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



least partly removed by aeration and ventilation, but removal is 

 difficult to accomplish in closed packages under the usual storage 

 conditions. The injurious gases can be absorbed by oils, a charac- 

 teristic which is the basis for the most practical method of scald 

 control now available— that of packing the apples in oiled (not 

 waxed) paper. 



CONTROL MEASURES 



Oiled wrappers should be used on apples of susceptible varieties 

 in packed boxes, and shredded oiled paper should be scattered 

 among apples in boxes and baskets that are faced and filled. 

 For each bushel of apples about V2 pound of shredded paper is 

 required. It must be well distributed in the package, with prac- 

 tically every apple more or less in contact with the paper. Oiled 

 wrappers should carry at least % gram of oil per sheet and both 

 wrappers and shredded oiled paper should have at least 15 percent 

 of their finished weight in odorless, tasteless mineral oil. Eighteen 

 percent or more of oil is desirable if lightweight paper is to be 

 used on the more susceptible varieties of apples. The apples 

 should be packed in the oiled paper as soon as possible after 

 picking. Unless this is done within 3 or 4 weeks after the fruit 

 is put in cold storage, it is not usually possible to overcome the 

 tendency to scald. 



(See 12, 27, A3, U, 51, 59, 105, 106, 109, 135, 136.) 



Side Rot 



(Phialophora malorum (Kidd & Beaum.) McColloch) 



Side rot, a disease of apple and pear, was listed in the original 

 version of this publication as sporotrichum rot and was described 

 with the group classed as bull's-eye rots. Since then the causal 

 fungus was reclassified (80). The rot produced by this fungus 

 on apples and pears is quite distinct from bull's-eye rot in most 

 respects and is therefore described separately. 



OCCURRENCE AND SYMPTOMS 



Side rot has been reported on pears grown in the northwestern 

 part of the United States and on apples grown there and in 

 Indiana, Virginia, West Virginia, and Maryland. It has been 

 observed on a wide range of varieties, but more frequently on 

 Winesap and Delicious than other varieties. 



Typical lesions are oval, but often they have slightly irregular 

 margins. They are usually less than 1 inch in diameter, are 

 slightly sunken, and have a dull appearance (pi. 7, E, F). The 

 color of the lesions varies from brown with a pale center to dark 

 brown. The surface is frequently cracked, but when it is not it 

 breaks with a pop under slight pressure. The texture of the de- 

 cayed tissue when the rot is active is wet and slimy. It separates 

 cleanly from the healthy tissue, leaving a saucer-shaped cavity 

 usually about y 16 to % inch deep. In certain cases where the 

 rot is less active, especially where the surface has been broken, 

 the texture is dry and spongy. The rot is tender and is not firm, 

 giving readily under pressure. 



The tendency of side rot lesions to have pale centers is the 

 reason that it is sometimes confused with bull's-eye rot. Although 



