162 
FLORIDA STATE HORTICULTURAL SOCIETY 
The chemical analysis of our virgin 
soils shows that in nearly every instance 
our soils are well supplied with the minor 
elements required by the tree roots, but 
usually lacking in sufficient quantities of 
the major elements, ammonia, potash and 
phosphorus. Therefore, fertilizers are 
manufactured and sold to supply these 
deficiencies, in the proportions which an¬ 
alyses and experience have taught are 
most needed. After fertilizers have been 
applied, analyses of the soil show a much 
larger content of these major elements 
than before. 
Experience has also taught, in a gen¬ 
eral way, that certain materials used in 
the manufacture of fertilizers, and from 
which the major elements of plant food 
are derived, are more suitable to the needs 
of citrus trees than certain other materials 
used in the manufacture of fertilizers for 
other kinds of crops. These different 
sources of plant food for the citrus tree, 
with their relative merits, have been dis¬ 
cussed from time to time before the Hor¬ 
ticultural Society and I will not take up 
time to enlarge upon them here further 
than to say that responsible fertilizer man¬ 
ufacturers know what sources are safe to 
apply to the citrus tree and which are con¬ 
sidered injurious, or unwise to use. It 
would be very foolish on their part to put 
out fertilizers made from unsuitable ma¬ 
terials. The financial success of the fer¬ 
tilizer manufacturer depends upon his sup¬ 
plying* his customers with the kind of 
plant food suitable to their crops. 
Unsuitable fertilizers would tend to 
cause disease, or if improperly balanced 
would most likely result in abnormal 
growth development or the production of 
fruit of undesirable quality. Therefore, 
insufficient growth, or the scant product¬ 
iveness of fruit, would seem to indicate 
that the fertilizer was what it was repre¬ 
sented to be, rather than that it was a 
failure, and most likely one or more of 
the other determining factors mentioned 
should be charged with the responsibility 
of the failure. 
No chain is stronger than its weakest 
link. Fertilizer is but one link in the 
chain of factors that govern satisfactory 
growth or crop production. That the use 
of fertilizer is both necessary and profit¬ 
able is known beyond all question of 
doubt, but that fertilizer alone should be 
credited with the success of the grove, or 
charged entirely with its failure, is absurd. 
It is not uncommon that fertilizers are 
used unwisely. They may be used in ex¬ 
cess of the quantity really needed, or, on 
the other hand, an insufficient amount ap¬ 
plied ; or they may be applied at the wrong 
season of the year. It is needless to say 
that unsatisfactory results from such un¬ 
wise use should not be chargeable to the 
fertilizer. 
It has been my privilege to be more or 
less in touch with a number of citrus 
groves in Florida, situated in widely dif¬ 
ferent sections and upon various types of 
soils, and to know something of the kinds 
of fertilizers used and to note the growth 
and crops of fruit produced in these 
groves. My observations have led me to 
the conclusion: 
1st. That different kinds of soil will 
give varying results, even when identical 
fertilizers are applied. 
