The author calculated the standard values of the latent load for the air-conditioned glasshouse growing tobacco plant.
From the standard radiation at outside of 824 kcal/m²⋅h, the standard values of incoming radiation of 602 kcal/m²⋅ h and 3, 926 kcal/m²⋅ day were obtained. Using the empirical formula of radiation (S_i↓) and evaporation (LE), LE=0.554 S_i↓-4.60 (cal/ cm²⋅h), we also obtained the standard values of evaporation (LE) of 288 kcal/m²⋅ h and 2, 880 kcal/m²⋅ day.
The ratio of plant growing bed area to room area, designated as the bed ratio (B), was investigated at various glasshouses and found 0.60±0.025. If the utilization ratio of the bed by the plant pots, named the plant occupation ratio (U), and the covering ratio by plant leaves on bed, named the shade ratio (γ), are decided to the crop kinds and the using condition of room etc., we can calculate the latent load (_pLE) by the following equation.
_pLE=LE×B×U×γ
For tobacco plant, B=0.60±0.025, U=1.0, γ=0.93±0.05, the standard values of the latent load for design are 161±15 kcal/m² (room) ⋅h, 275g/m² (room) ⋅ h and 1, 610±150 kcal/m² (room) ⋅day, 2, 750 g/m² (room) ⋅ day.

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Tobacco plants were grown on the following three kinds of ridges. Soil temperature, soil moisture and growth of tobacco of these ridges were studied. The first was the high ridge thoroughly covered with polyethylene film (thoroughly mulched ridge), the second was the conventionally mulched ridge of normal height (mulched ridge), and the third was bare ridge of normal height (non-mulched ridge) .
Maximum and average soil temperatures were the highest at the thoroughly mulched ridge, and the lowest at non-mulched one.
At thoroughly mulched ridge water vapor evaporated at the soil surface was forced to go downward into the soil and the latent heat in the water vapor was changed into the sensible heat in the soil and raised soil temperature. At mulched ridge the downward movement of water vapor was not so large as at thoroughly mulched ridge, and the temperature raising effect of mulched ridge was relatively small. At non-mulched ridge water vapor ran into air and gave small influence on soil temperature.
The influence of soil moisture increase on the thermal diffusivity was conspicuous at thoroughly mulched ridge.
Average soil moisture during the tobacco cultivating period was the lowest at thoroughly mulched ridge and the change of soil moisture was the least at thoroughly mulched ridge.
The quality of cured tobacco leaves was the best at thoroughly mulched ridge, and the worst at nonmulched ridge.

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We have introduced some theoretical equations concerning the nocturnal air cooling under tunnel cover. The effects of air temperature (θ₀) and sky radiation (R : which was replaced with the equivalent temperature θ_R) out of tunnel cover were unified as the effective temperature of outside air (θ_e) . The cooling characteristic was described with three nondimensional parameters (α, β, γ) which were defined from the film area ratio (H), the heat transfer coefficients of air turbulents at the both surfaces of tunnel cover, and the heat conductance of the underlying soil. The soil temperature (θ_s) was, on the other hand, decided by profile method.
Theoretical equations for culculation of the tunnelfilm temperature (θ_f) and the inside air temperature (θ_i) were as follows ;
θ_f=1/1+γθ_e+(1-1/1+γ)θ_s
θ_i=H/(H+1)(1+γ)θ_e+ {1-H/(H+1)(1+γ)} θ_s
when θ_e=αθ0+ (1-α) θ_R
The representative results were shown in Fig. 2, Fig. 3, and Fig, 6 for θi, and in Fig. 4 for θ_f.
The following conclusions were obtained ;
1) Under very clear sky with slight wind, the inside air temperature may fall lower than the outside.
2) The inside air temperature is also affected largely by the soil condition. The cooling rate is inversely proportional to the heat conductunce of soil.
3) The air temperature under trench cover (Fig. 5) is kept clearly warmer than under tunnel, as its film area ratio is smaller. Estimated values of the inside air temperature agreed well with the observed results (Tab. 2) .

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The combination effects of fluorescent colour lamp for the growth of tomato plant (var. Fukuju 2) were investigated.
Under the combination of red and blue fluorescent lamps, the growth was maximum when the ratio of red reached to 80-88 percent of all radiant energy (Fig. 1-5) .
In this combination, if a part of red was exchanged to orange light in order to spread the range of wave length, the growth of tomato plant became smaller. (Table 1) .
By this experiment, it became clear that the range of red wave length was not need so wide.
The addition of green light to the maximum growth ratio of red and blue light did not ircrease the growth.
So, it is recognized that the green light has no effect for growth of tomato plant (Table 2) .

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[in Japanese]

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