PEACH DISEASES 313 
the effect induced by the San José scale (Fig. 82). At first 
the spots are small and purplish red. As the diseased portion 
enlarges, a light-colored area develops in the center (Fig. 82). 
Later the spots are brown and confluent. In extreme cases 
the fruit becomes cracked and a flow of gum follows. 
Cause. 
The lesions described above are induced by the fungus 
Coryneum Beijerinckii. The chief period of infection appears 
to be from December to February; most inoculations occur 
about January 
first. In Cali- 
fornia no in- 
fections occur 
after the end of 
April; in Ore- 
gon these take 
place from May 
10 to June 15. 
Rainy weather yg. g2.— Coryneum-blight lesions on peaches. 
favors infection. 
The conidia of the fungus are carried to the buds, leaves and 
fruits, germination occurring in a short time in the presence 
of moisture. After infection, spore-cushions break through 
the skin of the various parts affected. These are visible to 
the naked eye as dark spots, and are most abundant about 
leaf scars and roughened portions of the bark on defoliated 
twigs in the spring and summer. They also develop on leaf- 
spots. The conidia appear to live through the summer lodged 
in the bud-scales, being very resistant to desiccation. 
Control. 
It has been found in the Pacific Coast regions that Coryneum- 
blight can be controlled by fall and spring spraying. Peaches 
should be sprayed about November first, just as soon as possi- 
ble after the fruit is harvested. Bordeaux mixture 6-6-50 is 
