J 
UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 624 
Contribution from the Bureau of Plant Industry 
WM. A. TAYLOR, Chief 
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 
California Citrus Varieties 
History of the Valencia Variety . . . 
Variability within the Variety . . . 
Occurrence and Frequency of Bud Varia 
tions 
Objects of the Investigations .... 
Plan of the Investigations 
Methods of Keeping Performance Rec 
ords 
Descriptions of Some of the Important 
Strains 
Page 
1 
2 
3 
4 
5 
6 
Page 
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 
