potatoes. The soil of such tract ought to be fertile and free from the various 
diseases which attack the potato plant. The tubers used in planting the 
seed tract are carefully selected each year from the seed plat of the prev¬ 
ious year. The surplus seed is used for planting the gneral crop, and in 
this way a stain of pedigree potatoes is gradually developed.” 
Culture. The best potato soil is a sandy or gravelly loam which 
contains an abundance of vegetable matter, and which is well under¬ 
drained. In the Greeley district the soil will average about four feet 
deep. Below this is an immense layer of gravel, which insures per¬ 
fect drainage. Vegetable matter is secured by plowing under alfalfa 
sod. Alfalfa is grown two years, then turned under in the spring 
and planted to potatoes. Two crops of potatoes are grown in suc¬ 
cession, then wheat is sown and the land again seeded to alfalfa, 
thus making a five-year rotation. The second crop of potatoes, how¬ 
ever, is rarely as good as the first, probably because of the increase 
of the fungus in the soil, and in most localities but one crop of po¬ 
tatoes should enter into the rotation system. 
A heavy alkaline soil, that has poor underdrainage, furnishes 
an ideal condition for the growth of this plant disease, and it is in 
such soils that potato failures are most frequent. But poor under¬ 
drainage in any soil is conducive to its growth. It will be seen, then, 
that cultivation and irrigation must be important factors in controll¬ 
ing the disease. Most people who attempt to grow potatoes make 
the mistake of using more water than is necessary for the best 
growth of the plants. The rows should be comparatively short, so 
that part of the ground will not need to be over-watered. The seed 
should be planted about four inches deep in rows 38 to 40 inches 
apart. The furrows should be about five inches deep for the first 
irrigation, and with subsequent irrigations they should be increased 
in depth. The idea is to make the furrows deep enough to supply 
sufficient moisture to the roots without saturating the upper portion 
of the ridge where the tubers form. Cultivation should follow as 
soon after as the ground is in condition to work. The condition of 
the soil and plants should always govern the amount and the fre¬ 
quency that water is applied. 
After all has been done in the way of culture, seed selection 
and a long rotation of crops, the vines and weeds should be collected 
and burned each season after the potatoes have been dug. This will 
destroy a great deal of the fungus that would infect other fields, as 
the vines are scattered by various means. 
8 
