16 CIRCULAR 6 5 9, U. S. DEPARTMENT OF AGRICULTURE 



product plants or otherwise at frequent intervals (fig. 1,B). Storage 

 rooms should be kept clean and sanitary at all times, and prior to 

 each season's use they should be either whitewashed or well disin- 

 fected or otherwise thoroughly cleaned and aired before any apples 

 are brought in. Whitewashing is simpler and generally preferable to 

 other measures that can be taken. If copper sulfate is added to the 

 whitewash, its disinfectant properties can be increased somewhat, but 

 from a practical standpoint this is of questionable value. It is espe- 

 cially desirable, however, to clean and disinfect the floor, which is not 

 whitewashed. Thorough scrubbing with water containing 2.5 percent 

 sodium hypochlorite and a suitable wetting agent is recommended. 

 There are a number of commercial preparations on the market suit- 

 able for this purpose. 



For disinfection sulfur dioxide, the gas produced by burning sulfur, 

 can be used. The proportion ordinarily used is 1 pound of sulfur 

 to 1,000 cubic feet of space. It should be burned in a metal vessel 

 placed on bricks or otherwise held off the floor. All openings should 

 be kept tightly closed for an hour or so in order to permit the maxi- 

 mum concentration of sulfur dioxide to be utilized. Ordinarily 

 formaldehyde candles can likewise be burned as in household disinfec- 

 tion, but formaldehyde is less satisfactory than sulfur dioxide because 

 of the persistence of the odor, and thorough airing out for a con- 

 siderable period afterward is required. Both sulfur dioxide and 

 formaldehyde are toxic and injurious to apples, and no fruit 

 should be placed in the rooms until all traces of gas have dis- 

 appeared. They are likewise strong irritants to eyes and mucous 

 membranes, and care must be exercised to avoid contact with the 

 fumes during or after fumigation. Doors or windows should be 

 opened to air the rooms thoroughly after fumigation and before 

 they are entered by workmen. For this reason it is feasible to 

 fumigate only during the season when the storage space is not 

 in use. 



Bruising and Other Mechanical Injuries 



The importance of bruising and other mechanical injuries in blue 

 mold infection emphasizes the need for preventing such injuries. 

 Pickers, sorters, and packers should wear gloves or cut their finger- 

 nails closely to prevent fingernail punctures, and care should be exer- 

 cised to remove all sand, splinters, and projecting nails in the fruit 

 boxes or baskets. Pickers should be provided with containers having 

 rigid sides rather than with picking bags (fig. 6) in order to prevent 

 bruising the apples when the picker leans against the container, as he 

 often does in picking from a ladder or in the tree. Pickers should be 

 required to empty the fruit carefully into the field boxes and should 

 never be allowed to drop apples more than an inch or two. Field boxes 

 should be filled less than level full, in order to prevent bruising the 

 fruit when stacked (fig. 7), and care should be exercised in lidding 

 the market packages to prevent the apples from being cut or badly 

 bruised. Use of adequate grading and sizing machinery, which moves 

 the fruit gently on belts or rollers, is an important factor in the reduc- 

 tion of bruising damage (fig. 8). Bad bruising often results from 

 not taking adequate precautions in handling the fruit in the packing 



