1846. 
THE CULTIVATOR. 
333 
enemies are the “peach-worm” and the “yellows.” “The first,” it is said “readily yields to the knife and 
the treatment of semi-annual examinations; the latter being a constitutional, consumptive, or marasmatic 
disease, for which no other remedy is as yet known or to be practiced, but extirpation and destruction .” 
The first article in the second number of the Horticulturist of which we would now offer any notice, is 
one on “The Blight in the Pear Tree,” by the editor. Mr. Downing believes that there are “two 
distinct maladies ” known by the name of blight. One, he thinks, is caused by insects, and the other by the freezing of 
the sap. He remarks—“ The insect blight we do not consider a malady of a very serious nature. As it 
begins at the extremity of the tree, at or near the ends of the branches, and as its spreading depends entirely 
upon the care or carelessness 
of the cultivator, it is his 
own fault if it ever destroys 
many trees. Experience and 
observation have convinced 
us that the pruning knife, 
vigorously applied the mo¬ 
ment the insect first com¬ 
mences his attack in June, 
and faithfully persisted in, 
will soon rid one's garden or 
orchard of this minute but 
most poisonous Scolytus .” 
As soon as a branch turns 
black, it should be cut off a 
foot below where it is af¬ 
fected or discolored. 
The “frozen sap blight,” 
Mr. D. thinks “another and 
much more alarming dis¬ 
ease,—that it doubtless ari¬ 
ses from the sudden freezing 
and thawing of the sap ves 
sels in winter.” Of this 
disease he speaks as follows; 
e ‘ If any one will carefully 
examine a tree affected by 
the frozen sap blight, he 
will notice spots on the bark 
of the trunk or principal 
The bark there is contracted, blackish, and is shrunk 
As 
Fig. 
iSsr-S:,' 
Wlfl 
branches, which have a dead or withered appearance. 
below the level of the surrounding healthy portions. This is often observable very early in the spring, 
the season opens, the tree starts into leaf, and grows luxuriantly: suddenly, about the middle of June, sometimes 
a little earlier or later, a terminal shoot, a branch, or the whole tree, droops and dies. 
“ If we pursue the examination a little further with the knife, we shall find the inner portion of the bark 
next the wood—in short, that part where the downward current of sap takes its course—has assumed a 
blackish hue. This taint is not confined to that part of the tree, viz., the limb or branch where the external 
symptoms of the blight are 
shown,but extends, more or 
through the whole of the 
rest of the tree, unless it 
is arrested by amputation 
in a very early stage.” 
Mr. Downing observes 
that—‘‘the frozen-sap blight 
is not confined to the pear 
tree alone. We hav e seen 
it in several other trees not 
entirel}' hardy in this lati¬ 
tude, or which suffer from 
winters of unusual severity. 
Such are the Ailanthus, 
the Catalpa, and the Spanish 
Chestnut.” 
From the fact that these 
diseased spots almost inva¬ 
riably appear on the south¬ 
ern side of the trees, Mr. 
D. thinks that the injury is 
occasioned “ by the too rap¬ 
id thawing caused by the 
sun’s rays which bursts the 
sap vessels, and is the im¬ 
mediate cause of the matter 
pq deposited on them. Were 
’ it the effect of frost simply, 
the evidences would appear equally on all sides of the trunk.” ,, ef Vnr fh 
In answer to the question “What is the remedy for the frozen-sap blight? it is observed Fo the 
blight in its milder forms, as we have already said, vigorous pruning is often sufficient to arrest its ui ler 
progress. When it has thoroughly passed into the system of the tree, there is no known remedy. Hut per¬ 
haps a still more important question to the orchard grower of pears is this: Is there no certain preven ive 
