35 



30 



25 



20 - 



15 



10 



Low oxygen injury (%) 



*** 



^H Roger* 

 IZZ Marshal 



2.26% 3% 



Oxygen concentration 



Figure 2. The incidence of low-O^ injury in Marshall 

 and Rogers Mcintosh fruit stored at 3% and 2.25 % O2 

 after the 1988 harvest. 



flesh browning characteristic of I0W-O2 injury has a rim 

 of normal, white tissue outside of the browned tissue 

 and under the skin. With further development, this 

 white rim disappears. 



Figure 2 shows the levels of low-Oj injury found in 

 Marshall and Rogers fruit. Even at 3% Oj (the recom- 

 mended level for CA storage of Mcintosh in New Eng- 

 land) Marshall fruit developed some internal I0W-O2 

 injury. At 2.25% O2, 32% of the Marshall fruit exhib- 

 ited internal I0W-O2 injury, while only 4% of the Rogers 

 fruit were damaged. This increased level of damage 



would represent a significant loss by a storage operator. 

 Storage operators must monitor their O2 concentra- 

 tions carefully and not allow O^ to drop below the 

 recommended value if they are storing Marshall Mcin- 

 tosh fruit. 



Because of its early coloring and ripening, 

 Marshall Mcintosh will undoubtedly be of great value 

 to the New England Mcintosh industry if Alar'''" is not 

 used in the future. However, we stress that it is not safe 

 to store Marshall fruit in CA with O2 concentrations 

 below 3%. 



•X» «!• ai» •S* •S* 



*j» •]« *f» *{* ^* 



Fmit Notes, Summer, 1989 



