No description available.

Thesis (Ph. D.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

The size of a raindrop is a middle-grade novel about a dandelion named Sterling and a little girl named Arianna who has a kidney disease which modern medicine and contemporary medical practices are failing to cure. The story examines a variety of political themes rising to the surface in our world today—race, gender, discrimination, colonialism and imperialism, genocide, healthcare, and more. It also explores existentialism through questions of life, purpose, and worth—questions which, ultimately are the real questions behind the political skirmishes of our time.

Control of Taraxacum officinale (dandelion) and other broadleaf weeds in turfgrass has been readily achieved with phenoxy herbicides, but the herbicide option has been revoked in many regions, necessitating alternative weed control strategies. One biological alternative is Sclerotinia minor, an Ascomycete fungus. The impact of S. minor on broadleaf weed dynamics and biotic interactions were studied in a turfgrass environment. The goal was to maximize effectiveness of a S. minor formulation as a biocontrol of dandelion using an ecological approach. S. minor efficacy was not affected by turf microenvironments and was similarly efficacious with spring or fall application. All accessions from a worldwide collection of dandelion and 32 turfgrass broadleaf species were susceptible to S. minor. Biocontrol efficacy was inversely correlated with dandelion age, but efficacy on all ages was enhanced in the presence of grass competition. When combined with regular mowing at 7-10 cm, the S. minor suppressive effect on dandelion was similar to the herbicide effect, particularly in the following season. Weed suppression was less with close mowing at 3-5 cm due to increased dandelion seedling recruitment. While spring herbicide application was effective to suppress dandelion population, the S. minor treatment has no residual activity, necessitating a second application to suppress seedling recruits. Root regrowth after S. minor infection was minimal and was further reduced in superior quality turf after season-long mowing, and after spring applications. S. minor infected dandelion seeds, reduced the dandelion seedbank, and reduced dandelion seedling emergence by 98%. S. minor did not affect the emergence or the total biomass of cool season temperate turfgrass species. Turfgrass quality was improved following S. minor application and populations of other broadleaf weeds were also controlled by S. minor. Understanding the biotic interactions within the turfgrass environment has rewardingly lead to successful integration of the S.minor biocontrol with the common management tools of mowing and over-seeding to achieve excellent control of dandelion and a healthy thriving turf.

No description available.

Indiana University-Purdue University Indianapolis (IUPUI) / This thesis offers a focused examination of thematically-related story-chapters that Ray Bradbury originally intended for his first novel concept—Summer Morning, Summer Night, a book set in the vivid memories of his own small-town Midwest childhood. The stories at the heart of this thesis were discarded from the project (often referred to by Bradbury as the “Illinois novel”) by the time that he published a portion of the original project as Dandelion Wine in 1957. As that novelized story cycle is perhaps the best-known of all Bradbury’s “Green Town” books, I intend to use it as a springboard for identifying and examining those stories that were discarded, left unfinished, or eventually published as stand-alone tales in other outlets. Since all of these stories were eliminated before Dandelion Wine emerged as the first published portion of the larger Illinois novel, I will further explore how their hypothetical presence or actual absence may have affected Dandelion Wine as a whole, from inception and development to publication and popular reception, as well as investigate what these tales may reveal about the evolution of Bradbury as a writer.

Success of hybrid poplar plantations will rely on the efficient management of nutrients and weeds. Relatively little is known about the root uptake characteristics of hybrid poplar and weeds, their belowground interactions and particularly, the quantitative understanding of nutrient uptake using mechanistic models under weed-competing conditions. Therefore, the objectives of this study were to investigate the effects of dandelion and quackgrass on the growth of hybrid poplar, to establish their root uptake characteristics and to quantify their nutrient uptake using the soil supply and nutrient demand (SSAND) model. In a pot study, hybrid poplar stem height, root collar diameter, shoot and root biomass, root length, and N, P and K uptake significantly decreased in the presence of dandelion and quackgrass weeds. Similar weed competition effects on growth of hybrid poplar were also observed in the field at the Pasture and Alfalfa sites where hybrid poplar was grown with and without weeds for 50, 79 and 100 days. In a hydroponic experiment, Imax values for NH4-N, NO3-N, P and K varied significantly among hybrid poplar seedlings and dandelion and quackgrass weed species and was greatest for dandelion followed by hybrid poplar and then quackgrass. The Km values were lowest for quackgrass compared to the other plant species for all of the nutrients. Simulation results from the SSAND model for the pot study showed that N uptake was underpredicted in hybrid poplar by 58 to 73%, depending upon soil type and weed treatment. Incorporation of N mineralization as a model input improve the hybrid poplar N uptake predictions by 24 and 67% in the Pasture and Alfalfa soil, respectively, when grown without weeds. SSAND model underestimated P uptake by 84-89% and overestimated K uptake by 28 to 59% for hybrid poplar depending upon the soil type and weed treatment. In the field, N uptake by hybrid poplar was in close agreement to measured N uptake in the control treatment. N uptake was greatly underestimated for both hybrid poplar and weeds in the weed treatment. Including changing water content greatly improves the N uptake by hybrid poplar and weeds in weed treatments. Results from this study suggest weed control is an essential practice to establish successful hybrid poplar plantations. Also, SSAND model can be an effective tool for predicting the nutrient uptake under two plant species competing environment if all the processes of nutrient supply are adequately described in the model.

Success of hybrid poplar plantations will rely on the efficient management of nutrients and weeds. Relatively little is known about the root uptake characteristics of hybrid poplar and weeds, their belowground interactions and particularly, the quantitative understanding of nutrient uptake using mechanistic models under weed-competing conditions. Therefore, the objectives of this study were to investigate the effects of dandelion and quackgrass on the growth of hybrid poplar, to establish their root uptake characteristics and to quantify their nutrient uptake using the soil supply and nutrient demand (SSAND) model. In a pot study, hybrid poplar stem height, root collar diameter, shoot and root biomass, root length, and N, P and K uptake significantly decreased in the presence of dandelion and quackgrass weeds. Similar weed competition effects on growth of hybrid poplar were also observed in the field at the Pasture and Alfalfa sites where hybrid poplar was grown with and without weeds for 50, 79 and 100 days. In a hydroponic experiment, Imax values for NH4-N, NO3-N, P and K varied significantly among hybrid poplar seedlings and dandelion and quackgrass weed species and was greatest for dandelion followed by hybrid poplar and then quackgrass. The Km values were lowest for quackgrass compared to the other plant species for all of the nutrients. Simulation results from the SSAND model for the pot study showed that N uptake was underpredicted in hybrid poplar by 58 to 73%, depending upon soil type and weed treatment. Incorporation of N mineralization as a model input improve the hybrid poplar N uptake predictions by 24 and 67% in the Pasture and Alfalfa soil, respectively, when grown without weeds. SSAND model underestimated P uptake by 84-89% and overestimated K uptake by 28 to 59% for hybrid poplar depending upon the soil type and weed treatment. In the field, N uptake by hybrid poplar was in close agreement to measured N uptake in the control treatment. N uptake was greatly underestimated for both hybrid poplar and weeds in the weed treatment. Including changing water content greatly improves the N uptake by hybrid poplar and weeds in weed treatments. Results from this study suggest weed control is an essential practice to establish successful hybrid poplar plantations. Also, SSAND model can be an effective tool for predicting the nutrient uptake under two plant species competing environment if all the processes of nutrient supply are adequately described in the model.

Thesis (Ph. D.)--Ohio State University, 2009. / Title from first page of PDF file. Includes bibliographical references (p. 151-168).