North American Fruit Explorers mailing list at ibiblio

["Dr. Lucky Pittman" <lucky.pittman@murraystate.edu>]

Bill wrote:
"And the city has been planting those flowering 
non-fruiting pears (I think that's what they are) everywhere, and 
they're all blooming, too." 

Well, unless the city planted ONLY one cultivar of callery pear, no
residents anywhere in the city have any other varieties growing, and none of
the grafted trees die(or self-destruct) back to their callery seedling
rootstocks, those will most assuredly NOT be non-fruiting trees.  
Each tree will produce myriad little dime-size or smaller fruits, which the
birds will eventually consume and spread the seeds throughout the landscape.
I don't know how aggressive they'll be in your locality, but I see callery
pear seedlings becoming almost as numerous as P.serotina and M.alba in every
untended fencerow or roadside ditchbank here, and on trips south to AL to
visit family, I can show you multiple-acre pear 'forests'(punctuated with
Albizia julbrissin, at least at their periphery) alongside outer-perimeter
roads and at Interstate highway exits. 
I used to while away the time on those road trips counting 'escapee' pears
either by their bloom in the spring, or by their persistent fall-color
foliage, still present into January, in central & north Alabama. Often
TNTC(too numerous to count).

Read 'The Coming Plague of Pears":
http://ipmnet.umd.edu/5-8art1.htm

Lucky Pittman
Hopkinsville, KY