Effects of Soil Fumigation and Cover Crops on Potential Pathogens, Microbial Activity, Nitrogen Availability, and Seedling Quality in Conifer Nurseries

Abstract

In three forest nurseries of the Pacific Northwest, fall fumigation with chloropicrin or dazomet led to an immediate increase in total microbial respiration and nitrogen availability, but levels were comparable to those in unfumigated plots when tree seedlings were sown the next spring. Population densities of Fusarium spp. and Pythium spp. in fumigated plots were reduced dramatically and stayed significantly below those in unfumigated plots throughout the 2-yr crop cycle (...)