VIEW ARTICLE

Effects of Cultural Practices and Biotic Soil Factors on Fomes annosus. W. D. Kelley, Research Associate, Department of Botany and Microbiology, Auburn University, Agricultural Experiment Station, Auburn, Alabama 36830; E. A. Curl, Professor, Department of Botany and Microbiology, Auburn University, Agricultural Experiment Station, Auburn, Alabama 36830. Phytopathology 62:422-427. Accepted for publication 8 November 1971. DOI: 10.1094/Phyto-62-422.

Field and laboratory studies were conducted to determine the influence of altered forest-soil environment on some activities of Fomes annosus. Cultural treatments applied to clear-cut slash pine Fomes-infested forestry plots were as follows: burned; burned and disked; and burned, disked, and seeded (one plot each) with lupine, oats, or rye. A control plot consisted of a natural forest stand. Samples of debris particles and soil were taken in January, April, and August and processed for microbial content or effect on F. annosus. Species of Trichoderma and Penicillium were the more prevalent colonizers of debris particles in natural forest soil, and the various cultural treatments caused these to either increase or decrease. Fomes annosus was not observed colonizing debris. Spores of Fomes germinated from 45 to 98% on sterilized soil, except that collected from the oats and rye plots in April, which revealed strong inhibition. Spores did not germinate on nonsterilized soil collected in January or August, but some germination occurred in April. Most severe inhibition was on oat-plot and burned-plot soils. Spore germination on agar containing plot-soil extracts varied greatly between soil sampling periods. Extracts of all plots inhibited germination below that on extract-free agar, most inhibition occurring with extracts from the oats and burned plots. Extracts in a basal medium had little effect on linear growth of Fomes. The highest percentage of microorganisms antagonistic to the pathogen was found in the oats and rye soils.