Life Sciences Commons^™

Molecular Marker Assisted Development And Stability Analysis Of Low Phytate, High Inorganic Phosphorus Soybean [Glycine Max (L.) Merrill], Suzannah Joy Wiggins

Masters Theses

Phytate [myo-inositol 1,2,3,4,5,6-hexakisphosphate] is a mixed cation salt of phytic acid which binds to other minerals, in many field crops including soybean [Glycine max (L.) Merr.]. Livestock with monogastric digestive systems lack the ability to break bonds between phytate and these minerals, causing phytate phosphorus (P) to be excreted in the waste and contributing to possible P and other mineral deficiencies. Discovery of single sequence repeat (SSR) and single nucleotide polymorphism (SNP) markers associated with low phytate QTL (cqPha-001 and cqPha-002) have aided in development of low phytate soybean lines. The objectives of this study were …

Integrated Strategies For Controlling Warm-Season Turfgrass Weeds, Matthew Thomas Elmore

Masters Theses

Herbicidal inhibitors of 4-hydroxyphenylpyruvate dioxygenase (HPPD) such as mesotrione, topramezone and tembotrione were evaluated in greenhouse experiments for activity against bermudagrass. While topramezone and tembotrione exhibited greater activity than mesotrione, none of these herbicides provided acceptable bermudagrass control. These herbicides reduced leaf tissue chlorophyll and carotenoid pigment concentrations in bermudagrass. Changes in turfgrass pigmentation were quantified using HPLC analogy as well as evaluations of visual bleaching and measurements of chlorophyll fluorescence yield (F_v/F_m). Results indicated that these more expeditious methods of evaluating HPPD-inhibiting herbicide activity (visual evaluations and F_v/F_m) cannot be used …

Impact Of Switchgrass Bioenergy Feedstock Production On Soil Carbon Dioxide Flux And Below Ground Soil Organic Carbon Storage In East Tennessee, Leah Denise Soro

Masters Theses

Bioenergy production from switchgrass has shown promise in restoring degraded soils and helping to mitigate greenhouse gas (GHG) emissions. CO₂ loss and C-sequestration in soils are important topics for research to better understand the environmental impacts of bioenergy crops. The need for more thorough research of the carbon cycle in soils used for bioenergy production precipitated the primary interest of this study. The specific objectives of this study were 1) to measure SOC under switchgrass production in order to predict storage of carbon in soils based on previous cropping history, land management, soil physical characteristics, and time; and to …

Establishment And Persistence Of Legumes In Switchgrass Biomass And Forage/Biomass Production Systems, Kara Spivey Warwick

Masters Theses

Switchgrass, Panicum virgatum, is being developed as an economically and ecologically sustainable biomass crop. Nitrogen is considered one of the most limiting inputs of switchgrass. Alternatives to synthetic nitrogen fertilization may be nitrogen-fixing legumes interseeded into switchgrass. The objectives of this research were: (1) develop efficient legume management strategies for switchgrass production systems, (2) evaluate and identify cool and warm-season legumes that can be grown compatibly with switchgrass, (3) determine whether switchgrass yields are increased by legume N-fixation, and (4) determine N-fixation of common (Vicia sativa) and hairy vetch (Vicia villosa).

This study examined the …

The Effects Of Living Mulches On Organic, Reduced-Till Broccoli Growth And Management, Sarah Elizabeth Broughton

Masters Theses

Conservation tillage programs have been successfully implemented for many agronomic cropping systems, but adoption of reduced tillage for vegetable crops has been slow. As many conventionally managed conservation tillage programs rely on synthetic herbicides for clean cultivation, alternative methods must be devised to suppress weed pressure and reduce reliance on mechanical cultivation to aid in the development of reduced tillage programs for organic cropping system. Strip tillage is a reduced tillage method that is well suited to vegetable crop production, and the utilization of cover crops and living mulches between rows provides a viable weed management option for organic systems. …

Control Of Glyphosate Resistant Horseweed (Conyza Canadensis) With Saflufenacil And Tank-Mixture Partners., Brock Steven Waggoner

Masters Theses

Field and labratory studies were conducted to determine the efficacy of saflufenacil alone and with mixture partners for burndown. Field studies were conducted in 2009 and 2010 to evaluate saflufenacil in mixtures with glyphosate, glufosinate, or paraquat for control of glyphosate-resistant (GR) horseweed prior to planting cotton. Saflufenacil and saflufenacil mixtures were applied 7 days before planting (DBP). Saflufenacil at 25 and 50 g ai ha-1 in mixture with all three non-selective herbicides provided similar GR horseweed control when compared to the current standard of glyphosate plus dicamba. Control of GR horseweed was also not different at the 25 and …

Effects Of No-Tillage On Crop Yields And Net Returns Across The United States, Dustin Kevin Toliver

Masters Theses

Farmers are always looking for ways to increase yields and profits and no-tillage may be a way to achieve this goal. However, a comprehensive study of the performance of no-tillage yields relative to conventional tillage yields and their net returns is lacking. This study evaluated the potential factors that influence differences in conventional tillage and no-tillage yields and net returns as explained by such factors as time, crop, precipitation, soil texture and geographic region. Data were collected from 442 paired tillage experiments growing corn, soybeans, cotton, oats, wheat and sorghum published in three refereed journals. Data were evaluated using a …

Effects Of Trinexapac-Ethyl And Winter Overseeding On The Morphological Characteristics And Traffic Tolerance Of Bermudagrass Cultivars, William D. Haselbauer

Masters Theses

Common bermudagrass [Cynodon dactylon (L.) Pers.] and hybrid bermudagrass [C. dactylon (L.) Pers. X C. transvaalensis Burtt-Davy] are some of the most common turfgrasses used on athletic fields. Subsequently, the traffic tolerance of commercially available cultivars and the effects of trinexapac-ethyl (TE) on bermudagrass athletic fields with or without perennial ryegrass are often limited. A two year study at the University of Tennessee was conducted under simulated athletic field traffic to evaluate the performance of bermudagrass cultivars as affected by TE and overseeding. Bermudagrass cultivars evaluated were Tifway, Riviera, Patriot, and Celebration. TE treatments consisted of an untreated …

Classification And Fertility Of Soils In The Big South Fork National River And Recreation Area Based On Landscape Position And Geology, Ryan H. Blair

Masters Theses

The Big South Fork National River and Recreation Area encompasses more than 50,585 hectares (125,000 acres) of the Cumberland Plateau along the border of Tennessee and Kentucky. Highly dissected and steep terrain have made accessibility to much of the park limited, thus little work has been done to investigate the formation of these soils. Seven native soil profiles were selected for chemical and physical analysis representing Pennsylvanian-aged acidic sandstone and shale geology and landforms. The objectives of this study included the characterization of selected native profiles by physical and chemical analysis, as well as classification using US Soil Taxonomy, to …

Impacts Of American Student Teachers On Twelve Community Members In A Rural New South Wales Community Australia: A Qualitative Study, Tera Shenae Bunch

Masters Theses

The purpose of this study was to evaluate the influences of American student teachers on a rural community in New South Wales, Australia. The study analyzed interviews with twelve participants of the American student teacher program in A Rural New South Wales community, Australia. Two researchers worked together to complete this study. Both researchers were student teachers with the New South Wales community for ten weeks and taught Agriculture in one the community‟s two high schools. After allowing one year to pass, researcher one returned to the community to interview twelve individuals involved with the program. The interviewed participants were …

“Growing Up Green: A Study Focusing On Environmental Attitudes, Knowledge And Focusing On Environmental Attitudes, Knowledge And Behaviors Of Elementary Children.”, Sarah Elizabeth Smith

Masters Theses

“Growing Up Green,” is a research based environmental education program that teaches children about recycling, energy conservation, and composting. This program was taught to fourth grade students at H.B. Williams Elementary School, in White House, Tennessee. The children were given a pre-test before the program and a post-test two weeks after the program. The pre and post-test was composed of three parts. The three parts tested their environmental attitudes, knowledge, and behaviors. The study found that most of the children already had positive attitudes toward the environment. While, their attitudes decreased minimally after the program, they still remained very positive. …

Effects Of Combinations Of Cropping Sequences And Biocovers On Yield Of Glyphosate-Tolerant Corn, Soybean, And Cotton Under No-Till, Jennifer Elizabeth Noe

Masters Theses

No-till acreage is increasing in the United States as producers begin to recognize the environmental and economic benefits of this management system. Although the potential to receive carbon credits or payments for maintaining or initiating no-till may encourage producers to employ these practices, crop yields will be a factor in management decisions. Our objective was to examine the effects of combinations of cropping sequences and winter biocovers upon glyphosate-tolerant corn, cotton, and soybean yields under long-term no-tillage at two locations in Tennessee. Research was conducted during the first four-year phase (2002-2005) of a two-phase agronomic systems study (2002-2009) at the …

Ground Cover Management For Conservation Tillage Burley Tobacco, Justin Lee Bryant

Masters Theses

There are several advantages of using conservation tillage management practices for burley tobacco production. These include reduced soil erosion, soil water conservation, and lower input costs. Inconsistent yields in past research and trials have made tobacco producers hesitant in adopting conservation tillage. This research was conducted near Springfield, Tennessee and Greeneville, Tennessee to investigate no-till and strip-till practices with different ground cover management techniques during winter and spring months in an effort to identify appropriate technologies. The first study evaluated cover management in established sod. Conventional tillage tobacco was compared to tobacco transplanted either no-till or strip-till into the following …

Rate And Timing Of Nitrogen Fertilizer In Burley Tobacco, Michael Randall Waynick

Masters Theses

Our objectives in this study were to evaluate the state recommendations for nitrogen, determine the effects of nitrogen on tobacco specific nitrosamines (TSNA), yield and quality, determine efficient nitrogen rates and evaluate the pre sidedress nitrate test (PSNT) as an indicator of nitrogen needs in burley tobacco. This study had nine nitrogen rates, in a split plot design with four replications. Main plots consisted of preplant nitrogen: 89.6, 179.2 and 268.8 kg/ha. Sub plots consisted of sidedress nitrogen: 0, 52 and 112 kg/ha. Soil nitrate-N was determined using the PSNT, with samples taken to a depth of 0.15 m three …

Comparison Of Sweet Corn Vigor With Ions And Sugars In Seed Leachate Of Five Isolene Pairs With Two Endosperm Types, Marla K. Faver

Masters Theses

Supersweet corn contains more sugar and less starch than traditional sweet corn which increases the sweetness of the kernel. Supersweet corn has increased in consumer popularity due to its sweeter flavor and ability to retain this sweeter flavor longer than traditional sweet corn. Two sweet corn (Zea mays L. var. rugosa) endosperm types (traditional and shrunken-2) are popular with consumers. The problem growers face with supersweet cultivars (shrunken-2) is poor seed vigor as shown by low field emergence and non-uniform stands.

Field emergence of plants was compared to laboratory germination for 5 sweet corn isoline pairs (genetically identical except for …

Effects Of Ozone During Soybean Seed Development On Seed Vigor, Karen A. Gerlach

Masters Theses

Soybean (Glycine max L. Merr. cv 'Essex', 'Forrest' and 'Clark') seed were obtained from Dr. Mulchi of the University of Maryland. Seed from 1989 and 1990 were from plants which were exposed to three regimes of ozone during seed development including charcoal-filtered (no ozone), non-filtered (ambient ozone), and non-filtered + 40 n11^-1 O₃. Seed from 1994 were developed with four pollutant regimes of ozone during seed development including charcoal-filtered (no ozone), non-filtered (ambient ozone), non-filtered + 40 n11^-1, and non-filtered + 500 u11^-1 CO₂. The objective of this study was to assess …

Anatomical And Sem Studies Of The Pericarp And Aleurone Layer Of Two Supersweet Corn Cultivars, Tufail Ahmed

Masters Theses

Supersweet corn (Zea mays L. var. rugosa.) which contain endosperm mutant shrunken -2 exhibits low seed vigor and poor field emergence especially when soil temperature is 10-15 °C. Based on their emergence in the field at low temperature, they can be divided into two groups as tolerant and sensitive cultivars. Two cultivars 'Illini Gold' (Tolerant) and 'Honey 'n' Pearl' (Sensitive) were studied to see any anatomical differences, holes and cracks in the pericarp and air pockets between pericarp and aleurone layer. Significant differences were found in the thickness of pericarp. 'Illini Gold' cultivar has thicker pericarp and thin walled aleurone …

Leakage Of Solutes From Imbibing Seeds Of Supersweet Corn Cultivars That Differ In Tolerance To Low Germination Temperatures, Linda Kull

Masters Theses

Supersweet types of sweet corn (Zea mays L. var rugosa) with shrunken-2 endosperm are preferred by consumers because of their extra sweetness and postharvest retention of good flavor. However, their acceptance by growers is hindered due to reduced field emergence, especially in cold soils. This reduced emergence is related to seed quality. To examine differences between supersweet corn cultivars which are tolerant and sensitive to low temperatures, two cultivars were chosen based on their emergence in the field at low temperatures (10-15 C). 'Illini Gold' was chosen as the tolerant cultivar and 'Honey'n'Pearl' as the sensitive cultivar. Seeds …

How Potassium Affects Emergence Of Five Supersweet Corn (Zea Mays L. Var. Rugosa) Cultivars With Low Temperatures, Nombasa Tsengwa

Masters Theses

Supersweet types of sweet corn (Zea mays L. var rugosa) are sensitive to low temperature during emergence and thus have difficulty in establishing stands in early spring. This study investigated how banded potash affected establishment of five supersweet cultivars of sweet corn in fields and growth chambers.

In the field, sweet corn cultivars were planted near Urbana, Il on April 18 and July 22, 1991 with three levels of potash (0, 45 and 90 kg/ha) banded at planting. Several parameters of growth and development were measured approximately 2, 4 and 6 weeks after planting. No significant effect of potash was …

Mechanisms Controlling Tolerance Of Lettuce Seed To High Temperatures At Germination And Emergence, Margaret A. Mnichowicz

Masters Theses

Lettuce (Lactuca sativa L.) seed germination is inhibited when temperatures are higher than 25-30 C. The extent of this thermodormancy is affected by both genetic and environmental factors. Lettuce seed of four seedlots of "Empire" produced in the summers and winters of two years were sown in the field in late summer and early fall at Yuma, AZ to determine stand establishment with high soil temperatures. The seedlots produced in the summer had higher percent field emergence than those produced in the winter. Also, seed of these four seedlots were germinated in petri dishes in a growth chamber at 20, …

Potential Mechanisms Related To Salt Tolerance In Bean Plants, Sandra Baumgartner

Masters Theses

Phaseolus vulgaris (navy bean) and P. acutifolius (tepary bean) were grown hydroponically and stressed with -0.25 MPa NaCl for 9 days beginning 22 days after planting. Chloride and sodium distribution in leaves and roots as well as percent ion leakage as an indication of membrane integrity in leaves were determined. Chloride levels in NaCl treated plants were significantly higher than in controls. Chloride levels were not significantly different between plant parts or between plant species. Sodium distribution differed significantly between the roots of navy and tepary but not between the leaves of the two species. Navy root tissue contained twice …

The Effect Of A Bacteriophage On The Competition Of Rhizobium Japonicum Strains For Nodulation Of Glycine Max (L.) Merr, Lori Kelley

Masters Theses

The symbiotic relationship between Rhizobium japonicum (Kir.) Buch. and Glycine max (L.) Merr. was the concern of this thesis. This relationship occurs naturally in soybean fields. In the field there are many different strains of Rhizobium. Some of these strains fix atmospheric nitrogen more efficiently than others resulting in a higher crop yield. The problem is the more efficient nitrogen fixers are out-competed by less efficient nitrogen fixers. In order to solve this problem the more competitive strains have to be controlled. There are two main ways to do this. One is to increase the number of the desired …

The Influence Of Atrazine (2-Chloro-4-(Ethylamino)-6-(Isopropylamino-S-Triazine) On The Severity Of Gibberella Zeae-Induced Seedling Blight Of Corn, Louis A. Heaton

Masters Theses

Three corn inbreds were grown in artificially inoculated, steamed greenhouse soil amended with atrazine (2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine) to determine the herbicide's effect on the severity of Gibberella zeae (Schwabe) Petch-induced seedling blight. Corn inbreds used were Gibberella-resistant (FR632), Gibberella-intermediate (FRMo17), and Gibberella-susceptible (C123^HT). Soils were amended with atrazine at rates of 2, 15, and 30 ppm.

Susceptible inbred seedlings showed no response to the herbicide with symptims equally severe in controls and all 3 concentrations of atrazine. Intermediate inbred seedlings grown in all atrazine amended soils showed significantly more severe disease symptoms than controls. Soil amended with …

Production And Utilization Of Sunflower Food Plots At Shelbyville Wildlife Management Area, Illinois, Duane T. Dust

Masters Theses

Three sunflower (Helianthus annuus) fields from 3.2 ha to 1.0 ha in size, planted on the Shelbyville Wildlife Management Area, Illinois were analyzed for seed production and utilization by birds. Seed in heads and on the ground were sampled and species and numbers of birds in the fields were censused at two week intervals from September, 1976 to February, 1977. Decline in seed availability was most rapid in the smallest field and least rapid in the largest field. Fields and portions of fields adjacent to wooded cover were also utilized more rapidly. American goldfinch (Spinus tristis) …

A Study Of Root Development Of Crop Plants In Relation To Soil Characteristics, Sunanda Sakharam Rao

Masters Theses

[From the Introduction] [Abbreviated]

The object of the present paper is to make a brief review of the work done on the root development of crop plants in relation to soil types. Besides reviewing the studies made on the subject, the various factors influencing the root habits are discussed briefly.

Role Of Extension Service In Rural Development, Sunanda Sakharam Rao

Masters Theses

[From the Introduction] [Abbreviated]

Of all the agencies and organizations cooperating with people in rural development work, the Agricultural Extension Service and its workers have a special and pivotal role. This is because both rural developoent and Cooperative Extension Service are educational programs involving large numbers of people, and they have the same fundamental objectives. The purpose for which this study was outlined was to discover how these programs differ by comparatively studying their educational nature.

Seed Certification In The Southeast, Sunanda Sakharam Rao

Masters Theses

[From the Introduction] [Abbreviated]

This paper is intended to be a review of the seed certification program operating in the United States. Here the certification is the responsibility of the individual states. The schemes are operated either by government agencies or by legally authorized seed growers associations.

The purpose of seed certification is to make available to the public high quality seed and propagating materials of superior crop plant varieties, so grown and so distributed as to insure genetic identity, varietal purity and mechanical quality. Fundamentally it is a system to improve yield and quality of field crops.