Table of Plum Cultivar Susceptibility to the Black Knot Fungus
Apiosporina morbosa  

 

Table of apple cultivar susceptibility to the black knot fungus, Apiosporina morbosa.

Plum Cultivar

Black Knot
Resistance Ratingz

Bluefre

HS

Bradshaw

S

Damson

HS

Early Italian

S

Fellenburg

S

Formosa

R

Methley

S

Milton

S

President

VR

Santa Rosa

R

Shiro

R

Shropshire

HS

Stanley

HS

zVR = very resistant. No control needed. (Very few cultivars in this category for any disease.)
R = resistant. Control only needed under high disease pressure.
S = susceptible. Control usually needed where disease is prevalent.
HS = highly susceptible. Control always needed where disease is prevalent. These cultivars should receive first priority when control is called for.