8S4 ttepori on Uxperiments tviih " BouilUe Bordelaise.'* 
Tlie dressing applied on all tlie plots was one of 20 lb. sulphate of copper, 
10 lb. of quick lime to 100 gallons of water. I made use of one of the hand 
hop-washers we use in Kent, and with slight modifications this machine is 
well adapted for the purpose. 
The first application was made on July 28, to plots of Beauty of Hebron, 
in which the disease had just appeared, and to Magnums, which were then 
perfectly free from it. On August 5, I treated tlie following varieties in 
another field, viz. : Imperators, Sutton's Abundance, and Chancellors, in 
which indications of disease were appearing. It may be interesting here to 
note that the first disease I observed amongst the Imperators was on plants 
immediately surrounding one plant of Beauty of Hebron, and which being 
itself badly affected had contaminated its more hardy neighboars. 
I have not (jiven the weight of diseased tubers in the following table. In 
the Beautj' of Hebron plots, however, 12-5 per cent, of potatoes were affected 
in the case of the untreated, as against 2'6 per cent, where dressed. These 
were dug early, September 2, and we were therefore able to weigh the un- 
sound tubers, but the other varieties were raised October 28 and .30, when 
the diseased tubers had completely rotted away. The results obtained were 
as follow : — 
Tariety 
Size of 
plot in 
poles 
Dressed plot 
Unclressed plot 
Increase 
Per plot 
Per acre 
Per plot 
Per acre 
Per acre 
Percent. 
c. q.lb. 
t. c. q.lb. 
c. q.lb. 
t. c. q. lb. 
t. 0. q. lb. 
" Beauty of Hebron " 
20 
25 0 26 
10 1 3 12 
23 1 20 
9 7 1 20 
0 14 1 20 
"■" 
" Abundance" . . . 
3 
4 0 7 
10 10 2 18 
3 1 16 
9 0 3 22 
1 15 2 24 
lC-6 
"ChanpcUor" . . . 
4 
5 3 25 
11 18 3 20 
4 3 11 
9 13 3 20 
2 6 0 0 
23-2 
" Magnum Bonuni " ' 
5 
G 3 1 
10 16 1 4 
4 1 16 
7 0 2 8 
3 15 2 24 
5875 
"Imperator" . . . 
8 
14 2 22 
14 13 3 20 
10 3 1 
10 15 0 20 
3 18 3 0 
3C-6 
' The Magnum plot was sprayed a second time on August 15. 
In spite of the unfavourable weather following the applications, rain 
prevailing throughout the month of August, the striking efficacy of the 
remedy is apparent. The advantage is not wholly or even chiefly derived by 
the previ-ntion of disease in the tubers, but rather from the prolongation of 
the life of the plant which ensues from tlie application. Instead of being 
cut off when the crop is but half grown, time is allowed the plant to fully 
develop its tubers, so that hardy and late kinds, such as Imperator and 
Magnum, benefit more than the Hebrons, which are much more susceptible 
to blight. Ilebrons were tlie only variety that .suffered to any e.xteftt in the 
tubers with me this season, although all the varieties had their haulms de- 
stroyed. Ilebrons, if plantud early, should, to a great extent, have obtained 
their growth before disease appears. The preservation of the bine in vigor- 
ous life accounts for the large crop we dug where the copper solution was 
used on tlie late varieties. 
It appears most important that the spraying should be very thorough. 
There should be no stint in the quantity of the dressing applied, so that 
every leaf if pos.'r^ible may receive its share. I am of ojuuion that it sliould 
not bo ap])licd earlier than the pei'iod at which disease usually appears. In 
Kent we have it about the last week in July. Otherwise a second spraying 
may be necessary. 'J'ho lime should be kept in suspension by stirring the 
liquid. "When properly done it appears to me that one a])plication will 
be found sufficient. 
