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
northwest,
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?
Thanks.