VOLUME LVII NUMBER 4’ 
THE | 
BOTANICAL “GAZEr se 
APRIL 19%4 
THE EFFECT OF SHADING ON THE TRANSPIRATION 
AND ASSIMILATION OF THE TOBACCO PLANT 
IN CUBA 
HEINRICH HASSELBRING 
(WITH ONE FIGURE) 
Introduction 
This paper gives an account of experiments conducted in West- 
em Cuba for the purpose of determining the effect on transpiration 
and assimilation in the tobacco plant of the cheese-cloth shade 
which is frequently used in that region for shading tobacco. A 
comparative study of the transpiration and assimilation of the 
tobacco plant under normal conditions and under the conditions 
induced by cheese-cloth shading is of interest for several reasons. 
First, although investigations' of the influence of different light 
intensities on transpiration have nearly always led to the conclusion 
that the rate of transpiration is decreased with a lessening illumina- 
tion, the experiments which have established this conclusion have 
necessarily been conducted with plants or parts of plants which 
could be kept under observation only for short periods of time, and 
often under laboratory conditions. Data permitting a comparison 
of the transpiration of plants under normal conditions with others 
of the same kind shaded during their entire development are not at 
* Kout, G., Die Transpiration der Pflanzen, etc. pp. 52-74. 1886; BURGERSTEIN, 
A., Die Transpiration der Pflanzen. pp. 85-103. 1904; Livrneston, B. E., Light 
intensity and transpiration. Bor. Gaz. 52:417-438. Ig1t. 
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