Narcissus Fire: Prevalence, Epidemiology, and Control in Western Washington. G. A. Chastagner, Associate Plant Pathologist, Department of Plant Pathology, Washington State University, Western Washington Research and Extension Center, Puyallup 98371. Plant Dis. 67:1384-1386. Accepted for publication 5 July 1983. Copyright 1983 American Phytopathological Society. DOI: 10.1094/PD-67-1384.

Fire, a disease of Narcissus caused by Botryotinia polyblastis, has been observed in western Washington since 1978, but disease development has often been confused with natural senescence of foliage. Apothecia arose from overwintered sclerotia in naturally infested leaf debris during two of the last 4 yr in experimental plots. Initial apothecial production during 1980 and 1981 occurred in early April and mid-March, respectively. Apothecial numbers reached a peak after 2 wk, then gradually declined during the next 3–4 wk. Subsequent foliar infections by conidia from infected flowers appeared in late April during both years despite differences in the time of apothecial production. Initial foliar infections have been followed by rapid disease spread and foliage death within 3–6 wk. Rapid distal, then proximal, yellowing from infection sites coupled with limited lesion development indicates that a toxin is involved in symptom development. Applications of benomyl in late April and mid-May have consistently provided effective control of this disease.