Delaware gazette and state journal. (Wilmington, Del.) 1883-1902, 1889-04-11

Special agent smith Gives His
Views upon tho Disease.

Special Agent smith Gives His
Views upon tho Disease.
Edwin Il. Smith, special agent of the
government assigned to inspect the peach
| yellows, has made n preliminary report
| of which tho following is an extract Civ
ing his opinion % to the cause of the
| disease:
From what precedes we are reasonably
safe Ia concluding that yellows is not due
TO climatic inilnences. Frosts, floods
and drouths may be modifying influences,
but are nothing more. Injuries by men,
quadrupeds mud borers may also be in
cluded in the list OF disproved theories.
They stand in no casual relation to this
disease. To the same category may be
added excessive cultivation, neglect OF
cultivation and neglect of pruning. So
also injury TO tap-roois, propagation by
buds rather than by needs, detective
drainsge, use OF animal nRnures, 10.
Some of these things may favor the de-
velopment of peach yell0ws, but think
none of them can cause II. The evidence
here set forth seems to establish this be
yond reasonable doubt. Probably most
Of my readers will be ready to admit that
soil exhaustion IL also an unsatisfactory
explanation. AS the oage now stands
this theory must DO set aside as untena.
lie. At least we need give no further
attention until more and stronger eyi.
dence ia adduced in its favor. | write
this with regret, for hoped to BIO able
to confirm this view, rs 1t would have
offered IN easy and practical solution Of
the whole difficulty.
Among supposed causes deserving fur
ther inquiry l should place root-aphides
and root-fungi. anu inclined TO believe
that neither one Is at the bottom of the
tronble; yet another summer in the field
would enable me TO speak more posi-.
lively.
What then remains? The larger fungi
are out OF the question, and / can think
of nothing else but micro organisms.
The spread of yellows from diseased buds
TO healthy stocks, which have carefully
verified, points strongly TO some con.
tagium yivum rs the cause OF the disease.
II micro organism bs really the cause,
1t probably occurs quite constantly in
some part OF each diseased tree, and this
must be established beyond question; II
mnst also be clearly distinguished from
similar organisms not related to tue
disease; and, finally, il must be Isolated
by cultivation in suitable nntritiye
media and be able to produce the disease
when inserted into healthy trees. II,
from q pure culture Of some micro.
organism peach yellows can he induced
In healthy trees, then the case IL closed
and there can be but one verdict. /
write this paragraph with ease, bnt the
work itself Is full of difficulties. Nature
does not yield her secrets upon the r1ere
asking. Only those engaged in similar
inquiries con have any adequate concep-
tion ofthe labor involved or OF the perplex
tiles which beset one at everystep. More.
over, in ouch an inquiry nothing can be-
promised in advance. The Investigator
and the public alike must take their
chances on the results. However, az l
have elsewhere stated, there seems to be
every encouragement for the renewed and
persistent prosecution of this inquiry,
BY suoh effort sources OF error will be /
discovered, difficulties overcome, and the |
truth finally established.