20, 2 Lee and Shino: Citrus-canker Control Experiments 148 
in fig. 1. These trees were not high, but afforded protection 
from the southwest typhoon winds to the citrus trees immediately 
adjacent to the north. The percentage of cankered fruits on 
these rows north of the windbreak is shown in Table 12. 
TABLE 12.—Showing the relation of windbreaks to the occurrence of citrus 
canker. 
Row, numbered from windbreak outward. Berl Cankered fruits. 
Number. |Per cent. 
Be oe cs cen kG den ae eUnL se eeeeabanman 2, 220 131 5.90 
are Rae SHA ROR SRO vet IE ge nb VS 7, 7 Mami EAE PE RA 2,718 531 19. 58 
We che ca oa he os ES do a cede Oecd cent iname ela tewinaeer anos 2, 523 934 87. 01 
> Ee RA AE eS ecg eg ge eM Ba Ay iP dg ipned Sg Re A Nes Fale Ge 2,929 1,210 41.31 
Bene Sey hae ee cae halons nandun ode aen EOE ubenedepeaeie 2,103 1, 134 53. 92 
Be a a so ee ew eee 2, 078 1, 258 60. 44 
Fe re ambien cel sce kas Ree eeRe Es ec bacdbadndicaasiy 2,218 1,331 60. 00 
_ eeR ee dace Og tilpe APMC Cncr acre ee Catia ete 2,711} 1,496| 55.18 
Cees ee ea eS aa ae a ee 2, 236 1,098 | 49.10 
MO Se eee 1,820 967 | 53.13 
Row 1 was nearest to the windbreak, while the height of the 
windbreak, perhaps at most 6 meters, was not sufficient to 
protect the trees in rows 4 to 10. It is evident from this that 
much can be done to reduce canker infection by (a) location of 
the orchard to avoid such violent winds as may occur in season- 
able periods favorable for canker development, and (0) the use 
of high, thick windbreaks. These conclusions have been cor- 
roborated repeatedly by field observations. 
INFLUENCE OF COPPER SPRAYS UPON THE QUALITY OF THE FRUITS 
¥ Although canker was materially reduced by the copper sprays 
in these experiments, there were considerable disadvantages, 
evident at harvesting time, following the use of such sprays. 
These were an increase in red-spider infestation on sprayed 
trees, an increase of sooty mold, Meliola cameliae, upon the 
fruits, and an increase of melanose. The occurrence of these 
diseases upon the plats is shown in Table 13. 
Table 18 shows very little sooty mold for unsprayed plats 
and for plats sprayed with lime sulphur and formalin. Plats 
sprayed with the copper mixtures show an increase to as high 
as 24 per cent of fruits affected with sooty mold; there is no 
evidence from this table that any one of the copper sprays 18 
less serious in this respect than the others. The explanation 
generally accepted for such an increase of sooty mold following 
