664 
Philippine Journal of Science 
1919 
as a disinfectant, and experiments in Malaya with other similar 
compounds are reported as being successful. Painting with a 
Bordeaux paste has also been recommended by a number of 
writers. 
Butler writes that, in India, the application of Bordeaux 
mixture, 6-4-45, to the parts of Para rubber trees most sus- 
ceptible to attack by pink disease has resulted in a reduction 
of the disease of from 50 to 75 per cent. The mixture was 
applied with a brush around the forks, for a foot or two down 
the stem, and up the branches. Two or three applications during 
the year appear to have produced the most satisfactory results. 
Butler states that over 200,000 trees were treated at a cost 
varying from 1 to 2 rupees an acre .(about 1.65 to 3.30 pesos 
per hectare). 
With reference to the practice of spraying as a preventive 
and remedial measure for pink disease, Petch states that ap- 
plications of Bordeaux, 5-5-45, against pink disease on cacao 
resulted favorably. His statement is but a brief mention of 
fact in connection with another subject, and he does not give 
his spraying data. Bancroft has also recommended the prac- 
tice of spraying without, however, giving his experimental data. 
So far as we know, the results discussed in this paper constitute 
the first experimental evidence of the value of spraying practices 
against pink disease. 
Orchard A at the Lamao station, which consists of various 
horticultural varieties and species of Citrus, was the most badly 
affected by pink disease and the control-experiment data and 
results for this orchard are presented in the following pages. 
The diagram (fig. 1) shows the position of the trees and the 
rows in the orchard, and also indicates the location of the cases 
of pink disease existing in October, 1917. 
The orchard was divided into plats as follows: Rows 1, 2, 
3, 4, 5, 6, in Plat I; rows 7, 8, 9, in Plat II; rows 10, 11, 12, in 
Plat III ; rows 13, 14, 15, in Plat IV ; rows 16, 17, 18, 19, 20, 
in Plat V. These plats were treated as follows: 
Butler, E. J., Fungi and Disease in Plants. Thacker, Spink & Co., 
Calcutta (1918) 505. 
^ Petch, T., Physiology and Diseases of Hevea brasiliensis. London 
(1911) 212. 
Bull. Dept. Agr. F. M. S. 1 (1912) 218. 
