here’s my work on pears
Pyrus Communis graft compatible with all pears makes a tree 90-100% of standard for european pears and 30-40% of standard for asians.
Pyrus Calleryana graft compatible with all pears makes a tree 100-110% of standard for european pears and 1%-5% of standard for asians (asian pears are EXTREMELY dwarfed on this rootstock)
Pyrus Betulifolia graft compatible with all pears makes a tree 110-120% of standard for european pears and 80%-90% of standard for asians
Pyrus Ussuriensis graft compatible with all pears makes a tree 50-60% of standard for european pears and 70%-90% of standard for asians
Pyrus Pyrifolia graft compatible with all pears makes a tree 100% of standard for european pears and 100% of standard for asians
Loquat (Eriobotrya japonica) graft compatible with some euros and asian pears, makes a tree 1-5% of standard both asian pears and european pears are EXTREMELY dwarfed on this rootstock and may not be long term compatible.