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. 
1914 1915 1916 oa 
Month. ‘ ‘5 . 
Daily | Tnaxi- | mini | Daily | Basa’| mane. | Daily | Hourly) Dally 
mum, mum. mum, | mum. mum, mum. 
km. km, km. km. km, km. km. km. km. 
January <2... 158.9} 28.0] 82.5] 116.0| 27.5] 89.0] 214.1] 86.0] 100.5 
Wobroary 2.022 25h 2 187.7 | 26.0} 104.0] 172.5] 27.5] 66.0] 166.0| 25.5) 68.5 
PMN ee oe ae, 204.6} 28.5] 105.5] 190.7| 28.0] 100.0| 188.8] 24.0! 125.5 
FU) | Pea uaear eens Serge 197.4} 84.0] 90.6] 227.8} 31.0] 150.0] 186.4| 26.0] 118.5 
MAY 198.0} 384.0} 92.0] 285.4| 35.0} 128.0] 180.7] 31.0] 122.5 
PONG ah csc Shs iacses 223.8) 64.0] 70.5} 174.6| 48.0] 84.5] 185.4] 89.5] 845 
Ac SEES ste on ahead 848.1{ 58.0] 70.5] 209.2] 36.5] 79.0! 169.8] 82.5| 29.0 
mdeast 2.552205 860.4] 58.0] 44.5] 258.7] 42.0] 98.5] 328.0] 48.0] 52.0 
September -___________. 244.7} 41.0] 78.0] 184.4] 86.0] 88.0] 186.1] 42.0] 76.0 
Metoher.... 8.5.27 52 124.6] 22.0 67.0 | 206.6 58.0} 65.0) 110.8) 22.0; 652.0 
November-.._.........- 126.2] 28.0] 65.5] 156.6] 68.0] 64.5) 189.7] 25.0/ 84.5 
| December ih cope cer ss 108.0} 18.0} 650.6] 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 igs 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 
