Doc. 18,1916 
Influence of Bordeaux Mixture on Transpiration 547 
of potted plants are materially increased by an application of Bordeaux 
mixture. 
A surface covering of dry, powdered copper sulphate was less effective 
in accelerating rates of transpiration than was a surface film of Bordeaux 
mixture, but was more effective than was a film of barium sulphate. 
The accelerating influence of Bordeaux mixture on the rates of trans¬ 
piration is much more pronounced when the spray is applied to abscised 
leaves than when applied to the leaves of potted plants. 
The influence of Bordeaux mixture in increasing the rates of water 
loss from abscised leaves becomes effective immediately after the spray 
dries upon the leaves. The highest average increased rates of trans¬ 
piration occurred during the first 2-hour period following an application 
of the spray. 
The effectiveness of a film of Bordeaux mixture for inducing increased 
rates of water loss from abscised leaves varies considerably with the 
different species. This, to a lesser degree, is true also with potted plants. 
LITERATURE CITED 
(1) Bain, S. M. 
1902. The action of copper on leaves ... Tenn. Agr. Exp. Sta. Bill., v. 15, 
no. 2, 108 p., 8 pi. 
(2) Bayer, Ludwig. 
1902. Beitrag zur pflanzenphysiologischen Bedeutung des Kupfers in der 
Bordeaux-briihe. 56 p. KOnigsberg. Inaug. Diss. 
(3) Briggs, L- J., and Shantz, H. L. 
1912. The wilting coefficient for different plants and its indirect determination. 
U. S. Dept. Agr. Bur. Plant Indus. Bui. 230, 83 p., 9 fig. 
(4) Clinton, G. P. 
1911. Spraying potatoes in dry seasons. In Conn. Agr. Exp. Sta. Bien. Rpt., 
1909/10, pt. 10, p. 73ST75 2 - 
(5) Dugar, B. M. 
1911. Plant Physiology ... 516 p. illus., New York. 
(6) -and CoouiY, J. S. 
1914. The effect of surface films and dust on the rate of transpiration. In Ann. 
Mo. Bot. Gard., v. 1, no. 1, p. 1-22, pi. 1. Bibliography, p. 20-21. 
1914. The effect of surface films on the rate of transpiration: Experiments with 
potted potatoes. In Ann. Mo. Bot. Gard., v. 1, no. 3, p. 3 S 1 — 35 ^* P 1 * l8 - 
( 8 ) Frank, A. B., and Kroger, Friedrich. 
1894. Uber den direkten Einfluss der Kupfervitriolkalkbrfihe auf die Kar- 
toffelpflanze. 46 p., 1 col. pi. (Arb. Deut. Landw. Gesell., Heft 2.) 
1894. Ueber den Reiz, welchen die Behandlung mit Kupfer auf die Kartoffel, 
pflanze hervorbrmgt. In Ber. Deut. Bot. Gesell., Bd. 12, Heft 1, p. 8-11 
(10) Hawkins, L. A. 
1912. Some factors influencing the efficiency of Bordeaux mixture. U. S. 
Dept. Agr. Bur. Plant Indus. Bui. 265, 29 p., 4 fig. 
(11) 
1910. The porous clay cup for the automatic watering of plants. In Plant 
World, v. 13, no. 9, p. 220-227, 3 fig. 
