88 BULLETIN 813, IT. S. DEPARTMENT OE AGRICULTURE. 
The method of keeping the individual-tree performance records is 
to pick each tree separately, assort the fruits, count and weigh them: 
make descriptive notes, photographs, and drawings of the trees, 
foliage, and fruits; and record these data so that after an adequate 
number of studies have been made conclusions as to varietal, strain, 
and tree behavior can be safely drawn. 
In these investigations eight strains of the Eureka lemon have been 
studied, their characteristics described, and the performance of 
typical individual trees recorded. 
Some of the lessons taught by these studies include the discovery 
of the importance of bud variations and the comparative value of 
the different strains arising from them, the necessity for and methods 
of isolating the valuable strains and eliminating the unprofitable 
ones through bud selection, the determination of the characteristics 
of the trees, flowers, and fruits of the different strains, and the 
origination and introduction of improved methods of propagation 
for conserving and improving the production of the lemon industry. 
The desirable strains can be isolated through bud selection based 
on tree-performance records and intimate tree knowledge. 
Undesirable healthy trees in established orchards can usually be 
successfully top-worked by the use of carefully selected buds. 
The undesirable unhealthy trees can be replaced in established 
orchards through replanting with desirable ones when proper atten- 
tion is given to the preparation of the planting holes and adequate 
care in irrigation and fertilization is given to the individual trees. 
Only fruit-bearing bud wood from superior parent trees selected 
on the basis of their performance records and intimate tree knowledge 
should be used for propagation or for top-working. 
In California, as a result of these investigations a department of 
bud selection has been established by the California Fruit Growers'' 
Exchange, a cooperative organization of citrus growers, whereby 
reliable bud wood from superior performance-record lemon trees 
can be obtained by all growers and propagators. 
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