The controlled atmosphere room must be gastight or it will not operate properly. The gas seal is critical for the successful operation of the C-A storage.
Therefore C-A storage rooms should be pressure tested for leaks annually before lading. A pressure blower is connected for the C-A room and air is blown into the room until the pressure reaches one inch water gauge. Most of the experiences in U. S. A. have shown that the room should not lose all the pressure (down to zero) in less than 30 minutes.
The study reported in this paper was made at two storages of Hokkaido University in Japan. These rooms were built in 1961 and 1962. By the theoretical analysis, the water height (h) of manometer is given by the formula.
h=h₀e^-λt
where t=time, min, h₀=water height of manometer at t=0mm, λ=leakage factor.
In 1961, we have constructed No. 2 room of Mc Intosh Apples, but we could not satisfy the gas contents required, because its λ was 0.33 (mm/mm.). In next year we have reconstructed No. 2 room for Mc Intosh and constructed No. 1 room for Delicious Apples. By the pressure test, λ was 0.026 and 0.01 respectively, and gas contents were kept easily. And one inch pressure drop in 30 minutes corresponds to λ=0.1. Therefore we can say that λ of C-A storage of Apples should be kept under 0.1 during season.

View full abstract

In 1959, 1960 and 1961, the experiments were carried out to make clear the characteristic growth of rice plants in high lands Surige (Hiraga town level 350m) and in seaside Shimooguni (Kanita town) where the north-easterlies named “Yamase wind” prevailed, comparing with inland districts (Kuroishi) in Aomori prefecture.
In order to investigate the effect of meteorological conditions on the late developmental stage of rice plants, paddy planted in pots were removed between inner districts and high lands or seaside region mutually on determined date (the heading date and the differentating stage of branch primorda).

View full abstract

Observed wind velocity profiles within crops are explained by using data on corn field by STOLLER and LEMON and on wheat field by PENMAN and LONG. An inter-relation of variation of turbulent diffusivity with height and wind velocity is obtained.
Normalized velocity profiles in corn field are shown for several wind velocities at a crop surface in Fig. 1-1. From the evidence that these profiles are in good agreement with each other, we can see that wind velocity gradient is proportional to wind velocity. We have
du/dz=p(z)⋅u (1)
p(z) is a function depending only on height, which results from the observed wind profiles within crop. If u=u_H at crop surface z=H,
u=u_He^-∫H_ZpdZ (2)
Normalized wind profiles in wheat field are also shown for moderate wind and for calm wind at crop surface in Fig. 2-1. On the figuer it is clear that the profile distinctively depends upon the surface wind velocity. If the relation between wind velocity gradient and wind velocity is expressed by the following equation for wheat field,
du/dz=p(z, u)⋅u (3)
p(z, u) is a function depending not only on height, but also on wind velocity. The values of p(z, u) at z=45cm are plotted against wind velocity in Fig. 2-2. If the difference of wind velocity between the two normalized profiles in Fig. 2-1 is neglected, the wind profile in wheat field can be also expressed as eq. (2) roughly.
Eqs. (1) and (3) may be deduced from the following consideration. Momentum flux is expressed as
τ=ρ⋅(1-F')⋅w'⋅u' (4)
where F' is the horizontal per cent area of leaves and stalks per unit volume. If
w'∝u and (u'²)^1/2∝u (5)
then τ=ρ⋅(1-F')⋅a⋅u² (6)
a is proportionality factor, assumed to be a function only of height. Kate of change in momentum flux is equal to the drag force offered by plants, that is,
dτ/dz=ρ⋅C⋅F⋅u² (7)
whers F is total area of leaves and longitudial section of stalks per unit volume, a function of height, and C is drag coefficient of plant, depending on height. From eqs. (7) and (8).
du/dz=1/2a(1-F')[C⋅F-d/dz{a⋅(1-F')}]⋅u (8)
Putting 1/2a(1-F')[C⋅F-d/dZ{a⋅(1-F')}]=p (9)
then du/dz=p⋅u (10)
If C is assumed to be a function only of z, p is also a function only of z. Then we can obtain the expression (1). In order to explain the relation between p and u for wheat field as shown in Fig. 2-2, we assume C is to increase in phase with wind velocity. Then we can also, explaine the expression (3) for wheat field.
If turbulent diffusivity K is defined by
τ=ρ⋅(1-F')⋅K⋅du/dz (11)
then K=a/pu (12)
It is seen that the K-profile is decided by three profiles of a, p and u. If a is assumed to be a constant through layer, K-profile is roughly estimated with observed profiles of p and u by use of K_H at a crop surface, where K_H can be computed from a well-known formula of turbulent diffusivity above a crop field, that is K=k⋅u_*⋅(z-d). Fig. 4 shows the K-profiles within a corn field by rough estimation.

View full abstract