Maybe your trees need more maturity if not fruiting and it’s a low chill variety. Also the rootstock is an important factor in the health and vigor of the trees. For example Citation rootstock is terrible in my yard and trees will be stunted.
Arctic Star, Double Delight, Maria’s Gold nectarines all grow clean for me. I don’t spray with anything. Spice Zee is clean if it’s dry when in bloom, mine will get russeting from thrips if the blooms don’t dry and fall off. If I hand remove them the fruit are not blemished.
Goldkist apricot, Flavor King pluot, Flavor Grenade, Burgundy, and Santa Rosa plums are effortless to grow for me, no bugs or disease issues. Flavor Grenade is a favorite, highly recommended.
Janet