I have peach trees that I spray with fungicide a few times a year.
I've always wondered how long it is necessary for the fungicide
to stay on the trees before it is effective. I live in the pacific
which is why they need to be sprayed (cold and wet winters),
which also makes it hard to time the sprayings. I was told to apply
the treatment in december, january, and early march. Following
that schedule has kept the peach leaf curl pretty much under control,
though I still see a mild amount. I'd like to know if I can just get
the stuff on the trees and not worry if its going to rain later that day,
or if it makes a difference if the stuff sits for a few days before it
starts to get washed off. Or is it more important to time the sprayings
early or later in each month according to current amounts of rain,
and/or temperature? For my own records, I can track when I spray,
and how long it stays before the first rain, and then whether I see
lots or little peach leaf curl the next spring. But there are too many
other variables involved for me to know what has the most impact.
Anyone know of any more definitive data on this subject?
As always start by carefully reading the label.
Then follow it.
The deal with fungicides is that they prevent the infection they don't
Spraying it after the fact is like putting the bullet proof vest on
top of the gunshot wound.
This is not just a recommendation. The label is the law.
Depends on the fungicide and the extent of the infection. All the
fungicides I can think of will kill spores on contact, and if the spores
have germinated and invaded the plant, some fungicides will kill them
too. However, if the fungus has really gotten a hold on the plant you
need a systemic fungicide to cure it. Systemic fungicides are not
recommended on plants which produce food (or more precisely, eating the
plant products from a plant on which systemic pesticides have been used
is not recommended).
Yes, of course I read the label and follow its guidelines.
But the labels on any fungicides I've read don't answer
my specific questions, such as how long the product
must remain on the tree in order to be effective.
And if the fungicide only prevents the infection, it seems
like there needs to be a continuous presence of the
fungicide to provide protection during all of the
vulnerable times. Again, there is nothing that
states that in specific terms, only vague and general
(like: 'during late fall/early winter'.) I understand that
labels can't be any more specific, as each site differs.
But it would be nice to have info, such as how many
inches of rainfall should be allowed to fall on the trees
between applications (so I could measure the rainfall,
and know when to reapply.)
But given the two answers I've seen, it is helful for me
to see the clarification that the fungicide is just killing the
spores. And I know what once infected, there's nothing
I can do (and I certainly don't want to put anything
systemic on the trees, I like to eat the peaches too!)
You might want to consider replacing the peach with one that doesn't need
spraying. 'Frost Peach' is one that was developed for the PNW climate and is
quite resistant to leaf curl as well as not requiring the same number of
heat days as other peaches in order to ripen fruit. It bears at a very early
pam - gardengal
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.