Webber: 
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The Improvement of Root-Stocks 
295 
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MARSH SEEDLESS GRAPEFRUIT TREES 
Average-sized trees chosen from the test rows of large and small nursery trees planted in the 
orchard June 1917 and photographed May 1919. These, too, have continued to show the same 
comparative difference in size as they had when in the nursery. (Fig. 2.) 
yet our policy has uniformly been to 
use all—good and bad _ alike—for 
propagation. Is it any wonder under 
these conditions that our trees though 
grown from the best selected buds 
should be variable in the groves? 
The Eureka lemon on a trifoliate 
stock is very markedly dwarfed while 
Valencias grow to good sized trees. 
The Florida rough lemon is usually a 
good stock while the Chinese lemon is 
commonly recognized as a poor stock. 
Different reactions on the bud caused 
by the influence of different stocks are 
well known to exist. When therefore 
such marked differences are found to 
exist in the sour and sweet orange seed- 
lings that we are using as stocks, is it 
any wonder that the budded trees in 
the nursery, even when selected buds 
are used, should grow differently and 
produce large and small trees and that 
these differences should continue to 
exist when the same trees are grown 
in the orchard? 
The evidence now available very 
strongly points to the conclusion that 
the differences in size of nursery trees 
such as those taken for the experiment 
outlined are mainly to be attributed to 
the different nature of the seedling 
stocks used. If this is true, and it is 
entirely in line with the evidence as 
well as with common sense and judg- 
ment, it is certainly an element of 
fundamental importance in citrus 
propagation. 
I would be remiss in caution if I did 
not call attention to the fact that one 
very important link in the chain of 
evidence is yet lacking, that is, the 
growing of good buds on known stocks 
of these various types to prove that 
certain ones give better growth than 
others. This evidence, however, is 
partially supplied by our known ex- 
