16 CIRCULAR 5 



It was found that where apples were washed by spraying there was 

 a greater accumulation of spores in the washing .solution than where 

 the apples were dipped or floated through the machines. Neither 

 acid nor alkaline Vv r ashing solution, however, had any apparent effect 

 as sterilizing agents within the time that apples were exposed to 

 them. Perennial canker spores were not killed by six days' exposure- 

 to either solution. No dependence could be had, therefore, on 

 the chemicals commonly employed for washing to prevent rots by 

 killing the spores. 



A number of disinfectants have been tried for the purpose of 

 killing spores of rot fungi in the washing solution. At present 

 there is no practical suggestion to be given in this connection, and the 

 use of disinfecting compounds in the washing solution or in the rinse 

 water is not recommended. 



Formalin appears to be useful in providing sterile machines at 

 the beginning of the day's packing operation. At the end of each 

 day's work 1 pint of formalin has been added to each 100 gallons of 

 washing solution. The machines are then run for 5 to 10 minutes and 

 allowed to stand overnight. The tanks may also be given a scrubbing 

 with a broom. In the morning they are again run for a few minutes 

 prior t o the replacing of the used solutions with fresh acid and water. 

 Where the machines can be thoroughly flushed out with clean water, 

 practically as good results can be obtained without the use of 

 formalin. 



Although the most satisfactory results have been obtained when 

 fruit has been dried before packing, no serious difficulties have 

 resulted from the presence of traces of moisture on washed fruit. 

 When the removal of the spray residue has been as thorough as pos- 

 sible and rinsing has been properly done no injury has occurred that 

 could be attributed to the action of water. 



Fruit packed with traces of moisture has dried quite readily both 

 in cold storage and in common storage, providing the relative 

 humidity has not been too high. Fruit in oiled or unoiled paper 

 wraps has dried more quickly than fruit stored unwrapped. 



When washed fruit is placed in storage in any large quantity it 

 is probably desirable to avoid the addition of moisture to the stor- 

 age air and to operate the storage at a somewhat lower relative 

 humidity than is customary until the fruit is dried. 



The opinion has been prevalent in some cases that the washing 

 of fruit tends to hasten its ripening. Numerous tests have not indi- 

 cated that such is a fact. 



Some apprehension has existed over the possibility of injury to 

 fruit handled while in a wet condition after the washing treatment. 

 This fear has been based on the observation that apples which have 

 stood in the rain tend to become turgid and are very susceptible 

 to bruising. Injury of this nature has not been a factor in washed 

 fruit. The length of time taken for the washing treatment is appar- 

 ently so short that there is no effect on the turgidity of the fruit. 



The washing of fruit, if done with proper equipment and under 

 reasonably sanitary conditions, will not consistently increase the 

 percentage of decay very materially and in some cases may not in- 

 crease it at all or may even reduce it below the proportion found 

 in unwashed fruit from the same lot. If there is an increase in decay 

 it may be due to the additional handling and consequent rots at 



