BUD VARIATION IN THE EUREKA LEMON. 
25 
Within some of the strains are marked variations of importance 
commercially, but not so striking as the variations which distinguish 
the strains themselves. These individual-tree differences in the 
strains should be taken into account by the performance-record 
keeper and this knowledge utilized in the selection of trees for top- 
working or for use as sources of bud wood. 
Fortunately there is a marked correlation between the quantity and 
quality of the fruits produced by the individual trees of the different 
lemon strains. The trees bearing the most lemons usually produce 
the best commercial fruits. In other words, the trees having the 
heaviest crops frequently develop the largest proportion of lemons 
of the first grade, as shown by their color, shape, size, texture, 
thickness of peel, juiciness, acidity, and the flavor of the juice. 
Usually the most productive trees show the fewest marked variations 
in fruits from the type of the strain to which they belong. This 
condition is fortunate in that it enables the grower to form a reliable 
conception of the value of the fruits of the individual trees from their 
production records. A similar correlation was found in the studies of 
the individual- tree production of the various strains of the Lisbon 
lemon, the Washington Navel orange, the Valencia orange, and the 
Marsh grapefruit. 
PRESENTATION OF DATA. 
The diagrams and tables presented herewith in summarizing the 
studies on the Eureka lemon variety have been prepared from indi- 
vidual-tree performance records of 117 trees in a single plat in a 750- 
acre citrus orchard near Corona, Calif. These trees are in a section 
of the orchard which was planted in the spring of 1904, nothing except 
a few crops of winter barley having been grown there previously. 
Records were begun on 111 of the trees in July, 1911, and 6 more 
near-by trees were added to the record plat in December, 1912. The 
original plat selected for this study included 116 trees, but 5 of 
them were badly injured, so that their records were not comparable 
with those from the other trees in the plat. Among the 117 trees 
included in this study there are typical examples of 6 of the 8 
most important strains of the Eureka variety, as follows: 76 Eureka, 
17 Shade Tree, 10 Small Open, 10 Dense Unproductive, 2 Pear Shape, 
and 2 Dense Productive. 
Individual- tree performance records have been secured in the same 
orchard on 135 additional Eureka trees. However, as these records 
have not been made for as long a period as the 117 trees in the original 
plat, the presentation and consideration of data in this bulletin will 
be confined to the records of the 117 trees. 
The average annual crop of each of these trees for the 6-year 
period from July, 1911, to June, 1917, inclusive, is shown in Table VI. 
The percentage of the most desirable fruit of the Green grade, pro- 
