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Volume 12, Issue 1
Displaying 1-12 of 12 articles from this issue
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S. UJIIE, K. MIYAMOTO, Z. KOJIMA1956 Volume 12 Issue 1 Pages 1-4
Published: July 20, 1956
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSIn Miyagi Agric. Exp. Stat., we investigated on the damages of rice grain caused by wind storm at the earing period, from 1949 to 1954.
And we found the following facts;
1. There is a close connection between the wind velocity on the paddyfield and that of the wind tower. Accordingly, by the measurement of the wind velocity of the wind tower, we could presume the wind velocity on the paddy-field.
2. The degrees of damage by wind storm are varied according to the distance from flagleaf to spike, and we recognized that C-type is mostly damaged and B, D-type are follow.
3. With an increase of the discoloured spiklet, the weight of the total grains and the quality of the grains are decrease. And especially, the tendency of decrease is prevalent on the year of low-temperature.
4. The relation of the estimation of the yield loss of rice (y) and the percentage of discoloured spiklet (x) is shown by the following formula.
y=-2.523+0.599x+0.028x2View full abstractDownload PDF (582K) -
J. HANYU1956 Volume 12 Issue 1 Pages 5-8
Published: July 20, 1956
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSAuthor investigated on the effects of the mountain ranges in Aomori prefecture to Yamase-winds, the prevailing easterlies, caused the cool weather damage in summer, 1954.
Their appearance days were determined by the wind directions of some points and the weather maps, and then their mean wind direction at each point was obtained (see Table 2). Their direction formed some continuous stream line deviated by the Ou range and the Tsugaru- and the Shimokita-peninsula ranges of mountain and others.
These topography affected not only wind direction but also air temperatures and sunshins, i. e. it is shown that these ranges of mountain have the protection effect to Yamase-winds (see Fig. 1).
The duration of sunshine of the side on the Sea of Japnn in Aomori prefecturs in July, 1954 was very long in proportion to the cool weather, but on the Pacific coast was short sunshin and cool (see Fig. 2).View full abstractDownload PDF (2269K) -
(7) Design of the wood belt and their preventive functionS. TANAKA, S. KAKINUMA, T. TANIZAWA, H. SANO1956 Volume 12 Issue 1 Pages 9-12
Published: July 20, 1956
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (534K) -
Y. OKAMOTO, Y. KANZAKI, H. INOUE, S. KOTAKA1956 Volume 12 Issue 1 Pages 13-16
Published: July 20, 1956
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSIn this paper, investigation on the frost damage of wheat plants which was found in Saitama Prefecture in April, 1955 is reported.
The results of the investigation are as follows; -
(1) This damage was found to be quite different from the frost damage which usually occurs in the North Kanto region. The latter causes death of young ears by frozen in wheat of high degree winter type. However, in the damage which we concern now, the death of young ears by frozen takes place in wheat of low degree winter type, and also the formation of ears on the lately developed tillers which usually are incapable of bearing, and the delaying of heading time were characteristic.
(2) The death of young ears was caused by the low temperature (-2.4C) on the 5th of April. Ratio of dead (frozen) stem number to the all stems was estimated on the field and which was 68.3% in the severely damaged field, 48.1% in the intermediately damaged field, and 23.3% in the lightly damaged field.
Such a difference in the damage was considered very likely as caused by the difference in the growth and developmental stage of the plants.
(3) As the result of the damage, the growth of the suffered plants was changed. The change was apparently recognized with the number of lately formed stems, the stem length, the stem diameter and the heading time, etc. High correlation was found between the degree of damage and the changing of the above-mentioned morphological characters, as well as between each of these characters.
(4) Effect of the damage of the yield of wheat was analyzed. The effect was apparently recognized in the decrease of complete grains, thus lowering the ratio of the complete grains to the whole, and also in the increase of quantity of incomplete grains and in the decrease of 1000 grains weight, etc. Actual decrease in yield was not found in the slightly damaged field, but decrease of about 30% and 70% in yield was found in the intermediately suffered and severely suffered field respectively. These defferences in the yield may be accounted for by the fact that the lately developed stems were capable of producing grains in compensation the decrease and this compensation differs with the defferent field.
(5) Therefore it is likely possible to estimate the decreased amount of yield of wheat caused by the frost damage by the productivity of the lately developed stems action as a compensating factor.
Significant correlations were found between the productivity and the number of days which the heading was delayed, length of stems, or diameter of stems, etc.View full abstractDownload PDF (604K) -
N. TANI, E. INOUE, K. IMAI1956 Volume 12 Issue 1 Pages 17-20
Published: July 20, 1956
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSWind velocity and temperature profiles and fluctuations in wind direction were observed over a rice field in Sept. 17-18, 1955. The mean wind velocity is measured with 10 small cup anemometers distributed logarithmically to a 6m. height pole, and thermistor thermometers are used for the measurement of temperature distribution.
Under the neutral thermal condition of the wind velocity of 1-5m/sec. at 2m. height, the zero-plane displacement d decreased and the roughness parameter z0 increased respectively with the increase in wind velocity. These facts are contrary to results reported before (Tani, Inoue and Imai 1954), the cause of this discrepancy seems to be due to the different condition of rice stalks in growth stage, density, flexibility etc.
A wind direction-meter with 50cm, long arrow made with aluminum plate sends the signal of direction angle to the recording system by means of an A. C. selsyn-motor. The recording chart is of 12cm. width which is corresponding to 130° direction angle, and the recording speed is regulated to be 2mm/sec. Recorded charts are read at every 2.5 seconds and these values are made use of in the following analyses.
The hystograms of wind direction show the normal distribution pattern with some excepts. The range of flucuation during 5min. is about 30° under the condition of small turbulence and 60-70° under that of large turbulence.
The lateral turbulent velocity ‹v2›1/2 is in proportion to the mean wind velocity U, but under the unstable condition it becomes larger than under the neutral or stable condition.
The lateral turbulent energy ‹φ2› and the autocorrelation R(t) with respect to the angle fluctuation φ are calculated for some 3 cases, and the following results are obtained:
(1) 1355-1400, 17th. The results indicate that the reading interval 2.5sec. of chart is too small to obtain the characteristic nature of the wind turbulence concerned.
(2) 1540-1545, 17th. The observation was carried out under the stable condition. The scale of the horizontal largest turbulon seems to be decreased so that the averaging time of 5min. seems almost comparable to the passage-time of that largest turbulon.
(3) 1343-1348, 18th. In this run, 1-R(t) shown to be in proportion to t2/3 as expected theoretically, and the characteristic time T0 at which R(t) becomes zero is shown to be about 60sec.
Considering that this characteristic time is much larger than the passage-time of the coupling turbulon directly influenced by the ground surface, which is estimated to be about 10sec., the authors suppose that the turbulons observed here are not the coupling ones but the topographical ones of the medium scale.View full abstractDownload PDF (563K) -
MASAO KUSAKABE1956 Volume 12 Issue 1 Pages 21-23
Published: July 20, 1956
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSWhen they appoint the mean date of the last frost days as the standard day for frost injury protection, it frosts very frequently after this day. The author proposed the day corresponds to M+2PE as the new standard day for frost injury protection, where M is the mean of the last frost days and PE is their probable error. As the so cold spring that it frosts after this day, occurs about 10% in probability, so this standard day is useful for the economical frost injury protection. (Fig. 1).
Then the author calculated M+2PE of various weather stations in Fukuoka Prefecture (Table 1), and drew their isogram (Fig. 2).
Fig. 3 shows the daily frequency of frosting at Fukuoka. It frosts more frequently on 15-17, 22, 27 and 28, April, than the other days. These characteristical days are recognised at Iizuka, Saga and Hita. So, they must take care of frost injury on these days.View full abstractDownload PDF (384K) -
S. SATO1956 Volume 12 Issue 1 Pages 24-26
Published: July 20, 1956
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSThe yields of the paddy rice (y) in the warmer districts in Japan are mainly proportional to the sunshine-duration (s) in autumn, but are increased or decreased according to the air-temperature (t) in summer; the optimum temperature (t0) averaged in summer is about 27.2°C, and the yields are poor in both cases of cooler summer and too hot summer.
The above relation are expressed by the following equations. See Figs. 2 and 3.
y(KAN/TAN)=10.1+0.27s+31.87e-4.36(t-27.19)2
or y(%)=9.0+0.21s+25.41e-4.32(t-27.2)2
(note) KAN/TAN≅3.75kg/1000m2View full abstractDownload PDF (426K) -
T. FUJIKAWA1956 Volume 12 Issue 1 Pages 27-29
Published: July 20, 1956
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESS -
S. KANESEKI1956 Volume 12 Issue 1 Pages 30-32
Published: July 20, 1956
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSThe evaluation of evapo-transpiration was taken over a paddy field in order to examine the utility of the Thornthwaite's method based on aerodynamic considerations which lead to the equation (1).
The values of the specific humidiy and total run of wind obtained with the aid of the relatively simple apparatus, namely, thermocouple psychrometer and Robinson type small anemometer, to keep the practicality are shown Table 1.
Houtly values of the rate of evapo-transpiration were evaluated from equation (1) by taking the zero-plane displacement d=47cm for the reasonable value from the observation and compared with the values of the direct measurement (see Fig. 1, Table 3).
The present experiment suggests that the practical application of the Thornthwaite's method will be possible to evaluate the evapo-transpiration from the natural surfaces by improving the method of observation.View full abstractDownload PDF (375K) -
T. MATSUDA1956 Volume 12 Issue 1 Pages 33
Published: July 20, 1956
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (130K) -
R. YAKUWA, T. MAEDA1956 Volume 12 Issue 1 Pages 34-36
Published: July 20, 1956
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (426K) -
1956 Volume 12 Issue 1 Pages 37-39
Published: July 20, 1956
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (523K)
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