"A precise description of this disorder was recorded by Dunlap and Thompson 
(46), when they referred to bitter pit and deep pit of the apple. Samples 
selected for this study were those described as deep pit.'' Since Simmons' 
study appears to be concerned more with cork spot than bitter pit, the paper 
is reviewed with cork spot, 
Anatomical studies made by Simmons disclosed much malformation in cel- 
lular structure with pectic protuberances extending into the intercellular 
spaces in the affected areas of apples. Abnormal growth of the cell is indica- 
tive of some stress occurring early in the growth of the fruit. Newly developed 
cells, arising from stimulated or injured cells appeared to be unable to compete 
with normal cells for nutrition for survival, thus the pitted areas enlarged. 
His studies tend to show why the tissues surrounding pits are abnormal. Al- 
though not dead or discolored, the tissues are found by processors to behave 
somewhat like scar tissues and to remain hard after cooking. 
Barden and Thompson (11) made a detailed study of the anatomy of develop- 
ing vascular tissues of the pedicel of the York Imperial apple. The study was 
to determine whether applications of boron sprays caused any changes in the 
vascular development. The study covered one year in which the incidence of 
cork spot was high and one year in which it was low. Vascular development was 
very similar for the two seasons, and they reported no indication of any re- 
lationship between vascular development and cork spot, or between boron sprays 
and vascular development. 
Internal Breakdown 
Unfortunately, the disorder considered here as internal breakdown is not 
only known by other names in other parts of the world, but may also be defined 
differently or poorly. Kidd and West 10/ discussed and illustrated a number of 
disorders under the name of internal breakdown. A 40-year collection of litera- 
ture since their publication points clearly to the need for clarification of 
such terms as internal breakdown, mealy breakdown, physiological decay, Jonathan 
breakdown, senescence breakdown, and others. 
In the United States internal breakdown has been characterized as a 
breaking down and browning of the interior of the apple. The riper side of the 
apple is often more seriously affected than the greener side and the blossom 
half is more susceptible than the stem half. Either a part or the entire fruit 
may be involved. The affected area usually starts at the peel and extends in- 
ward, but there may be a narrow margin of healthy tissues between the peel and 
the affected area. During the earlier stages, the flesh may be moist, but it 
later becomes spongy and mealy, especially in some varieties such as Grimes 
Golden, McIntosh, and summer varieties. The skin may retain its normal appear- 
ance, or become dull or brown. Some varieties crack badly. In brief, internal 
breakdown represents the end of the life of the apple or complete senescence, 
Any internal disorder of the apple might be argued to be a kind of break- 
down and, therefore, the name internal breakdown is not a desirable term, Per- 
haps senescence breakdown would be a more accurate name for this disorder. 
Internal breakdown occurs mostly on large (1), overmature apples and on 
those that have been forced late in the season, Factors that increase suscep- 
tibility to the disorder are: holding apples on the trees too long, presence 
10/ Kidd, F., and West, C. Functional Diseases of Apples in Cold Stor- 
ages Dept. Sei. and Indus. Res. Food Invest. Bd. Spec. Rpt. 23, 1925. 
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