teraction effects of Allium spp . residues , concentrations d soil temperature on seed germination of four weedy ant species san

Soil in laboratory microcosm experiments was amended with dried and milled crop residue of onion (Allium cepa L. cv. Mission) or garlic (A. sativa L. cv. California Early). The amend ments, along with the additional factors of amendment concentration (0, 1 or 3% (w/w)) an soil temperature (23 or 39 8C), were evaluated with respect to germination of seeds of th weedy annual plants Echinochloa crus-galli (L.) Beauv. (barnyardgrass), Portulaca oleracea (common purslane), Sisymbrium irio L. (London rocket) and Solanum nigrum L. (black nigh shade). Deleterious effects of seed exposure to 39 8C versus 23 8C were demonstrated i ECHCG, POROL, and SSYIR; and to increasing amendment concentration and the [concen tration temperature] interaction in all four plant species tested (P < 0.05). The effect o garlic versus onion amendment was significant only in SOLNI, where garlic residue demonstrated more herbistatic and/or herbicidal activity. The results of these experimen showed that the garlic and onion plant residues were capable of causing significan reductions in seed germination during their decomposition in soil, but only at elevate (39 8C versus 23 8C) soil temperature. At the agricultural level, activity of these residues coul be exploited as a component of integrated weed management using appropriate cro sequencing, and may extend utility of soil heating treatments (e.g. solarization) for wee control to cooler climates or seasons, or for shorter treatment durations. # 2007 Elsevier B.V. All rights reserve Corresponding author. Tel.: +1 559 646 6500; fax: +1 559 646 6593. E-mail address: [email protected] (J.J. Stapleton). avai lab le at www.sc iencedi rec t .com journal homepage: www.elsev ier .com/ locate /apsoi l Abbreviations: ECHCG, Echinochloa crus-galli; POROL, Portulaca oleracea; SSYIR, Sisymbrium irio; SOLNI, Solanum nigrum. 9-1393/$ – see front matter # 2007 Elsevier B.V. All rights reserved. :10.1016/j.apsoil.2007.07.003 ease cite this article in press as: Mallek, S.B. et al., Interaction effects of Allium spp. residues, concentrations and soil temperature on ed germination of four weedy plant species, Appl. Soil Ecol. (2007), doi:10.1016/j.apsoil.2007.07.003 co tic he du St So w Ru lim or ca ta id us m bu th