BLUE MOLD DECAY OF DELICIOUS APPLES 5 



Ripeness During Storage 



In 1948 the effect of maturity and ripeness on severity of bruising 

 was studied. The apples were bruised at intervals during the storage 

 season. 



Pressure-test data were obtained (table 2) to indicate the differences 

 in firmness of the immature and overmature fruits. The pressures 

 dropped significantly during storage, as shown by readings taken in 

 December, February, and March, but the differences in firmness at 

 harvesttime were maintained as ripening progressed in cold storage. 



Bruise diameters were increasingly large on lots of apples bruised 

 as the storage season advanced. Bruises on the overmature fruits 

 were consistently larger throughout the storage period than those on 

 immature fruits. 



The results of this investigation show that in the commercial han- 

 dling of overmature and ripened apples, extra care should be taken 

 to avoid additional bruise damage. 



Factors Related to Infection 



Bruising 



A comparison of decay at bruised areas with that at nonbruised 

 areas of the same fruits following inoculation with blue mold indi- 

 cated that many times more decay develops in bruised tissue than in 

 nonbruised tissue, the amount of decay being dependent upon the 

 severity of bruising. In 1947 comparatively little decay developed 

 even on bruised fruit, when it was not inoculated, and no decay was 

 found in the apples that were neither bruised nor inoculated. (See 

 table 3.) 



Increased decay susceptibility caused by bruising was demon- 

 strated again in 1948 (table 4). All the overmature apples bruised 

 and inoculated, after they had been held in cold storage until February 

 and March, developed decay in the bruises, whereas only 17.6 and 15 

 percent of these apples, respectively, decayed in nonbruised areas. 



Bruising of apples with the blue mold fungus present occurs 

 throughout the commercial preparation of this commodity for con- 

 sumption. Extremely favorable conditions for inoculation are pro- 

 vided, however, when wet apples are handled roughly. Such condi- 

 tions occur in handling apples that have been exposed to rain in the 

 orchard after picking, and in handling sweating fruit after its removal 

 from cold storage, or during the washing and packing operations. 



Maturity 



Maturity of the fruit markedly influenced bruise damage in 1947 

 (table 1) and in 1948 (table 2). The results of inoculation studies 

 for those years are summarized (tables 3 and 4) . 



