The average operation stored 21,000 bushels, but 50% of 

 the operators have a capacity of 15,000 bushels or less. The 

 average CA room size was 7,100 bushels, but the capacities 

 ranged from 600 to 33,000 bushels per room. Thirteen of 

 the CA storages have only 1 or 2 rooms, while 10 have 3 or 

 4 rooms, 4 have 5 rooms, and 1 has 7 rooms. All but 4 

 operators stored only their own fruit, yet 84% of the fruit 

 was destined for the wholesale market. Mcintosh com- 

 prised 77% of the stored fruit. These members all show 

 clearly that the CA industry in Mcintosh is dominated by 

 small storages where the operator stores only his own fruit. 



Room Maintenance Characteristics . About two- 

 thirds of the rooms use freon as refrigerant, and the 

 remainder use ammonia. Only about two-thirds of the 

 operators test the rooms for leaks annually, a serious 

 oversight by the remaining operators. For pressure relief 

 in the room, 82% use breather bags, 21% use U-tubcs, but 

 7% apparently lack a designed relief system. (Percentages 

 may exceed 100% because some operators have different 

 equipment on different rooms.) In only two-thirds of the 

 rooms are floors covered with water before sealing, and 

 only 4 operators attempt to measure humidity in the 

 rooms. About 75% of the rooms use lime boxes to scrub 

 COj from the atmosphere. 



Establishing CA Conditions . During precooling, only 

 one-fifth of the operators actually measure fruit tempera- 

 tures. Only 39% of the respondents typically fill a room 

 within 1 week, and 50% require 1 to 2 weeks for filling. 

 (When rooms are opened, 21% typically are emptied in 2 

 to 4 weeks, while another 21% require 8 to 12 weeks.) 

 Liquid nitrogen was used in 43% of the rooms to generate 

 an atmosphere, in most of which 5% O^ was reached within 

 3 days. However, one-third of the rooms utilize only fruit 

 respiration to generate the atmosphere, which requires 

 more than 7 days for 5% O^ to be reached. 



Monitoring the Storage Atmosphere . In about one- 

 third of the storages, thermocouples or thermistors are 

 used to monitor temperature, and more than 2 locations 

 per room are monitored in one fourth of the storages. 

 However, nearly 50% of the rooms have only a thermome- 

 ter at the door for measuring temperature. Three-fourths 

 of the respondents calibrate their temperature-monitoring 

 devices annually. 



All storages monitor O^ and CO^ with an Orsat. Only 

 8 storages use a pump to draw air from the room to the 

 Orsat. Only 7 storages monitor the atmosphere more than 

 once per day, and 3 reported monitoring it less than once 

 per day. 



Desired storage conditions for Mcintosh varied 

 widely. Half of the operators did not state their desired 

 temperature, and of those who did, two-thirds set the 

 temperature at less than 37°F. For O^ levels, less than half 

 of the respondents try to keep the room at 3%. Eleven 

 operators try to keep Oj between 3 and 4%, and 5 try to 



maintain Oj at 4 to 5% O^. Sbc operators run rooms at less 

 than 3% O^, but no one tries to go below 2%. Half of the 

 storage operators try to maintain 5% COj, and nearly half 

 try to keep CO^ at less than 5%. 



Atmosphere Variations . Operators were asked to 

 identify typical atmosphere fluctuations in "good" rooms 

 and in "difficult" rooms. In good rooms, about half 

 reported temperature variations of no more than l°Ffrom 

 the set point, and about one-third reported that it varied no 

 more than 2°F. For Oj, about half reported variation of no 

 more than 0.5%, but 6 said that it typically fluctuated more 

 than 1% from the desired value. For CO^, responses were 

 almost identical to those for Oj. 



One quarter of the operators reported no "difficult" 

 rooms. Of those who have such rooms, wide variations in 

 Oj or COj were more common than in temperature. When 

 asked what condition was most difficult to maintain in their 

 storage, half of the operators noted Oj and none noted 

 temperature, while one-fourth said there was no real 

 difference. When asked what kind of atmosphere injury to 

 fruit was most frequent for fruit in their storages, 7 identi- 

 fied freezing, 6 identified brown core, 2 identified COj 

 injury, and 1 identified low-O^ injury. 



An Evaluation 



This survey clearly show that some of the difficulties 

 with fruit quality that CA operators experience when the 

 fruit come from storage arise from the sizes of the opera- 

 tions. To optimize the benefits from CA, a room should be 

 at atmosphere within 7 to 10 days after the first fruit in the 

 room were picked. 



Since half of the CA storages in Massachusetts consist 

 of only one or two rooms, and half require more than 1 

 week to fill a room, it appears that many operators lack the 

 volume to fill quickly enough to achieve full benefits of CA. 

 How much benefit these operators lose depends on how 

 ripe the apples become, how long it actually takes to 

 achieve CA conditions, and how well the storage operates. 

 Their problems are also compounded by slow pack-out 

 rates. Once the CA condition is broken, fruit begin to 

 ripen faster, and when 21% of the storages require 8 to 12 

 weeks for pack-out, much ripening occurs after breaking 

 the CA seal. These operations may benefit substantially 

 from division of the rooms, so that they can be both filled 

 and emptied faster. 



Once a room is filled, it is critically important that it be 

 sealed and brought to atmosphere quickly. One-third of 

 the CA rooms still employ only fruit respiration to achieve 

 atmosphere pull-down, which takes more than a week. 

 Fruit condition is lost during this time — needlessly. 

 Liquid nitrogen is easy to use to generate rapidly a low-O^ 

 atmosphere, and is especially applicable to small storages. 

 No storage should use fruit respiration to generate a CA 



18 



