19, 2 
Lee: Citrus-canker Control 
133 
Table 4.— Representative wind velocities in Manila, expressed in kilometers 
per hour, compiled from the annual reports of the Philippine Weather 
Bureau. 
Month. 
1014 
1915 
1916 
Daily 
mean. 
Hourly 
maxi- 
mum. 
Daily 
mini- 
mum. 
Daily 
mean. 
Hourly 
maxi- 
mum. 
Daily 
mini- 
mum. 
Daily 
mean 
Hourly 
maxi- 
mum. 
Daily 
mini- 
mum. 
km. 
km. 
km. 
km. 
km. 
km. 
km. 
km. 
km. 
January.. — 
158.9 
28.0 
82.5 
116.0 
27.5 
39.0 
214.1 
36.0 
100.5 
February 
187.7 
26.0 
104.0 
172.5 
27.5 
66.0 
166.0 
25.5 
68.5 
March. 
204.6 
28.5 
105.5 
190.7 
28.0 
100.0 
188.8 
24.0 
125.5 
April 
197.4 
34.0 
90.6 
227.8 
31.0 
150.0 
186.4 
26.0 
118.5 
May 
198.0 
34.0 
92.0 
235.4 
35.0 
128.0 
180.7 
31.0 
122.5 
June 
223.8 
64.0 
70.5 
174.6 
43.0 
84.5 
185.4 
39.5 
84.5 
July 
848.1 
53.0 
70.5 
209.2 
36.5 
79.0 
169.3 
32.5 
29.0 
860.4 
53.0 
44.5 
258.7 
42.0 
98.5 
328.0 
43.0 
52.0 
September _______ _ 
244.7 
41.0 
73.0 
184.4 
36.0 
38.0 
186.1 
42.0 
76.0 
October 
124.6 
22.0 
67.0 
206.6 
58.0 
65.0 
110.8 
22.0 
52.0 
November 
126.2 
23.0 
65.5 
156.6 
68.0 
64.5 
139.7 
25.0 
84.5 
December 
108.0 
18.0 
50.5 
167.5 
68.0 
62.5 
145.0 
23.5 
90.0 
During the summer season cyclonic disturbances are frequent, 
when wind velocities of 60 or more kilometers an hour are not 
unusual, and even a velocity of 195 kilometers an hour has been 
recorded by the Weather Bureau. Such winds are usually ac- 
companied by rainfall and are a serious handicap in combating 
citrus canker, in as much as they disseminate the canker or- 
. ganism at a time when all conditions favor the development 
of canker. More extensive data and references upon the climate 
of the Philippines may be obtained in the publication of Father 
Coronas, (4) of the Philippine Weather Bureau. 
PREVIOUS LITERATURE UPON CONTROL METHODS FOR CITRUS CANKER 
The available literature on investigations upon the control of 
citrus canker is not extensive. The first note of the effect of 
spraying against citrus canker is that of Wester, (18) who, in 
the dry season of 1912 in the Philippines, was able, by applica- 
tion of Bordeaux mixture, to control a disease which he regarded 
as citrus scab. In the wet season, however, he reports his 
spraying methods to have been unsuccessful against the disease. 
He later identified the disease as citrus canker instead of citrus 
scab. Stevens (16, 17) has reported spraying conducted by grow- 
ers and nurserymen against canker in Florida to be impractic- 
able, but has not described the spraying methods employed. 
Wolf (21) described control methods using variations of Bor- 
deaux mixture against the disease on grapefruit trees in 
