countries, and representatives o£ business with interests in 

 CA storage. Here is a summary o£ the information from this 

 Conference that I think would be of interest to Northeastern 

 fruit growers. 



A major development of CA storage of apples is the demon- 

 stration that apples can be successfully stored at about 1% 0^, 

 with considerably better retention of quality than at the normally 

 recommended 0^ concentrations. Research in a number of places, 

 most notably England, Nova Scotia, and Michigan, has produced 

 very successful results, especially on soft varieties like Mcintosh. 

 However, as Dr. E.C. Lougheed of the University of Guelph, Ontario 

 put it: "Low oxygen storage is not for everyone. The user must 

 be prepared to take risks." And he might have added, the user 

 must be prepared to take a number of extra precautions and to be 

 extra careful in storage management. 



The primary risk is that storing near 1% Oy offers extremely 

 little margin for error. We have long known that 3% 0^ is a con- 

 servative recommendation, but it allows for some error. With 

 low-0^ storage, precision is essential. For example, a tiny leak 

 in the CA sample line could cause loss of an entire room of fruit 

 due to fermentation. Either a new sampling system must be employed 

 or else very careful and frequent cross-checking of atmospheric 

 composition must be made. In England, Cox's Orange Pippin rooms 

 need to be read every hour, so they have developed automatic con- 

 trol systems for low-0^ storages. However, in North America once- 

 a-day readings appear to be satisfactory if done with sufficient 

 precision. 



Different speakers emphasized different limitations of low- 

 0-, storage of apples. Dr. Perry Lidster, in Nova Scotia, empha- 

 sized that only less mature apples (judged by a starch test) could 

 be stored in low 0^; more mature ones developed a form of internal 

 browning. He also found temperature to be critical for Mcintosh, 

 and recommends 35-36 F. Several speakers emphasized that CO2 had 

 to be very close to 01 with low-0^ to avoid low-0^ injury. 



The benefit from low-0-^ storage is a much slower ripening of 

 the fruit in CA. Dr. Lidster estimates that Mcintosh can be kept 

 18 months in low-0^ CA, and ones kept 6-10 months are much firmer 

 and less ripe than ones in normal CA for the same length of time. 

 Certainly, low-0-, storage is something that will receive much 

 attention in the next few years. We have no experience with it in 

 Massachusetts, but are very wary of its use in most of our storages . 

 It is clear that it can work, but it is also clear that substantial 

 new risks are involved and only a storage operator who has an excell- 

 ent storage system and who is willing to invest great care and signi- 

 ficant risk should consider employing it at this time. 



