WHITE-PINE BLISTER RUST. 87 
phur in parallel experiments. The following statement has reference 
to spraying that was done every two weeks through the summer : 
It was realized that the spray would have to be applied to the under sides of the 
leaves to be effective, and though this was done as thoroughly as possible in our work, it 
must be admitted that it takes so much time and care that satisfactory spraying of this 
land would be out of the question in a commercial way. Owing to frequent rains dur- 
ing the summer, the best results were not obtained from this work, but even allowing 
for this it was certain that, though the rust can be greatly reduced by spraying, it can 
not be controlled sufficiently to prevent the spread of infection. Consequently, what- 
ever value spraying methods may have as a means of protecting individual planta- 
tions, they are likely to be of little use in combating the disease as a national pest. In 
this connection, it has been suggested by the Dominion Botanist that since spraying 
will not completely control the rust, it may work a positive harm by keeping the in- 
fected leaves longer on the bushes in the fall, and thus materially extend the period 
during which infection of the pine may take place, providing, of course, that the in- 
fection of pines is possible throughout the whole season. 
Stoddard, in 1918 (23), carried out a spraying test in Connecticut, 
with the following results : 
Spraying experiments for the control of the blister rust were conducted on red and 
black currants. Results were nearly negative on red currants because of lack of in- 
fection. On black currants spraying gave nearly complete control throughout the 
season. However, such careful and frequent spraying had to be done that it is not 
considered to be a practical method of control. 
No experiments have been made in the spraying of pines, as it has 
appeared useless in larger trees where the infections have occurred. 
Seedlings in seed beds of nurseries may perhaps be protected from in- 
fection by spraying, as has been suggested by Clinton and McCormick 
(14) . It should be well tested under extreme conditions (106) . 
CLOSE PASTURING OF RIBES. 
The use of animals to feed on the leaves of Ribes is feasible if the 
area is pastured heavily until well cleaned up. Sheep are very close 
feeders and undoubtedly can be thus utilized (23, p. 7). Goats are 
the most promising animals for the purpose, however, as they are 
omnivorous feeders. This method can be recommended only for 
areas where small pines are absent or too few to be of value. 
REMOVAL OF DISEASED PARTS AND DISEASED PLANTS OF RIBES. 
The removal of the infected leaves has been attempted in a few 
lots of Ribes nigrum in nurseries, but it is costly and merely palliative 
in that it is usually only postponing more drastic measures. The 
cutting back of infected Kibes bushes has been tested in a few 
instances, but like the plucking of the leaves, it is usually unsatis- 
factory, since the bush remains to take infection another season. 
The removal of diseased plants only of Ribes is unsatisfactory, 
as it has been found that it requires repeated visits through the season 
for the removal of plants which Lave developed the disease since 
