Effect of age of cocomposted MSW and biosolids on weed seed germination

The influence of municipal solid waste (MSW) and biosolids compost maturity on germination of several weed species seeds was evaluated. Ivyleaf mornin g glory (Ipomoea hederacea L.), barnyard grass (Echinochloa crus-galli L.), common purslane (Portulaca oleracea L.), and corn (Zea mays L.) were selec ted as plant indicators to determine the compost maturity stage with maximu m germination inhibition. Extracts were prepared from immature (three day-o ld, four week-old, eight week-old), and mature (one year-old) composts. Ext ract from eight week-old compost decreased percentage germination, root gro wth, and germination index (a combination of germination percentage and roo t growth), and increased mean days to germination of each indicator specie. Extract from eight week-old compost was evaluated for effect on germinatio n percentage of 14 economically important weed species. Extract from eight week-old compost inhibited germination of most weed species, except yellow nutsedge (Cyperus esculentus L.) for which tubers were used as propagules. Extracts from immature (three day, four week, and eight week-old) compost w ith acetic acid concentrations of 2474, 1790, and 1776 mg.kg(-1), respectiv ely, delayed and reduced germination percentage of important economic weed species. These results suggest that immature MSW-biosolids compost might be utilized as an alternative method of weed control in the alley-ways of row crops.