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Volume 65, Issue 3
Displaying 1-7 of 7 articles from this issue
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Full Papers
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Hiroki OUE, Zhaozhong FENG, Jing PANG, Akira MIYATA, Masayoshi MANO, K ...2009 Volume 65 Issue 3 Pages 239-248
Published: March 10, 2009
Released on J-STAGE: October 30, 2009
Advance online publication: September 11, 2009JOURNAL FREE ACCESSIn aims to estimate stomatal O3 flux and predict the yield loss of wheat in eastern China, the focus was on developing a stomatal conductance (gs) model and a photosynthesis (P) model of a wheat flag leaf. To date, relationships between the relative yield of European spring wheat and the stomatal O3 flux of the wheat flag leaf have been presented by Pleijel et al. (2000), UNECE (2004) and many researchers with high correlations on the basis of the open-top chamber experiments.
The gs and P of flag leaves and other winter wheat leaves were measured, both in the ambient field and FACE (Free Air Concentration Enrichment) field, whereby the O3 concentration ([O3]) was artificially elevated, on 6 days from before heading to before harvest, 2008. The gs model was developed by a multiplicative approach with a maximum value of gs (gsmax) multiplied by modifications of photosynthetically active radiation incident on the leaf (PARl), accumulated exposure of O3 over a threshold concentration of 40 ppb for daylight hours (AOT40) at the canopy top, phenology, VPD and the time of day. A relationship between gs/gsmax and P/Pmax (Pmax is the maximum value of P) of a flag leaf measured in PARl=2000 μmol m-2 s-1 was represented by a linear regression line with a slope of 1.0 and intercept of 0.0. Therefore, the P model was developed by the multiplicative approach with Pmax multiplied by modifications of PARl for P and the same other parameters as the gs model. The models reproduced the gs and P of a flag leaf and even those of the other leaves successfully.
For the practical use of these models, [O3] at the canopy top ([O3]canopy) and PARl were also modeled. By applying the logarithmic profile of [O3] above the canopy, and modeling the roughness length for [O3] (z0O3) with the wind speed, the [O3]canopy was reproduced successfully. To model PARl, the inclination factor of a leaf (Fl) was decided so that the modeled vertical profile of shortwave radiation within the canopy could fit the measurements using the vertical two streams shortwave radiation model (e.g. Oue, 2003a; 2003b). Fl at z=0.6-0.8 m, where most flag leaves exist, was found to be from 0.4 to 0.6 for a wheat canopy of LAI=5.View full abstractDownload PDF (923K)
Full Papers (in Japanese)
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Hirakazu SEKI2009 Volume 65 Issue 3 Pages 249-259
Published: March 10, 2009
Released on J-STAGE: October 30, 2009
JOURNAL FREE ACCESSTargeting resource management and the effective utilization of waste of plant origin, experiments involving NO (nitrogen monoxide) adsorption by charcoal filter were conducted. The charcoal filter used is made from driftwood into dams and from waste lumber.
According to the experimental results, the amount of equilibrium NO adsorption of the charcoal filter was 40-1300 times as much as that of the soil filter used in the previous paper. Based on the experimental results of the NO breakthrough curve from the charcoal filter and the theoretical analysis of the mass transfer process, the NO adsorption characteristics of the charcoal filter were recognized. It was experimentally and theoretically shown that the fundamental main mechanism of the adsorption by the charcoal filter is the surface diffusion into the micro-pores except in the short early stage, during which the Knudsen diffusion in the meso-pores is the main mechanism. A practical equation that properly shows the stepwise change in the adsorption rate was proposed, and the physical meaning of parameters in the equation was explained through interpretation of the adsorption mechanism.
The adsorption ability would differ based on the kind of materials involved, and that was left for future work examining the details of the charcoal filter structures.View full abstractDownload PDF (1306K) -
Keisuke YAMAZAKI, Hiroshi KUMAKURA, Makoto YAMADA, Masaki ISHIWATA, Hi ...2009 Volume 65 Issue 3 Pages 261-272
Published: March 10, 2009
Released on J-STAGE: October 30, 2009
JOURNAL FREE ACCESSThe effects of overnight illumination with a green light on flower bud emergence and growth in strawberry plants were investigated while comparing the effects of overnight illumination with yellow light, which is usually used as an illuminator for moth control.
Five cultivars of strawberry runner plants whose terminal flower buds had been artificially induced were subjected to overnight illumination for 73 days using either green or yellow light of varying irradiance (0.02-0.10 μmol m-2 s-1), and the subsequent flower bud emergence were observed.
The results showed no delay in flower bud emergence under green light in comparison with the control (non-illuminated) up to 0.06 μmol m-2 s-1 for ‘Akihime’, ‘Sagahonoka’ and ‘Benihoppe’. Under yellow light, on the other hand, there was no delay in flower bud emergence up to 0.06 μmol m-2 s-1 for ‘Sagahonoka’, and up to 0.04 or 0.02 μmol m-2 s-1 for ‘Benihoppe’ or ‘Akihime’ respectively. Although ‘Sachinoka’ showed no delay in the emergence of the primary axillary inflorescence under green light up to 0.04 μmol m-2 s-1, the flower bud emergence was already delayed under yellow light at 0.02 μmol m-2 s-1. ‘Tochiotome’ showed no delay in flower bud emergence under green or yellow light, but under yellow light, the number of leaves in axillary branches for ‘Tochiotome’ increased. In addition, in all cultivars under yellow light, there was a tendency for the petiole and leaf lengths to increase spindly, and for the leaf color to become paler with increasing irradiance. These results indicate that even at higher irradiance, green light has little effect on flower bud emergence and on leaf growth in comparison to yellow light.
We conclude that the use of green light for moth control is highly beneficial to strawberries, which have photoperiodic responses and show high sensitivity to light, in comparison with that of yellow light.View full abstractDownload PDF (972K) -
Tomoki USHIYAMA, Satoshi INOUE, Hiroyuki SHIBAIKE2009 Volume 65 Issue 3 Pages 273-281
Published: March 10, 2009
Released on J-STAGE: October 30, 2009
Advance online publication: September 17, 2009JOURNAL FREE ACCESSWindbreak nets are most often used to prevent agricultural wind damage, since they are cheap and easy to install. However, little is provided concerning the dynamical characteristics of such windbreak nets, hampering the design of windbreak planning through the quantitative use of the latter. We measured both dynamical characteristics and wind fields around popular five windbreak materials using a wind tunnel. Subsequently, we tried to simulate the measured wind field using a numerical atmospheric model. The measured wind fields show various flow patterns around windbreaks well known in literature, with recirculating eddies for two spunbonded fabric windbreaks. The relationship between the wind field patterns and porosities of the windbreaks is more or less the same as in past studies, while the numerical simulations reproduce wind fields around the three popular windbreak nets fairly well. It is confirmed that the wind tunnel measurements and numerical simulations are reliable means to reproduce realistic wind field around popular windbreak nets.View full abstractDownload PDF (1076K) -
Tomohiro MARUOKA, Hisanori ITOH2009 Volume 65 Issue 3 Pages 283-296
Published: March 10, 2009
Released on J-STAGE: October 30, 2009
JOURNAL FREE ACCESSThis study predicts cherry blossom (Prunus yedoensis) flowering in Japan during global warming periods. First, by developing current models for cherry blossom flowering, a model suitable for assessing the climate impact is constructed. This model can predict the dormancy breaking and flowering dates by temperature data alone at any points and for any periods. Applying this model to actual data for 25 years (1979-2003), the average RMSE (root mean squared error) of predicted flowering dates in comparison to actual ones at 36 points in Japan is 2.87 days.
An indicator of the southern border of flowering is also proposed. The flowering model is applied to projected future temperature based on the IPCC A2 scenario. The predictions for the years 2032-2050 and 2082-2100 indicate that flowering dates will become much earlier than at present in cold regions, while later along the coasts in warm regions. It also shows that cherry blossoms will not come out in Tanega-Shima and southern Kyushu, which are currently the southern flowering borders.View full abstractDownload PDF (2063K)
Short Papers
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Fumiki HOSOI, Yohei NAKAI, Kenji OMASA2009 Volume 65 Issue 3 Pages 297-302
Published: March 10, 2009
Released on J-STAGE: October 30, 2009
JOURNAL FREE ACCESSThe leaf inclination angle distributions of wheat (T. aestivum cv. Norin 61) canopy were estimated at different growth stages (tillering, stem elongation, flowering, and ripening stages) by using a high-resolution portable scanning lidar. The canopy was scanned three-dimensionally by optimally inclined laser beams emitted from several measuring points surrounding the canopy and 3-D point cloud images in each growth stage were obtained. After co-registration of lidar images between different measurement positions, leaves were extracted from the images and each leaf was divided into small pieces along the leaf-length direction. Each of the pieces was approximated as a plane, to which normals were then estimated. The distribution of the leaf inclination angles was derived from the angles of these normals with respect to the zenith. Consequently, distinctive features of the leaf inclination angle distributions at each growth stage clearly emerged. The mean leaf inclination angles on 6 April, 26 April, 16 May, and 5 June were 53.9°, 45.3°, 44.3° and 56.1° respectively and the standard deviations were 19.6°, 22.2°, 21.7° and 19.5° respectively. Moreover, laboratory measurements confirmed that the mean and standard deviations of the absolute error of lidar-derived leaf inclination angles were 4.3° and 2.0°, respectively.View full abstractDownload PDF (1247K)
Research Notes (in Japanese)
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David R. MEARS, Arend J. BOTH, Limi OKUSHIMA, Sadanori SASE, Masahisa ...2009 Volume 65 Issue 3 Pages 303-308
Published: March 10, 2009
Released on J-STAGE: October 30, 2009
JOURNAL FREE ACCESSThe challenge now is to find alternative energy sources that can provide a significant portion of the requirement for modern greenhouses already adopting the best available conservation practices. Simulation modeling, even with relatively simplistic modeling techniques, can provide a preliminary analysis of the expected contribution of various proposed alternative energy scenarios. The results for cogeneration fuel cells, heat pumps and industrial waste heat sources were reviewed here. The cases presented indicate the potential for a relatively simple approach for making a first level evaluation of possible energy management scenarios. The cases examined all indicate the importance of thermal storage as a management tool to increase the utilization of investments in alternative energy systems, where the energy to be delivered is not stored in the form of fossil fuel. The cases also indicate, in cases where CO2 is being supplemented, that the additional hours of greenhouse closure provide benefits in addition to the provision of heating and cooling.View full abstractDownload PDF (808K)
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