Effects of Small-Scale Aerobic Composting on Survival of Some Fungal Plant Pathogens. G. Y. Yuen, Graduate Assistant, Department of Plant Pathology, University of California, Berkeley 94720. R. D. Raabe, Professor, Department of Plant Pathology, University of California, Berkeley 94720. Plant Dis. 68:134-136. Accepted for publication 15 August 1983. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-134.

Aerobic composting for 21 days eliminated Armillaria mellea, Rhizoctonia solani, and Verticillium dahliae from colonized plant residues and killed Sclerotium rolfsii sclerotia sealed in glass vials or mesh bags. For eradication of the three pathogens protected in plant material and the sclerotia sealed in glass vials, the material containing the pathogens had to be turned with the compost every 2 or 3 days to expose the pathogens to the high temperatures in the center of the compost pile. S. rolfsii sclerotia in mesh bags, however, were killed even when exposed to sublethal temperatures in the corners of the compost bin. Inactivation of these sclerotia required various lengths of exposure depending on location and time of burial during the composting process. Temperatures in the center of the 0.7-m³ bin reached as high as 70 C, with temperatures above 45 C lasting 10–14 days. Temperatures in the corners did not reach levels lethal to the pathogenic fungi.