Potato Culture in Colorado 
11 
cut surface, and, in a measure at least, stop the premature rotting 
of the cuttings; even leaving the cut seed for a few days un¬ 
treated seems to have the same result. 
Mature versus Immature Seed 
Much has been said and written as to the relative value of 
immature seed as compared to mature seed, but no definite con¬ 
clusion has been reached by the practical grower. The favorable 
results obtained by potato experts with the use of immature seed 
would indicate there are some advantages in the use of this kind, 
but in most cases the immature seed had been grown in seed plots 
from hill selection, and naturally would show the result of such 
selection, rather than from the intrinsic value of the immaturity. 
It is undoubtedly true, as one would expect, that in an immature 
seed the buds or eyes are relatively more active because they are 
younger and would start to grow more quickly than eyes from 
a well matured tuber. Whether there is any particular gain in 
the rapid development of the sprout is questionable. However, 
what is often termed immature seed is not immature seed at all, 
but seed that is full matured in every respect, except that the 
tubers are below medium in size, and this is obtained by closer and 
late planting of the seed plot. Under average farm conditions, 
the mature seed has given satisfaction, and we are not yet ready 
to advocate a new departure. 
Greening the Seed 
The practice of exposing the tubers intended for seed to 
the sunlight and air for a period of one or two weeks before 
planting is advocated by some growers in Colorado. It is particu¬ 
larly valuable in the South in connection with the planting of the 
second crop of tubers, as it hastens the growth of the plant. When 
potatoes are exposed to the air and light, the tuber begins to 
function in the same manner as the green branch or a leaf. In 
other words, it turns green, showing the development of chloro¬ 
phyll, or a green coloring matter, and with this begins to sprout. 
This sprouting is equivalent to the new growth on trees and 
bushes in the early spring, so that the greening process is simply 
a method of stimulating the growth activity of the buds. When 
this is obtained, the tubers are planted, and the shoots will soon 
come out of the ground. In Colorado, this practice may some¬ 
times be resorted to, especially if unseasonable weather delays 
the planting. Progress can then be made by greening the potatoes, 
so as not to lose too much time after planting before the potatoes 
come up. Under average normal conditions, it is questionable 
whether there is any real advantage in this practice, and further. 
