The united opinion. [volume] (Bradford, Vt.) 1881-1970, 1894-07-13
Potato Blight.

EDITOR OPINIoN.-So MANY are inorir
ing about spraying potatoes for blight that
II seems best u Issue another circular lattar
giving directions for the use of r ,rdea,,I
mixture. We are satisfied after five wears
| experience that II pays to spray ali Tnnta'
toes in Vermont with this mixture w. P0'"'
| Our potato vines are attacked Inv two die
tinGt D,lgtlts, Inc early blight attacks
earlier potatoes, spreading slowly in INV
ana august, causing premature death Of
vines but no rot The late blight ATTACKS
later potatoes in August and Sentembar
spreading rapidly in warm, moist we eatReI'
ana is followed by rot The early hlight IL
a complex trouble caused by the attacf2C Of
insects as well as fungi. It is already an
ptarlng on early potatoes Being a com
pllcated disease, it is less perfectly CON
trolled by spraying than is the late BLIGHT
Our results last summer showed that it can
be at least partially checked by Bordeanx
mixture. The late blight and rot is a
fungus disease. and B0rdeax mixtnre
properly applied is an almost perfect rene.
dy. BY It's use we have invariably kent
our later potatoes alive through September
ana nave lost but very few from rot The
result has been that our Yield of later pOta
toes has been more than doubled by spray
ing. Every potato grower should try it
thls summer, especially on medium and
late potatoes.
The formula for Bordeaux mixtuge is:
rive pounds copper sulphate, five pounds
lime must be fresh not air slackedl tiftv
gallons Zone barreI water. Dissolve the
copper sulphate in clean wooden or brass
vessel, SLACK the lime in another vessel, then
dilute with water to a thin WhiteWash and
strain it into the copper solution. Stir
Thoroughly and add water to make about
fifty gallons Zone gallon.
use:
l. KEEP YOUR N1yTIrPE CTpAN Cbino
Jumps or llme. etc, IN the mixture will clog
pump or nOZZleS. Therefore, Thoroughly
clean all vessels to begin with Strain all
water and copper solutions through cheese
clOtn unless they are perfectly clean Strain
the lime whitewash through some c0arser
clQlJl OF sieve and throw away all the dregs
and Jumps.
z 70 DISSOLVE BLUE vITRIoL-Itmay
be quickly dissolved in water by heating in
a brass kettle to the boiling point. or by
pouring boiling water over it. The most
way we found, however, is to
dissolve in cold water 10y putting it in a
course sack and Suspending this in the top
of tub or barrel OF water. AS fast as the
heavy solution forms it settles to the bottom
and fresh water rises. BY using a gallon
of water for each pound Of blue vitriol it
will dissolve in few hours in this way.
3. KEEP STOCK SOLUTIoN.-We find
it most convenient to dissolve considerable
and to keep it on hand in a covered blrrel.
We put in pound Of VitriOIfor each gallon
Of water, and as we wish it from time to
time We simply stir it up and dip out as
many gallons OF the solution as we wish to
use pounds of blue vitriol.
f. OTHER CONVENIENT METHODS-To
avoid the trouble of weighing. the blue Wit
'lOl may be measured out five pounds
EQUALS two quaTtS), and the line added by
est. This test consists in pouring a few
irOps of the solution of ferro-cyanide of
potassium Il OF. in OF. water) into the
mixture. If there is not enough lime in the
mixture this solution will at once turn
but if enough lime has been add
ID there will be no change of color
5, CAUTIoN.-StrOng copper sulphate
olution alone will kill the leaves. Fresh
y Stacked lime neutralizeS the sulphate
nd prevents this .cauStic action. If not
ure that the lime is fresh or good or that
hat enough is added, the mixture should
e tested as described in 4, or few plants
My should be sprayed at first to test its
ctiOn.
=. POTATO Observation-Disclosures mix
nre will not alone kill the potato bugs.
Id Paris green when needed at the rae
= pound to fifty gallons
T. WHEN TO sPRAY.-Remember that
bordeaux mixture is preventative. not
ure. and the first application should be
lade before the disease appears. The fol-
)WlpS udteS IOr spraying potatoes are
ased on our experience at Burlington:
Early potatoes planted April to May s.
pray about July l, 15 August, and again
needed.
Medium potatoes planted May to May
spray about July Is, August ], Is, and
gain if needed.
Late potatoes planted May Is or later
pray about August l, IA. % and again if
eeded.
3. How TO APPLY IT.-The mixture NAV
2 put on in any way so as to cover the up
or surface of all the leaves. The best way
do this is with force pump which has
BOD spraying nozzes attached. Unfortu-
ately but few have those pumps. Ap-
wing with common watering pot or
18th pail and broom or wiSp of hay takes
ore time and patience, as we'll as more of
e mixture, but if thoroughly done will
We good results. In most cases where
Altering pot is used it will work better if
e holes rose are enlarged with an awl.
pply thoroughy-it will not injure the
mes. providing the mixture has been prop
'ly made.
Further information will be freely given
answer to any letters of inquiry
L. K. JOINS, BOtanist.
Experiment Station. BurIlnptOn- VT