You are not currently logged in.
Access your personal account or get JSTOR access through your library or other institution:
If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Diurnal Patterns of Pollen Emission in Ambrosia, Phleum, Zea, and Ricinus
Eugene C. Ogden and Janet V. Hayes
American Journal of Botany
Vol. 56, No. 1 (Jan., 1969), pp. 16-21
Published by: Botanical Society of America, Inc.
Stable URL: http://www.jstor.org/stable/2440389
Page Count: 6
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
Hourly measu rements of pollen emission were made from cultivated plots of Ambrosia, Phleum, Zea, and Ricinus over the course of several pollination seasons as part of a study of pollen dispersion from known sources. A characteristic diurnal emission pattern was found for each genus Ambrosia pollen emission normally begins an hour or two after sunrise, peaks a few hours later, and decreases through the afternoon. Phleum starts during the night, peaks about 2 hr after sunrise, and declines slowly through the day. Zea emits pollen fairly uniformly during the period from 2 hr after sunrise to about sunset, while Ricinus pollen was collected from several hours after sunrise to late afternoon with a peak in mid-morning. Daily patterns often vary from the seasonal mean in response to changing meteorological conditions.
American Journal of Botany © 1969 Botanical Society of America, Inc.