1) In order to observe the effect of acclimatization, comparative examination of growth and development of the plant, yield of crop, and seasonal variation of santonin content was carried out during June 16 to October 1, 1953, on the second year growth of
Artemisia kurramensis Qaz., grown from the seed obtained in January, 1952, from the plant cultivated at Kasukabe since 1951, and of the plant grown from the seeds of Pakistan origin (Table I). It was found that the second year growth also showed far better results in the acclimatized plot than in the Pakistan plot, the maximum of the yield of crop per 10 ares on air-dried basis and santonin content of the acclimatized plot being 163.2kg. (harvested July 1) and 1.98% (harvested August 1), respectively, and 77.2kg. (harvested August 1) and 1.47% (harvested July 1), respectively, in the Pakistan plot.
2) It was found that, although the first year growth of
Artemisia kurramensis shows weak growth, small yield of crop, and low santonin content, its growth becomes suddenly active during the second year, and both the yield of crop and santonin content increase markedly (cf. Tables I and III).
3) The seasonal variation in santonin content of the third and fourth year growths of this plant showed approximately the same tendencies as that of the second year growth and the santonin content itself was no different from that of the second year growth (Table II). According to four cultivation experiments in the past, the santonin content reaches the maximum during the early part of September in the first year growth, and in July, especialy during the early part, in the second, third, and fourth year growths. They all seem to have no relation to the appearance of flower buds and such season is generally at the height of vegetative growth.
4) It was found that the plant survived longer after harvest when only one-half of the shoots was harvested rather than the whole shoot of one plant.
5) The first year growth, in the case where seedlings were brought up in the open air, gave better yield of crop and santonin content than that in the case where seedlings brought up in the glass house.
6) Detailed observations on the flowering and seed-setting of this plant revealed that it is self-sterile and is a short-day plant (cf. Table IV).
7) The plants cultivated with protection from rain druing October to January under plastic roof or in the glass house showed seed-setting but those left in the open air failed to show seed-setting. Such a fact is assumed to indicate the necessity of a dry atmosphere and a suitable temperature.
8) Suitable temperatures for the germination of pollens seem to lie in the range of 15-20° (cf. Table V). The pollens stored in a desiccator with drying agent retained germination power for about one month but those kept in natural state lost such a power in about six days.
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