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Volume 44 (2009)
- Issue 4 Pages 185-
- Issue 3 Pages 127-
- Issue 2 Pages 65-
- Issue 1 Pages 1-
Volume 44, Issue 1
Displaying 1-5 of 5 articles from this issue
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Original Papers
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Shaikh Tanveer HOSSAIN, Hideki SUGIMOTO, Jun YAMASHITA, Joel M. ALCARA ...2009 Volume 44 Issue 1 Pages 1-9
Published: March 16, 2009
Released on J-STAGE: September 16, 2009
JOURNAL FREE ACCESSIn direct-sowing rice culture using cloth mulch, puddling and leveling (P & L) is usually done 2 days before the mulching (sowing). However, the mulching is very difficult, due to the muddy condition of the soil. Comparative studies were made to observe the effects of the timing of P & L, that is, P & L 10 days before mulching (P10) vs. P & L 2 days before the mulching (P2), on the operator's physical stress, the rice growth, and grain yield. Basal fertilizer was applied 2 days before the mulching in the P2 treatment (P2-B2), and topdressing was applied at 29 days before heading in all treatments. For the P10 treatment, timing of the basal fertilization was set at 14 (P10-B14) or 3 (P10-B3) days before the mulching.
Results revealed that the timing of basal fertilization had no significant effect on the growth and grain yield between P10-B14 and P10-B3 treatments. The operator's physical stress was very low due to higher soil hardness in the P10-B14 treatment ; however the grain yield was 12% lower than that of the P2-B2 treatment due to lower percentage of ripened grain. Because of the lower inorganic nitrogen of the soil, the growth of leaf area was suppressed and dry matter production was lower in the P10-B14 treatment, which resulted in lower percentage of ripened grain. To increase the grain yield of the P10-B14 treatment, future research is needed to consider the application amount and timing of topdressing, and also to reduce the gap between P & L time and mulching.View full abstractDownload PDF (373K) -
Kiyo YAMADA, Jun YAMASHITA, Tiejun MIAO2009 Volume 44 Issue 1 Pages 11-19
Published: March 16, 2009
Released on J-STAGE: September 16, 2009
JOURNAL FREE ACCESSThis paper investigates the stress of a static worker using work load, pulse rate and chaos system analysis to determine the effect of rest during work for stress reduction, and the effect of caffeinated coffee on the body of a static worker. The method used in three experiments to create stress for the static worker was the Uchida-Kraepelin test. The first experiment showed that drinking a beverage was better than not during 5-minute breaks. The second experiment included a 20-minute break providing the subjects with beverages with and without caffeine. When the correct answers were checked along with pulse rate and chaos attractors, the effect of the break time was more positive for those who drank caffeinated coffee. The number of subjects was increased from 10 to 38 and we applied the double-blind test to investigate the detailed effect of caffeine. The subjects were required to work up to 150 minutes. The 150-minute test was divided into 10 rounds with 15 minutes in each round. Based on the results, the subjects who drank caffeinated coffee exhibited better performances on the test than those who drank non-caffeinated coffee. The pulse rate test showed that consuming caffeine resulted in the reduction of the pulse rate. Based on the findings, break time was very important for static work. Likewise, drinking caffeinated drinks can improve body performance.View full abstractDownload PDF (997K) -
Hiroyuki SHIRATSUCHI, Hisashi KITAGAWA, Akio OGURA, Kazuyasu NAKANISHI ...2009 Volume 44 Issue 1 Pages 21-28
Published: March 16, 2009
Released on J-STAGE: September 16, 2009
JOURNAL FREE ACCESSUsing a “seed-mat” consisting of hardened rice seeds glued onto a molded rice-hull mat covered with soil glued on, we raised rice seedlings without nursery boxes. The objective of this study is to elucidate the workability of “no-box seedlings” using seed mats. We raised conventional and no-box seedlings in a plastic greenhouse to compare the labor time, weight and tensile strength of seedling mats, characteristics of seedlings and transplanting accuracy between the two seedlings. The labor time required to prepare the no-box seedling was 20.7min/20seedling mats (almost equivalent to 10a), which was about one third that required to prepare the conventional seedlings. The weight of no-box seedling mats was 2.8kg and less than half of that of the conventional seedling boxes. The tensile strength of the no-box seedling mats was 169N/28cm and slightly less than that of the conventional seedling mats, which was strong enough to be rolled and handled without damage. The no-box seedlings were raised one to six days longer than the conventional seedlings. As a result, the no-box seedlings were as tall as the conventional seedlings. Leaf age and seedling weight of the nobox seedlings were similar to or slightly greater than those of the conventional seedlings. When mechanically transplanted, the rate of missing hills of the no-box seedlings was higher than that of the conventional seedlings, but less than 7%. The no-box seedlings save labor time to prepare for raising seedlings in spring and reduce labor intensity to handle the seedling mats.View full abstractDownload PDF (711K)
Research Papers
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Kazunori ISHIKAWA, Tadashi BABA2009 Volume 44 Issue 1 Pages 29-34
Published: March 16, 2009
Released on J-STAGE: September 16, 2009
JOURNAL FREE ACCESSEffects of gibberellin (GA) with 1-(2-chloro-4-pyridyl)-3-phenylurea (CPPU) application at different dates after full bloom were investigated for producing enlarged and high quality berries in streptomycin(SM)-treated ‘Fujiminori’ seedless grapes.
1) Applying GA with CPPU 10 or 15 days after full bloom continuously increased berry size even after the beginning of veraison. Decline in L* value and peak of a* value of skin were delayed one week by either treatment.
2) The rate of seedless berries increased by the SM treatment. Later application of GA with CPPU produced heavier berries. Rachis elongation was suppressed by applying GA with CPPU 10 or 15 days after full bloom. Later application of GA with CPPU caused lighter skin color and lower Brix.
3) In conclusion, applying GA with CPPU 5 days after full bloom produced dark skin color of seedless berries and moderately compact clusters in SM treated ‘Fujiminori’ grapes.View full abstractDownload PDF (583K) -
Kazunori ISHIKAWA, Tadashi BABA, Hiroyuki FUJISAWA, Tatsuya SEKI2009 Volume 44 Issue 1 Pages 35-40
Published: March 16, 2009
Released on J-STAGE: September 16, 2009
JOURNAL FREE ACCESSExperiments were conducted to clarify the effects of lower concentrations of streptomycin (SM) application on seedlessness percentage and bunch quality of ‘Fujiminori’ grapes.
1) Application of 100ppm or 200ppm SM before flowering produced approximately 100% seedless berries. 100ppmSM induced lager berries and rachis and lower acidity compared to 200ppm SM (conventional). No deleterious effects were detected in berries treated with 100ppmSM.
2) Application of 100ppmSM with 25ppm gibberellin (GA) at the flowering stage in aim to reduce labor also produced enlarged berries, but lowered seedlessness percentage compared to the single SM application before flowering. Application of 200ppmSM with GA three days before full bloom produced berries that were nearly 100% seedless and of high quality in terms of color, sweetness and acidity.View full abstractDownload PDF (482K)
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