The host range of the knapweed nematode, Subanguina picridis (Kirjanova) Brzeski, under controlled environmental conditions was extended to include, in addition to Russian knapweed, Acroptilon repens (L.) DC., plant species within the Centaureinae, and Carduinae subtribes of the Cynareae tribe of the Asteraceae family. Examination of host response to nematode infection revealed that Russian kna...

A Russian knapweed (Acroptilon repens) shoot culture system, initiated from shoot tip culture, was used to generate a source of host plant tissue for the rearing of the nematode Subanguina picridis, a biocontrol agent for Russian knapweed. Young shoots growing on solid B5G medium in petri dishes developed galls on leaves, petioles, and shoot tips 7 days after release of 50 nematodes onto the su...

Species richness and diversity are important indicators of ecosystem function and may be related to plant community resistance to invasion by nonindigenous species. Our specific objective was to determine the influence of clopyralid plus 2,4-D, glyphosate, and fosamine, at different application rates and timings, on richness and diversity of total species, total native species, and total nonnat...

The knapweed nematode, Subanguina picridis, forms galls on the leaves, stems, and root collar of Russian knapweed, Acroptilon repens. After being revived from a dormant, cryptobiotic state, second-stage juveniles required at least 1 month in a free-living state before becoming infective. Galls were induced on relatively slow-growing host plants that retained their apical meristems at or near th...

The objective of this study was to test the potential for using a single-entry procedure to revegetate Russian knapweed– and green rabbitbrush–infested rangeland. I hypothesized that simultaneously applying an herbicide and seeding in the fall would produce the highest establishment and growth of desired species. For Russian knapweed, treatments included three seeding rates (zero, low, and high...

russian knapweed (acroptilon repens l.) is a perennial weed of aceraceae that is becoming a dominant weed in suitable conditions. in order to find an ecological non-chemical approach for controlling russian knapweed and studying the possibility of using flower-eater mite (aceria acroptiloni shevchenko & kacalev) (acari: eriophyidae), a series of studies including field survey and field experime...

in order to evaluate the response of russian knapweed seeds to cardinal temperatures a factorial experiment was conducted base on completely randomized design with 3 replications. russian knapweed seeds (collected from irrigated and rainfed wheat fields), and germination temperatures (constant temperatures of 10, 15, 20, 25, 30 and 35° c) were used as first and second levels of the experiment. ...