October 24, 1891. 
THE GARDENING WORLD 
115 
BOUILLIE BORDELAISE 
AND THE POTATO DISEASE. 
In former issues we have given the result of experi¬ 
ments carried on both in this country and on the 
continent, with the mixture of sulphate of copper 
and lime known as Bouillie Bordelaise, which for 
some time past has been receiving a considerable 
amount of attention as a remedy or preventive for 
the Potato disease (Phytophthora infestans). The 
experiments on the continent have furnished results 
so satisfactory that the French Government has ad¬ 
vocated the general adoption of the fungicide by the 
growers of that country. Messrs. R. Veitch & Son, 
Exeter, have also found very beneficial results to 
their Potato trials by spraying with the mixture. 
Quite a different result comes from Reading, 
where Messrs. Sutton & Sons have been carrying out 
a very extensive series of trials during the past 
summer, following the recommendations of the 
Board of Agriculture as published in May last, as 
to the number of sprayings which should be given 
and the interval between each. Considerable interest 
attaches to the experiments from the fact that 278 
varieties of Potatos were subjected to treatment, 
while the plots or trials reached a total of 810. Each 
trial was divided into two equal portions, one of 
which was sprayed, while the other was allowed to 
take its natural course, in order to check the results 
obtained after dressing. The total weight of sound 
Potatos obtained from the 8x0 rows that were un¬ 
dressed was 5 tons, 8cwts. 2 qrs. 5 lbs., while that 
obtained from the same number of dressed rows was 
only 4 tons, iycwts. x qr. 1 lb., giving an increase of 
11 cwts. 1 qr. 4 lbs. in favour of the undressed plots, 
or a little over 10 per cent. The result is as disap¬ 
pointing as it was unexpected, not only to the growers 
themselves, but to the public generally, which is 
looking forward to a practicable means of combatting 
the disease successfully. 
The trials cannot, however, be considered as con¬ 
clusive, nor that they entirely disprove the results 
obtained by other experimenters. Science never 
adopts a creed, and in this case there are no doubt 
several coincidental causes at work which, in a 
measure, may combine to frustrate the result of the 
trials. For instance, the soil at Reading is generally 
of a poor and hungry nature, favourable to the clean 
growth of Potatos, and unfavourable to the rapid 
spread of the disease owing to an insufficiency of 
moisture. This is in a measure borne out by the 
fact that the early varieties had matured their crops 
before the disease made its appearance. On the 
other hand, however, we are brought face to face 
with the fact that the dressed plots of these varieties 
suffered a decrease of weight compared with those 
that received no dressing at all. The growth of the 
tubers where the foliage had been dressed must 
have been checked. It would have been very 
interesting, and perhaps have afforded a clue to the 
results, if a record had been made from time to time 
of the effects of the mixture upon the foliage. In the 
present instance the Bouillie Bordelaise cannot be 
looked upon in the light of a fertiliser. 
Experiments on heavy, rich soil, where the disease 
is usually very virulent, especially in wet seasons 
like what the past has been, would be well worthy 
of trial by way of contrast to the above on a light 
and hungry soil. Equally significant, however, is 
the fact that Regents, Woodstock Kidney and 
Victoria, which are very liable to be destroyed by 
disease, gave more satisfactory results. -A row 
of Woodstock Kidney that had been dressed gave a 
weight of 27 lbs., while an undressed one of similar 
length gave only 20 lbs. In like manner a dressed 
row of Victoria showed an increase of 6 lbs., and 
seven rows of Reading Giant gave an increase of 
25 lbs., although one line showed a decrease. 
Three lines of Dalmahoy showed a total increase of 
22 lbs.; two lines of Village Blacksmith gave an in¬ 
crease of 3 lbs. ; two lines of Vicar of Laleham gave 
14 lbs.; of fifteen lines of Best of All, six lines 
showed a loss of weight after dressing, while nine 
lines showed a total increase of 16 lbs.; thirteen 
lines of Satisfaction gave an increase of 21 lbs., but 
five of them showed a loss of weight. A number of 
other varieties showed a slight increase, including 
Fox’s Seedling 3lbs.. Forty-fold ilb., Jersey Fluke, 
Reading Abbey, and White Rock 3 lbs. each, Queen 
of the Valley 8 lbs., Reading Giant 4 lbs., Peach 
Blow 1 lb., and Windsor Castle 15 lbs. The above 
constitutes practically all the cases of increase 
as far as the named varieties in cultivation are 
concerned. 
Disease resisting varieties come prominently to the 
front as instances where spraying may not only be 
dispensed with, but profitably so ; and herein lies the 
crucial point. According to the results Bouillie 
Bordelaise was injurious rather than otherwise, 
inasmuch as the sprayed plots showed a decrease of 
weight compared with those which had been left 
alone. The total loss would include the deficiency 
in the weight of tubers, time, labour, machinery and 
material for spraying with. Of forty-six lines of 
Abundance, thirty-five of them showed a decrease, 4 
were of equal weight, and seven of them were abo/e 
the standard; the decrease on the whole amounted to 
1 cwt. and 18 lbs. Magnum Bonum showed even a 
greater deficiency, for thirty-one rows showed a 
decrease of 1 cwt. 2 qrs. 14 lbs., or 5 87 lbs. to the 
line. In various other cases the deficiency varied 
from | lb. to 7 lbs., and in exceptional cases 11 or 12 
lbs. None of these figures appear very striking, but 
over a large area the deficiency would be great. The 
question for scientists to solve, is the cause of the 
decrease, for it must follow that if the Bouillie 
Bordelaise had no injurious effect, the sprayed lots 
would crop as heavily as those that had not been so 
treated. 
Experiments were also carried on with a large 
number of seedlings not yet in commerce, and the 
bulk of them only under number. Curiously enough, 
the larger number of plots showed a result quite 
different from that obtained with the old varieties. 
The increase was not great, but it varied from 0 5 to 
16 lbs. per row that had been sprayed. The decrease 
of weight in the unsprayed plots varied from 0 5 to 
25 lbs. In both cases, however, the difference either 
way was not great as a rule, say from 2 to 4 lbs. 
Such differences might, in many instances, depend 
upon the fertility of the varieties themselves, as it is 
well known that many kinds have their own pecu¬ 
liarities. 
Special field experiments were made with three 
varieties, namely Sutton’s Ringleader, White Beauty 
of Hebron, and Chancellor. Of the first two, 
5 poles were dressed and an equal area undressed. 
The first named showed a decrease in weight of 
2 cwts. i qr. 23 lbs., where subjected to spraying; 
and the second was also lighter by 2cwt. nibs. 
Only 2\ poles of Chancellor were subjected to the 
dressing, and they showed an increase of 1 lb., as 
compared with the unsprayed 2J poles. On the 
whole then the results have been unfavourable to the 
employment of Bouillie Bordelaise, except in the 
case of varieties that are peculiarly liable to the 
disease. 
The results of the official experiments both in 
England and Ireland will be looked forward to with 
interest, so as to prove or disprove the efficacy of 
Bouillie Bordelaise ; for as many of the varieties 
liable to be badly affected by the Phytophthora are 
amongst the best in point of quality, it would be a 
public boon to find some remedy or palliative for the 
disease. 
m » 0 
DELPHINIUM VESTITUM. 
The bulk of our garden varieties of Delphinium 
are forms or hybrids of D. elatum, D. formosum 
and a few others, all of which are usually very tall 
and vigorous plants, especially if planted in rich, 
well tilled and manured soil. There are several 
species of a showy nature from the Himalayas, both 
dwarf and tall. The dwarf ones might well be taken 
in hand by those concerned in the improvement of 
Delphiniums, and a new race thereby evolved, 
which could hardly fail to find favour with those 
whose gardens are limited for space. D. vestitum 
is flowering at present upon the rockery at Kew, and 
comes from the Himalayas. The stems are only 
18 in. high, and furnished at the base with ample 
and deeply five-lobed leaves. The specific name 
would seem to apply to the flowers, which are clothed 
on the outer surface with downy hairs. The sepals 
are large and blue or purplish-blue, forming, as in 
other species, the most conspicuous feature of the 
flower ; the petals, on the contrary, are small, black 
and covered with yellow hairs as> in the case of D. 
formosum. The late flowering is, no doubt, due in 
part to the wet nature of the season, as often hap¬ 
pens in the case of the improved garden forms of D. 
elatum andD. formosum. 
('Mtanimts from f(jq tthndtr 
nf ©ri^nte. 
Apple Scab and its prevention. — The Journal 
o/Micology (American) gives an account of some ex¬ 
periments which were carried on with the view of 
preventing the development and spread of Apple 
Scab on a fruit farm near Ithaca, Richland County, 
U.S.A. The weather during the early part of sum¬ 
mer was excessively rainy, and this did much to frus¬ 
trate the objects of the experiments, by washing 
away the fungicides which were applied to the trees 
by spraying apparatus. The fungicides consisted of 
(1) copper carbonate dissolved in ammonia, also 
suspended in water, (2) sulphur powder, (3) the com¬ 
pound of ammoniated copper sulphate and ammonium 
carbonate. The sprayings were given at different 
times from May 5th to September 2nd. When the 
fruit were gathered they were sorted into three 
qualities, as to freedom from the fungus quite 
independent of size, namely (1) those quite free 
from scab, (2) those showing scab spots but not 
sufficiently large to seriously damage the fruits, and 
(3) badly-affected fruits. The results of the various 
trials showed that it was very important that one 
spraying at least should be given before the expansion 
of the flower buds. Copper carbonate dissolved in 
ammonia was as effective as twice the amount of the 
same material suspended in water ; but the import¬ 
ance of the latter experiment was demonstrated from 
the fact that Paris Green could be employed in the 
same spraying to prevent the ravages of the Codlin 
Grub. 
The sulphur powder seemed to increase the viru¬ 
lence of the fungus, but that result might have been 
the result of its solubility, and liability to be washed 
away by the heavy rain. The mixture of ammonium 
carbonate and ammoniated copper sulphate gave the 
best results of all the applications, as a larger per¬ 
centage of the fruit was free from scab. 
Larva form Singapore. —Fortunately for us, 
our climate serves largely to protect us from an in¬ 
vasion of insect enemies which reach us from all 
parts of the world amongst [importations of plants. 
Several of them succeed in establishing themselves 
in hothouses much to our discomforture, by their 
rapidity of increase and destructive habits, or the 
annoyance they cause us. Doubtless the greater 
number of such pests which reach our shores from 
foreign countries, and especially from warm climates, 
soon perish, judging from the number of various crea¬ 
tures which reach Kew annually. A larva of striking 
appearance was recently picked from the root of an 
Orchid which arrived in a case of plants from Singa¬ 
pore. It measured i^gin. in length, and ^in. in 
thickness,and except that it tapered slightly toward the 
head, was perfectly cylindrical. It was of a bright shin¬ 
ing brown with exception of the upper side of the first 
four segments, including the head and the last one 
which were darker, and the whole resembled a piece 
of polished mahogany. The dark portion of the 
segments just mentioned were densely covered with 
fine depressions or punctures resembling those of a 
thimble, but smaller. It had four rows of spiracles 
for breathing, those on each side of the middle line 
of the back being the most prominent. Its six short 
legs were accommodated in a depressed portion in 
the usual position close to the head, while the rest of 
the under-surface was glossy and smooth. The rings 
or segments, however, were well marked, and the 
body as a whole seemed well adapted for moving 
through hard soil. Comparing the creature with 
British insects, it closely resembled a giant wire- 
worm. 
How Fungus spores get Distributed. —In the 
case of fungi which grow exposed to the atmosphere, 
or when the spores become exposed, the wind serves 
to convey them in all directions, and they grow 
wherever they find a suitable host plant. Birds, 
squirrels, and other animals also serve as a means of 
conveyance. The spores of fungi which live on the 
roots of plants get distributed by beetles, rats, mice, 
rabbits, and other creatures which burrow under th 
soil; and when roots are gnawed or injured by those 
or other animals, they are thus exposed to attack by 
the spores of parasitic fungi, which find a suitable 
and easy means of entering the tender tissues thu 
exposed 
