Coi.oijAiK) Pr.ANT Diseases 
61 
on the farm by selecting seed from the few plants that survive on a 
badly diseased field. Seed from such plants will show a remarkable 
degree of resistance. If this selection is continued for several years 
a highly resistant strain may be developed. 
GOOSEBERRY 
Mildew (Sphaerotheca mors-uvae) ( 61 ) — Mildew is the most 
serious disease of the gooseberry in Colorado. 
xV whitish cob- 
webby growth ap- 
pears on leaves, 
stems and fruit 
turning darker in 
color late in the 
season. In severe 
cases the fruit may 
be rendered worth- 
less. During the 
early summer lots 
cf small summer 
spores are formed 
on the Avhite cob- 
w e b b y growth, 
which aid in scat- 
tering the disease 
from plant to 
plant. In late sum- 
mer small black spore cases are developed on the surface of affected 
parts. These contain spores which on account of the protection of 
the spore case serve to carry the fungus over winter. 
Gooseberry mildew may be held in check by spraying with potas- 
sium sulphide, one ounce to two gallons of water. Apply first spray 
when the buds begin to open. Follow with additional applications at 
intervals of ten days or two weeks until fruit is ready to pick. 
White-Pine Blister Rust — see Pine. 
MILLET 
Smuts (Ustilago crameri and U. panici-miliacei) ( 78 ) — Smut is 
the most important disease of millet in Colorado. There are two 
kinds of millet smut. The foxtail millets are affected by U. crameri. 
This fungus replaces the individual kernels with a black mass of 
Gooseberry mildew on fruit. 
