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SOm POINTS OF INTEREST ON HARVESTING AW STORAGE OF APPLES 



Pre-hairvest drop hormones ; Introduction of new hormones for pre-harvest drop 

 control during the past few years is rapidly changing the materials picture. It is 

 possible that 2,U>5-trichlorophenoxyacetic acid (2,U,5-TA) may be useful in this 

 regard. Present results indicate that it will delay drop on Idclntosh longer than 

 naphthaleneacetic acid and will not hasten ripening as much as 2,U^5-TP (Color-Set, 

 Color .Lok, etc.). We have just completed a test on Mcintosh comparing 2,[i,5-1!^ 

 with 2,ii,5-TP amd will report the results when we have the data in shape. 



Importance of quick cooling of fruit after harvest ; It is important to cool 

 our apples to 32" ^'* as rapiaiy as possiDie alter narvest if one is to get the 

 longest possible marketable life from an apple. A test run last year showed that 

 if apples are stored for the first month at i;0° F, instead of 32° F, they will lose 

 much of their storage life, Mcintosh held at U0° F. for the first month and 32° F. 

 thereafter were 1,2 lbs, softer on February h than comparable apples held at 32° F. 

 all season. This represents a loss of 21; days of storage life, Cortland held in 

 similar fashion were 1,7 lbs, softer on February 7 than comparable fruits at 32° F. 

 This represents a i;3 day loss in storage life, Tlie inability to cool the fruit 

 rapidly to 32° F. in storages is a real problem and often is a primary reason for 

 the presence of soft apples which come from storages in January and February. 



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Present ideas on ripening gases which emante from apples : Recent research at ' 

 several Universities indicates that ripe apples not only produce the ripening gas 

 ethylene but also one or more other volatiles which may stimulate the rate of 

 ripening of less mature apples. The production of ethylene and other volatiles is 

 much greater from ripe apples (drops) than from hand picked firm fruits. Conse- 

 quently, it is desirable to store drops separately rather than in rooms with hand 

 picked fruit which one wishes to keep in storage for an extended period of time, A 

 few bushels of ripe apples may stimulate the rate of ripening aJid scald development 

 of all the less mature apples in the room. 



Present status of air-purification for apple cold storages . Now that air 

 purification units using activated coconut shell carbon have been tested for ten 

 years the following general statements concerning them can be made, (l) Coconut 

 shell carbon is the best of the known adsorbents for adsorbing apple volatiles. 

 Growers should expect to receive coconut shell carbon and should accept no 

 substitutes, (2) It makes little difference whether one uses manufactured units or 

 suitable home-made types. The carbon can be used satisfactorily in cannisters and 

 horizontal or vertical trays. (3) These units have generally added 2 weeks to a 

 month to the storage life of Mcintosh. (U) These units do not adsorb much ethylene 

 but apparently they \vill remove other ripening gases. (5) Air purifiers are out- 

 standing in their ability to remove storage odors which may tend to give apples an 

 "off" flavor. (6) Storage scald cannot always be controlled by these units. On 

 many varieties it is as satisfactory as oiled paper in this regard. However, these 

 carbon units will not control scald on Cortland, Shredded oiled paper is superior 

 to carbon for scald control on Cortland in our tests over the past 3 seasons. 



Storage troubles ; Scald on Cortland and Greening are serious problems. Also, 

 Baldwin Spot (bitter pit) can be serious on such varieties as Baldwin and Soy. 



Scald is usually most serious on the earliest picked lots. In other vrords, 

 the more mature the fruit when picked the less apt it is to scald. However, some 

 years are more severe scald years than others. Since apples will develop typical 

 scald symptoms much more rapidly at room temperature than under cold storage 

 conditions, it is advisable to take a few apples of scald susceptible varieties out 



