Aug. i6, 1920 



Ripening and Storage of Bartlett Pears 



495 



while the early lots from Suisun show a marked increase during storage. 

 This indicates the value of wrapping in preventing loss of moisture from 

 fruit. 



Examination of somewhat later lots picked during the commercial 

 season shows no increase in dry weight while the fruit is in storage, and 

 in many cases it shows an actual decrease. All the storages used were 

 comparatively high in humidity, otherwise there might have been a 

 loss due to more rapid evaporation from the fruit. 



An examination of the lenticels of the fruit of the dififerent lots was 

 made as the fruit was freshly picked. A number of pears were put in 

 methylene blue solution and after soaking a short time were removed 

 and the lenticels examined under a microscope. It was found that the 

 methylene blue readily penetrated the lenticels of the immature, early 

 picked fruit. Fruit picked at the opening of the commercial season, how- 

 ever, had a layer of brown, suberized tissue formed in the lenticel, which 

 prevented the penetration of the blue solution. Later in the season 

 pears immersed for a considerable length of time and then rinsed in 

 water showed only a very faint blue ring about the outside of the len- 

 ticel. The corky layer had apparently almost completely stopped pene- 

 tration of the solution. Even when an immersed pear was placed under 

 reduced pressure for a time and then under full atmospheric pressure 

 the solution did not penetrate the lenticels. 



With practice, this condition of the lenticels can be detected by the 

 brown color of the corky growth without the use of a microscope and 

 dye solution. It appears that this change in the lenticels may be a 

 valuable aid to present methods of determining when the fruit is in 

 condition to pick and handle without danger of shriveling or wilting. 



EFFECT OF TIME OF PICKING UPON LENGTH OF TIME FRUIT MAY BE 



STORED 



Table V shows the number of days between the time the fruit was 

 picked from the tree and the time of full yellow ripeness. The Yakima 

 fruit is not included, since the number of days in transit and the fact 

 that one lot was delayed en route makes an accurate comparison impos- 

 sible. 



Table V. — Number of days required for fruit to become soft, yellow ripe at different 



temperatures of storage 



Sacramento, Calif. 



Date of picking. 



June 12 



18 



July 5 

 12 



Aug. 13 



Num- 

 ber of 

 days at 

 70° F. 



14 



14 

 14 

 14 



Num- 

 ber of 

 days at 

 40° F. 



45 

 32 

 33 

 24 



Suisun, Calif. 



Date of 

 picking. 



June 10. 

 July I . 



10. 



22. 

 Aug. 6 . 



Num- 

 ber of 



days at 

 70° F 



15 

 14 



13 

 12 



Num- 

 ber of 



days at 

 40° F 



49 

 41 



32 

 28 



Medford, Oreg. 



Date of 

 picking. 



July 19. 



Aug. 8. 



28. 



Num- 

 ber of 



days at 

 70° F 



Num- 

 ber of 



days at 

 40° F. 



31 

 26 



23 



