Life Sciences Commons^™

Estimation Of Base Temperatures For Nine Weed Species, Scott J. Steinmaus, Timothy S. Prather, Jodie S. Holt

Biological Sciences

Experiments were conducted to test several methods for estimating low temperature thresholds for seed germination. Temperature responses of nine weeds common in annual agroecosystems were assessed in temperature gradient experiments. Species included summer annuals (Amaranthus albus, A. palmeri, Digitaria sanguinalis, Echinochloa crus-galli, Portulaca oleracea, and Setaria glauca), winter annuals (Hirschfeldia incana and Sonchus oleraceus), and Conyza canadensis, which is classified as a summer or winter annual. The temperature below which development ceases (T_base) was estimated as the x-intercept of four conventional germination rate indices regressed on temperature, by repeated probit analysis, …