January 9, 1886. 
THE GARDENING WORLD 
295 
THE POTATO EXPERIMENTS 
AT CHISWICK. 
The following summary of results of experiments 
made at Chiswick in 1884 and 1885, for the purpose of 
testing the efficacy of the system of “earthing-up” 
advocated by Mr. Jensen, was read by Dr. Masters, on 
behalf of the sub-committee appointed to carry out the 
experiments,'at the last meeting of the scientific com¬ 
mittee of the Royal Horticultural Society on the 8th 
December:— 
The experiments made at Chiswick for the purpose 
of testing the value of the Jensenian plan of moulding 
Potatos as a preventive of the Potato disease were carried 
out in the present year in essentially the same manner 
as in the preceding year. A few slight modifications 
were adopted to facilitate the making of the record, 
and the tubers were placed at rather wider distances, 
the rows being now 4 ft. apart, but these changes did 
not in any way interfere with the fair comparison of 
the results of the two years, the number of plants in 
each row being the same. The chief differences in 1885 
consisted in the longer time the Potatos were left 
in the ground. Thus in 1885 the longest duration of 
moulding was 118 days on section i. of each row, as 
contrasted with 83 days in 1884. The shortest 
moulding period in 1885 on section v. was 62 days as 
compared with 27 days in 1884. The Potatos were 
examined on March 31st by the committee previous to 
planting, and all diseased and “suspicious” tubers 
eliminated. During growth they were inspected at 
stated intervals, and their condition noted. The season 
was for the most part warm and unusually dry, and no 
appearance of disease was noticed at any time on the 
haulms. On the 10th of October, the weather for some 
days previously having been wet, the tubers were lifted 
and carefully examined by Mr. Shirley Hibberd, Dr. 
Masters, and Mr. Barron. Two unmistakeably diseased 
tubers were noted during the uplifting on row 3 
(Adirondack), and three on row 2 (Recorder). Others 
that appeared suspicious were sent to Mr. George 
Murray, who after adopting appropiate methods of 
cultivating the fungus, reports that only one was 
really diseased. It should be remarked that the pecu¬ 
liar red spots in the substance of some of the tubers 
noted the previous year were not observed at'all, though 
carefully looked for. 
As the immediate object of the experiments has again 
failed in its fulfilment, owing to the slight develop¬ 
ment of the fungus, a detailed report seems unnecessary, 
though the documents are at hand for preparing it if 
thought desirable. A few general remarks, based on 
the results of the two years taken together, may be of 
interest. 
1. The amount of produce under the varied condi¬ 
tions of the experiment. 
2. The effects of long or short periods of earthing- 
up, and of not earthing-up at all. 
3. The consequences of bending the haulms in the 
manner recommended by Mr. Jensen. 
4. The results obtained from planting whole tubers 
and cut sets. 
1. The Aggregate Produce from all the rows of 
Recorder in 1884 was 257 lbs. ; iu 1885, 254 lbs. 8 ozs.; 
shoving a decrease of 2 lbs. 8 ozs. in 1885, and a total 
amount for the two years of 512 lbs. 8 ozs. The 
corresponding figures in the case of Adirondack are 
455 lbs. 9 ozs. in 1884, 434 lbs. 12 ozs. in 1885, showing 
a decrease of 20 lbs. 13 ozs. in 1885, and a total amount 
for the two years of 890 lbs. 5 ozs. Thus the 
actual produce of all the rows of each variety was so 
nearly alike in the two years as to be all but practically 
identical. On the whole, there was a decrease in 1885, 
in spite of the tubers having been allowed to r emain 
longer in the ground than in 1884. This decrease 
may, perhaps, be accounted for by the prolonged 
drought, but the close approximation in the amounts 
of produce in the two years respectively seems to afford 
an indication of the success of the method employed in 
carrying out the experiments. 
2. Effect of Earthing-up on the Amount of 
Produce. —When the results of the two years are 
combined it comes out clearly (in the case of Recorder), 
under all conditions of growth, that the greatest 
weight of produce (irrespective of quality) -was obtained 
from those sections which were earthed-up for the 
shortest time. Some of the largest tubers were met 
with in these sections, but mixed with a largs number 
of smaller tubers, while their general quality was 
uneven and relatively bad. 
The same general remarks do not, however, apply 
to Adirondack, which shows more variation in this 
respect, and in which the largest, as well as the 
best and most even, tubers were frequently found 
in those sections which had been earthed-up for 
the longest time. It may be suggested that the 
* results obtained show the probability that the 
process of earthing-up differs in its effects materially in 
the case of different varieties of different habit of 
growth, texture, &c. At any rate, it may be useful to 
call attention to this subject with a view to future ex¬ 
periments, the more so as little or nothing is known of 
the relative effect of earthing-up on different varieties. 
Potatos Grown without Earthing-up. —In both 
years four “control rows” were planted, two of each 
variety, the object being to afford a comparison between 
the Jensenian system of moulding and the natural con¬ 
dition of growth, in which no “moulding” at all 
occurs. * 
The total produce for the two years on row 5 (Recor¬ 
der, whole), amounted to 100 lb. 4 ozs., an amount 
considerably in excess of the yield from any of the 
moulded rows of this variety (row 2, 48 lbs. 6 ozs. ; 
row 8, 91 lbs. 13 ozs.) On row 11 where cut tubers 
were planted, the yield for the corresponding period 
was 87 lbs.—also somewhat in excess of the crops on 
the corresponding two rows subjected to moulding (row 
1, 68 lbs. 1 oz., and row 7, 80 lbs.) The tubers on 
row 5 and row 11 were noted as much mixed in size, 
some of those on row 5 being much coarser and larger 
than on the other rows of the same variety, while 
many others found lying on the surface were green and 
small. They had also been the subject of insect attack 
and injury by slugs and millipedes to a much greater 
extent than the tubers in the other rows. 
Of Adirondack left to itself the total produce of 
the whole tubers (row 6) for the two years was 186 lbs. 
—an amount greatly above the quantity on the corres¬ 
ponding moulded rows (row 4, 129 lbs. : row 10, 150 
lbs. 14 ozs.). In the case of the cut sets (row 12), the 
total amount for the two years was about the same, 
viz., 182 lbs. 14 ozs., and also largely in excess of the 
corresponding moulded rows (row 3, 113 lbs. 5 ozs. ; 
and row 9, 128 lbs. 6 ozs.) The same remarks as to 
quality apply to the unmoulded rows of Adirondack as 
to those of Recorder. 
It is clear, then, that under all circumstances, the 
actual produce was greater in the unmoulded rows, but 
that, while some excellent tubers may be grown in 
this way, the general bulk is much mixed, comprising 
numerous tubers unfit for consumption, but which 
might possibly have some advantage (so far as the plant 
is concerned) in point of physical health over those 
moulded up. The small green tubers, for instance (if 
not affected by disease), might furnish stronger plants 
than those grown beneath the surface, while their 
noxious flavour might repel rather than attract pre¬ 
datory insects, &c. 
3. The effect of bending the Haulms or other¬ 
wise. —In each year two rows of each variety were allowed 
to grow without interference, while in other two rows 
of each variety the haulms were at regular intervals of 
time bent downwards. There was no opportunity 
afforded in either year of testing the value of this 
practice as a preventive of disease, but the average 
amount of produce in the two years from the erect and 
the bent tops respectively shows the effect of the check 
to growth occasioned by the bending. The average 
produce of the two years on rows seven and eight (Re¬ 
corder, erect tops) was 81 lbs. 6 ozs., on rows one and 
two (bent tops) 76 lbs. 2 ozs. 
The corresponding figures in the case of Adirondack 
are 139 lbs. 10 ozs. for the unbent haulms (rows 9 and 
10), and 126 lbs. 1 oz. for the produce of the bent tops 
(rows 3 and 4). 
4. The Effect of the Employment of Whole 
Tubers or of Cut Sets.— In the central rows, as 
before stated, the greatest weight of produce of Recorder 
in both years was obtained from the whole tubers, the 
totals being 100 lbs. 4 ozs. on row 5 (whole), and 87 lbs. 
on row 11 (cut). 
K In the case of Adirondack, the total produce in the 
case of the whole tubers (row 6) = 186 lbs., shows only 
* It may here be noted that no special rows of Recorder or 
Adirondack were set apart and moulded in the ordinary way, 
because for the immediate object of these experiments such a 
course was unnecessary, the experimental rows being contiguous 
to a large area devoted to the cultivation of numerous kinds of 
Potatos in the usual way, so that had the disease appeared, 
ample means of testing the effects of the ordinary, as compared 
to the Jensenian, system would have been afforded. 
a slight excess over the [yield from the cut tubers 
(row 12) = 182 1bs. 14 ozs. In 1884 the produce from 
the cut tubers (95 lbs. 10 ozs.) was slightly in excess of 
that from the whole tubers (91 lbs. 4 ozs.); in 1885, 
however, the balance is much in favour of the whole 
tubers, i.e., 94 lbs. 12 ozs. as against 87 lbs. 4 ozs. 
The whole tubers of Recorder subjected to moulding 
in various degrees, yielded in the two years a total 
crop of 176 lbs. 3 ozs., i.c., 91 lbs. 13 ozs., from erect, 
and 84 lbs. 6 ozs. from bent tops. 
The cut tubers of the same variety for the same 
period supplied 148 lbs. 1 oz. =80 lbs. from the erect, 
and 68 lbs. 1 oz. from the bent tops. 
The whole tubers of Adirondack pooduced a yield of 
279 lbs. in the two years, of which 150 lbs. 14 ozs. were 
yielded by the erect, and 129 lbs. by the bent haulms. 
The cut tubers of the same variety yielded during 
two years a total of 241 lbs. 9 ozs., viz, 128 lbs. 6 ozs. 
from erect, aud 113 lbs. 3 ozs. from bent haulms. 
Iu general terms it may be stated as a result of these 
experiments that (1) earthing-up produces a crop of 
more uniform and of superior quality, though less in 
actual quantity ; (2), that bending the haulms occa¬ 
sions a diminished yield ; (3), that a larger aggregate 
produce is derived from planting whole tubers than 
from the employment of cut sets. 
-—>¥<-*- 
The Amateurs’ Garden. 
THE GREENHOUSE. 
Washing Plants. —There are few occupations more 
useful, or attended with greater benefit to the plants at 
this season, than that of washing them with a sponge 
and soft soapy water, in the case of those which are 
simply dirty and not affected with scale or other insect. 
For the latter strong Tobacco-water, Nicotine-soap, 
or some other insecticide must be used first, and the 
plant then washed with clear water. Strong leathery¬ 
leaved plants, such as Camellias, Aralias, India-rubber 
plants, which in the neighbourhood of towns in the 
winter months soon get coated with a deposit of soot 
and other abominations, should be sponged as often as 
convenient, and Palms delight in the same treatment. 
Small Orange-trees, which are good amateurs’ plants, 
often get infested with scale, and there is no better time 
than the present for ridding them of this pest. A 
small moderately hard brush, used with care, is the 
best thing for dislodging this enemy, and if the plants 
are looked over again in about a fortnight, those which 
escape the first operation may then be got rid of. If 
any of these plants are found to have the soil in the 
pots soddened and sour, they should be carefully 
turned out of the pots and have the drainage examined, 
as that is the seat of the mischief. 
THE VEGETABLE GARDEN. 
Walks and Edgings. —Next to ill-cultivated crops 
nothing looks worse in a garden than badly kept 
untidy edgings of -whatever they may consist. If they 
are of Box, and not very old, yet requiring to be 
patched in places, the present time affords a favourable 
opportunity for doing it ; but if there are many gaps 
it is always more satisfactory to re-make than to mend, 
and often very little more trouble. Take up the old 
Box with a fork, then divide it into suitable sized 
pieces, trim the roots a little, chop out a straight 
trench with the spade, re-lay the plants, treading 
them in firmly, and the work will be complete. For 
our own part we are not enamoured of Box edgings, 
preferring what is generally called a dead edging— 
that is to say edgings of bricks set on edge, tiles if of a 
good colour, or stones—oil the border-side of which we 
can plant many small neat-growing things, such as 
Mossy Saxifrages, Aubretias, Thrift, Gentians, and 
other low or prostrate-growing plants that will to a 
great extent hide whatever material is used for the 
edging. There is a charm about edgings of this 
character that is entirely wanting in edgings of one 
uniform pattern ; and[there is another great advantage, 
we can apply that famous weed killer, Smith’s, with 
more freedom and less risk of doing harm. 
HARDY FRUIT GARDEN. 
Pruning and Training. —The amateur who has 
only a limited number of fruit trees in his garden has 
little excuse for neglectiug them, as we are sorry to say 
so many do, presumably from a want of knowing what 
to do, and a consequent fear of doing harm rather than 
