EASTERN-GROWN APPLES 6 



"maturing" refer to those changes that take place in the fruit on the 

 tree that would influence the quality of the fruit after harvest. The 

 terms "ripeness" and "ripening" refer to those changes that take 

 place in the fruit that make it suitable for eating. Changes in the 

 fruit after harvest would be ripening changes, but such changes may 

 also occur while the fruit is still on the tree and may accompany or 

 follow the maturity changes. 



When apples first reach a stage of development at which they are 

 considered mature they are generally in an unripe stage and are 

 "hard," green in ground color, and unsuitable for eating. If they are 

 permitted to remain on the tree, further maturity changes may take 

 place, so that the fruit would develop higher flavor and better texture 

 than if picked at the earlier stage and ripened. Ripening changes also 

 take place during this time on the tree and the fruit will have become 

 softer and less starchy and will approach a "firm ripe" condition in 

 which it may be suitable for eating. 



When the apples remain on the tree a sufficient length of time they 

 will become "ripe" and suitable for eating immediately, but would be 

 "overmature" for storage purposes as they would quickly become 

 mealy and flat in flavor owing to loss of acidity and aroma. The 

 storage and dessert qualities would be inferior to apples picked at 

 optimum maturity and then ripened. It would be possible under this 

 usage of the terms "maturity" and "ripeness" to have "immature" 

 apples that would ripen, since apples picked before they are mature 

 might eventually acquire a yellow skin and fairly mellow texture, and 

 the starch might be hydrolyzed to sugar. This fruit might shrivel 

 and would lack the characteristic flavor and texture of the variety. 



In making an inspection, the firmness of a lot of apples is gen- 

 erally estimated by the pressure of the thumb, by the way the flesh 

 cuts or breaks, and by chewing. It is possible to determine the 

 firmness of the flesh rather accurately by means of the pressure 

 tester described by Magness and Taylor. 4 Magness et al. 5 and others 

 have followed the softening of apples both on the tree and during 

 ripening in storage at various temperatures. They have found that 

 while the fruit was maturing on the tree there was generally a 

 gradual softening as it became more mature and that particularly 

 in storage the rate of softening was closely correlated with ripening. 

 As the ratings for ripeness are based largely on firmness it would 

 seem desirable to determine the firmness by means of the pressure 

 tester and if possible to convert the pressure-test readings into such 

 inspection terms as "hard," "firm," etc. In order to do this it would 

 be necessary to determine for each variety the range of pressure 

 tests representative of each stage of ripeness. 



The purpose of the investigations reported in this circular was to 

 determine these ranges for a number of commercially important 

 varieties of apples grown in the Shenandoah-Cumberland Valley. 

 It may be that somewhat different relationships between firmness 

 and ripeness would be found in apples grown under distinctly dif- 

 ferent climatic or cultural conditions. Also, the apples used in these 

 investigations were ripened at both high and low temperatures and 



4 Magness, J. R., and Taylor, George F. an improved type of pressure tester for .the 

 determination or fruit maturity. U. S. Dept. AgT. Dept. Cir. 350, 8 pp., illus. 1925. 



5 Magness, J. R., Diehl^ H. C, Haller, M. H., Graham, W. S., Carrick, D. B., Howlett, 

 F. S., Marshall, R. E., Plagge, h. H., and Raleigh, G. J. the ripening, storage, and 

 handling of apples. U. S. Dept. Agr. Bui. 1406, 64 pp., illus. 1926. 



