TY - JOUR AU - Mircetich, S. M. John AU - Refsguard, James AU - Matheron, Michael E. TI - Blackline of English walnut trees traced to graft-transmitted virus JF - California Agriculture JO - Calif Agr Y1 - 1980/11/01 VL - 34 IS - 11 SP - 8 EP - 10 PB - University of California Agriculture and Nature Resources SN - 0008-0845 UR - http://www.ucanr.edu/sites/calagjournal/archive/?article=ca.v034n11p8 AB - Studies show that blackline can be spread from diseased to healthy trees by budding or grafting as well as by natural means.