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o£ softening can be misleading. Do not delay harvest of Alar* - 

 treated fruit ; a significant amount of the firmness difference be- 

 tween Alar*-treated and untreated fruits will disappear rapidly 

 during storage. Ethrel* hastens maturity, and despite our belief 

 that Ethrel*-treated fruits can be stored if^ harvested at the right 

 time, we think that it's extremely dangerous to try to CA-store 

 Ethrel*-treated apples commercially. The hormone-type Stop-drop 

 sprays also promote maturation, and should be used with this under- 

 standing. 



Further complicating the maturity problem is the use of red 

 strains and dwarfing rootstocks. Since for marketing reasons har- 

 vesting is usually gauged by red color, the red strains are prob- 

 ably an advantage to proper storage management since less mature 

 (and longer keeping) fruit may be harvested. However, among the 

 strains of 'Delicious' it is well known that some red strains ma- 

 ture well ahead of others. Therefore, it cannot be assumed that 

 red strains are just like the standard strains except for color; 

 other criteria must also be watched. It is very likely that some 

 rootstocks influence maturity, although this must yet be defined, 

 European studies suggest that fruit from M.9 rootstocks have 

 higher Ca levels and less bitterpit than fruit from M.M.104 root- 

 stocks. Again, you cannot assume that fruits from dwarf ing-root- 

 stock trees are the same as those from seedling-rooted trees. You 

 must watch these fruits closely. 



Just when to harvest apples for maximum storage life is per- 

 haps the most frustrating question to face. In Massachusetts, 

 flesh firmness of at least 15 to 17 lbs (if Alar*-treated, 16 to 

 17 lbs) is considered essential for 'Mcintosh' if they are to be 

 stored in CA. Most of the problems of immaturity can be dealt 

 with, but most of the problems of overmaturity cannot be overcome 

 except through rapid disposal of the fruit. Overmaturity is likely 

 the greatest cause of storage problems. It is better to pick a 

 little too soon than a little too late. 



Pre-storage operations . It is absolutely essential that apples be 

 cooled quickly and thoroughly before storage if they are to be 

 stored effectively. Ideally, the fruit should be cooled to 32°F 

 within 24 to 36 hours after harvest. Use of bulk bins increases 

 the cooling problem. Cooling systems of many older storages were 

 designed for slower loading rates than occur with use of bulk bins. 

 The bulk of fruits within bins interferes with heat exchange: cen- 

 ters of the bins remain warm long after the surfaces have cooled. 

 Furthermore, arrangement of the bins in the storage room often is 

 without regard to correct air flow patterns, and cooling is delayed 

 still further. Few growers have any idea what the temperature of 

 their fruit actually is in the storage. Those who have measured 

 it have been surprised; air temperature is a very poor gauge of the 

 apple temperature. Inadequate cooling undoubtedly is another major 

 source of storage problems. 



