18 MISC. PUBLICATION 168, U. S. DEPT. OF AGRICULTURE 



treatment, but disinfection does not replace sanitation, careful 

 handling, and prompt cooling. 



Delay in cooling shipments caused by slow loading, belated icing 

 of the cars, or loading of warm fruit gives an opportunity for the 

 rot to develop and so increases the probability of loss. Delay in 

 moving the cars also increases this probability by giving the 

 fungus a longer time in which to work. 



(See 5, 6, 12, 37, US, 58, 59, 60, 65, 1U, 133, 136.) 



Box-Wood Scald 



In 1928 Fisher (39) reported injury on apples from contact 

 with boxes made of heartwood Douglas-fir (Pseudotsuga taxifolia 

 (Poir.) Britton). The injury occurred when the wood and fruit 

 were wet. Box-wood injury has not been observed in recent years. 

 It is possible that changes in the spray program are responsible 

 for the absence of injury, but this has not been established. 



(See 39.) 



Brown Core and Internal Browning 



Brown core and internal browning are nonparasitic diseases, 

 heretofore described separately, that appear to have a common 

 cause. It is suspected that they are the same disease differently 

 manifested in certain varieties of apple, but the fact has not 

 been established. In general, the conditions appear on fruit grown 

 at low temperature and without sufficient sunlight. This basic 

 relation was demonstrated in New York (125) by shading certain 

 limbs of the tree, which increased susceptibility of Mcintosh to 

 brown core. In California (97) the shading of entire trees of 

 Yellow Newtown increased susceptibility to internal browning. 

 Both disorders are increased by low-temperature storage (30° to 

 32° F.), 



BROWN core 



In the United States brown core occurs principally in New York 

 and New England. It is more serious in Mcintosh than in other 

 varieties, but it may occur in Rhode Island Greening, Twenty 

 Ounce, and Baldwin. It occurs throughout Canada on varieties 

 such as Mcintosh, Fameuse, Baldwin, Wagener, Grimes Golden, 

 Gravenstein, and Yellow Newtown. It also occurs in Australia, 

 where it is known as core flush. 



There are no external symptoms of brown core ; therefore it is 

 necessary to cut the fruit to detect the disorder. It first appears 

 as a slight browning or discoloration of the core tissue between 

 the seed cavities (pi. 9, E). Later, a part or all of the flesh between 

 the seed cavities and the core line may become brown. In other 

 cases, especially in Mcintosh, there are, in addition to the 

 browning between the seed cavities, brown wedge-shaped streaks 

 penetrating beyond the core line into the surrounding flesh (pi. 

 9, F, G). This stage resembles internal browning as found in 

 Yellow Newtown. There is no sharp line separating the diseased 

 and healthy tissues. 



Brown core may be confused with cork due to boron deficiency. 

 If the disorder is cork, however, there usually are small, corky 

 spots scattered through the flesh in addition to any discoloration 

 of the core tissue. 



