All issues
Volume 33, Issue 1
Displaying 1-7 of 7 articles from this issue
- |<
- <
- 1
- >
- >|
-
Michio SHIROMA1977 Volume 33 Issue 1 Pages 1-6
Published: June 15, 1977
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSThe author studied the solar radiation in Okinawa in an attempt to find whether the irradiation in Okinawa is sufficient for pineapple culture. Results obtained are as follows:
The geographical distribution in the vicinity of Okinawa of global solar radiation estimated from the mean of possible sunshine percentage is shown in Fig. 1. Although Okinawa's annual global radiation is estimated at 130.5k ly/year, one of the largest amounts in Japan, the radiation in spring and winter is as small as in Kyusyu, despite Okinawa is in lower latitudes.
The global radiation calculated from cloud amount data indicates that Okinawa ranks among the small radiation areas of major pineapple growing areas in the world (Table 2).
Based on the light saturation point of 30klux to 50klux for the Smooth Cayenne variety obtained by Nose and others from 24 hourly carbon dioxide exchange experiments with intact plants 5 to 8 months old after planting, an attempt was done to evaluate photosynthetically useful solar radiation available to the variety in pineapple growing areas. Relationship between whole global radiation R (k ly/month) and the global radiation RP (k ly/month) integrated up to the radiation intensity equivalent to the illumination of a light saturation point has been obtained from radiation data for Naha, Okinawa,
RP=a log10R/b,
where, a and b are empirical constants depending on light saturation point.
Assuming that the above formula is applicable for other pineapple growing areas in Taiwan and Hawaii and that RP is regarded as photosynthetically useful radiation, the radiation available to the Smooth Cayenne variety in Okinawa and the two areas has been calculated as shown in Table 4, using the estimated global solar radiation in Table 1. The result shows that the radiation in Okinawa in spring and winter is considerably smaller than that in the two areas.
It may be concluded from these studies that solar radiation in Okinawa, where the Smooth Cayenne variety is grown most, is not necessarily sufficient for the culture of this variety.View full abstractDownload PDF (704K) -
Seishi ISOBE1977 Volume 33 Issue 1 Pages 7-12
Published: June 15, 1977
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSMeasurements of horizontal and vertical components of the turbulent heat flux were undertaken above a change in surface conditions from bare ground to withered turf. The eddy correlation technique with signals from a pair of sonic anemometers yielded turbulent heat fluxes by means of bandpass RC filters and a correlation analyzer. The downwind component of the heat flux has decreased with distance downwind of the leading edge of turf.
For winds greater than 1m/s, a power function is fitted to variation of the downwind component with its exponent increasing with thermal stability of flow and decreasing with flux value at the leading edge. The horizontal gradient of the downwind component is obtained by means of fitting a curve to experimental fluxes. The vertical gradient of the vertical component is given by use of empirical relationships found between downwind and vertical components. The horizontal gradient of the downwind component of heat flux, which is normally neglected in the conventional model of local advection, is found at a level of 35cm and 1m from the leading edge to be approximately 20% of the vertical gradient of the vertical component under very light winds at night.
In the internal boundary layer developed above the turf, the horizontal gradient of the downwind component counteracts the vertical gradient of the vertical component. Above it, however, the former enhances the latter. These effects could lead to a distribution of the vertical heat flux at the turf surface varying more rapidly with downwind distance very close to the leading edge than prediction of the conventional model. Further downwind, they could also indicate a less rapid change of the vertical flux compared to the model. The resulting contraction of the transitional area can be associated with modification of dew-fall areas, which could be of biological significance.View full abstractDownload PDF (737K) -
The structure of a model and its application to butter-head type lettucesGenji OHARA, Tadashi TAKAKURA1977 Volume 33 Issue 1 Pages 13-17
Published: June 15, 1977
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESS -
(VIII) Relation between Leaf Water Potential before Sunrise and at Daytime of Satsuma Mandarin (Citrus unshiu MARC.) treesToru MAOTANI, Yutaka MACHIDA1977 Volume 33 Issue 1 Pages 19-23
Published: June 15, 1977
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSThe purpose of this paper is to investigate the feasibility of predicting leaf water potential before sunrise (ψmax) from the potential during 13:00-14:00 (ψmin) and of obtaining an index accounting for fluctuations of ψmin in Satsuma mandarin (Citrus unshiu MARC.) trees. We were unable to find an indicator accounting for the fluctuations of c min under various environmental conditions. However, our data suggested a possibility of estimating ψmax from the leaf water potential at about 19:00. ψmax for trees on the soil of similar properties could also be estimated from ψmin/VPD where VPD is vapor pressure deficit.View full abstractDownload PDF (531K) -
Yoshiyuki MORITA, Hiroyoshi HASHIMOTO1977 Volume 33 Issue 1 Pages 25-30
Published: June 15, 1977
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (662K) -
The Society of the Agricultural Meteorology of Jap1977 Volume 33 Issue 1 Pages 31-33
Published: June 15, 1977
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (434K) -
Yoshiaki Mihara1977 Volume 33 Issue 1 Pages 35-40
Published: June 15, 1977
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (2207K)
- |<
- <
- 1
- >
- >|