N€VS : 



JOMAL OF AGRIfllLTDRAllSEARCB 



Voiv. XIX Washington, D. C, August i6, 1920 No. 10 



INVESTIGATIONS IN THE RIPENING AND STORAGE 

 OF BARTLETT PEARS ^ 



By J. R. Magness'^ 



Scientific Assistant, Horticultural and Pomological Investigations, Bureau of Plant 

 Industry, United States Department of Agriculture 



INTRODUCTION 



Physiological studies carried on in connection with the development, 

 ripening, and storage of the Bartlett pear reveal the fact that the factors 

 involved are somewhat different from those connected with the handling 

 of most other fruits. Pears of this variety are not usually allowed to 

 ripen on the tree but are picked as soon as they have attained suitable 

 size for marketing and have reached the condition at which experience 

 has shown they will ripen off the tree without shriveling. The exact 

 tests and sizes that are usually used to determine this degree of devel- 

 opment vary somewhat in different sections. Usually no fruit is har- 

 vested until it reaches 2),{ to 2)^ inches in diameter; and such factors 

 as the ease with which the stem separates from the branch, the plump- 

 ness of the fruit, or the degree to which the blossom end is smoothly 

 rounded out, the extent to which the sides of the locules or seed cavities 

 have drawn away from the seeds, and the depth to which the tissue 

 crushes when pressed in by the finger are used to determine when the 

 fruit has developed sufficiently to ripen in good condition if removed 

 from the tree. Bartlett pears, when "ripe" off the tree, become soft 

 and full yellow in color. This is the condition referred to by the term 

 "ripe" in this paper. 



In the Rogue River district of Oregon a mechanical pressure test (9)^ 

 has been used to some extent during the past year to determine the time 

 of picking, but in the other pear districts of the Pacific coast the meth- 

 ods enumerated above have been followed. 



If the pears are left on the trees until they are fully ripe, they are of 

 a very inferior quality. Very often the inside is soft and decayed before 



' This paper gives the result of a portion of the work carried on under the project "Factors Affecting 

 the storage Life of Fruit." 



' The writer wishes to express appreciation to W. S. Ballard, Pathologist, United States Department 

 of Agriculture, for the use of apparatus and for many helpful suggestions. 



• Reference is made by number (italic) to "Literature cited," pp. 499-500. 



Journal of Agricultiual Research, Vol. XIX, No. 10 



Washington, D. C. Aug. 16, 1920 



U.S. (473) Key No. G-aoi 



