Thermal inactivation of weed seeds and tubers during drying of pig manure.

Abstract

Propagules of 7 plant species were subjected to heat treatments comparable to industrial processing. Propagules of all species, which had been preincubated 1 day in pig slurry, responded to heat treatment in an oven in the range from 50 to 104 degrees C. Brassica napus and Solanum nigrum were the most heat-sensitive species. The viability of their seeds was greatly reduced after 15 min at 50 degrees C. Seeds of Amaranthus retroflexus, B. napus, Chenopodium album and S. nigrum were inactivated after 3 min at 75 degrees C, seeds of Echinochloa crus-galli and tubers of Cyperus esculentus after 3 min at 90 degrees , whereas seeds of Abutilon theophrasti only slightly responded to 3 min at 104 degrees . Heating seeds of A. theophrasti at 104 degrees with steam resulted in much less viability than heating at the same temperature in the oven. More than 1 day preincubation in slurry positively affected thermal inactivation of E. crus-galli seeds and C. esculentus tubers at 75 degrees , but not of A. theophrasti seeds at 75, 90, and 104 degrees . (Abstract retrieved from CAB Abstracts by CABI’s permission)