Digital Commons Network^™

Susceptibility Of Adult Colorado Potato Beetle (Leptinotarsa Decemlineata) To The Fungal Entomopathogen Beauveria Bassiana, Ellen Klinger

Electronic Theses and Dissertations

Factors influencing the susceptibility of adult Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), to the fungal entomopathogen, Beauveria bassiana (Bals.), were studied. In an assay comparing trials between a): laboratory reared, non-diapausing beetles and b): field collected, post-diapausing beetles, survival of B. bassiana treated beetles was higher for non-diapausing adults, however, control mortality was higher for post-diapausing adults. In a similar assay with field collected pre- and post-diapausing beetles, survival of B. bassiana treated individuals was higher for post-diapause adults and control mortality was higher for post-diapausing adults than pre-diapausing beetles. In a third experiment, the effect of time from …

The Use Of Green Fluorescent Protein For Transgene Monitoring And Detection Of Pollen Distribution And Gene Flow Patterns Under Field Conditions., Laura C. Hudson

Masters Theses

There have been many recent and new possibilities for crop improvement since the development of techniques, which allow for the transfer of novel genes into host plant genomes. Fitness enhancing genes that confer disease, drought, and herbicide resistance to important food crops such as corn (Zea mays L.), soybean (Glycine max L.), canola (Brassica napus L.), and rice (Oryza sativa L.) will be invaluable tools to feed the exponentially growing human population world wide.

This widespread use of transgenic crops has increased the risk of transgene escape into the environment. …

Determining The Factors That Control Respiration And Carbon Use Efficiency In Crop Plants, Jonathan M. Frantz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the literature on plant respiration, there are two viewpoints concerning the source of respiratory control: supply (photosynthate availability) or demand (temperature dependent) limitations. While different studies indicate the primary dependency for respiration is either the supply or demand side, the two paradigms cannot both be true. The relative importance of each paradigm may depend on a number of factors including period of time during which respiration is measured, phase of plant development, environmental conditions, and species.

Studies were performed using continuous CO₂ gas-exchange instrumentation to monitor short- and long-term changes in whole canopies of lettuce, tomato, soybean, and …

The Short And Long-Term Effects Of Herbicide Application In Maine Clearcuts On Ant Communities (Hymenoptera: Formicidae), Kerry Frances Lough

Electronic Theses and Dissertations

The short and long-term effects of glyphosate application on the diversity and abundance of ants in Maine clearcuts was assessed in a two-year study. Glyphosate is applied to release coniferous trees from suppression by competition with deciduous vegetation after a forest is clearcut. Previous research indicates glyphosate has limited immediate and long-term effects on non-target fauna, though specific species can be affected. Limited research on the effects of herbicides on insects indicates some initial decrease in insect populations. Beneficial insects, such as pollinators and predators, positively influence the forest ecosystem, but little research has examined the effects of herbicide application …

Physiological And Biochemical Aspects Of Agrobacterium-Wheat (Triticum Aestivum L.) Interactions, David L. Parrott Jr.

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Agrobacterium tumefaciens and A. rhizogenes are the causal agents of gall or hairy root disease, but normally the bacteria do not cause disease in wheat. However, both bacteria grew without inhibition when exposed to intact or wounded wheat roots or embryos, and they colonized wheat root surfaces to levels similar to dicotyledonous plants. A. tumefaciens and A. rhizogenes induced 23% cell death after a 1-h exposure to wheat embryo cells grown in 7.4 mM O₂, while the extent of cell death at 2.1 mM O₂ was 8%. Contact with A. tumefaciens or A. rhizogenes caused cultured wheat …

Use Of Ground-Based Canopy Reflectance To Determine Radiation Capture, Nitrogen And Water Status, And Final Yield In Wheat, Glen L. Ritchie

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ground-based spectral imaging devices offer an important supplement to satellite imagery. Hand-held, ground-based sensors allow rapid, inexpensive measurements that are not affected by the earth’s atmosphere. They also provide a basis for high altitude spectral indices.

We quantified the spectral reflectance characteristics of hard red spring wheat (Triticum aestivum cv. Westbred 936) in research plots subjected to either nitrogen or water stress in a two year study. Both types of stress reduced ground cover, which was evaluated by digital photography and compared with ten spectral reflectance indices. On plots with a similar soil background, simple indices such as the …

Effect Of Drought, Flooding, And Potassium Stress On The Quantity And Composition Of Root Exudates In Axenic Culture, Amelia Henry

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Root exudates include important chelating compounds and can change the rhizosphere pH by several units. These changes are essential for nutrient uptake and can also alter solubility of soil contaminants and increase plant uptake. Mild root-zone stress may increase exudation and more severe stress can damage membranes and increase root turnover, all of which increase root-zone carbon. Increased carbon from this rhizodeposition can increase microbial activity, which might help degrade contaminants. We studied the effect of three types of stress on root exudation of crested wheatgrass (Agropyron cristatum): low K⁺, drought, and flooding. These stresses were …

The Vascular Flora Of The Tablelands: A Natural Region In The Northeastern Section Of The Knobs Of Kentucky, Kim L. Feeman

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science and Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Kim L. Feeman on January 22, 2003.

Spatial Heterogeneity Of Soil Nutrients, Nitrogen Dynamics, And Vegetation In A 3rd Order Stream Floodplain In Southwestern West Virginia, David Allen Dick

Theses, Dissertations and Capstones

Soil processes often exhibit spatial heterogeneity within ecosystems and this heterogeneity may influence community structure. This study was conducted to determine spatial patterns and variability of soil nutrients and plant communities within different vegetation types in a stream floodplain in southwestern West Virginia. One 5-m × 5-m site was established in each of three vegetation/drainage types: pasture (PA), old field (OF), and wetland scar (SC). Pasture and SC sites were located ~25 m apart on flat bottomland; the OF site was located on a moderate slope 6.3 m above bottomland, ~200 m from PA and SC. A 10-m × 1-m …

Sugarcane Seed Response To 2,4-D And Alternative Herbicides For Red Morningglory (Ipomoea Coccinea L.) Control, Jonathan Daniel Siebert

LSU Master's Theses

Field studies conducted over two growing seasons evaluated the effect of 2,4-D applied at 1.6 kg ai/ha to LCP 85-384 sugarcane (Saccharum interspecific hybrid) 7, 5, 3, and 1 wk before planting (WBP). Sugarcane was planted in mid-September using both whole stalk and billet (45 cm) seed pieces. When 2,4-D was applied 5 wk or closer to planting, sugarcane shoot emergence and population averaged across planting methods was reduced 5, 7, and 28 wk after planting (WAP) when compared to the nontreated control. Sugarcane height in one of two years was reduced when 2,4-D was applied 5 wk or closer …

Variation In The Severity Of Mummy Berry Disease Among Lowbush Blueberry Clones, Laura Penman

Electronic Theses and Dissertations

Lowbush blueberry production is important for the economy of Maine and the Maritime provinces, and mummy berry disease, caused by Monilinia vaccinii- corymbosi, often reduces plant stand vigor and fruit production. The severity of mummy berry disease among clones of lowbush blueberry were measured in four fields over a two year period (2001 and 2002). In each of 37 clones,lO flowering stems with and without symptoms of blight were randomly selected at flowering to represent "diseased" and "healthy" stem populations, respectively. The severity of leaf and flower blight and fruit mummification was measured for each of these stems, and the …

Effect Of Stand Density On Behavior Of Leaf Area Prediction Models For Eastern White Pine (Pinus Strobus L.) In Maine, Micah D. Pace

Electronic Theses and Dissertations

There is little debate within the forest science community that leaf area (LA, the surface area of live foliage) or leaf area index (LAI, the total surface area of live foliage per unit of ground area) are important variables, central to enhancing the understanding of forest growth and many forest ecosystem processes. The ability to accurately measure LA1 has become a research priority and has resulted in various methods of estimation for a variety of species and regions. In this study LA estimation models for Pinus strobus L. were developed, tested, and compared across a wide range of densities for …

The Composition Of Cryptophytes (Geophytes) And Other Plants In The Northern Jarrah Forest Of Western Australia: An Analysis Of Logged And Old Growth Forest, Conrad C. Slee

Theses : Honours

Forests are decreasing globally and there are pressing requirements for ecologically sustainable forest management to be implemented at all scales. There has been some criticism of the public managers for forests and the processes used to select reserve systems and silvicultural methods used. Limited research has been conducted on the effects of logging on the plants of the northern Jarrah forest of south western Australia, While fire is a major disturbance event, disturbance during logging operations may remove non-commercial trees, understorey shrubs and change soil conditions. Some plants that regenerate from below ground storage organs such as Cryptophytes (Geophytes) may …

A Comparison Of Microbial Communities In Soil With And Without A Sugarcane Cropping, Carolyn Faye Savario

LSU Master's Theses

Sugarcane (inter-specific hybrids of Saccharum) is grown largely under long-term monoculture production in Louisiana. This can lead to a complex problem termed "yield decline" that results in poor root health and reduced productive capacity of sugarcane. This problem has been documented to be a limiting factor for sugarcane production in diverse regions, including Louisiana, Hawaii, Jamaica, and Australia. Previous work showed that biological factors affect root health and contribute to yield decline. The objectives of this study were to increase our understanding of microbial communities in sugarcane soils, to determine if there are differences in microbial communities associated with sugarcane …

Ten Years Of Change In Beech Stand In North Central Maine Long Affected With Beech Bark Disease, Amanda Farrar

Electronic Theses and Dissertations

In Maine, northern hardwood stands long affected by beech bark disease often still have high numbers of beech trees. This is mostly due to sprouting, and most new stems become severely infected with the disease. Beech that are resistant to the scale insect, Cryptococcus fagisuga Lind., the inciting factor for the disease complex, do exist and often occur in clumps of root sprout origin. In 1989 a long-term study of the effects of commonly used seasonal harvesting regimes on regeneration initiation and survival was established in north central Maine. Treatments included harvest season (winter or summer) and intensity (clearcut or …

Effects Of Biological Control And A Ryegrass Rotation On Rhizoctonia Disease Of Potato, Marin Talbot Brewer

Electronic Theses and Dissertations

Rhizoctonia solani is an important pathogen of potato capable of reducing tuber yield and quality. Integrated, sustainable methods including biocontrol and effective crop rotations are necessary for control of this pathogen. Twenty-eight potential biocontrol organisms were tested for efficacy against R. solani on potato in a series of greenhouse trials. Organisms tested consisted of field isolates of Paenibacillus polymyxa, Pseudomonasfluorescens, Penicillium sp., Trichoderma sp., and Rhizoctonia zeae; known biocontrol isolates including Laetisaria arvalis, Verticillium biguttatum, Cladorrhinumfoecundissimum, and Stilbella aciculosa; and commercial products of Bacillus subtilis (Kodiak), Trichoderma virens (SoilGard), and Trichoderma harzianum (Rootshield). Different formulations and rates of several fungal …

Variability In Water Use By Phreatophytic Banksia Woodland Vegetation Of The Swan Coastal Plain, Western Australia, Sandra Jane Zencich

Theses: Doctorates and Masters

Seasonal changes exist in source-water utilisation by Banksia woodland species overlying a shallow aquifer on the Swan Coastal Plain in Western Australia These were studied to identify the importance of groundwater as a water source to this vegetation. Intra-and interspecific variation in seasonal water use was investigated across the dominant overstorey and understorey species, with particular emphasis on species of different rooting morphologies. Seasonal water use was investigated across a topographical gradient ranging from a groundwater depth of 2.5 to 30 metres, a scenario representative of the coastal sand-dune system. An examination was also made of the response of woodland …

Patterns Of Water Uptake And Rhizosphere Salinity In Casuarina Obesa Miq. During A Drying Period At Lake Toolibin, Western Australia, Patrick J. Mitchell

Theses : Honours

Lake Toolibin is one of a few remaining freshwater lakes in the central wheatbelt of Western Australia. Since monitoring began at Lake Toolibin in the early 1970's groundwater levels have risen to within 1-2 m of the lakebed with an accompanying migration of salt. The site-specific nature of water uptake in Casuarina obesa Miq. (the dominant lakebed tree species) and rhizosphere salinity were explored spatially through analyses of soil properties (groundwater depth and salinity, particle size and components of soil water potential ψ₁). Plant water sources (using δ²H signatures) and water availability (based on ψ_{leaf …}

Sedimentological And Plant Taphonomic Evaluation Of The Early Middle Devonian Trout Valley Formation, Jonathan Allen

Honors Theses

The Trout Valley Formation of Emsian-Eifelian age, outcropped in Baxter State Park, Maine, consists offluvial and coastal deposits preserving early land plants. Massive, crudely bedded conglomerate represents deposits of proximal braided channels on an alluvial fan complex. Lithic sandstone bodies in channel-form geometries represent deposits of river channels draining the Acadian highlands whereas associated siltstones represent overbank deposits, intertidal flats, and tidal channels. Localized lenticular quartz arenites represent nearshore shelf bar deposits that were storm influenced. The majority of plant assemblages preserved mainly in siltstone lithologies are allochthonous and parautochthonous, with only one autochthonous assemblage identified in the sequence. Plant …

Control Of Tomato Late Blight (Phytophthora Infestans) With Biocides On Tomatoes (Lycopersicum Sculentum) In The Community Of Carmen Pampa, Belonging To Coroico Municipality (Nor Yungas, La Paz), Rosemary Gutiérrez Coarite

Theses and Dissertations

In Bolivia, tomato acreage is 6717 and has a yield of 12005 kg/ha and the total production is 80,636 TM. Departments that harvest tomato are Santa Cruz, Cochabamba and La Paz, Santa Cruz being the department that shows the highest rates of production with 40653 TM in comparison with La Paz which has a production of 3109 TM and Cochabamba of 2420 TM. The principle factors in affect are, the best climatic conditions in Santa Cruz, while Cochabamba and La Paz have differences in seasonal changes (National Institute of Statistics, 1998). The importance of the tomato harvest lies in consumption …

Evaluation Of Quinoa (Chenopodium Quinoa Willd) At Different Spacings Between Furrows And Plants In The Mamani Community, José Ferrufino Miranda

Theses and Dissertations

This study addressed spacing between furrows and plants in the cultivation of the quinoa variety Patacamaya. This study took place from 1999 to 2000 in the Mamani community, Ingavi, La Paz, Bolivia. The Patacamaya variety is a cross between Samaranti (sweet) and Kaslala (bitter), with a vegetative cycle of 145 days (semi-early). It has large grains, is sweet, and has a high grain yield. The spaces between furrows were 40, 60, and 80 cm in an experimental design of randomly divided plots with four repetitions. The spaces between furrows were implemented in large plots and the plant spaces as sub-treatments …

Biology And Ecology Of Leptographium Species And Their Vectos As Components Of Loblolly Pine Decline, Lori G. Eckhardt

LSU Doctoral Dissertations

Loblolly pine (Pinus taeda L.) decline (LPD) has been present in upland sites of central Alabama since the 1960s. Symptoms of LPD (fine root deterioration, short chlorotic needles, sparse crowns, reduced radial growth) begin in the 30-40 yr age class, resulting in premature death at ages 35-50. Previously, declining loblolly was diagnosed as littleleaf disease (LLD); however, site conditions associated with LPD are different from LLD sites. Littleleaf disease only occurs on eroded, heavy clay soils and is secondarily associated with the fungus, Phytophthora cinnamomi. In contrast, LPD occurs on sandy, well-drained soils and is associated with Leptographium spp., as …

Studies On Rice Transformation And The Use Of Transformed Plants [Electronic Resource], Qiming Shao

LSU Doctoral Dissertations

This research was conducted to enhance utilization of the Liberty herbicide resistance transgene in rice. Non-lethal methods to determine the sensitivity of transgenic rice plants to hygromycin B and Liberty were developed, tested and used in this research. Four homozygous transformed plants were selected to make reciprocal crosses with their non-transformed parent cultivars Taipei 309 and Nipponbare. Their resistances to Liberty and hygromycin B were controlled by the closely linked single dominant genes bar and hpt. Some non-resistant phenotypes in the F2 populations were due to gene silencing. The bar gene in some of these plants were allelic and some …