Dip Treatment for Control of Blackstem on Populus Cuttings. J. A. Walla, Research Analyst, Department of Plant Pathology, North Dakota State University, Fargo 58105. R. W. Stack, Associate Professor, Department of Plant Pathology, North Dakota State University, Fargo 58105. Plant Dis. 64:1092-1095. Copyright 1980 American Phytopathological Society. DOI: 10.1094/PD-64-1092.

Blackstem of Populus cuttings has reduced production of salable plants by more than 50% in a North Dakota forest nursery. Isolations from cuttings indicate that Cytospora chrysosperma is the primary pathogen. Inoculum or asymptomatic infections are present on cuttings before winter storage. Most cankers develop from cut ends of cuttings. A dip treatment in thiram before winter storage increased production of salable plants by more than 50% compared with the control.

Keyword(s): Northwest poplar, Norway poplar.