So i would really like to not come off pretentious or rude with this statement and it applies to insects much more than fungal and bacterial diseases.
And this comes into the idea of plant it and it will come so what kind of eco systems is everyone making. All of our fruit plants grass etc is really just there to support pests insects.
What do you guys do to encourage beneficial insects and predators to come in? I try to make a eco system for my plants and have homes for lady bugs, lace wings, beneficial wasps and apply beneficial nematodes as well as not put anything around to kill the beneficials who unlike the pests have not developed multiple resistances to pesticides fungicides and herbicides. For me it took about four years to get mason bees and three years or so for the wasps.
I also brew compost teas and spray beneficial bacterias for diseases and try to cull out the plants that don’t really want to live here but most things will probably become infected at one point and either learn how to fight the pathogen off or succumb to it.
As far as Bavays Gage goes it has been a slow growing tree for me that has tight crotch angles but is very workable, I will double check what rootstock mine is on. It is the most resistant of the few plums i have, mildly hit by aphids and is only mildly hit by the japanese beetles.
Opal is in its first leaf in ground and is on St Julian it has been hit hard by the japanese beetle but its also a young plant and may not be able to fight them off as well however it was left alone by the aphids.
Superior J plum gets hit super hard by aphids and is basically the only plant in my yard i have seen them on besides bavays and anise hyssop patch that wasn’t receiving water. She blooms very early and yet once pollinated has held tight to her young blossoms / fruit through frost.