242 
are tlie principal means by which the fungus is carried through the 
winter and the presence of an ascigerous form, described by Sorauer, 
seems almost'unnecessary to a maintenance of the disease in a region 
once infested. 
The practice of allowing stocks to remain in the nursery rows when 
leaf-blight has affected them so severely as to render them unbud- 
able, seems unwise when considered from a hygienic standpoint. 
Such stocks are almost sure to harbor the parasite in its winter form 
upon their slender branches, which are lacking in vigor. It is from 
these stocks that the disease apparently spreads to other plantings of 
seedlings in the vicinity and to such budded stocks as are susceptible. 
It would seem advisable, therefore, that when leaf-blight causes a large 
number of failures in the seed bed, the diseased seedlings should be 
headed back to within 1 or 2 inches of the ground and all side shoots 
likely to harbor the parasite removed. Such procedure would un¬ 
doubtedly decrease the liability to so early an attack of the disease 
and enable growth to be made before the malady had time to spread 
from infected localities. The same immunity as that shown by rap¬ 
idly growing “buds” may prove here a valuable factor. It has been 
objected, however, that the simultaneous appearance of several shoots 
from the headed back seedling would jirevent, or at least materially 
hinder the budders in their work the following fall. This obstacle 
could be overcome by the early removal of all but one shoot. It seems 
to me that this method of eradicating the disease is sufficiently prom¬ 
ising to warrant a thorough test. The matter of protecting seedlings 
by wind-breaks has not been thoroughly tested to my knowledge, and 
from observation on the spread of the disease I am inclined to believe 
it is worthy a systematic trial. The freedom from leaf-blight, which 
isolated blocks of pear seedlings often show, tends to confirm the ob¬ 
servation that the malady travels quite slowly from seedling to seed¬ 
ling. In an experimental block of seedlings mentioned below it 
required nearly two months for the disease to travel from the east to 
the west end, a distance of 150 feet. 
Two quite distinct experiments were made with a view of preventing 
this disease, one inaugurated in 1891 to test the effect of fungicides 
upon stocks, and the other carried on during the season of 1892 with 
seedlings in the seed bed. The results of only the former experiments 
are recorded here and an account of the latter is reserved for future 
publication. 
EXPERIMENTS WITH STOCKS. 
These experiments were inaugurated in the spring of 1891 and con¬ 
tinued until the fall of 1892. The stocks planted in 1891 were sprayed 
both seasons, the design being to ascertain the effects of two consecu¬ 
tive years. The results are here presented briefly and the minor details 
are to be found at the close of the article. 
