[NAFEX] disease on persimmon trees

Jwlehman at aol.com Jwlehman at aol.com
Sat May 21 22:42:49 EDT 2011


Hello all,

You are describing what I've been calling "Persimmon Leaf Drop (PLD)." Some 
years it is worse than others. The real down side is it can reduce the 
fruit crop. Persimmon flowers appear at the leaf axil where the leaf joins the 
stem. Something generates abscisic acid, abscising the leaf. Generally when 
this happens the flower also is abscised. Less flowers, less fruit. I've sent 
leaf samples to Purdue and they find no pathogens. It may be, as previously 
suggested, low oxygen to the root system due to all the rain we have had. 
Three years ago it was so bad the end of May the ground under the trees was 
bright green. Last year leaves started dropping early May, rains stopped, 
leaf drop stopped and had a good crop. Others on sand don't seem to have the 
same degree of problem. 

I'm not sure that is the problem but don't have a better idea. Ed Fackler 
said he has seen the same in apples with extremely wet springs. 

I've not been able to connect the black spots you mentioned with PLD. One 
cause of the black spots is a fungus, Fusicaladium. That fungus also attacks 
the fruit, hardening the skin and when the fruit enlarges in ripening the 
fruit cracks and spoils. I know of no fungicides labeled for control on 
persimmon. Damp weather seems to promote it's spread. 

Another black leaf problem doesn't seem to be detrimental. The leaf veins 
turn black but the leaf continues to live or the leaf tissue turns black and 
likewise continues to live. 

With the fungus, the center of the black spot usually dies and turns brown, 
typical of leaf fungus. 

Jerry L 
Indiana


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