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Volume 14, Issue 4
Displaying 1-11 of 11 articles from this issue
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I. IIZUKA1959 Volume 14 Issue 4 Pages 121-123
Published: March 31, 1959
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSSince it is said that evergreen fruit trees, the water absorption of which is very much reduced at low temperature, often suffer more from the dryness of winter wind than from its coldness, the water content of the Tanaka loquat tree was investigated in the cold season. The water content of the leaves was measured with the impedance bridge which had special measuring terminal plates, and that of the trunk was measured with a hundredth millimeter dial guage and indicated in terms of radius fluctuation. The results of the investigation was summarized below.
1. The daily water content of the leaves reached the minimum at 4 p.m. and the maximum at 2 a.m., the range of fluctuation being 2.5 percent. That of the trunk showed much the same change.
2. In the daytime, the water content of the leaves of the outer crown was larger than that of the inner crown and reached the minimum at noon. The water content of the leaves of the inner crown reached the minimum 6 hours later, and so did that of the trunk 2 hours later than that of the leaves of the outer crown. The similar type of fluctuation was observed in the water content of those three.
3. The water content of the leaves was largest on rainy day and smallest on windy day, the difference being about 4 percent at the largest. The water content of the leaves on fine day was about 1 percent larger than on windy day. It may be said that the loquat leaves have so numerous hairs that they can keep transpiration down a little. It may be for this reason that the water in the leaves did not show great change in amount. It is suggested, therefore, that the loquat trees do not suffer very much from dry winter wind in warm regions.View full abstractDownload PDF (404K) -
S. TANAKA, S. KAKINUMA, Y. TAKAHASHI1959 Volume 14 Issue 4 Pages 124-126
Published: March 31, 1959
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSManuring of night soil onto wheat fields has been customary and well under way, but in the winderosive zone ascaris-eggs in excrement is to be borne with flying soil and is referable to the cause of parasitic disease.
The experiment by wind-tunnel shows: the ascaris-eggs begin to move away by dint of the wind-velocity, about 4 meters per second, and to fly a long way off on the float in case 6m/sec wind rises.
Also, judging from the shape of ascaris-eggs and its specific gravity, it is conceivable that the parasitic forms should move easier and to float away farther than the same bulk of soil.
We have investigated the infection rate on roundworm both in the winderosive farm-land zone and in the nonerosive paddy-field zone, in 9 settlements respectively, The average rate of infection in the former fields is 60% and 25% is in the latter paddies.
Considering the above-mentioned differance, various terms aside, it is a matter of course that the winderosion is one of the elements which increase the parasitic infection rate.View full abstractDownload PDF (399K) -
(5) On the Relation between the Temperature and the Critical Period of the Action of the Brain Hormone in the Tussur-silkwarm Antheraea pernyi GK. NISHIMURA, S. KURIHABA1959 Volume 14 Issue 4 Pages 127-129
Published: March 31, 1959
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSThe authors tried too determine the effective duration of brain hormone to the imaginal differentiation in pupal stage by extracting the brain from Antheraea pernyi pupa which being held at constant and natural environment. In general, the development of the pupa for imagination takes 22-24 days when it is held at 20-21°C and total effective temperature is 220-264 degree days. The threshold temperature for pupal development is 10°C.
According to these data the elapse of time that brain hormone becomes effective is determined. The results of experiment are as follows.
1) The period that the brain hormone becomes effective is 5 or 6 days when the hybernated pupa is held under temperature of 21-21°C. In this case the total effective temperature is 50-55 degree days.
2) Ih the pupa of 1st generation, the period in which brain hormone becomes effelive is 3-4 days under natural environment and the total effective temperature is 50 degree days.
3) In the pupa of 2nd generation, the total effective temperature is 55 degree days under natural environment, but the effectiive temperature is lower than the case of 1st generation, so the pupal period is very much postponed.
4) The period of brain hormone becomes effective for female is 1 day shorter than that for the male.View full abstractDownload PDF (482K) -
(6) On the Total Effective Temperature from the Pupation to the Imaginaion in the Tussur-silkworm, Antheraea pernyi GK. NISHIMURA, T. YAMADA1959 Volume 14 Issue 4 Pages 130-132
Published: March 31, 1959
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSThe total effective temperature for the pupal stage of Antheraea pernyi was measured under room temperature (21-23°C) and natural condition.
1) The total effective temperature for the hibernated pupae is 240-260 degree days when the pupae are kept under the temperatures of 21-23°C.
2) The total effective temperature for the pupae of 1st generation is 240-270 degree days under natural condition.
3) The threshold of 2nd emergence lies just intermediate between the both periods in which the total effective temperature reach to 240 degree days in daily average temperature and in daily maximum ones.View full abstractDownload PDF (419K) -
Y. NAKAGAWA, Y. TSUBOI1959 Volume 14 Issue 4 Pages 133-136
Published: March 31, 1959
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSIn order to investigate the heat flux to the soil, the author carried out the observatious of soil temperature, the volume percent of dry soil, water and air be contained withn the soil from November to December in 1957 at Tateno, Ibaragi Pref.
The results are as follows;
1) The heat capacity (ρc) of the soil is calculated form following formla indirectly,
ρc=ρ(0.20x1+x2+0.24x3)
where x1, x2 and x3 be observed exactly by using volumenometer are volume percent of dry soil, water and air be contianed withn the soil, respectively, ρ is the density of the soil.
The heat capacities of some soils is shown in Tab. 1., and the daily course of the heat capacity of the soil layer from 0cm to -1cm is shown in Fig. 1. and it is recognized that the heat capacity shows higher value at about sunrise and lower at evening.
2) The heat fluxes to the soil which was calculated from the distributions of soil temperature is compared when the daily change of heat capacity in the soil surface layer was ignored or not, and it is certainly that both values are nearly equal as shown in Fig. 2.
3) Considerable agreement of the heat flux to the soil be calculated from the temperature distribution with that directly by heat flow meter was found as shown in Fig. 3.View full abstractDownload PDF (505K) -
The Plant Temperatures under the Freezing Method and the Combustion Method as a Countermeasure of Frost ProtectionY. NAKAGAWA, Y. TSUBOI1959 Volume 14 Issue 4 Pages 137-140
Published: March 31, 1959
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSIn order to investigate the effect of freezing method and combustion method as a countermeasure of frost protection, the author carried out observations of plant temperature in 1956 and 1957.
The results are as follows:
1) The time marches of the plant temperature under freezing method are shown in Fig. 2., and it is recognized that the plant temperature of freezing plot is equal to 0°C through the water sprinkling, although the plant temperature of non treatment shows lower than 0°C.
2) The relation among the necessary sticking water volume to plant which maintains the plant temperature to 0°C, wind velocity, and air temperature is shown graphically in Fig. 3., and it is certainly that the necessary sticking water volume increases with decreasing air temperature and with increasing wind velocity.
3) The time marches of difference of air and plant temperature at the height of the trellis under combustion method are shown in Fig. 4., and it is recognized that the radiative effect of the burner to the plant is small.View full abstractDownload PDF (576K) -
Y. TSUBOI, S. KUBO1959 Volume 14 Issue 4 Pages 141-144
Published: March 31, 1959
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESS1) We have studied on the effects of wind velocity generated in the wind tunnel on the flowering and fertilization of rice plant at the heading stage.
2) Because the flowering of the rice plant was affected by meteorological factors, such as temperature, humidity and solar radiation, in the present experiment, the effect of wind velocity on the flowering was not clarified.
3) The percentage of abortive grains increased as the wind velocity became higher, and this was more definite in the recessive spikelets.
4) The fertility percentage of spikelets flowered before the day of treatment was high, and it seemed that the effect of the wind on such spikelets was slight.
Recessive spikelets are apt to be affected by wind, but dominant ones are not.
Therefore it may be said that the number of recessive spikelets which flower after the day of treatment controls the sterility percentage of the ear.View full abstractDownload PDF (625K) -
S. OKUDA1959 Volume 14 Issue 4 Pages 145-150
Published: March 31, 1959
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSThe value of salinity in Kojima Bay decreased promptly for about 100 days after closing its outlet on account of inflow of fresh water from rivers and outflow of sea water through sluice gates.
The present study was designed to investigate some factors which controll the exchange phenomenon of fresh and sea water in the bay on the ground of observed values of salinity, records of water level and data of meteorological elements.
The vertical mixing by wind wave and horizontally asymmetric distribution of salinity by Coriolis force were not significant in the bay.
The mixing of fresh and sea water in stratified flow at early stage depends on the salinity difference between upper and lower layers, and the author assumed a linear relation between the ratio r (salinity of outflow water/mean salinity in the bay) and mean salinity S,
r=1-K(S-a)
(a, salinity of inflow water; K, constant parameter)
Under this assumption the solution of differential equation of salinity change was given by next formula.
S=C/K-aepQ/Vt/C-epQ/Vt(p=1-Ka, C=KS0-Ka/KS0-1)
(S0, initial salinity; Q, flow rate; V, volume of wate in the bay; t, time after closing of outlet) This formula can express the tendency of observed salinity change more appropriately than the formula suggested by Jansen who assumed constant r.View full abstractDownload PDF (890K) -
Y. TSUBOI, Y. NAKAGAWA1959 Volume 14 Issue 4 Pages 151-153
Published: March 31, 1959
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSIn order to carry out a study on the injury of rice plant caused by briny wind in its heading stage, rice plants were treated by the artificial briny wind of 12m/sec wind velocity in a wind tunnel spraying salt-water. The results obtained are summarized as follows:
1. The volume of salt adhered to the ears and leaves of rice plants closely related to the concentration of salt-water to be sprayed.
2. The discolouration of ear, the degree of leaf withering and the degree of sterility were accerelated with the increase of the volume of salt adhered to the ear.
3. The critical volume of salt to cause the injury was estimated to be about 1.0mg per ear in present experiment.
4. It was recognized that the sooner the rice plants treated by briny wind were washed by water and the greater the volume of salt adhered to the rice plants, the greater the effect of washing is.
5. The reduction of rice yield which may occur by briny wind injury seems to be predictable by inspecting the external change in the appearance of rice plant.View full abstractDownload PDF (408K) -
1959 Volume 14 Issue 4 Pages 154-157
Published: March 31, 1959
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (626K) -
[in Japanese]1959 Volume 14 Issue 4 Pages 158-160
Published: March 31, 1959
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (517K)
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