Symptoms, spread, and control of canker stain of Plane trees.
AbstractCeratocystis fimbriata f. [sp.] platani [41, 258] causes a serious disease of Platanus in E. areas of U.S.A. Isolates from plane, almond, apricot, and oak were non-pathogenic to sweet potato, nor were isolates of C. fimbriata from sweet potato, almond, apricot, and oak pathogenic to plane in tests at Rutgers Univ. Isolates from plane were able to invade 2-week-old wounds in June, and summer inoculations gave 100% infection. Transmission was achieved from cultures to healthy trees by Colydium lineola, Laemophloeus biguttatus, Coloplerus semitectus, C. unicolor, C. niger, Carpophilus lugubris, and 3 unidentified nitidulids, and from diseased to healthy trees by L. biguttatus, C. lugubris, Cryptarcha ampla, and Colopterus semitectus. Viable ascospores were isolated from faecal pellets of Carpophilus lugubris. The opt. temp, for mycelial growth and spore production was 25°C. ; none occurred at 10 or 35°. The thermal death point for conidia was 46° and for ascospores 50° (10 min.), while ascospore masses survived 35 days at 28°.
Treatment of wounds with 0.2% phenyl Hg nitrate in gilsonite varnish before or after inoculation did not prevent infection. In further trials 5 of 9 small cankers were cured by applications of semesan bel; good protection was also afforded by phenyl Hg propionate.