12 



BULLETIN 601, U. S. DEPARTMENT OF AGRICULTURE. 



at the end of the 6-day holding period, while that commercially cut 

 showed a little over 40 per cent — less than half as much. 



The effect of precooling is shown best in the commercially cut 

 lettuce. In the precooled lots practically all the lettuce was in 

 marketable condition at the end of the 6-day holding period, and 

 70.9 per cent was prime, while the nonprecooled lots showed an 

 average of 6.7 per cent of worthless lettuce and only 40.1 per cent 

 prime. The high temperature at which the lettuce was held after 

 its withdrawal from the refrigerator car caused it to decay very 

 rapidly, as the lower part of figure 8 plainly indicates. The amount 

 of worthless lettuce in the various lots three days after their with- 

 drawal from the car is particularly worth noting. Contrasting one 

 extreme of handling with the other, as shown in figure 8, the pre- 

 cooled carefully handled lettuce showed 10 per cent worthless and 

 65.6 per cent prime, whereas the nonprecooled commercially handled 

 lettuce showed 48.7-per cent worthless and 3.4 per cent prime. 



Table IV. — Average percentages of decay in sixteen experimental lots of carefully cut and 

 commercially cut, lettuce held six days in an iced car at Palmetto, Fla., during the 

 season of 1913-14- 





At withdrawal. 



Three days after witddrawal. 



Treatment. 



Carefully 

 cut. 



Commer- 

 cially cut. 



Repacked. 



Undisturbed. 





Carefully 

 cut. 



Commer- 

 cially cut. 



Carefully 

 cut. 



Commer- 

 cially cut. 



Nonprecooled: 



Heads showing slight drop-rot, 



8.6 

 1.4 



36.2 

 22.5 



27.1 

 25.5 



25.6 

 69.2 



22.9 

 30 



19.8 



Heads showing bad drop-rot. per cent. . 



73.8 



Total drop-rot ' do.. 



10 



58.7 



52.6 



94.8 



52.9 



93.6 



Heads showing bacterial rot do. . 







2.4 



7. 5 



5.8 



7.8 



9.2 



Precooled: 



Heads showing slight drop-rot, 

 per cent 



Heads showing bad drop-rot. per cent. . 



1.6 







24 

 4.5 



14.6 

 11.1 



36.5 

 41.8 



22.6 

 13.7 



25 

 57.3 



Total drop-rot do. . 



1.6 



28.5 



25.7 



78.3 



36.3 



82.3 



Heads showing bacterial rot do. . 







. 7 



2.6 



3.4 



6.4 



8.5 



1 In some cases both drop and bacterial decay were found on the same head. As these diseases were 

 recorded separately, the total of all forms of decay may appear to amount to more than 100 per cent 

 in some instances. 



A glance at Table IV and the diagram shown in figure 9 gives a 

 convincing impression of the effect of precooling and of careful cut- 

 ting upon the development of decay. In the carefully cut non- 

 precooled lots only 10 per cent showed serious signs of drop-rot at 

 the first inspection, at which time the comparable commercially 

 handled lots showed 58.7 per cent. In the carefully cut precooled 

 lots, the drop-rot was so slight as to be of almost no commercial im- 

 portance, whereas in the commercially cut nonprecooled lots more 



