(1) 水耕培養した水稲について盛夏の候に於ける昼夜の水温の高低が地上部及び地下部の生育に及ぼす影響を験べた。
(2) 昼夜の水温の何れかが適温 (31℃) より高い場合 (37℃) には, 地上部及び地下部の生育が不良となつた。又このような高水温による生育の阻害は夜間の水温を適温 (31℃) より数度下げることによつて軽減されるように見られた。

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The three elements of water-loss in the paddy field-evaporation from water surface, transpiration from the rice plants and percolation to the depth of ground were measured. The results obtained are given in Tables 1-3 and Fig. 2.
Evaporation from water surface in the paddy field gradually decreased with the lapse of growing time and became almost constant after late August.
Transpiration increased with the lapse of growing time, and showed two peaks in the cultivating term. The first peak is at the ear-developing stage (late August) and the second at the early stage of ripening (late September).
Percolation was great in midsummer with continuous clear weather, and exudation was great in rainny season (BAIU and early autumn). The great percolation or exudation depend on the characters of the local topography, soil structure, and underground water level.

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In northern Japan, close attentions have been paid to the temperatures of rice-field in reference to the injuries of low temperature to the rice plant.
In the plains of south-western Japan, the conditions are rather contrary.
It should be noticed that the water- and soil-temperatures become so high the customary management of irrigating water as unfavorable for the crop growth in mid-summer season. See Tables 1 & 2.

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In the plains of south-western Japan, the artificial regulation to lower the water-and soil-temperatures in the rice-field is more favorable for the crop growth than the customary management of irrigation (irrig. with stagnant water).
One of the methods to lower the field-temperatures is the irrigation with running water.
Several experiments as for the above mentioned phenomena were performed during from 1947 to 1952. and the results obtained are shown in Tables 2-7.
There is no need to irrigate with running water during the whole irrigating term. The temp.-regulation taken only in summer season exerts fairly good effects on the crop.

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We have the theoretical formula to determine the temperature of the water flowing from the intake (of weir type) of a dam for the next two cases of the weter temperature T in a pond. If z is the depth of any point and H is a constant depth, the mean temperature T of the flowing water are
T=T₀/2a(√H+a)²+r²-√(H-a)²+r²), when T=T₀ for z≤H and T=0 for z≥H, and
T=β/4a{(H+a)√(H+a)²+r²-(H-a)√(H-a)²+r²-2a√a²+r²
-r²logH-a+√(H-a)²+r²/H+a+√(H+a)²+r²·a+√a²+r²/-a+√a²+r²}
when T=β(H-z) for z≤H and T=0 z≥H, a and r are the parameters that express the lengths and β is a constant.

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The aims of this study are the improvement of microclimatic conditions in the wheat or barley field.
In this paper, the ridges of E-W direction are compared to the ridges of N-S direction, and the insolation quantity on the sloped faces (angle of inclination i=15°) of the ridges is calculated as to the four directions. (Used factors: Solar constant I₀=1. cal. cm^-2. min^-1., Latitude φ=33°12′ N at HAINUZUKA)
The difference of the insolation quantity on the soil surface of the E-W ridge from that on the N-S ridges is small in the early growing term, and the difference becomes large in the late growing term. (See Fig. 2, A)
The insolation quantity on the wheat plants of E-W ridge is larger than that on N-S ridge in the early growing term, but the states become reverse since the second decade of March. (See Fig. 2, B)
The growth and yields of wheat plant are showed in Table 1 and 2, and the ears in the N-S ridge were 20% heavier than those of E-W ridge. In winter, the insolation quantity on the South slope is the most, on the East or West slope is the second and the same as that on horizontal surface, and on the North slope is very small: but there are little differences among four sloped faces in summer. (See Fig. 3)

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1. This article dealt with the effect of artificial shortening and prolongation of the period of Anthetaea pernyi pupae upon the emergence of the adult, and the development of the larva, the voltinism and the characteristics of cocoon (namely; cocooning the weight of cocoon and cocoon layers) in the secondary generation.
2. The first emergence of the adult either of univoltine or bivoltine brood begins after elaps of 19 to 26 days by keeping the pupa under the condition of temperature (20°to 21°C) from December 10th. The period and the duration of emergence are shortened by keeping the pupa in the above described temperature later (January 27 th.) than earlier date (Jan. 10 th.) by which the dormancy of the pupa is easily broken. The percentage of emerging moth is not affected by the length of hibernation term.
b) It can be seen visibly that the univoltine brood pupae require longer time before the begining of adult appearance and the percentage of emerging moth is so larger than those of bivoltine brood.
The duration of emerging out perfectly in both blood is similar.
3. By artificial prolongation of the hibernating period, the effect is summarised on the following topics.
a) The duration between the emergence of the adult and the hatching of the larva is shortened and the percentage of emerging moth became less. The duration of emergence and number of deposited egg is normal.
b) The secondary larval stage is shortened.
c) The ratio of good cocoons is reduced, the weight of cocoon, cocoon layer and the ratio of cocoon layer are increased.
d) The percentage of hibernating pupae in secondary generation is increased.

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桑樹の矮小枝の伐採が畦間に於ける温度分布に及ぼす影響を明かにするために, 信州大学繊維学部桑園において1951年9月に8時から18時に亘つて畦間気温の測定を行い, その結果を Isopleth 及び垂直分布・日較差等にて表わして考察した。
1) 標準区・根桑伐採区共に高温部は午後2時頃に地上100cmの部位にあらわれ, 両区共に桑樹の樹冠面近くに一つの受熱面が推定される。
2) 今一つの高温部が対照区では午前10時頃20cmに見られるが, 伐採区では午後2時にこれより更に顕著な高温部が地表面及びその近くに出現する。
3) 各測定点の1日の平均温度・最高温度及び温度の日較差の垂直分布を見ると, 両区は共に100cmの部位高いが, 20cm以下では反対となり, 対照区でこれに等の値が最も低かつた地下5cmが, 根桑伐採区では最も高い値を示した。
4) 各測定点の1日の最低温度の垂直分布は, 両区共下の方ほど低い傾向を示し, 地下5cmが各高さを通じて最低の値を示した。
5) 以上の結果を通覧すると, 矮小枝の伐採は桑園の受熱面を低下させ, 為に地面及びこれに近い部分の畦間気温を対照区に比して明かに高め, またこれ等の部分の温度の日較差を著しく大きくすることが判つた。

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As the interstice of a wind break or hedge causes wind path, the wind velocity increases and wind erosion is often promoted.
According to our investigation, the accelerated wind velocity at the interstice within a shelterbelt reached to about 120% of standard velocity. It was found that Sodegaki which was slanted off from the artificial hedge was more effective than the right-angled one.
On the occation when the hedge were pierced with a road, the zigzaged Sodegaki was most effective and the blowing through the interstice was ceased.

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Diurnal maximum and minimum temperature (air temperature at 200, 150, 100, 50, 10cm. heights and soil surface temperature) at the inside and outside of the persimmon field were observed from April 1, 1952 till March 31, 1953.
From Fig. 1-6, the distinctive microclimatological temperature relationships in the persimmon field are recognized.

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This paper both includes the difference of micro-meteorological characteristics with the luxuriancy of the trellis of grapes and that when the soybean was planted in the field under the trellis.
This investigation was carried out for several days in both summer and autumn, i.e., July 14-15, August 20-21 and November 5-6, 1953, in a vineyard in Tokyo Agricultural Experiment Station.
It was samely recognized that there were two layers of thermal importance, i.e., the soil surface and the trellis of grapes as seen in the 1st Report.
The vertical distribution of temperature and the relative humidity distribution are shown respectively in Fig. 1, 2 and Tab. 4, 6 with the luxuriancy of the trellis of grapes.
The micro-meteorological characteristics in the vineyard was not influenced even when the soyhean was planted under the trellis, shown in Fig. 3, because the trellis has large influency upon the micro-climatology in the vineyard.

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1. The late frost damage in this area begins usually from the middle of the last decade of April and threatens all through May. But, in the spring when the weather advances, it sometimes occurs earlier. Therefore, it is insufficient to learn only the perilous period in calendar, but is necessary to duly deliberate the frost-tolerance of crops variable at each stage of their growth. The writers accordingly accumulate the temperatures over 3°C of the daily mean air temperatures from Jan. to the previous day in considerationthe so-called accumulative temperaturein order to get anindex which indicates the growth stage of the crops. As far as this area is concerned, we found that it is the begining of the perilous period of frost damage when the index becomes 150°C.
2. We next studied statistically on the relation between the existence of frost its predictor based on the date obtained these 44 years.
Using these results, we may forecast the forming of frost with the following measures.
Step 1. —First of all, decide whether the prognostic pressure pattern is of frosty type or not as is shown in Fig. 2.
Step 2. —In the case of the late frosty pressure pattern, read the air temperature and the vapour tension at 6 P. M. In TE diagram (i.e. Fig. 3), take P whose coordinates are these readings in order to decide section in which P is located.
(a). When P is in Section A, the succeeding morning is frosty in 92-100% probability. (b) When P is in Section D, the succeeding morning is free from frost in 98-100% probability. (c). When P is either in Section B or C, one has, furthermore, to rely upon the following means.
Step 3.—(a). When the weather is clear or fine at 6 P. M. and the weather is forecasted to be clear till the succeeding dawn, it forms in 76-94% probability if P is in Section B, and in 31-66% probability if P is in Section C. (b). In the case of the weather different from the above mensioned conditions: —In order to have frost in the succeeding dawn, we have upper limits of air temperature at 6 P. M. for each weather condition shown in Table 3. Under these conditions, the frost is expected with in the confidence limits of occurrence probability indicated in the last column of the table.
3. When the frost is expected with the above mentioned measures, we can estimate the frost intensity by the following means.
Step 1—(a) When P is in Section C at T-E diagram, the expected frost in the successive dawn is weak in 72-100% probability. (b). When P is either in Section A or B in the figure, it has to be forecasted according to the following measures.
Step 2— From the weather conditions at 6 P. M. and the successive prognostic weather, the frost is judged to be strong within the confidence limits in the last column of Table 5 in accodance with the weather conditions of the table.

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To protect the crops from the wind damage, farmer often put up the straw fence in farm field. Author investigated the effect for varing the fence condition (See Fig. 1) in farm field.
Main results are as follows:—
1. effect of protection against wind.
Fig. 2 shows the variation of wind speed difference between A plot(no fence)and B plot(ordinary fence) or C plot (surrounded, by fence), with increasing of the wind speed at A plot.
The variation curves are more conspicous in the difference between C and A, and more greater in night than in day time. This implies the effect of protection against wind in night is much larger than in day time.
2. Prevention of dust.
To measure the removment of dust in these plots, we used the aluminium dishes 7cm in diameter, 2cm in depth) are poured water about half of it to prevent jumping out of the dust by wind.
The water are took off by drier. Results of this are shown in Tab. 3, 4 and Fig. 3.

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Among other methods to prevent wind erosion, the methods of increasing resistance-erosive nature in soil is the most randy from the view point of cultivation. The study in this field is urgent. We have made a basic experiment on the relation between the amount of water contained in quartzsand and the wind velocity required to initate soil movement, with the intention of preventing erosion by means of irrigation.
The diameters of seven kinds of quartz-sand particles are respectively 2.0, 1.0, 0.8, 0.5, 0.2, 0.1, 0.05mm. The wind-tunnel used is Effel type wind-tunel of sand, the length of which is 8.0m. The experiment room is 3.0m in length. On the floor are laid pebbles with the diameter from 4.0mm to 6.0mm. In the the midst is put the materials to be tried.
Of all the kinds of particles those with the diameter of more than 0.15mm. have the more increased nature with the longer the diametor. Those of 0.2mm in diameter are most apt to move, which those under resistance-erosive 0.2mm have more resistance-erosive tendency.
In accordance with the increase of the amount of contained water, each size of paricles show increased resistance-erosive nature when the amount of contained water reaches a certain degree, resistance-erosiveness also rises up suddenly
The relation between the amount of water contained in the mixture of more than two kinds of particles and the wind velocity required to initiate soil movement is represented by the following expression.
V_(n)=V_a(n)r+V_b(n)r′+V_c(n)r″+……±e
V_(n)……the wind velocity required to initiate soil movement, in the case that the parcentage of contained water is n.
V_a(n), V_b(n), V_c(n)—the same as above, of the particle, diameters of which are a, b and c r, r′, r″—Percentage of mixture
e —Variation
(N.B.) The range in which this expression is to be applied is below the point where resistance-erosiveness increases abruptly.

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The isothermal lines of the mean air temperature of the warmest and the coldest month are shown on the map in order to indicate in a look the temperature climate of the northern and southern semisphere and to collate with the limit of the distribution of some crops in the world.

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For the production of salt from the sea water, to evaporate water from fogs artificially made of sea water falling though the unsaturated air is one of available methods to concentrate the salt. On adopting this method, it is necessary to determine the most effective drop size of fogs which are made by a sprayer, considering the evaporating efficiency and horizontal distance of flight by wind.
We studied its size by field observations and simple numerical calculations and conclude that the most effective drop diameter of fog is about 0.1-0, 2MM., when the height of jet of the sprayer is about 10M for the wind velocity on the coast of Seto Inland Sea.

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