BUD VARIATION" IN THE WASHINGTON NAVEL ORANGE. 127 
recorded on which data had also been secured for six years, and 
column 4 shows the rank secured by the same trees on the basis of 
their 6-year performance records as shown in Table II. The facts 
that the same trees appear in the first three ranks in both summaries 
and that the other trees represented are so nearly identical in their 
rank for the two periods show that for all practical purposes per- 
formance records of full-bearing trees for four years are as satisfac- 
tory as those for six years. 
This is additional evidence in support of the general proposition 
that the variation in the amount of the annual crops produced by a 
given series of individual Washington Navel orange trees is relatively 
uniform throughout the series each year; that is, the highest produc- 
ing trees in any one year are in general the highest producing ones 
each year, and the lowest producing ones remain at the bottom of the 
list continually. Table VI also offers additional support of the general 
proposition that individual trees are relatively very stable over a series 
of years in the character and the amount of their fruit production. 
Table VI also shows the relative ranks of the lowest producing 
trees recorded for both the 4-year and 6-year periods. The indi- 
vidual trees listed here are even more nearly identical in their rank 
for the two periods than were those in the highest producing ranks, 
giving additional evidence in support of the truths just stated. 
Table VII shows the annual performance record of a tree of the Pro- 
ductive Washington strain for the season of 1914 and also the 6-year 
period performance record of the same tree. This table is presented 
for the purpose of comparison with Table VIII, showing the annual 
and period performance records of a tree of the Unproductive strain, 
and with Table IX, showing the annual and period performance 
records of a tree of the Wrinkled Australian strain. These tables 
illustrate the form in which the data have been recorded during all 
the investigational work on which this publication is based, except 
that in order to economize space the form for recording the detailed 
data for 1914 has been rearranged. 
These records show the comparative behavior of typical examples of 
three Washington Navel orange strains which are of great importance 
in the study of the origin of varieties by bud selection. The marked 
variations in the quantity and commercial quality of the fruit borne 
by these trees illustrate the relative value of these strains and are 
typical of the differences in production that exist in other strains of 
this variety. 
