A bacterial disease of cotton plants caused by the pathogen Xanthomonas malvacearum, characterized by angular black lesions on the stem and fruiting branches.
Origin
Early 20th century.
Definition of blackarm in US English:
blackarm
noun
US
A bacterial disease of cotton plants caused by the pathogen Xanthomonas malvacearum, characterized by angular black lesions on the stem and fruiting branches.