Theses and Dissertations at Montana State University (MSU)
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Item A morphological and histological study of the underground organs of the Canada thistle(Montana State University - Bozeman, College of Agriculture, 1934) Griffin, Chester W.Item Differences in lipids on Canada thistle leaves as influenced by ecotype and site(Montana State University - Bozeman, College of Agriculture, 1970) Hodgson, Jesse MoroniItem Interactions between ants (Hymonoptera: Formicidae) and Aphis fabae Scop. complex (Hemiptera: Aphididae), on Cirsium arvense L. Scop (Compositae)(Montana State University - Bozeman, College of Agriculture, 1988) Lang, Ronald FranklinItem Soil movement and residual aspects of chlorsulfuron and its control of Canada thistle (Cirsium arvense (L.) Scop.)(Montana State University - Bozeman, College of Agriculture, 1983) Dyer, William E.Item The insect fauna of Canada thistle, Cirsium arvense (L.) Scop. in southern Montana(Montana State University - Bozeman, College of Letters & Science, 1982) De Smet-Moens, HildeItem Sclerotinia spp., a potential biological control agent of Canada thistle (Cirsium arvense [L.] Scop.)(Montana State University - Bozeman, College of Agriculture, 1984) Brosten, Brenda SimmondsItem Studies with Puccinia obtegens for biological control of Canada thistle (Cirsium arvense)(Montana State University - Bozeman, College of Agriculture, 1981) Turner, Sherry KayItem Effects of training on cattle grazing spotted knapweed and Canada thistle(Montana State University - Bozeman, College of Agriculture, 2013) Tierney, Katie Rene'; Chairperson, Graduate Committee: Bret E. OlsonSpotted knapweed (Centaurea stoebe L.) and Canada thistle (Cirsium arvense (L.) Scop.) are changing and degrading North American rangeland ecosystems by replacing native grasses and forbs. Conventional control methods are often not cost-effective. Using livestock to manage invasive species offers a potentially cost effective alternative. The objectives of our first study were to determine if: 1) cattle trained to consume spotted knapweed and Canada thistle in 2004 retained their training in 2011, 2) calves and yearlings of the 2004 trained cattle consume more spotted knapweed and Canada thistle than calves and yearlings from untrained cows, and 3) yearlings trained to graze Canada thistle in mid-July consume more of the weed than untrained yearlings in late July and late August. In our 2011 study, trained cattle did not spend more time grazing spotted knapweed or Canada thistle than untrained cattle. In 2011, calves and yearlings from trained cattle did not spend more time grazing spotted knapweed or Canada thistle than those from untrained cattle. Yearlings trained to graze Canada thistle consumed similar amounts as untrained yearlings when grazed in July and less than untrained yearlings in August. The objectives of our second study were to determine if: 1) individual cattle spent similar amounts of time grazing spotted knapweed in 2011 and 2012, and 2) individual yearlings affect time spent grazing spotted knapweed of their peers. Individual animals tended to spend similar amounts of time grazing spotted knapweed in July of 2011 and 2012. Grazing yearlings, that tended to spend high or low amounts of time grazing spotted knapweed, together did not affect their time spent grazing this weed. Cattle innately grazed spotted knapweed (20-50% of their time grazing) and, to a much lesser extent, Canada thistle (0-17% of their time grazing); training did not result in greater amounts of time spent grazing these weeds. Individual cattle with the innate behavior to graze spotted knapweed can be identified and retained in herds to potentially increase grazing of spotted knapweed. With proper grazing management, cattle grazing can be used as one tool in an integrative approach to control spotted knapweed on rangelands.Item The establishment, drought tolerance, and weed suppression potential of multispecies sod(Montana State University - Bozeman, College of Agriculture, 2009) Stark, Jennifer Grace; Chairperson, Graduate Committee: Lisa J. Rew.Re-seeding is a frequently used technique to revegetate disturbed areas, but often leaves bare ground prone to weed invasion. Mixtures of drought tolerant or native species in sod could be used as an alternative to seed to provide rapid establishment of desirable plant communities that may potentially reduce weed emergence, survival, and productivity. Additionally, the reinforcement material required to aid transport of multispecies sod could further contribute to weed suppression and sod establishment. The objective of this study was to evaluate the weed suppression and establishment potential of multispecies sod. Three experiments were each subject to a water regime ranging from 2.54 cm of water/week to natural precipitation, and repeated over two/three years. In the first two experiments (A and B) Brassica napus (canola) was used as a surrogate weed species and sown either below the multispecies sod to represent weed seed bank, or above the multispecies sod to represent weed seed rain. In experiment A, B. napus was sown at six densities; while in experiment B reinforcement materials (nylon netting control, coconut-straw, jute, excelsior) were added below the sod and B. napus was sown at one density. B. napus suppression by multispecies sod, with or without reinforcement material, was evaluated by recording seedling emergence, survival and above-ground biomass. Multispecies sod, especially combined with reinforcement material, suppressed a large proportion of seedling emergence. The seedlings that did establish produced less vegetative and seed biomass as water decreased. In the second season of both experiments no seedlings survived to maturity. The establishment success of the multispecies sod was evaluated through repeated measures of percent sod cover over two/three years. The results suggested that the multispecies sod was able to establish and persist under natural precipitation. The third experiment evaluated the ability of multispecies sod to suppress Cirsium arvense (Canada thistle) vegetative propagules in two different habitat types, bare ground or multispecies sod, under high and low water treatments. More C. arvense shoots emerged in the bare ground, suggesting that multispecies sod could act as a buffer zone and reduce the vegetative spread of perennial weeds if used as a revegetation strategy.Item Vegetative reproduction and the integrated management of Canada thistle(Montana State University - Bozeman, College of Agriculture, 2009) Sciegienka, Joanna Katarzyna; Chairperson, Graduate Committee: Fabian D. Menalled.Canada thistle (Cirsium arvense (L.) Scop.) is an aggressive, introduced creeping perennial weed that flourishes in a wide variety of environments. Its deep, creeping root system and colony forming tendencies make it one of the most difficult weeds to control. A strategy that incorporates a better understanding of the biology of Canada thistle into the development of an integrated management plan that includes herbicides and biological control could help reduce the dispersal and impact of this species. The objectives of this work were to: 1) determine how Canada thistle emergence and growth are affected by changes in root size, biomass, burial depth, and soil moisture and 2) compare single and joint impacts of herbicides and biological control agents on Canada thistle growth. Objective 1 was carried out in a greenhouse and in field conditions. To monitor Canada thistle emergence and growth responses, a completely randomized factorial design was used in the greenhouse, and a randomized complete block design was used in the field. Models were developed to predict emergence and growth patterns based on available water, burial depth, and various root metrics. For the exception of available water, the same predictors were used in field conditions to predict Canada thistle emergence and growth. The variables that were manipulated were able to significantly predict the responses measured, and we concluded that available water, root burial depth, and root weight, length, diameter, and volume are indicators of emergence likelihood, emergence time, shoot and root growth, and shoot number. Objective 2 was carried out in greenhouses and field settings. Three herbicides were evaluated with and without insects to determine reduction in Canada thistle root and shoot biomass in the greenhouse. One herbicide was also used at a low rate and evaluated singly and in combination with a stem-boring weevil (Hadroplontus litura (F.)) and a pathogen (Pseudomonas syringae pv. tagetis) to determine effect on Canada thistle response in the greenhouse and field. We failed to reject our null hypothesis of additivity between control agents, and concluded that integrating individual control methods yields greater Canada thistle control than any singular method.