Blackleg (bacterium - Erwinia carotovora subsp. atroseptica): The lower parts of affected stems develop an inky black , slimy , foul-smelling , soft rot. Leaves near tops of vines curl upward and become stunted. Aerial tubers usually form in leaf axils. Severely affected plants die. Tubers from affected plants show black stem-end discoloration and sometimes a severe black soft rot in storage. Plant certified, healthy seed in well-drained soil. Cut seed tubers with a disinfected knife. Treat seedpieces and cure properly before planting.
