Browsing by Subject "Population density"

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    Management effects on lowest pod placement and yield formation in soybean.
    (2010-11) Kluver III, Robert Wesley
    Chapter Summary: In recent years, increased harvest loss for soybean [Glycine max (L.) Merr.] due to low forming pods has been noted in southern Minnesota. These harvesting losses come from the inability of the cutterbar on harvesting equipment to be operated close enough to the soil surface to gather low formed pods. In order to better understand the effects of management strategy on height and nodal characteristics and their relation to lowest pod height, studies were conducted in the southern Minnesota region in 2008 and 2009 to investigate plant density, relative maturity, row width, mulch color, and stand reduction. Increasing population density from 19 to 43 plants m-2 increased the height of the lowest pod from 12.2 to 15.8 cm. The relative maturity of soybean varieties also affected the height of the lowest pod, increasing it from 10.9 to 18.8 cm going from a late MG 0 and a late MG II variety. Changes in row width revealed there was no significant effect on the height of the lowest pod. Red colored mulch produced a significantly higher lowest pod height at 14.7 cm compared to no mulch which had a height of 13.0 cm. Stand reduction studies revealed that lowest pod height could be reduced from 15.9 to 11.5 cm when population was reduced from 43 to 19 plants m-2 as late as R3. Only population density was found to affect LPH and internode length simultaneously, so the impacts seen on LPH do not appear to be primarily working through differences in internode length.
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    Using an accelerated vehicle retirement program (AVRP) to support a mode shift: Car purchase and modal intentions following program participation
    (Journal of Transport and Land Use, 2015) Lachapelle, Ugo
    To stimulate the economy and reduce greenhouse gas emissions from older vehicles, most accelerated vehicle retirement programs (AVRPs) provide participants with incentives to purchase a new, less-polluting vehicle. The province of Québec also designed its AVRP as a mode-shift tool by providing alternative travel incentives to participants. Alternatives include public transit passes, rebates on bicycles and car-sharing memberships. In the absence of post-program assessment, the theory of planned behavior is used to assess participants’ modal intentions and intentions to purchase a new or used vehicle following participation. A subset (22 percent) of program participants (2009-2011; n=9070) filled out an optional survey about vehicle purchases and travel intentions. Age, gender, income, distance traveled in the previous year and perceived access to public transit were used as independent variables in logit and multinomial logit regressions. Car purchase intentions and traveling by car were associated with greater distance traveled. Higher-income participants were more likely to purchase new vehicles, and lower-income people and students were more likely to purchase used vehicles or refrain from any purchase. Alternative travel intentions were each associated with different sociodemographic characteristics. Québec’s program offers a promising incentive-based opportunity to influence mode shift if favorable circumstances are in place to enhance access to alternative travel modes.