Mining operations often generate tailing dams that contain toxic residues and are a source of contamination when left unconfined. The establishment plant community over the tailings has been proposed as containment strategy known phytostabilization. Previously, we described naturally occurring mine colonizing plants such Acacia farnesiana, Brickellia coulteri, Baccharis sarothroides, Gnaphalium...

Thirty-two weeds commonly found in the organic soils of southwestern Quebec were evaluated for host suitability to a local isolate of the northern root-knot nematode Meloidogyne hapla under greenhouse conditions. Galls were observed on the roots of 21 species. Sixteen of the 21 had a reproduction factor (Pf/Pi = final number of M. hapla eggs and juveniles per initial number of M. hapla juvenile...

Belowground interactions between herbaceous native species and nonnative species is a poorly understood but emerging area of interest to invasive-species researchers. Positive feedback dynamics are commonly observed in many invaded systems and have been suspected in California grasslands, where native plants associate strongly with soil mutualists such as arbuscular mycorrhizal fungi. In respon...

Chromosome counts of Asteraceae are reported from Mexico, the United States, the West Indies, Peru, and Bolivia. First counts are reported for 27 species, eight infraspecific taxa, and three interspecific hybrids in Brickellia, Chrysanthellum, Cirsium, Egletes, Erigeron, Flaveria, Gnaphalium, Heterotheca, Hieracium, Hymenothrix, Koanophyllon, Layia, Lessingia, Pectis, Sclerocarpus, Stuessya, Ta...

A combination of tebuthiuron (25%) and diuron (50%) called Bimate* was evaluated for pre-emergence and postemergence weed control. An early post-emergence application was the best treatment. No phytotoxicity to either plant or ratoon cane was recorded when the recommended rates of 4,O kg of Bimate per ha were used on soil containing 8 to 30% clay, and 5,O kg of Bimate per ha on soil containing ...

Two California native perennial grasses, nodding needlegrass [Nassella cernua (Stebbins & R.M. Love) Barkworth] and California barley [Hordeum brachyantherum Nevski ssp. californicum (Covas & Stebbins) Bothmer, N. Jacobsen & Seberg], were compared with a conventional grass cover crop, ‘Blando’ brome (Bromus hordeaceus L.), as well as resident (weedy) vegetation and a clean cultivated control fo...