FORECAST OF FIRST DAY WHITE BIRCH POLLEN RELEASE WITHOUT TOOLS FOR OBSERVATION OF THE WHITE BIRCH

To forecast the first day of white birch (Betula platyphylla var Japonica) pollen release without tools, we examined the daily growth of leaves in addition to observing the trees at a distance, e.g. from a car or bus. Release began 3 days after leaves could be identified from sprouts. It also began...

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Bibliographic Details
Published inJIBI INKOKA TEMBO Vol. 44; no. 6; pp. 471 - 475
Main Author Nishizawa, Shinji
Format Journal Article
LanguageJapanese
Published Society of Oto-rhino-laryngology Tokyo 2001
Subjects
first day
forecast
leaves
pollen releasing
white birch
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Summary:To forecast the first day of white birch (Betula platyphylla var Japonica) pollen release without tools, we examined the daily growth of leaves in addition to observing the trees at a distance, e.g. from a car or bus. Release began 3 days after leaves could be identified from sprouts. It also began when twigs or the joints of male flowers disappeared due to the growth of leaves, or spaces between leaves or twigs were filled with grown leaves. No indicator for the release was found 3 days before release even when the tress were observed at a distance. Therefore, observing the growth of leaves will enable anyone to forecast the release 3 days in advance.
ISSN:0386-9687
1883-6429
DOI:10.11453/orltokyo1958.44.471