Internal Bark Necrosis in Southeastern Arizona Apples

Trees in the experimental plot (Angel Valley Orchard, Bonita, Az) were chosen for the following symptoms of IBN: 2 -year and older wood was blistered with necrotic centers in the cortex; in some trees, the outer layers of bark were scaly and peeling. Trees were planted in 1985 and were Starkspur Ultrared variety. The site had been previously farmed to cotton and corn. Furrow irrigation is used. The soil type mapped in the experimental area was a Tubac sandy loam.