depth of the bruise also should be considered. Dedolph and Austin (26) fol- 
lowed this suggestion to advantage in their study of impact bruises. 
Many small bruises that do not seriously affect the appearance of apples 
may puncture the skin and permit the invasion of rot-producing fungi (91, 121). 
Hardenburg (46) pointed out that bad bruises are potential avenues of blue mold 
rot infection to almost the same extent as skin punctures. Wright and Smith 
(121, 122) showed that, depending on apple maturities, blue mold infections at 
bruised areas averaged from 55 to 70 percent and a tenth or less of this at 
nonbruised areas. English, Ryall, and Smith (27) noticed many lenticel infec- 
tions in the bruised areas of apples. Southwick and Hurd (95) reported that a 
single severe bruise on an apple may increase moisture loss by more than 400 
percent. Phillips (82) believed that impact bruising was responsible for the 
onset of senile breakdown after 3 to 6 weeks. Although most harvested produce 
is well covered with micro-organisms, the skin of apples offers good protection 
from them provided it is unbroken (46). Thus, bruise control is a most impor- 
tant step in decay or rot control (28, 36). See also section on Market Dis- 
eases. 
While there is some difference in bruise resistance of different varie- 
ties of apples, this difference probably is less than growers and handlers 
imagine (38). Perkins (78) found that more than one-third of the McIntosh 
apples on retail display were badly bruised. Van Waes (104) found that even 
when this variety was carefully handled, bruising still amounted to about 17 
percent by the time the apples left the farm, 33 percent by the time the apples 
were through storage operations, 49 percent on delivery to retailers, and 59 
percent before they reached the customer. Similar apples not carefully handled 
were 85 percent bruised by the time they reached the storage. A study in 1949 
showed that bruising was present on about 20 percent of Gravenstein apples be- 
fore they reached the wholesaler (15). Delicious apples on display in Los 
Angeles during the springs of 1953 to 1956 showed two or more bruises the size 
of quarters on 18 to 32 percent of the fruits (36). In 1948, McColloch and 
Hansen =’ found no consistent difference in bruising losses between eastern and 
northwestern apples on the Washington, D. C., and Baltimore, Md., markets. 
Studies are in progress in Japan on the possible culture of apples that may 
resist bruising (87). 
Lott (61) studied bruise damage from hail on Golden Delicious, Starking, 
Grimes Golden, and Jonared. He found that no rots developed on slightly injured 
fruit when it was stored at 31° F, and 90 to 95 percent relative humidity for 
60 days. Severe rot occurred, however, when the hail damage was very severe. 
Rot was most serious in Golden Delicious and in Grimes Golden. 
Farm and Orchard 
The bruising that apples receive on the farm or in the orchara varies 
with apple size and maturity, with equipment and handling techniques, and with 
the supervision of personnel. In nearly all cases larger, softer, and more 
mature apples bruise more easily (44, 78, 119). Burt (14) noted that McIntosh 
apples of only 9 pounds firmness (as measured with a Magness-Taylor pressure 
tester) were 21.6 percent bruised during experimental packing. Apples of 12 
pounds firmness bruised 4.5 percent. Fruit that tested 17 pounds bruised 1.4 
5/ See, footnote 3; bps 134. 
137, 
