498 
fair play, and although it may stop the growth 
for a few days, still the crop of Potatoes is 
always excellent. Nothing more is required 
but to admit plenty of air, and give water. 
Potatoes are also grown largely in hooped 
beds in the open ground. In the latter case 
the tubers are sprouted, as before. The beds 
or ridges are dug out 2 feet deep in January, 
filled with hot dung, and covered with soil to 
the depth of 10 inches. The Potatoes are taken 
up and planted 5 inches deep, and over them 
Radishes are sown. The ridges are then hooped 
Fig. 1259.—Phytophthora infestans. 
THE GARDENER’S ASSISTANT. 
and successional crops planted in January and 
February. . 
Insect Pests.—Potatoes are assailed by a host 
of insects, but in a healthy state wireworms 
are the most injurious. See chapter on this 
subject. 
Curl.—Potatoes are sometimes attacked by a 
disease which towards the close of the eigh- 
teenth century excited considerable alarm. In 
this disease the shoots become curled when 
young, and their growth is arrested; the leaves 
are curled and crumpled, and no tubers, or only 
small and worthless ones, are pro- 
duced. When the leaves first curl 
there is no sign of fungus, but at 
a later stage the stem and leaves 
become more or less studded with 
blackish, minute velvety patches. 
These are due to the production of 
dia or spores of a fungus known as 
Macrosporium Solan. Spraying the 
Potatoes sufficiently early with 
dilute Bordeaux mixture prevents 
the disease from doing serious mis- 
chiet. 
Scab is a disease in which rough 
patches are formed upon the sur- 
face of the tubers. Though not 
very injurious it is very preva- 
a, Young plants, with spores proceeding from stomata. 6, Section of Potato-leaf, showing the o 1 
mode in which the mycelium creeps amongst the loose tissue of the leaf. lent, most Cl Ops being more or 
over, allowing about 2 feet of space in the 
middle, between the mould and the hoop. 
They are covered with mats and straw; but as 
soon as the Radishes come up they are un- 
covered daily, and covered again every night. 
This is continued till the Potatoes are ready for 
digging in May, for sometimes large losses are 
occasioned by cold weather in April. Nothing 
more is done to the hooped beds beyond supply- 
ing them with water. 
Pot Culture.—This is very simple; it is merely 
necessary to plant the sets in 8- or 11-inch pots, 
one set in the smaller and three in the larger 
size, filled to within 2 or 3 inches of the top 
with light rich soil. The pots may then be 
placed near the glass in a vinery, Peach-house, 
or pit, where a temperature of from 50° to 60° 
is maintained. With the exception of water- 
ing, and putting more earth in the pots as the 
plants advance in growth, no further attention 
is required. It is advantageous to sprout the 
sets previous to planting, as already recom- 
mended. 
Forcing may be commenced in December, 
less affected. It is often considered 
as a sign that the Potato attacked is good and 
floury. 
Potato DISEASE. 
This is the popular name for one of the most 
terrible of plant scourges (Phytophthora infestans, 
fig. 1259). It was first observed near Boston, 
U.S.A., also in Denmark and Norway, between 
1840 and 1842, and by 1845 it had spread all 
over Europe, doing immense damage. Although 
the injury done at the present day is not so 
severe as during the first decade after its in- 
vasion, it is still with us, and during damp, ~ 
warm seasons does a considerable amount of 
injury. In addition to the cultivated Potato, 
the disease also attacks several cultivated ex- 
otic species of Solanum, the common British 
S. Dulcamara, and the Tomato. 
The earliest indications of the disease are the 
appearance of small brownish blotches on the 
leaves ; these gradually increase in size, followed 
by a curling of the leaves, and in an excep- 
tionally severe attack the leaves and stems 
become blackened and decayed within a few 
days, emitting a disagreeable smell. 
innumerable large olive-brown coni-- 
cintageeainl a * Pee 
