The question most frequently asked us during these years has 

 been: Is calcium level influencing storage life of Mcintosh? It 

 is more difficult for us to answer this question for Mcintosh than 

 Baldwin, because we do not have a large block of Mcintosh trees 

 known to be calcium-deficient, as we do with Baldwin. Neverthe- 

 less, we last year conducted a number of calcium experiments on 

 Mcintosh trees and fruit, and by compiling all the data, an inter- 

 esting pattern has consistently emerged: calcium deficiency does 

 seem to exist in Mcintosh and it does seem to be influencing stor- 

 age life of apples. 



In September, 1973, we harvested fruit from a block of 10- 

 year-old Mcintosh trees at Belchertown that varied in leaf calcium 

 levels. Bushel samples were stored in 32°F air until January. 

 After 1 week at room temperature, these samples were assessed for 

 disorders and some fruit were peeled and analyzed for calcium. 

 The results are in Table 1. The amount of calcium in the flesh of 

 these apples was very low, and the fruit at the highest level had 



Table 1. Flesh calcium levels, bitter pit, and decay of Mcintosh 

 apples following 4 months storage in 32°F air. 



Flesh calcium 

 range ( % ) 



Number of 

 trees 



Bitter 

 i%L 



pi t 



Decay 



(%) 



6 

 5 

 1 



9 

 4 

 1 



about twice as much calcium as the ones at the lowest level, a sur- 

 prisingly large range. The apples with more than 0.0150% calcium 

 were almost free of bitter pit and decay, whereas those below 

 0.0150% had substantial amounts of both disorders. 



In another experiment, Mcintosh 

 dips in calcium solutions and stored 

 were assessed and analyzed as above, 

 again that above 0.0150%, bitter pit 



that had been given postharvest 

 in 32°F air until February 

 The results in Table 2 showed 

 was virtually absent, and also 



Table 2. Flesh calcium levels, bitter pit, and internal breakdown 

 of Mcintosh apples following 5 months storage in 32°F air . 



Flesh calcium 

 range (%) 



Number of 

 sampl es 



Bitter pit 

 (%) 



Internal breakdown 



in 



0107 - 



0126 - 



0153 - 



0177 - 



0124 

 0147 

 0175 

 0195 



16 



12 



8 



5 



that above this level 



was reduced to about 50% 



