Browsing by Author "Wyse, Donald"

Now showing 1 - 3 of 3
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    Biological Control of Canada Thistle in Wetland Prairie Restoration
    (Minnesota Department of Transportation, 2007-10) Eichstaedt, Kari; Wyse, Donald; Johnson, Gregg
    Pseudomonas syringae pv. tagetis (Pst), a phytopathogenic bacterium, was evaluated as natural biological control agent for Canada thistle [Cirsium arvense (L.) Scop.]. Canada thistle patches exhibiting symptoms of Pst infection commonly occur along roadsides in association with perennial grasses and a grass litter layer. Field experiments were conducted to determine if grass and litter provide an environment that supports Pst infection of Canada thistle or if grass, litter, and soil collected from infected Canada thistle patches act as inoculum sources for Pst infection of Canada thistle. This experiment provides evidence that grass and litter are important components of the landscape that support the natural Pst infection of Canada thistle, and perennial grass competition has potential to manage Canada thistle in roadside rights-of-way and wetland restoration sites. A previously published Pst specific primer set was determined to require high Pst populations for detection.
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    Management Practices for Weed Control in Roadway Rights-of-Way
    (Minnesota Department of Transportation, 2007-10) Arika, Caleb; Wyse, Donald; Nieber, John L.; Moon, Roger D.
    By law, Departments of Transportation are required to control noxious weeds along highway rights-of-way (ROWs). Since 2000, District 4 (D4) of Minnesota Department of Transportation (Mn/DOT) adopted a survey design consisting of n= 7, 3-mi segments to quantify infestations of Canada thistle (Cirsium arvense (L.)(Scop.), leafy spurge (Euphorbia esula L.), and poison ivy (Toxicodendron radicans) in chosen regions of the district. In 2004 and 2005, a second survey design was added to see if stratification by ecozone in D4, and greater numbers of 1/4-mi segments could improve precision. Comparison of matching sample statistics from the 3-mi and 1/4-mi plans in each year indicated the two plans yielded equivalent estimates of mean acres per roadway mile of each weed (a = 0.05). However, precision at the district level was much greater in all cases with the 1/4-mi plan. In addition, weed abundances varied substantially among ecozones (a < 0.05); this knowledge will allow managers to direct control efforts to problem areas. Finally, a combination of computer based mapping and resampling of the 1/4-mi segments observed in the two years suggests that additional improvements in precision and efficiency are likely to occur if segment lengths are shortened to 125' or less. Shorter segments would reduce inspection costs, increase sample sizes, improve precision, and possibly allow conversion from an area-measurement approach to one based on presence or absence of chosen weeds in selected segments. Plans are underway to compare the latter two approaches in 2007.
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    Perennial Sunflower Provides Food and Ecosystem Services
    (2011) Kantar, Michael B.; Betts, Kevin; Stupar, Robert M.; Hulke, Brent; Wyse, Donald
    Global population is projected to reach nine billion people by 2050, and the human population will need an adequate food supply and methods for sustainable production (Baulcombe et al., 2009). Over the past century, agriculture has greatly increased crop yields and productivity. However, this increase in productivity has often come at the expense of long term environmental sustainability through overuse of fossil fuel-based fertilizers, and the depletion of fresh water and arable land (Tilman et al., 2002). Addressing environmental damage is essential for the production of adequate food. Future cropping systems will need an increased emphasis on ecosystem services (Costanza et al., 1997). Ecosystem services can be incorporated into the landscape by increasing nutrient and water efficiency in major crops, adjusting agronomic practices (timing and duration of irrigation and nutrient applications), and by using perennial crops to help maintain healthy nutrient levels, control erosion and pests, and to keep water clean (DeHann et al., 2005; Baulcombe et al., 2009; Jackson and Berry, 2009; Glover et al., 2010). The objective of this research is to use current genetics and plant breeding techniques to introgress genes for perennial habit from Helianthus tuberosus L. (2n=6x=102) into domesticated sunflower (Helianthus annuus L., 2n=2x=34). H. tuberosus is part of the secondary gene pool of sunflower and has been used as a donor of many disease resistance traits making it an excellent donor for perennial habit. Because of previous success in gene transfer from H. tuberosus, we believe we will be successful in transferring perennial habit into annual sunflower.