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Volume 21, Issue 1
Displaying 1-8 of 8 articles from this issue
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K. YABUKI, H. USHIYAMA1965 Volume 21 Issue 1 Pages 1-4
Published: August 10, 1965
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSOn studies of plant growth using growth cabinet or greenhouse, there have been paid little attention to carbon dioxide concentration of air. However it is supposed that owing to circulated re-using of air for air-conditioning in growth cabinet of phytotoron, the carbon dioxide concentration is quite decreased and the plants do not grow properly. Therefore, it is necessary to cultivate plants under the normal concentration of carbon dioxide. The same problem should be considered in greenhouse.
Even in the case of carbon dioxide nutrient system which practically used recently, it is necessary to keep the effective and economic level of the carbon dioxide concentration.
The authors tried to make the automatic controlling equipment of carbon dioxide concentration in closed system culture.
The heat conductivity principle was used for determining CO2 concentration. The circuit and piping of it are shown in Figs. 1 and 2. After the standard air (outside air or carbon dioxide free air) is sucked into the reference and detector cells of the bridge, the bridge is balanced by the balancing resistance r2. And then, the bridge is unbalanced a fixed value which correspond to a given concentration of carbon dioxide of the cabinet air with the regulating resistance r1 and the cabinet air is sent to the detector cell. Untill the carbon dioxide concentration in the growth cabinet reachs a given value, the bridge is retained in the unbalanced condition and the magnetic valve of carbon dioxide bomb opens and the carbon dioxide is sent into the cabinet. The syncronous rectifying circuit is equiped so as not to open the magnetic valve by the opposite unbalance of the bridge when the concentration becomes higher than the fixed value.View full abstractDownload PDF (554K) -
(1) An estimation of dangerous zone concerning frost damage to fruit treesY. NAKAGAWA1965 Volume 21 Issue 1 Pages 5-9
Published: August 10, 1965
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSFruit trees are in danger of frost damage in cases where their average date of flowering stage is very close to the date of the last hoarfrost, because the fruit trees are the most sensitive to freezing in the flowering time.
From this point of view, the difference between the average date (A) of the last hoarfrost and the average date (B) of full bloom stage was adopted as an index of the risk with respect frost damage This index was applied to apple, peach and pear. The frequency of occurence of frost damage increases with decreasing the index value (B—A).
The results obtained in this manner are shown in Tables 1, 2 and 3. These tables show, in general, Suzuka and Hirano are the most dangerous places with respect to frost damage, because of early flowering and late date of the last hoarfrost. On the contrary, the frost damage scarcely occured at Sakata where the flowering date is late and the date of the last hoarfrost is early (Fig. 2).
Highly significant difference was recognized, furthermore, between full bloom stage of Jonathan and air temperature in April as shown in Tables 4, 5 and in Fig. 1.
Even in regions where there are no data on the flowering date of fruite trees, it is possible to know indirectly hazardous areas for planting fruite trees from the stand point of frost damage using a close relationship betwen air temperature in April and the date of the last hoarfrost. Figs. 3 and 4 show the results oftained by such a indrect method.
It is shown in Fig. 4 that Fukaura, Tomari, Oma, Mimaya, Wakinosawa and Tanabu are relatively safety places concerning frost damage, while Shichinohe, Tago and Ozawaguchi are dangerous places.View full abstractDownload PDF (610K) -
K. TAKEDA1965 Volume 21 Issue 1 Pages 11-14
Published: August 10, 1965
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSA differential equation, which prescribes velocity distribution in plant canopies and was derived in a previous paper, is solved for a given plant density-height relation, i.e. a parabolic relation. The obtained solution contains a Bessel function of νth order and represents a probable profile which is connected to a logarithmic profile, in the space over the plant canopy. Correspondingly, the roughness parameter and the zero-plane displacement are determined uniquely. Also the depth of the laminar sublayer is discussed and is proved to vary inversely with the frictional velocity.View full abstractDownload PDF (463K) -
S. IWAKIRI1965 Volume 21 Issue 1 Pages 15-21
Published: August 10, 1965
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSResults of observations on evapotranspiration in both early seasonal cultivation and ordinary cultivation systems for four years (1960 to 1963) are presented. Mean daily totals of evapotranspiration in both cultivation systems were nearly the same, but the extreme of daily total in evapotranspiration in early cultivation exceeded that in the ordinary cultivation. The difference in extremes arises from the fact that the period with dense plant canopy in the early cultivation coincides with the period of most intensive insolation in year.
Evaporation from an ordinary small pan was found to agree fairly well with evapotranspiration from paddy fields and to be used as a rough measure of it. The heat balance and the combination methods were applied to estimating the evapotranspiration. The latter was found to be more promising than the former for operational use.View full abstractDownload PDF (883K) -
T. ARAI1965 Volume 21 Issue 1 Pages 23-27
Published: August 10, 1965
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSIn this paper, the amount of observed evaporation was compared with those calculated with two methods. The data on evaporation were quoted from the new climatic tables for Japan published recently by meteorological agency. The evaporation from a shallow water was calculated by PENMAN method (E0) and socalled gradient method (E). Other theoretical and empirical formulas were not very suitable for our purpose, because of the need of detailed climatic data and of emirical constants that vary with places. It is reasonable to expect that the two methods give the same results since the both are on the basis of the principle of heat balance.
In the calculation of evaporation by PENMAN method, the data on incoming short wave radiation with Robitzsch actiongraph were used and the value of albedo of water surface was taken from Budyko's (1959) textbook. The following equation was used to caluclate the evaporation from water surface by the gradient method.
E=k{e(θ∝)-ed},
where k is the evaporation coefficient, e (θ∝) the saturation water vapor pressure (mb), ed the water vapor pressure at the shelter height (1.5m) and θ∝ the terminal water temperature (the same to daily mean of water temperature), The evaporation coefficient was obtained from the data on the heat transfer coefficient reported by several researchers and found to be 0.42mm/day. mb. The terminal water temperature was calculated by the heat balance method on the basis of climatic data.
The results so obtained are presented in Table 1. This table shows the fair agreement in amount between the evaporations calculated by the two methods except of the months with wind velocity higher than 3 or 4m/sec. The discrepancy between them in the period of wind velocity higher than 3 or 4m/sec seems to be due to the assumption of a constant value in the evaporation coefficient. As can be seen in Fig. 1, the ratio (E/Rn) and ratio (E/obs) show the remarkable annual variation with higher values in winter and relatively constant values in warm season. The value of ratio (E/Rn) in. warm season was found to be in the range 0.8 to 0.9 and it was somewhat larger than those obtained by other researchers.
In order to obtain a more simple equation than the two methods used here, the data on evaporation were treated and obtaind the following empirical relation.
E=Rn+1/0.06D-5.4, mm/day
where Rn is the net radiation equivalent (mm/day) and D the saturation deficit (mb). This relation is very convenient for the operational use.
The significant discrepancy in amount between pan evaporation and evaporation estimated by heat balance method seems to indicate that pan evaporation is not very reliable in scheduling the use of water resource,View full abstractDownload PDF (676K) -
K. KOBAYASHI1965 Volume 21 Issue 1 Pages 29-30
Published: August 10, 1965
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (261K) -
Z. UCHIJIMA1965 Volume 21 Issue 1 Pages 31-34
Published: August 10, 1965
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (658K) -
I. WATANABE1965 Volume 21 Issue 1 Pages 35-37
Published: August 10, 1965
Released on J-STAGE: February 25, 2010
JOURNAL FREE ACCESSDownload PDF (499K)
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