Agronomy and Horticulture Department


Date of this Version



Published in Botanical Gazette, Vol. 68, No. 6 (Dec., 1919), pp. 393-424. Copyright 1919. Used by permission.


Transpiration has been of special interest to many investigators for a long time. At first it was considered without reference to environmental factors, but later, as more observations were made and these factors were noted to have a marked effect upon the water loss, they were taken into consideration. Many of the data assembled have been limited to plants during the growing season, so that it has seemed profitable to obtain not only quantitative data on winter losses, but also a comparison of the relative transpiration of conifers and broad-leaved trees in summer and winter.