BUD VARIATION 
Washington Navel Orange ‘‘Running Out’’ as a Variety—-Reason Found to be 
Due to Wrong Methods of Propagation—Can be Conserved by 
Utilization of Good Bud Variations and Avoidance of 
Bad Ones—Methods of Practice. 
A. D. SHAMEL 
Physiologist, Bureau of Plant Industry, U. S. Department of Agriculture, Riverside, 
California. 
F THE many factors influencing 
the production of a fruit tree, 
there is one which until lately 
has been often overlooked, and 
which we wish to consider briefly as it 
affects the navel orange industry of 
California. 
This factor is the variation in types 
of trees and fruits resulting from the 
propagation of sports or mutations. 
While we do not wish to under- 
estimate the importance of other factors, 
we do feel that the relation of variable- 
type trees and fruits in our groves to 
profitable orange growing has_ been 
largely overlooked by everyone con- 
cerned. We hope to be able in this 
discussion to call attention to the 
importance and significance of the 
condition of bud variability existing in 
our orange trees, from the viewpoint of 
six years of continuous investigation of 
this matter, and to offer some sugges- 
tions in this connection for the improve- 
ment in production, both as regards 
quantity and quality of the Washington 
Navel orange variety. 
It will not be possible here to go into 
any of the details of our experiments 
and observations. In a general way 
these investigations have been carried 
on by means of continuous individual 
tree study. In our experimental plots 
we have usually selected 100 trees for a 
performance record plot. Frequently 
we have several plots in one orchard, 
so as to take into account all possible 
differences in soil conditions in a given 
orchard. 
In addition to these select plots, 
where detailed individual tree and fruit 
studies are made, we have been able to 
study individual tree performance record 
data secured by several orange growers. 
These data are usually made up of the 
amount of fruit produced by each one 
of the trees in the orchard, together 
with some notes as to the commercial 
quality of the product of each tree. 
VARIETY BADLY MIXED 
The results of our investigations have 
shown clearly that in the Washington 
Navel orange variety we have a number 
of diverse types, many of which are 
undesirable and worthless. It is our 
observation that the younger groves, 
that is, those farthest removed in time 
from the parent trees, show a larger 
proportion of these inferior types than 
the older orchards, or those not so far 
removed from the two parent trees. In 
other words, our experience shows that 
owing to the lack of careful bud selection 
and to poor propagation methods, the 
proportion of poor type trees is con- 
stantly increasing in the younger bud 
generations. This process of varietal 
deterioration in varieties propagated 
from seed is frequently called the 
“running out’? of the variety. As a 
result of many observations in different 
navel orange orchards, varying in age 
from the first planted grove in California 
to those just coming into bearing, we are 
reluctantly forced to the conclusion 
that the Washington Navel orange 
variety is “running out.” 
1 Part of an address before the California State Fruit Growers’ Convention, Visalia, Cal., 
November 19, 1915. 
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