18 
The Colorado Experiment Station 
1 
* 
Figure 11. 
perithecia or spore cases, but doubtless would toward the end of 
the season and the next spring be ready to shed their spores and 
renew the species in the succeeding crop of young canes. Theoretic¬ 
ally, the disease should be prevented by spraying the young canes 
with a good fungicide like Bordeaux mixture or lime-sulphur 
mixture, but it would be necessary to give the first spraying when 
the young shoots are only three or four inches high. This should 
be repeated once a week until the canes of the previous year begin 
to blossom.” 
As mentioned above, during the latter part of September or 
the first of October, there appear on the gray discolorations of the 
brown splotches numerous tiny black pustules under the epidermis 
of the new canes. These resemble little pimples pushing up under 
the skin and are the developing perithecia or spore cases of the 
fungus (See Fig. 8.) They mature early in the spring, producing 
a large number of spores or seed which are destined to spread the 
disease. The pustules break through the epidermis, burst and lib¬ 
erate millions of spores to be carried by the wind to new tender 
canes just coming through the ground, or at best but a few inches 
