FLORIDA STATE HORTICULTURAL SOCIETY 
113 
of the trees. Bone is a very safe source of 
slow ammonia. Be sure that fertilizer 
and bluestone are scattered out evenly as 
far as the roots extend. Broadcast if 
roots meet in the middles. Remember that 
fertilizer can be added much easier than it 
can be taken away or the effect of an over¬ 
dose counteracted. 
When trees are frenched deep plowing 
or deep cultivation should be discontin¬ 
ued; in fact, deep plowing or deep culti¬ 
vation should never be included in grove 
practice. Any unfavorable condition of 
drainage or setting should be remedied. 
The fertilizer should have a low ammonia 
analysis of which half or more should be 
from slow acting sources such as bone. 
Quite liberal applications of good stable 
manure will be beneficial. Bluestone 
should also be used. If the frenching is a 
result of lime injury the recovery of the 
trees will probably be slow and the use of 
stable manure will be found to be espe¬ 
cially helpful. Just what the effect of 
spreading sulphur around the trees will 
have has not been definitely settled yet. 
In conclusion, it might be said that a 
great deal of worry, expense, loss of tree 
growth and fruit might be saved by fa¬ 
miliarizing growers with the various 
symptoms of dieback and the methods of 
handling so that they can check the trouble 
before much harm is done. ,, 
-: Have you ever tried sulphate 
of iron in checking the frenching? 
Lenfest: At present I do not know the 
effect of it. That is one thing that I don’t 
know anything about at all. Lots of dif¬ 
ferent conditions can cause frenching. 
The cause of the trouble should be found 
if possible and removed. If it is a grove 
practice, discontinue that practice. 
Skinner: From your observation in or¬ 
ganic ammoniation, is there any difference 
in the ability of sources to give this die¬ 
back condition? 
Lenfest: I cannot say about the ni¬ 
trate of potash which has been in use for 
several years. I have made this statement 
to a number of growers. I told them to 
run a race with me to produce dieback and 
I would take nitrate of soda to bring it 
on. 
Skinner: Have you ever had any ex¬ 
perience in grapefruit where the leaf 
turned badly frenched and dropped off? 
Have you any idea what causes it? 
Lenfest: I have seen that condition 
but I don’t know what it is. It may be 
something in the fertilizer or Mr. Cline 
may have some recent information on 
that. 
Cline: We are in somewhat the same 
fix that you are. We know that borax 
will produce it. 
-: I want to give one instance of 
organic ammonia. Some years ago I was 
feeding cattle. I put them in stalls and 
saved all the fertilizer and on an old seed¬ 
ling grove I hauled out 200 one-horse 
wagon loads. On top of that I put an ap¬ 
plication of commercial fertilizer. I never 
found a bit of dieback from it. I did find 
a very much increased growth of fruit. 
-: Can dieback be caused by 
hardwood ashes? 
Lenfest: I don’t know. It is valuable 
as a source of potash, but what its further 
action is, I don’t know. 
