PMC

(A). Shoot blight and dieback of entire branches on Sweet orange ‘Tarocco Scirè’ injured by wind. (B) Symptoms of shoot blight incited by Colletotrichum infections on Sweet orange ‘Tarocco Scirè’ injured by wind. (C) Gumming associated with citrus shoot blight on Sweet orange ‘Tarocco Scirè’. (D) Leaf mesophyll collapse and necrosis caused by wind on leaves of ‘Tarocco Scirè’ sweet orange. Conidiomata of Colletotrichum are visible on necrotic lesions as black pin point-dots.

Distribution of fire blight and black shoot blight among cities and districts in Korea (2016–2021). Colored cities/districts imply accumulated production of diseases in each year. Red, gray, and yellow shading indicate cities/districts where fire blight, black shoot blight, or both diseases were reported, respectively.

Fire blight symptoms of apple flowers, shoot and rootstock. a Symptomatic flower stem/fruit stem (scoring value 2) with ooze b) Shoot necrotic lesion < 5 cm (scoring value 5) c) Rootstock blight, showing the sharp separation between healthy and symptomatic tissue

Control of blossom and shoot blight incidence in 2012 (A,B) and in 2013 (C,D) after 1–2 trunk injections of ‘Gala’ apple trees with protective compounds. WIC, water injected control; ASM, acibenzolar-S-methyl; PH, potassium salts of phosphorous acid (potassium phosphites); SS, streptomycin sulfate; NINIC, non-injected non-inoculated control. (A,C) Blossom blight incidence means across the three time points within one treatment followed by different letters are significantly different (t-test, 2012: p < 0.1, 2013: p < 0.05). (B) Shoot blight incidence means between treatments within one time point followed by different letters are significantly different (t-test, p < 0.1). (D) Shoot blight incidence means across the three time points within one treatment followed by different letters are significantly different (t-test, p < 0.05). Error bars represent SEM.