The earliest stage of growth at which the internode elongation can occur under submerged condition was observed in Bangladesh floating rice followed by Thai rice, Burmese rice and Vietnamese rice, and Indian rice in the subsequent order.

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[in Japanese]

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Ten rice varieties selected to represent true floating, semifloating, non-floating and semi-dwarf types were seeded in pots every month and the number of elongated internodes and days from seeding to heading were recorded.
It was found that floating rice varieties tended to have a larger number of elongated internodes than other types of rice at comparable heading time.

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Considering the grass yields from year to year, this study was carried out to clear some effects of seasonal variation of heading rate on the root growth of grasses, dallisgrass and bahiagrass, in the field.
Both dallisgrass and bahiagrass, regardless of cutting treatment, increased their total number of stems and roots, as well as the number of reproductive stems in summer. However, when the heading rate became higher, the rate of tillering was decreased, and the tillers readily changed into reproductive stems at young stage, resulting in a decrease in the percentage of vegetative stems. Therefore, this change brought about the decrease in the number of roots per tiller and the weight of individual root in both vegetative and reproductive stems from early to late summer.
On the contrary, in autumn when the number of reproductive stems decreased, tillering was increased and these tillers increased the number and weight of roots, and survived beyond winter to become fully developed reproductive stems after spring growth.
Such seasonal changes in top and root growth as mentioned above seem to relate the evidence that the herbage yields of dallisgrass and bahiagrass increased in summer and decreased gradually towards the end of summer.

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