BUD VARIATION" IN THE WASHINGTON NAVEL ORANGE. 29 



and their importance in commercial fruit growing understood. With 

 available means it is impossible adequately to present the character- 

 istic differences of the strains so that one unacquainted with them 

 can appreciate and understand them thoroughly. 



Within the strains of the Washington Navel orange 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, as discovered early in the history of these investiga- 

 tions, a marked correlation exists between the quantity and the qual- 

 ity of the fruits produced by the individual trees of the different 

 strains. The most productive trees usually produce the largest 

 proportion of fruits of the first grade and of the most valuable com- 

 mercial sizes. Usually such trees show the fewest marked variations 

 in fruits from the type of the strain to which they belong. This 

 condition enables the fruit grower to gain from his records of pro- 

 duction of the individual trees a reliable conception of their com- 

 parative value. 



PRESENTATION OF DATA. 



All the diagrams and tables presented herewith, with the excep- 

 tions noted in the following paragraph, have been prepared from 

 individual- tree performance records of 481 Washington Navel orange 

 trees located in groves planted in 1902 near Riverside, Cal. These 

 records cover the period from 1912 to 1915, inclusive. 



Of these performance-record trees, 151 were selected in 1910, so that 

 data for six years have been secured from this number, as shown in 

 Tables II and III. From the tree of the Yellow Thomson strain 

 records have been secured for only three seasons, and from the 

 eight Golden Nugget trees only two seasons' records have been 

 obtained. 



The performance-record trees include typical examples of seven 

 of the thirteen most important strains and of four of the minor 

 strains of the Washington Navel orange, as follows : Three hundred 

 and sixty-five Washington, 51 Thomson, 35 Unproductive, 13 Yel- 

 low Washington, 8 Golden Nugget, 2 Wrinkled Australian, 1 Yel- 

 low Thomson, 4 Thomson-Washington, 2 Sporting Thomson, 1 

 Sporting Washington, and 1 Washington-Thomson. Examples of 

 the other important strains and of several minor strains occur as 

 individual fruit and limb variations in many of the trees under ob- 

 servation. 



