Jahniella bohemica Part II

Abstract This note continues the “Cannabis Clinic” series, presenting diseases and pests of hemp, featuring colour illustrations of signs and symptoms. The fungus Jahniella bohemica damages hemp stalks in Europe. In the previous issue of “Cannabis Clinic” we illustrated Jahniella bohemica and showed how this fungus has been confused with Leptosphaeria acuta, a fungus that infests nettle stalks. Jahniella bohemica has also been confused with Septoria cannabis, a fungus that usually attacks hemp leaves, but sometimes attacks hemp stalks. We now illustrate differences between these species, using novel methods of microchemistry, and emphasize the signs and symptoms of S. cannabis infestation.