CURRANT DISEASES 205 
the young leaves. The ascospores germinate and their germ- 
tubes enter the leaves, wherein mycelium is developed. In a 
short time the leaf-tissue is killed in local areas and the result 
isa spot. Finally asexual, summer, fruiting bodies are formed. 
These are black, spherical structures, called pycnidia, occupy- 
ing the central portion of the lesion. At maturity each pycnid- 
ium is filled with long, curved pycnospores. These ooze out 
and are scattered promiscuously. Some perchance fall on 
currant or gooseberry leaves; they germinate and cause spots. 
Some time during the summer (June to August) the affected 
leaves fall, and preparations for the winter are again made by 
the fungus. Damp cloudy weather favors the fullest develop- 
ment of Mycospherella Grossularie. 
Control. 
The spraying schedule for currant-anthracnose is reliable 
for the control of this leaf-spot. Five to seven applications 
of lime-sulfur used at the rate of one gallon of lime-sulfur solu- 
tion (commercial concentrate) to fifty gallons of water are 
effective. Finely ground sulfur (dust), ninety parts, and 
powdered lead arsenate, ten parts, has been shown to be satis- 
factory. The spray or dust should be applied: (1) when the 
first leaf-clusters appear; (2) subsequently every two weeks 
until the first of August. (See Control of Currant Anthrac- 
nose, page 208.) 
REFERENCES 
Stewart, V. B. Dusting nursery stock for the control of leaf diseases. 
Experiment for the control of the leaf spots of currants. Cornell 
Univ. Agr. Exp. Sta. Cire. 32:8-9. 1916. 
Stewart, V. B. Some important leaf diseases of nursery stock. Sep- 
toria leaf-spot of currants and gooseberries. Cornell Univ. Agr. 
Exp. Sta. Bul. 358: 198-200. 1915. 
Pammel, L. H. Spot diseases of currants and gooseberries. lowa 
Agr. Exp. Sta. Bul. 13: 67-70. 1891. 2 
Pammel, L. H. Treatment of currants and cherries to prevent spot 
diseases. Experiments with currant spot diseases. Iowa Agr. 
Exp. Sta. Bul. 30: 289-291. 1895. 
