actual percent scald observed. While the trend of the 

 data seems encouraging, the reliability of the 

 predictions is not acceptable. Furthermore, this 

 equation gave much worse results when applied to 

 fruit harvested from other orchards in new England. 

 We are continuing to pursue an effective predictive 

 system, but as of now, we have not produced a tool in 

 which we have confidence. 



Based on nearly 15 years of experiments with 

 Cortland, we draw the following conclusions about 

 scald susceptibility of this cultivar in New England: 



1 . Scald susceptibility varies enormously from site to 

 site, and also from year to year within a site. 

 Because your fruit did or did not scald last year is 

 not a reliable index of what they will do this year. 



2. Susceptibility declines as fruit mature and, to 

 some extent, as they experience increasing 

 exposure to temperature below 50"F before 

 harvest. However, delaying harvest to obtain 

 scald resistance can result in soft fruit that develop 

 senescent breakdown. 



3. We still cannot predict scald development on 

 Cortland. 



4. At this time DPA is the only reliable method of 



controlling scald on Cortland. Unlike with 

 Delicious, we have not been able to predict the 

 concentrations needed to control Cortland scald. 

 5 . Because Cortlands are scald-free at removal from 

 storage does not mean they will remain scald-free 

 when they warm to room temperature. Most scald 

 symptoms develop after storage of this cultivar. 

 Effective scald control treatment at harvest time is 

 your best assurance that Cortlands will remain 

 scald-free during their shelf life. 



We wish to express sincere thanks to the following 

 people who contributed greatly to this work by 

 providing samples of fruit for study: Mr. Joseph 

 Sincuk, HRC, Belchertown, MA, Mr. Dana Clark, 

 Clark Orchards, Ashfield, MA, Mr. Evan Darrow, 

 Green Mountain Orchards, Putney, VT, Mr. Timothy 

 Smith, Apex Orchards, Shelbume, MA, Mr. Mark 

 Tuttle & Mr. Robert Tuttle, Breezelands Orchards, 

 Warren, MA, Professor William G. Lord, University 

 of New Hampshire, Dr. James Schupp, University of 

 Maine (now at Cornell University's Hudson Valley 

 Laboratory), and Dr. David Kollas, University of 

 Connecticut. Without their help this study could not 

 have been done. 



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



