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UNITED STATES DEPARTMENT OF AGRICULTURE 



BULLETIN No. 624 



Contribution from the Bureau of Plant Industry 

 WM. A. TAYLOR, Chief 



Washington, D. C. PROFESSIONAL PAPER 



July 25, 1918 



CITRUS-FRUIT IMPROVEMENT 



A STUDY OF BUD VARIATION IN THE 



VALENCIA ORANGE 



By 



A. D. SHAMEL, Physiologist in Charge, L. B. SCOTT, Pomologist, and C. S. 



POMEROY, Assistant Pomologist, Fruit-Improvement Investigations 



Office of Horticultural and Pomological Investigations 



CONTENTS 



Page 



California Citrus Varieties 1 



History of the Valencia Variety .... 2 

 Variability -within the Variety .... 3 

 Occurrence and Frequency of Bud Varia- 

 tions 4 



Objects of the Investigations 5 



Plan of the Investigations 6 



Methods of Keeping Performance Rec- 

 ords 7 



Descriptions of Some of the Important 



Strains 8 



Individual Variations of Fruits .... 12 



Minor Variations of Fruits . . . . . . 13 



Lessons Taught by These Investigations 13 



Presentation of Data 14 



Comparative Value of the Strains ... 114 

 The Unintentional Propagation of Unde- 

 sirable Strains . 115 



The Isolation of Strains through Bud 



Selection 116 



Top-working Undesirable Trees .... 118 



Summary 119 



WASHINGTON 

 GOVERNMENT PRINTING OFFICE 



1918 



