Diseases. Brown rot, scab.
Insects. Plant bugs, Oriental fruit moth, leafrollers.
Tufted apple bud moth. See petal fall spray.
Plum curculio. See petal fall spray.
Green peach aphid. If this aphid is present, add Actara, Lannate, or Provado.
Pesticide Recommendations for Nectarines, Shuck Split, Shuck Fall