The Progeny Grove as a Basis for Citrus 
Fruit Improvement 
T. Ralph Robinson, Bureau of Plant Industry, Washington, D. C 
It is not my intention to review in detail 
the investigational work which has dem¬ 
onstrated the feasibility and value of es¬ 
tablishing actual pedigreed strains of 
standard citrus varieties. The use of tree- 
performance records has been fully ex¬ 
plained in a number of publications easily 
available, and in talks to this society and 
elsewhere, Mr. L. B. Scott, of the Depart¬ 
ment of Agriculture, has explained the 
workings of the system as successfully 
carried out in California under the leader¬ 
ship of Mr. Shamel and Mr. Scott. 
I do, however, want to quote a para¬ 
graph from Mr. A. D. Shamel’s bulletin 
on “Citrus Fruit Improvement,” to indi¬ 
cate the basic reasons for undertaking the 
bud-selection project. He says: “The 
established and proved citrus varieties are 
the most valuable possession of the citrus 
industry. The conservation, standardiza¬ 
tion and stabilization of these varieties 
should receive most careful consideration 
by citrus propagators and growers. 
“The deterioration or Tunning out’ of 
these varieties through unintentional prop¬ 
agation of undesirable strains is responsi¬ 
ble for a large proportion of the low yields 
of inferior fruits in many citrus orchards. 
The introduction of new varieties to take 
the place of those that have become un¬ 
profitable by reason of the use of careless 
methods of propagation is usually a mat¬ 
ter of experiment. The establishment of 
new varieties requires long periods of time 
to prove their value to the grower and to 
introduce them to the markets.” 
In the fall of 1920 I spent a few weeks 
in the citrus sections of California and 
had the opportunity to inspect with Mr. 
Shamel some of the young bearing groves 
propagated from bearing fruiting branch¬ 
es of selected parent trees, the selection in 
each case being based on actual records of 
tree yields covering periods of five years 
or more. 
The uniformity shown in these groves 
(which we are calling “progeny groves”), 
together with the early and heavy fruiting 
habit, was most striking and convincing. 
Even if there were not present in our cit¬ 
rus groves any appreciable percentage of 
unproductive or off-type trees, the raising 
of the average in quality and quantity 
would fully justify the work of establish¬ 
ing these truly pedigreed strains. The 
word “pedigree” is often abused when 
used in connection with tree propagation. 
In animal breeding a pedigree means 
something quite definite—it is backed by 
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