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 fortimate 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 variet}", 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 wiU 

 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- 



