Published: March 01, 1988
    Released on J-STAGE: March 19, 2010
    DOIhttps://doi.org/10.11248/jsta1957.32.1
    JOURNAL FREE ACCESS
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    In Bangladesh deepwater rice, plant age at which the internode initiates elongation due to submergence during lag phase or interphase between tillering and panicle initiation was from the 7th to 17th leaf stages. Elongation ability of the deepwater rice varied according to varieties from different land levels. Among the three variety groups from three land levels, better elongation ability was observed in lowland varieties, while elongation ability was poor in medium highland varieties and intermediate in medium lowland varieties.
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  • Fundamental Studies on Mechanical Properties of Long Grain Rice Varieties
    II. Bending properties of long grain rice
    Surasak BAMRUNGWONG, Takaaki SATAKE, Danilo VARGAS, Shigeru YOSHIZAKI
    1988 Volume 32 Issue 1 Pages 6-15
    Published: March 01, 1988
    Released on J-STAGE: March 19, 2010
    DOIhttps://doi.org/10.11248/jsta1957.32.6
    JOURNAL FREE ACCESS
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    Two long grain indica varieties (KDML105 and IR60) and two short grain japonica varieties (Koshihikari and Nipponbare) were subjected to three-point bending under controlled atmospheric conditions.
    Results indicated that the rice kernels showed an elastic behavior under the moisture content range of 11.6-18.8% d. b. The bending breaking load values of the long grain rice of about 15-40N were comparatively low to those of the short grain rice which were about 27-68N. It was further indicated that the long grain rice kernels were relatively weaker in bending than in compression with the same mosture content. The weakness of long grain rice in bending over that of the short grain rice was confirmed considering its breaking energy of about 0.30-1.38mJ for the former and about 0.80-3.02mJ for the latter. Furthermore, the modulus of elasticity of the rice kernel due to bending was about 3.2-6.8GPa and 3.2-7.4GPa for the brown and milled rice of the long grain rice, respectively, and about 0.89-1.5GPa and 0.96-1.6GPa for the brown and milled rice of the short grain rice, respectively. The tensile strength for the brown and milled rice of the short grain rice was found to be 26.7-55.3MPa and 19.7-49.9MPa, respectively. Comparatively, the tensile strength for the brown and milled rice of the short grain rice was found to be 17.0-36.9MPa and 14.0-30.6MPa, respectively. In addition, the tensile strength of long grain rice was about 1/14-1/7 of the compressive strength, while for the short grain rice it was about 1/17-1/10 of the compressive strength with the same moisture content.
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  • Relationships between Leaf Water Potential and Photosynthesis of Coffea arabica L. Grown under Various Environmental Conditions as Affected by Withholding Irrigation and Re-irrigation
    Michio KANECHI, Naotsugu UCHIDA, Takeshi YASUDA, Tadashi YAMAGUCHI
    1988 Volume 32 Issue 1 Pages 16-21
    Published: March 01, 1988
    Released on J-STAGE: March 19, 2010
    DOIhttps://doi.org/10.11248/jsta1957.32.16
    JOURNAL FREE ACCESS
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    The effects of a progressive decrease and restoration in leaf water potential (ψleaf) following interruption of water supply and re-watering on net photosynthesis (Pn) and transpiration (Tr) of mature coffee leaves were examined under different environmental conditions (25°C day/20°C night temperature-unshaded, 25/20°C-shaded and 33/28°C-unshaded) . After withholding water supply, ψleaf, Pn and Tr decreased most rapidly under a combination of high-light and high-temperature conditions, however, ψleaf at the wilting point was the lowest in the shaded condition (about -4.5MPa) . Pn decreased linearly in 33/28°C-unshaded, and curvilinearly in 25/20°C-shaded conditions with decreasing ψleaf. The pattern of Pn in 25/20°C-unshaded leaves was intermediate between the other two. After re-watering, ψleaf recovered completely on the next day and the restoration of Pn required five days in all the experimental plots. Stomatal conductance tended to decrease earlier than mesophyll conductance, suggesting that the initial decrease in Pn under progressive water stress was triggered by stomatal closure.
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  • Integrated Cultural Practices to Reduce Chinese Cabbage Tipburn and Internal Rot in the Tropics
    Hideo IMAI, Chin-hUA MA, Den-lIN WU
    1988 Volume 32 Issue 1 Pages 22-34
    Published: March 01, 1988
    Released on J-STAGE: March 19, 2010
    DOIhttps://doi.org/10.11248/jsta1957.32.22
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    In summer Chinese cabbage cultivation, both tipburn and internal rot are very serious problems which are generally thought to be caused by calcium definiciencies attributable to a variety of environmental, physiological or nutritional factor.
    Research was initiated by AVRDC soil science laboratory from 1983 to solve this serious obstacle and by 1985 a soil and crop management techniques had been developed which greatly reduces the tipburn and internal rot in summer grown Chinese cabbage in the tropics.
    Tipburn was caused by NH4-N toxicity, limited root development, root damage, and rapid growth. Therefore, the following cultural practices are effective to reduce greatly tipburn: Avoiding NH4-N application at head intiation, increasing soil CEC and minimizing soil moisture fluctuation by compost application, water management and mulching, avoiding heavy application of fertilizer, suppressing the initial plant growth by covering outer leaves with rice straw and N split application.
    On the other hand, internal rot was caused by limited Ca translocation into head leaves, vigorous growth rates and round-shaped heading cultivar. Therefore, foliar spray of citric acid, covering outer leaves before head formation, N split application, selecting of long headed cultivar and acceleration of rooting by water management are all effective ways of minimizing internal rot.
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  • Effects of Short-term Waterlogging on Growth and Yield of Yard Long Bean (Vigna sinensis var. sesquipedalis)
    Eiji NAWATA, Shoji SHIGENAGA
    1988 Volume 32 Issue 1 Pages 35-45
    Published: March 01, 1988
    Released on J-STAGE: March 19, 2010
    DOIhttps://doi.org/10.11248/jsta1957.32.35
    JOURNAL FREE ACCESS
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    Seed yield of yard long bean was significantly reduced by waterlogging at vegetative stage, and not affected by the same treatment at reproductive stage, whether inoculated or not. The similar tendency was observed in young pod yield, although there were no significant differences among the treatments. Both seed and young pod yield were reduced in inoculated plants. Vegetative growth and several characteristics in relation to yield were also affected by the treatments. The causal factors in plant responses to the treatments are discussed.
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  • [title in Japanese]
    [in Japanese]
    1988 Volume 32 Issue 1 Pages 46-55
    Published: March 01, 1988
    Released on J-STAGE: March 19, 2010
    DOIhttps://doi.org/10.11248/jsta1957.32.46
    JOURNAL FREE ACCESS
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  • [title in Japanese]
    [in Japanese]
    1988 Volume 32 Issue 1 Pages 56-61
    Published: March 01, 1988
    Released on J-STAGE: March 19, 2010
    DOIhttps://doi.org/10.11248/jsta1957.32.56
    JOURNAL FREE ACCESS
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  • [title in Japanese]
    [in Japanese]
    1988 Volume 32 Issue 1 Pages 61-65
    Published: March 01, 1988
    Released on J-STAGE: March 19, 2010
    DOIhttps://doi.org/10.11248/jsta1957.32.61
    JOURNAL FREE ACCESS
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  • [title in Japanese]
    [in Japanese]
    1988 Volume 32 Issue 1 Pages 66-69
    Published: March 01, 1988
    Released on J-STAGE: March 19, 2010
    DOIhttps://doi.org/10.11248/jsta1957.32.66
    JOURNAL FREE ACCESS
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  • [title in Japanese]
    1988 Volume 32 Issue 1 Pages 69-73
    Published: March 01, 1988
    Released on J-STAGE: March 19, 2010
    DOIhttps://doi.org/10.11248/jsta1957.32.69
    JOURNAL FREE ACCESS
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