Germination of jointed goatgrass (Aegilops cylindrica Host.) seed in nitrate nitrogen (NO−3-N), gibberellic acid (GA3), or distilled water was studied in the laboratory, and depth of emergence of seedlings from soil was studied in the greenhouse and laboratory. After 14 days in germination chambers in distilled water, no difference in percent germination of 1-yr-old or freshly harvested seed existed between 10, 15, or 20 C. Jointed goatgrass seed germinated at temperatures ranging from 10 to 35 C and responded to temperature more than to NO−3-N. Seedlings did not emerge from below 5 cm in greenhouse and 6 cm in laboratory studies even though germination occurred. Jointed goatgrass has the seed germination and seedling emergence characteristics to develop into a severe annual grass weed in winter wheat (Triticum aestivum L.)-producing regions, particularly where reduced-tillage practices are utilized.

Bioassay techniques were evaluated for the determination of chlorsulfuron {2-chloro-N-[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino] carbonyl] benzenesulfonamide} residues in soil and water. A linear response of corn (Zea maysL.) primary root length to chlorsulfuron concentrations (InX+1) of 0.0 to 16.0 μg/L was observed in the water bioassay. Several soil extraction bioassay methods were attempted and found to be highly variable. A Ca(OH)2soil extraction bioassay technique produced a linear response of primary corn root length to chlorsulfuron concentrations ranging from 0.0 to 64.0 μg/kg. The efficiency of the Ca(OH)2extraction bioassay was determined by the use of14C-chlorsulfuron. Recovery efficiency at 1.0 μg/kg was 74% and averaged 62% at all higher chlorsulfuron concentrations.