UNITED STATES DEPARTMENT OF AGRICULTURE 



r ^^lfos In Cooperation with the 



Agricultural Experiment Stations of Massachusetts, New York (Cornell 

 University), Ohio, Michigan, and Iowa 



DEPARTMENT BULLETIN No. 1406 



Washington, D. C. T August, 1926 



THE RIPENING, STORAGE, AND HANDLING OF APPLES 



By J. R. Magness, Physiologist, H. C. Diehl, Assistant Physiologist, M. H. 

 Haller, Junior Pomologist, and W. S. Graham, Junior Physiologist, Office 

 of Horticulture, Bureau of Plant Industry, with the cooperation of D. 13. Car- 

 rick, New York Agricultural Experiment Station at Cornell University, F. S. 

 Howlett, Ohio Agricultural Experiment Station, R. E. Marshall, Michigan 

 Agricultural Experiment Station, H. H. Plagge, Ioiva Agricultural Experi- 

 ment Station, and G. J. Raleigh, Massachusetts Agricultural Experiment 

 Station. 



CONTENTS 



Page. 



I. Studies of the ripening of apples 1 



Introduction : 1 



Experimental methods 2 



Soil and cultural conditions 4 



Weather conditions 4 



Increase in size of fruit 5 



Softening of apples on the tree 7 



Pressure test as a measure of fruit maturity 12 



Ground color of apples 13 



Ease of separation from the tree 15 



Color of seeds 17 



Length of growing season 17 



Tests for time of picking 21 



Summary of Part 1 2H 



II. The ripening of apples in storage as influenced by temperature 25 



Influence of temperature on rate of softening 25 



Rates of softening at different temperatures 27 



Influence of storing at low temperatures on softening rate when removed 



to high temperatures 35 



Influence of time of picking on softening of apples stored at various 



temperatures 37 



Yellowing of fruit in storage as affected by temperature 39 



Changes in chemical composition of apples stored at different tempera- 

 tures 40 



Respiration rate of apples at different temperatures 45 



Summary of Part II 4S 



III. The handling of apples for storage 51 



Temperatures prevailing in air-cooled storages 51 



Testing common-storage houses 54 



Varieties of apples for common-storage holding 55 



Time of picking apples for common storage 56 



Removing the fruit to the common-storage house 59 



Handling apples for cold storage 00 



Summary of Part III 61 



Literature cited 64 



I. STUDIES OF THE RIPENING OF APPLES * 



INTRODUCTION 



The determination of the best time to remove apples from the tree 

 is one of the most important problems which the fruit grower must 



1 Part I of this bulletin is based on contributions of data supplied jointly by the nine 

 persons mentioned under the general title. 



82956—26 1 1 



