BLUE MOLD DECAY OF DELICIOUS APPLES 



13 



and 22 percent of those in boxes B and C were decaying. The fifth 

 (and final) inspection, at the end of 8 weeks, showed the decay in 

 boxes B and C to be nearly as great as that in box A. 



Table 8. — Blue mold decay of Delicious apples that had been bruised, 

 inoculated, and held in storage for 29 days at different temperatures t 

 then placed in laboratory cold storage from which inspections were 

 made at biweekly intervals, harvest of 1949 





Box A 



Box B 



Box C 



Inspection 



Decay 



at 



bruised 



areas 



Decay 



at 

 non- 

 bruised 

 areas 



Decay 



at 



bruised 



areas 



Decay 

 at 



non- 

 bruised 



areas 



Decay 



at 



bruised 



areas 



Decay 

 at 



non- 

 bruised 



areas 



1st (29th day of stor- 

 age) 



2d 



Percent 

 33. 4 



51. 4 



52. 8 

 55.6 

 55. 6 



Percent 

 5.6 

 5. 6 

 8.3 

 8.3 

 8.3 



Percent 

 8. 3 

 22. 2 

 38.9 

 47.3 

 50.0 



Percent 

 

 



8.3 

 8.3 

 8.3 



Percent 



1.4 



22. 2 



38. 9 



Percent 

 

 



3d 







4th 



47. 3 J 



5th _ ___ __ __. 



47. 3 5. 6 









A similar relation existed on the unbruised portions of the apples. 

 The apples in box A had 5.6 percent decay at the first inspection; this 

 increased to 8.3 percent during the subsequent inspections. No 

 decay on unbruised portions of the fruits appeared in box B until the 

 third inspection, when 8.3 percent was found, whereas in box C no 

 decay of the unbruised areas occurred until the final inspection, when 

 5.6 percent was found. 



No decay occurred in the apples that had been neither bruised nor 

 inoculated. 



These results reemphasize the importance of rapid cooling of apples 

 and of maintaining adequate cold-storage temperatures during their 

 entire handling, to prevent decay at bruises during the storage period 

 and to retard decay after removal of the fruits from cold storage. 



Summary 



An association between bruising and susceptibility to decay has 

 long been observed, but there has been little experimental data on the 

 relation between them. The present studies illustrate the suscepti- 

 bility of bruised tissue to blue mold decay, the influence and relative 

 importance of such factors as maturity and ripeness of apples on 

 bruising damage and subsequent decay, and the effects of handling 

 methods on decay development in bruised fruits. 



Bruising damage, measured by the diameter of the bruised area, 

 was found to relate directly to the firmness of the apples and, conse- 

 quently, to increase with advanced maturity and ripeness. 



Decay after inoculation of freshly made bruises increased with 

 bruising damage and with softening of the fruits as a result of matura- 

 tion and ripening. 



