ON FARM GARDENING. 63 
Diseases and Enemies. — Not counting dry weather, 
which sometimes robs the farmer of two-thirds of his crop, 
there are four diseases which exert a disastrous influence on 
the potato, and which are liable to occur any season. Two 
of these diseases are of the leaf and stem and two of the 
tubers. 
The two leaf troubles are respectively known as blight or 
downy mildew and the Macrosporium disease. The two 
tuber troubles are scab and rot. 
Leaf Blights. — No attempt will be made here to sepa- 
rately describe the two leaf diseases. Both destroy the foli-^ 
age and check the further growth of both vine and tuber. 
The leaves turn brown or black, and the stem quickly wilts 
and falls. There can be no growth of tuber without vigo- 
rous health of vine. Spraying with Bordeaux mixture, in 
advance of the occurrence of any disease, is recommended. 
Bordeaux mixture for this purpose is made by using six 
pounds of copper sulphate and four pounds of quick lime, 
dissolved in separate wooden vessels, and the lime water 
poured into the dissolved blue stone. This should be diluted 
with water sufficient to fill a forty-five gallon barrel. Paris 
green to the amount of from one-quarter to three-quarters 
of a pound to the barrel should be added, to destroy beetles 
and other insects. 
The vines should be sprayed five or six times, beginning 
when they are 6 inches high, at intervals of ten days or two 
weeks. During rainy weather the spraying should be more 
frequent than during clear weather. The object is to pro- 
long the life and vigor of the vines. The cost of the five or 
six sprayings, including labor at $1.50 per day, is put at not 
above $6 per acre, while the crop at stake may be affected to 
the extent of scores of bushels. 
Scab and Rot — The evidence about scab and rot is still 
contradictory, but it is likely that these diseases will pres- 
ently be under control. 
