Characteristics of Scaid Susceptibility 

 and Development on Cortland Apples 

 in New England 



Sarah A. Weis, William J. Bramlage, and William J. Lord 

 Department of Plant & Soil Sciences, University of Massachusetts 



Postharvest development of scald is a severe threat 

 for certain cultivars of apples. Cortland is particularly 

 susceptible, so much so that growers would likely have 

 discontinued production except for the discovery that 

 scald could be controlled by treatment with 

 diphenylamine (DPA). Even today, however, 

 Cortland fruit stored long-term carry a significant risk 

 of scald development. 



In the Spring 1998 issue of FruitNotes, we 

 reported on the success we have had in predicting scald 



susceptibility of New England Delicious apples, using 

 equations based on harvest date, preharvest tempera- 

 ture, and harvest starch score of the fruit. At the same 

 time that we have been studying scald prediction for 

 Delicious, we have also been attempting to develop a 

 similar prediction system for Cortland. For reasons we 

 are unable to explain, we have failed in these efforts 

 with Cortland. However, during our experiments we 

 have learned much about scald development on this 

 cultivar, and here we report some of these findings that 



H] On removal from storage ■ Following 7 days at 68 F 



Figure 1 . Scald development following 20 weeks of 32^ air storage of Cortland apples (harvest dates vary). 



Fruit Notes, Volume 64 (Number 2), Spring, 1999 



