54 HINTS ON RAISING FARM CROPS 
rado Beetle, more commonly referred to as 
the potato bug, and leafhoppers are the chief 
insect enemies. 
Early blight appears during moist seasons 
on the leaves of the potato plant as dark, ir¬ 
regular spots. Late blight has nearly the same 
appearance, only somewhat later in the season. 
The best preventative known for this disease 
is Bordeaux mixture, which consists of a mix¬ 
ture of blue vitriol and stone lime. This mix¬ 
ture is sprayed upon the leaves, not once, but 
several times during the season, if the blight 
is serious. Scab is a very common disease of 
potatoes, and is usually rather difficult to erad¬ 
icate, especially if the potatoes are raised on 
the same ground, year after year, or if scab- 
infected seed is used in planting the next 
crop. The surest way to eliminate scab from 
potatoes is to plant scab-free seed, in ground 
that has not had potatoes in for about five 
years. The formaldehyde treatment, explained 
in detail in one of the earlier chapters of this 
book is about the best method of treating po¬ 
tato seed infected with scab, but this method 
will be of little help if the ground is not free 
of the disease, also, because scab spores have 
the ability to live in the soil several years. 
The potato bug is an annual pest that causes 
a great amount of damage, sometimes entire¬ 
ly ruining the crop if steps are not taken to 
stop the ravage. To kill these pests, a stom¬ 
ach poison is used, arsenate of lead, or Paris 
green being the common poisons used. These 
chemicals are mixed with water, and sprayed 
on the vines of the potato plant. This poisons 
