Burlington weekly free press. [volume] (Burlington, Vt.) 1866-1928, 1892-08-18

POTATO BLIGHT.
Dotnnist Jones o: the Experiment sta
tion Gives Some Valuable Facts for

Earmera.
STATE AGRICULTURAL EXPERIMENT STA
TIoN, BURLINGTON, Vt, Aug. -, 1892. (
Tho true blight or rust has appeared on
the potato leaves, and the weather is favor
able for the rapid aud destructive spread of
the disease. Unless preventive measures are
| taken at once there will be much loss from
tine rot. Those who intend to use tho
Bordeaux mixture should not delay an hour
| longer than is necessary.
| Since sending you my former letter two
| weeks ago largo number OF letters Of in
quiry have been received which emphasize
| the need of further information by the
| farmer as to the so.called "new disease OF
| the potatoes.
This disease has attacked early potatoes
very generally throughout the State. 1t is
all entirely different and distinct disease
from the true blight and it Is very impor-
tunt that all potato growers learn to dis
| tinguish the two malat!ies. \ circular
which it is hoped will aid them in doin <
has been sent to the postmasters throughout
tie state for free distribution.
The most important practical differences
| between the diseases noted in this circular
are as follows:
| Flrsr-Tho spores Of the fungus which
causes the true blight or rust pass from
the blighting vines to the tubers causing the
rot No rotting of the tubors is caused by
tho new disease.
Socond-The true blight or rust at
tacks later potatoes worst. The new dis
ease" is confined to early potatoes.
Third-Tho true blight or rust can be
checked by spraying with the Bordeaux
mixture. The new disease is not SO easily
checked by spraying.
The following points will aid in distin-
gushing the two Diseases
New Disease-Practically everything in
the way OF diseased potato leaves up to this
date, August II, has been the new dis
ease This is everywhere on early potu-
toes, so far as we can learn. The diseased
plants appear sickiy and OF yelowish cast,
instead OF a dark healthy greon. Soon the
leaves turn yellow and die. The death be-
gins on un.njured leaves about the tip and
edges, and the leaves die rather slowly, so
that thoy become crisp and curl at the
tip and edges as the disease progresses.
The trouble is worse Oh leaves that have
been partially oaten ny potato bugs or other
insects. Whenever the leave is injured the
disease attacks it and spreads from those
spots. Thus leaf may show score or
more of black spots varying in size from a
pm mead 10 iAafUic. III some pieces OF
early potatoes every leaf is dead or dy!n
Blight-Nery few potato growers will
MISTAKE the true blight or rust when they
see it. This disease is commencing to show
on later potatoes. The large blush black
spots appear on the leaves at any place.
The disease spreads 80 rapidly that the whole
leaf is killed in day or two. There is not
time for it to dry and curl but it hangs limp
and rottiug from the stem. The surest eVi
dence OF the blight as distinguished from tbs
new disease is tho presence of tee mildew
which causes the blight, 1t can easily bt
seem on the under side OF the rapidly blight
irg leaves as delicate white mildew which
looks like frost work upon or about tbs
edges of the black spots.
l.. Il. JONES, Botanist.