I got to thinking today, I have a single kieffer pear tree planted from lowes last year on the corner of my property. I have no other fruit trees at the moment. I know kieffers are self pollinating but will produce heavier if cross pollinated. I guess what i'm wondering is, without another pollinator are we talking like 10 pears self pollinated vs 1000cross pollinated on a mature tree or is it more like 700 vs 1000? I realize a lot of factors go into this but just curious when everyone says "cross pollinated will produce heavier" how much heavier one really should expect.