FLORIDA STATE HORTICULTURAL SOCIETY 
4i 
Mr. Floyd: A leaf of that age might 
not show it anew. 
Mr.-: Does it have to do with the 
size of the leaves? 
Mr. Floyd: Not necessarily so, al¬ 
though affected leaves are likely to be un¬ 
dersized. 
Another probable indication of an 
abundance of phosphoric acid is the de¬ 
velopment of large numbers of buds on a 
stem into branches. This development of 
the buds was quite marked on plants 
which were fed with large amounts of 
acid phosphate in the course of some ex¬ 
periments carried out at the Experiment 
Station. (This bud development gives 
rise to a rather bushy growth. 
Mr. -: Where there is a multipli¬ 
cation of short terminal growth does that 
indicate it? 
Mr. Floyd: Possibly so. Sometimes 
that short terminal growth is due to other 
adverse conditions. The appearance of 
the tree at any particular time is due to 
the combined influence of a number of 
growth factors. When a different com¬ 
bination of these factors occurs, a differ¬ 
ent appearance of the tree may result. 
Short, slender growth of a yellowish color 
indicates an imperfect combination of in¬ 
fluencing factors. 
I know the grove to which you refer, 
and do not believe that the particular 
type of growth shown there has been 
brought on by an over-abundance of 
phosphoric acid. 
Mr. Temple: What is the evil effect 
of phosphoric acid? 
Mr. Floyd: We have not been able to 
find any killing effect from the use of 
amounts of phosphoric acid comparable 
to those that have ever been used in grove 
practice. Of course, the roots would not 
grow in a soil consisting largely of a 
source of phosphoric acid, as for example, 
acid phosphate or steamed bone, but that 
is outside the question because such 
amounts are never used in grove practice. 
Mr. Temple: I mean an over-appli¬ 
cation. Does it have any actual delete¬ 
rious effect on the tree itself? 
Mr. Floyd. Only to the extent that 
has been mentioned in this discussion. 
Mr. -: When you say “crinkly,” 
do you mean frenching? 
Mr. Floyd: No, I refer to the shape 
of the leaf. Frenching refers to the color 
of the leaf. 
Mr. Sample: I would like to ask the 
latest discovery of the cause, prevention 
and cure of frenching. I know you have 
made some diligent search along that line. 
Mt. Floyd : You have asked me a big 
question, and I cannot give you the an¬ 
swer which you would like. Frenching 
is a form of yellowing of the leaves. It 
is characterized by a lack of green color 
between the veins of the leaf. It is prob¬ 
ably induced by some disturbance of the 
roots. This disturbance may be either of 
a physical or chemical nature. 
Frenching in plants other than citrus 
is frequently induced by the roots being 
attacked by nematode worms. Investi¬ 
gators in California have found the roots 
of citrus trees showing frenching or 
Mottle Leaf to be attacked by a species of 
nematode worms, and they are inclined 
to believe that much of the frenching of 
the citrus trees in that State is induced 
by that cause. Although this worm has 
been reported to have been found on cit- 
