on the tree by mid-September. Losses in orchards on the Eastern Shore of 
Maryland ranged from 10 to 75 percent. Varieties most affected were Golden 
Delicious, Grimes Golden, Rome Beauty, and Northwest Greening. Those moder- 
ately affected were Delicious, Stayman, and York Imperial; least affected were 
Arkansas and Winesap. Weaver (175) suggested that the abundant inoculum 
(spores) in the orchards, together with above-normal rainfall during August, 
may have induced the extensive botryosphaeria rot during 1952, 
Eid and Heuberger (50) found the peak of spore production of Botry- 
osphaeria ribis in the orchard occurred from June 1 to July 15. Optimum cli- 
matic conditions for spore germination were 100 percent relative humidity and 
a temperature range of 77° to 86° F. Apparently fruits were susceptible to 
infection from June first until harvest in October. | 
Wallace and associates (174) found that the amount of water-insoluble 
material in the pulp of Golden Delicious apples at different stages of maturity 
decreased with maturation. Susceptibility of the apples to Botryosphaeria 
ribis, Glomerella cingulata, and Physalospora spp. occurs at a specific stage. 
They suggest a relationship between susceptibility and reduction in water- 
insoluble materials. 
Fulkerson (55) found that mature detached apples inoculated with Botry- 
osphaeria ribis decayed more rapidly at 75° and 65° F. than at 85° and 55°. At 
the favorable temperatures of 75° and 65° a soft, bleached rot usually occurred, 
whereas, at 85° and 55° a firm, brown rot was produced. 
Lewis and Shay (85) reported botryosphaeria rot causing serious losses 
in southwestern Indiana in 1950 and 1951. Sound appearing fruits at harvest 
rotted rapidly at room temperature. In some cases fruits rotted after they 
were packed and sold. 
Several investigators (67, 85, 136, 140) have reported substantial re- 
duction or control of botryosphaeria rot in the orchard and after harvest by 
the use of certain fungicidal sprays. 
McColloch 6/ found that fruits with the early (speck) stage of botry- 
osphaeria rot, which appeared to be arrested at harvest, did not develop at 
32° F., but a considerable percentage developed decay after they were removed 
from cold storage. Tests on agar indicated that the fungus made no growth at 
temperatures below 45°. 
Blue Mold Rot (Penicillium expansum Thom) 
During the years that spray residue removal was a serious problem, and 
vigorous washing measures were used in the Northwest, blue mold rot, especially 
at the lenticels was a serious problem, 
English and others (52) found that fruits packed while wet developed no 
more decay than those packed dry. They reported that lenticels and washing 
injuries constituted the principal avenues of infection in dual-process washed 
apples and that a severe washing process increased both the number of open 
lenticels, as indicated by dye tests, and the number of lenticel infections. 
Passing apples through a heavily contaminated washing solution followed by a 
clean rinse caused only a slight increase in amount of decay. If, however, 
contaiminated apples were not rinsed, decay was greatly increased. They found 
6/ McColloch, L. P. Unpublished data. 1953. 
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