Abstract
AbstractUnderstanding the effects of crop management practices on weed survival and seed production is imperative in improving long-term weed management strategies, especially for herbicide-resistant weed populations. Kochia [Bassia scoparia (L.) A.J. Scott] is an economically important weed in western North American cropping systems for many reasons, including prolific seed production and evolved resistance to numerous herbicide sites of action. Field studies were conducted in 2014 in a total of four field sites in Wyoming, Montana, and Nebraska to quantify the impact of different crop canopies and herbicide applications on B. scoparia density and seed production. Crops used in this study were spring wheat (Triticum aestivum L.), dry bean (Phaseolus vulgaris L.), sugar beet (Beta vulgaris L.), and corn (Zea mays L.). Herbicide treatments included either acetolactate synthase (ALS) inhibitors effective on non-resistant B. scoparia or a non–ALS inhibiting herbicide effective for both ALS-resistant and ALS-susceptible B. scoparia. Bassia scoparia density midseason was affected more by herbicide choice than by crop canopy, whereas B. scoparia seed production per plant was affected more by crop canopy compared with herbicide treatment. Our results suggest that crop canopy and herbicide treatments were both influential on B. scoparia seed production per unit area, which is likely a key indicator of long-term management success for this annual weed species. The lowest germinable seed production per unit area was observed in spring wheat treated with non–ALS inhibiting herbicides, and the greatest germinable seed production was observed in sugar beet treated with ALS-inhibiting herbicides. The combined effects of crop canopy and herbicide treatment can minimize B. scoparia establishment and seed production.
Highlights
Bassia scoparia has been documented to be problematic in many major crops grown in the Great Plains such as sugar beet (Beta vulgaris L.), corn (Zea mays L.), and dry bean (Phaseolus vulgaris L.) (Blackshaw 1990; Schweizer 1981; Weatherspoon and Schweizer 1970; Wilson et al 1980)
Bassia scoparia density, seed production per plant, and seed production per square meter differed by location; overall treatment trends were generally consistent throughout all four locations of the study (Figure 1)
There was a significant herbicide by crop interaction for B. scoparia density (Table 3)
Summary
Bassia scoparia has been documented to be problematic in many major crops grown in the Great Plains such as sugar beet (Beta vulgaris L.), corn (Zea mays L.), and dry bean (Phaseolus vulgaris L.) (Blackshaw 1990; Schweizer 1981; Weatherspoon and Schweizer 1970; Wilson et al 1980). It is often one of the first summer annual weed species to emerge in regions where it is naturalized, making it a highly competitive species (Friesen et al 2009). In the Northern Great Plains, 151 GDD will typically accumulate by early to mid-April (30-yr average of April 7 in Scottsbluff, NE, and April 12 in Huntley, MT), with an additional 556 GDD accumulating by the end of May
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
