[in Japanese]

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[in Japanese]

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Morphological changes in the aerial part of plant due to environment were investigated on flue-cured tobacco grown on the field of 4 locations with different soil types and climatic conditions.
The results are summarized as follows:
1) Under the combined conditions of high temperature, weak sun light and fine soil structure, tobacco grew continuously resulting in the production of vague symptoms of ripeness on the leaves. Thus, the life span of the leaf was apt to be limited artificially through the process of cultivation practice.
2) In the period of 40 days after the transplantation, the growth of leaf was affected mainly by air temperature, beyond that stage, however, by soil type.
3) For the completion of leaf-length, longest period of days were required at 14°C. Higher and lower temperatures reduced the days for maximum leaflength.
With regard to leaf-shape, measured on the basis of length/width ratio, the above cited day-temperature relation was variable by soil type. For example, on granite soil and volcanic loam, most days were required at 14°C and 16°C, respectively, On volcanic black soil, on the other hand, the days had a tendency to be prolonged with the increasing air temperature.
4) Completed length and shape of leaves exhibited a characteristic appearance throughout every stem positions. The difference of the appearance by districts was thought to be brought about mainly by the influence of soil types and partly by climatic conditions, (Fig. 7 and 8)
5) On the stem position above 8-13 leaves, a linear correlation was observed between internode length and the order on the stem. The gradient of the regression line which varied by soil type was steepest in tobacco grown on granite and sandy soils.
6) The increase of stem diameter followed a S-type growth curve. The stem of the tobacco grown on granite soil required most days to attain to a half of the maximum diameter.
7) Phyllotaxis of tobacco plant changed by stem position from 1/2 to 2/5 in the seedlings of seed bed stage and from 3/8 to 2/5 in the plants of thefield stage. These transitions occured at different stem positions in accordance with the difference of environment by districts.

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