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Volume 45 (2010)
- Issue 4 Pages 195-
- Issue 3 Pages 165-
- Issue 2 Pages 99-
- Issue 1 Pages 3-
Volume 45, Issue 4
Displaying 1-3 of 3 articles from this issue
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Original Papers
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Hidetaka NAKAYAMA2010 Volume 45 Issue 4 Pages 195-201
Published: December 20, 2010
Released on J-STAGE: June 20, 2011
JOURNAL FREE ACCESSTreating flowers with phytohormones has been considered necessary for stable fruit setting in plastic house culture of tomatoes. Compared with buzz-pollination, which vibrates flower clusters mechanically, spraying phytohormones requires less labor but it produces a higher proportion of puffy fruits.
Recently, a new buzz-pollination method, which pollinates flowers easily by vibration of flower clusters by wind using a blower, was developed. To examine the effectiveness of this new method, its labor intensity, rate of fruit setting and proportion of puffy fruits were compared with the conventional buzz-pollination method and phytohormone treatment.
The working time of pollination per plant with the new buzz-pollination, conventional buzz-pollination and phytohormone treatments was 2.8, 7.5 and 6.7 seconds, respectively. Buzz-pollination must be administered two or three times per week whereas one phytohormone treatment per week is enough. Estimated total pollination time of the new buzz-pollination method ranged from 8.2 to 9.6 hours per 1a, almost the same as the phytohormone treatment. This indicates that there is little difference in the labor intensity between the new buzz-pollination and the phytohormone treatment. Moreover, the rate of fruit setting in the new buzz-pollination was equal to the phytohormone treatment and no puffy fruit was observed with the new buzz-pollination.
These results indicate that the new buzz-pollination is a useful method for stable fruit setting in plastic house culture of tomatoes.View full abstractDownload PDF (769K) -
Hideto KUROSAKI, Hiromi OHMORI, Masuyuki TAKAICHI, Hidekazu SASAKI2010 Volume 45 Issue 4 Pages 203-211
Published: December 20, 2010
Released on J-STAGE: June 20, 2011
JOURNAL FREE ACCESSHigh-wire tomato training system requires plants to be periodically lowered. This is hard work because of the heavy plant weight and the awkward handling position. To determine the best handling position for workers, we analyzed muscle loads by using surface electromyograms. Over a season, the average load created by a suspended plant in a greenhouse was 45 N. We analyzed loads in simulated work from integrated surface electromyogram (iEMG) data. Among 10 muscle parts, the trapezius top and front deltoid showed the clearest responses to the load over the vertical distance to the training wire. The relationships between iEMG values and the load at these muscle parts were nearly linear. The iEMG responses were almost the same in one-arm work and two-arm work. For calculations, handling distances were converted in to the worker's height (height ratio). iEMG values were smallest at a height ratio of 0.45-0.55 at the top of the trapezius and of 0.60-0.65 at the front deltoid. Under actual greenhouse conditions, the optimum height of the wire above the work platform was estimated to lie in a height ratio range of 0.60-0.80, which allows good arm movement. The muscle loads of the front deltoid seemed to increase as the horizontal distance to the training wire increases. Too near, however, and the worker collides with the leaves. Therefore, a suitable horizontal distance was considered to be a height ratio of 0.25-0.30.View full abstractDownload PDF (1216K)
Research Paper
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Hiroyuki FUJISAWA, Yuki MORIYA2010 Volume 45 Issue 4 Pages 213-218
Published: December 20, 2010
Released on J-STAGE: June 20, 2011
JOURNAL FREE ACCESSThis study was conducted to investigate the influence of mulching cultivation using moisturepermeable polyethylene nonwoven fabric on soil moisture, tree growth, and fruit quality in scions of 12-year-old apple (‘New Jonagold’) trees grafted onto JM1, JM7, and M.9vf rootstocks.
1) Although mulching resulted in a decrease in soil moisture, the soil remained rather humid (pF, approximately 2.0).
2) Shoot elongation and fruit weight in trees grown under mulching cultivation appeared to be lower than those in the control condition, irrespective of the rootstock. This might be attributed to the decrease in soil moisture.
3) Peel color at the calyx end of fruits appeared to improve with mulching, irrespective of the rootstock. Peel color at the equatorial region of fruits from scions grafted on JM7 and M.9vf was not affected by mulching, whereas it was reduced by mulching in the case of scions grafted on JM1.
4) Mulching did not affect the Brix or acidity values of the fruits, regardless of the rootstock.View full abstractDownload PDF (708K)
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