28 The Colorado Experiment Station. 
work better in the machines. It is claimed by some that this treat¬ 
ment reduces the rotting of the seed.* 
PLANTING. 
Machine Planters are universally used in Colorado. The chief 
reason for this is that hand planting would be too laborious and 
expensive to be profitable, but if hand planting were not too expen¬ 
sive, it would not be satisfactory as machines do much better work 
than could be accomplished by hand. With the planter, the soil is 
furrowed, the seed dropped in place, and covered, all within a space 
of three or four feet, so there is no opportunity for the drying 
effects of the atmosphere to injure the chance for the germination 
of the plants. Where the plow and hand dropping is used the soil 
is very liable to become dried, as the planted tuber is in most cases 
covered with dry soil. 
Picker Planters. — The Aspinwall, Evans, Superior, and 
Eureka are common types of the picker planter, and while each is 
different in detail, and some have been more thoroughly tried out 
than others, they all do practically the same work, are all automatic, 
and only require one man for operation. 
Non Picker Type. —The Robbins Planter feeds the seed by 
dropping from between the spokes of a horizontal wheel and re¬ 
quires a second man to correct the drop, so that in this case the 
accuracy of the planter depends on the accuracy of the operator.f 
Depth of Planting. —No hard and fast rule can be laid down as 
to the depth to plant potatoes. Much depends upon the moisture 
and soil conditions, and slope of the land. Ordinarily, where the 
soil is in good condition so far as moisture is concerned, and dan¬ 
ger of frost is passed, two or two and one-half inches beneath the 
surface level is sufficient depth, while on flat land, in good con¬ 
dition, potatoes are sometimes planted only one inch deep.i Where 
the soil is apt to dry out, or where planting in dry soil, it is neces¬ 
sary to go deep in order to insure moisture. Deep growing va¬ 
rieties do not need to be planted as deeply as more shallow kinds. 
In the Higher Altitudes. —Where there is enough fall to keep 
water below the tuber bed and where the ground is apt to be touched 
with frost before the potatoes are dug in the fall, it is well to plant 
* Any dust will do the same so far as drying the cut surface of the 
potato is concerned. Dry Bordeaux mixture was also tried, along with 
other materials, at the Experimental farm in the year of 1907. This 
mixture did not prove satisfactory, as the copper sulphate in the mixture 
tended to shrivel the potatoes and apparently decreased their vitality. 
fSee the subject of Stands in this bulletin, and the per cent, of 
stands obtained by different machines on the 1910 plots. Robbins planters 
were used at Greeley and Carbondale; Aspinwalls at Montrose and 
Parshall. 
tin speaking of depth of planting, it is understood that the depth 
below the surface is meant, and not depth below the planter ridge. 
