The daily sentinel., 1906-12-13
A NEW DISEASE
Makes Its Appearance in the Alfalfa
Fields of Colorado Says Prof.
Paddock, of the State Ag-
ricultural College.

The following interesting state
ment regarding a new disease that
has fastened its fangs upon alfal-
ia, the great stock feed of the west.
is from the pen of Prof. Paddock Of
the state agricultural college, and
has just been made public:
up to the present time the AL
falfa plant in Colorado has been par
ticularly free from disease. 1t is
true that leaf-spot is always present
and in damp situations n mildew Of
ten makes its appearance The form
er disease causes considerable
amount of damage in the aggregate
but after all its presence is not usual
ly considered. But recently bac-
terial blight has appeared and in
some locations and localities it has
been quite destructive. The purpose
of this bulletin is to call attention to
this newer disease and through this
means get in touch with infected To-
Calities
Complaints have come to the eN-
pertinent station from one locality
for the past two seasons of the dying
out of alfalfa plants in the spring
The growers could scarcely believe
that the troble was due to winter in
jury since IL had not occurred before
under similar conditions, and since
dead plants were found alike on high
and low land. and on wet and on dry
situations. The presence of numbers
of small maggots in the decaying
crowns was the most popular theory
advanced to account for the dead
plants. On visiting the fields early in
the spring 1t was evident that winter
injury could not have caused the
damage and that the maggots We're
only present because of the decay and
not a cause of il.
In June OF the present year. we
had the first opportunity of inspecting
the fields during the growing sea-
son. The cause of the injury was
now apparent as the numerous
blackened stems from which n thick
juice was oozing plainly indicated a
bacterial blight. and subsequent eX-
animation has shown this to be the
probable cause of the trouble.
The first evidences of disease to
be noticed by the casual observer is
a short. weak and light cOlored grow
tn of the first crop. and the stems
even over a large field. may not aver
age over a foot in height at the time
the first cutting is made. A close cN-
animation shows that majority of
these stems are discoloTed, in fact
nearly black, for a portion of their
length, and drops of dried juice will
be found on many of them. Such
stems are also very brittle, and cas-
lily broken. The disease apparently
does not kill many plants the first
year. but in time so many of the
plants die that the fields are use
less
The disease evidently runs its
course for the season with the first
crop and those plants which have suf-
ficient vigor makes satisfactory grow
tn for the second and third cuttings
and little or no trace of the blight is
seen during the remainder of the
season. But the following spring
a renewal of the outbreak may be ex-
pected.
THE plants begin to die after the
blight has been abundant for more
than one season and as the decay
appears in the crowns of the plants
ana NAV involve the tap root. The
crown buds are thus destroyed or the
nutrition may be so interfered with
that the plants die.
Almost nothing is known of this
blight as yet, consequently remedial
measures cannot be discussed except
that It seems to be advantageous to
cut the first crop early and to delay
the date of the first irrigation until
after this time if possible.
The horticultural section of the
experiment station solicits cores
pondence with any one who has rea-
son 10 believe that this disease is
present in his fields. Means have
been devised for combating most
plant diseases and we believe that
this one will be no exception. How
ever. 1t is important that its nature
be understood at the earliest possible
moment and one of the important
means to this end is through the eX-
perience of growers. 1t is this rea-
son that we invite cooperation