132 The Philippine Journal of Science 1922 
showed some growth, new since last winter, but this was all well hardened 
and matured, and considered to be past the stage for development of in- 
fection. The pruned plats showed considerably more of this type of 
foliage than did the untreated plats. All of the trees showed that many 
of the old leaves had dropped during the winter and the trees were largely 
foliated with leaves formed since last January. The total amount of 
foliage of the trees in the pruned plats was appreciably greater than that 
of the trees in unpruned plats. A considerable drop of the young, newly 
formed fruits was observable throughout the orchard. Although time did 
not permit of an actual count, the observations indicated that the fruit 
drop was considerably less on the pruned plats than on the unpruned plats. 
Altogether, the general thrift of the pruned plats was very much greater 
than that of the untreated plats. 
The field notes following the second application may also be of 
interest. 
DISCUSSION OF SPRAYING METHODS, SECOND APPLICATION, 1919 
Lead arsenate, neutral, was added as a paste, at the rate of 2 pounds 
for every 50 gallons of spray; this was used uniformly throughout all 
sprayed plats. The purpose was to check the chewing insects which have 
been very numerous in the past few months. What Mr. Kondo calls blister 
moth has also been very common, and this was observed last fall to be 
very active in disseminating canker. It is hoped that the lead arsenate 
will be a means of checking this dissemination of canker. 
Careful examination was made of the trees in the different plats. Sev- 
eral trees in the control plats showed very new cankers. Two trees in 
the formalin plats showed no foliage or fruit cankers as yet. 
On plats 2, 6, and 15 there was a slight leaf fall. These plats were 
sprayed with lime sulphur (of a density of 25° Baumé) 1 part to 33 parts 
of water, plus 2 pounds of lead arsenate (neutral paste) to 50 gallons of 
solution. The mature, well-formed leaves were the ones that dropped, 
while the young, new, actively growing leaves were apparently not injured. 
There was no visible lesion of any sort on the fallen leaves. The loss 
of leaves was not serious, and apparently no well-formed fruits were caused 
to drop. The trees are at present in a condition in which they need all 
possible leaf surface and the leaf drop is regrettable from that standpoint. 
On the formalin 1 to 100 plat (plat number 11) there was also a slight 
leaf drop. This plat was sprayed with formalin 1 to 100, plus lead 
arsenate (neutral paste) in, the proportion of 2 pounds to 50 gallons of the 
mixture. In this case, however, the affected leaves were the young, actively 
growing, light-colored ones, while the matured leaves showed no ill effects 
whatsoever. Upon the fallen leaves and upon the young leaves upon the 
tree, white-colored, killed areas of tissue showed where the formalin mix- 
ture had injured the tissue. There were no indications whatsoever of 
injury on the fruit. 
Careful examination of the plats for new cankers was made. On the 
pruned plats numbers 1, 2, 3, 4, and 5 no new canker lesions were observed. 
Some new lesions were observed in sprayed but unpruned plats; such 
lesions were all foliage cankers, however, and no fruit infections were 
seen. They were, at this time, so few as to cause no alarm. Upon the 
unsprayed plats, those entirely untreated, considerable amounts of new 
