North American Fruit Explorers mailing list at ibiblio

["William C. Garthright" <billg@inebraska.com>]

When thinning fruit the other day, I noticed a lot of brown spots on the 
leaves of my New Century (Shinseiki?) Asian Pear. But there were no 
spots at all on the leaves of my Starking Hardy Giant (Olympic?) Asian 
Pear standing right next to it, although there were a few on the Hosui 
on the other side of my yard. Note also that the New Century is a very 
small tree, with lots of space around it (so far), and that it's been 
very, very dry here this year (on the other hand, I've run a sprinkler 
on my strawberries a couple of times, and the tree has gotten wet from 
that). I imagine that it's some kind of fungal disease?

I assume that I need to spray a fungicide, but I've had trouble finding 
one for pears. I have never used a dormant spray on pears (I use dormant 
oil with lime sulfur on many other trees), because I've read that 
dormant sprays weren't necessary for pears. The Captan I find here - 
alone or in combination sprays - isn't registered for pears. Immunox 
can't be used on pears, apparently, nor Chlorothalonil, in the 
formulations I've found (and since I read that it's been implicated in 
honeybee Colony Collapse Disorder, I haven't wanted to spray it during 
the growing season). I found some Mancozeb, but it's not rated for any 
fruit at all, except grapes. And a lot of other things can't be used 
once leaves open, it seems.

One fungicide I've heard is rated for pears is Ferbam, but that's one of 
the many chemicals I can't find anywhere around here. Maybe it's not 
rated for residential use?

Any suggestions? Maybe this won't be a huge problem, anyway, but this 
tree isn't overly vigorous (one year after planting, we had that hard 
April, 2007, freeze that nearly killed it - I was shocked when it 
finally started leafing out again). Should I just do a dormant spray 
with lime sulfur next spring?

Frankly, I have a hard time finding sprays of any kind that I can use on 
a variety of fruit trees. And I suspect that I've got worms in the Asian 
pears already (mostly, this is because I've got strawberries around 
them, so I can't spray while they're blooming). Oh, well, I'm still very 
much a newbie at this, and I'll get it figured out eventually.

Thanks,

Bill
Lincoln, NE (zone 5)

--
I am an optimist. It does not seem to be much use being anything else. - 
Winston Churchill