Skip to main content
. 2019 Mar 6;14(3):e0213293. doi: 10.1371/journal.pone.0213293

Fig 4. Scion and rootstock cross sections from ‘HoneyCrisp’ apple trees grafted onto M.9 (clone NIC 29) with rapid apple decline.

Fig 4

Three cuts of 5 cm were made above and below the graft union at the scion-rootstock junction. The following discoloration scale was used to estimate healthy and pigmented necrotic wood area in symptomatic apple trees: DS = 1, external wood discoloration, DS = 2, internal wood discoloration, DS = 3, co-occurrence of external and internal wood discoloration, DS = 4, edge-shaped discoloration (<50%), DS = 5, edge-shaped discoloration (>50%), and DS = 6, circular discoloration.