10 - 



ter and spring. Consequently, Mcintosh for CA should have a flesh 

 firmness of 15 to 17 pounds. This requirement applies irrespective 

 of the use of Alar. Although Alar may provide excellent pre-har- 

 vest drop control and retard the rate of flesh softening for Mcin- 

 tosh until mid-October or later, the fruit is not generally firm 

 enough beyond October 1, to be suitable for CA storage. Remember 

 that when relatively soft, ripe fruit are placed in CA storage, 

 fruit of poor quality is ^ery apt to be present at the end of the 

 storage period, no matter how well the CA storage room is operated. 



CA Storage Room Operation : To reduce the tendency of fruit 

 to scald and lose flesh firmness, apples should be transported from 

 the orchard to a refrigerated storage room within a few hours. 

 Ideally, the fruit should be cooled to 30-32 F within 24 to 36 

 hours after harvest. Even though this ideal is not accomplished, 

 the fruit should be stored in air until the temperatureof the ap- 

 ples reaches 30-32°F, regardless of the fact that 37-38 F is the 

 CA operational temperature. Generally, the keeping quality of Mc- 

 intosh is improved by cooling the fruit to 30-32 F in spite of the 

 fact that sealing of the room may be delayed several days. 



After sealing a CA Mcintosh room(which is also suitable for 

 Cortland, if the apples are properly treated for scald control), 

 the temperature should be allowed to rise to 37-38 F as the carbon 

 dioxide (CO^) level increases (to 3% for the first 4 weeks and 5% 

 thereafter) and the oxygen (Op) level declines to 3-4%. These at- 

 mospheres must be obtained within 20 days after the CA room is 

 sealed to meet the legal requirements for CA rooms. In well con- 

 structed rooms these atmospheres are usually obtained within 10 

 to 15 days. Use of nitrogen generating systems, purging with cyl- 

 inder nitrogen, reducing air velocity within the storage room and 

 the use of "breather" bags all are ways of hastening the rate of 

 oxygen decline and helping maintain it at the 3-4% level. 



seale 

 ti vel 

 s i g n i 

 able 

 1 evel 

 bette 

 gen 1 

 seal e 

 prove 

 3.5%. 

 el an 



A wery 

 d w h i 1 

 y rapi 

 fy a V 

 to dem 

 was r 

 r than 

 evel d 

 d. Al 

 d by m 

 Ther 

 d risk 



rapi d 

 e the 

 d rate 

 ery ga 

 onstra 

 educed 



s i m i 1 

 id not 

 so , th 

 a i n t a i 

 efore , 



s e r i 



oxygen 

 fruit w 

 . Of c 

 s - 1 i g h t 

 te that 



from 2 

 ar appl 



reach 

 e k e e p i 

 n i n g an 



there 

 us low- 



drop 

 as we 

 ourse 



room 



appl 

 0% to 

 es he 

 3% un 

 ng qu 



oxyg 

 is no 

 oxyge 



may 

 11 ab 

 , a r 



as w 

 es f r 



3% i 

 Id in 

 til 2 

 a 1 i ty 

 en le 



reas 

 n inj 



indicate t 



ove 32°F a 



a p i d d e c 1 i 



ell. Howe 



om CA room 



n a few ho 



an adjace 



weeks aft 



of Mclnto 



vel at 2.5 



on to main 



ury. 



hat the CA room was 

 nd respiring at a rela- 

 ne in oxygen level may 

 ver, we have not been 

 s where the oxygen 

 urs kept significantly 

 nt room where the oxy- 

 er the CA room was 

 sh apples is not im- 

 % rather than at 3.0- 

 tain a 2.5% oxygen lev- 



We do not encourage CA operators to attempt to improve the 

 marketable life of apples by reducing the temperature of Mcintosh 

 CA rooms to 35-36 F. There is some evidence that this reduction 

 in temperature (compared to the recommended 37-38°F) may improve 

 the keeping quality of Mcintosh slightly. On the other hand, there 



