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Silica Concentrations In Dominant Vegetation Species Of Wax Lake Delta, Louisiana, Danielle M. Soileau
Silica Concentrations In Dominant Vegetation Species Of Wax Lake Delta, Louisiana, Danielle M. Soileau
LSU Master's Theses
Coastal deltaic wetlands colonize dynamic environments and experience fluctuations of salinity, river connectivity, sediment dredging or deposition, and periods of inundation resulting in unique vegetation and soils. Louisiana’s coastline is experiencing enhanced loss of coastal deltaic wetlands in coastal basins where the Mississippi River no longer is connected to waterways and channels that would normally provide freshwater and sediments representing the abandonment phase of the delta cycle. There is a coastal basin in the central regions of the state, the Atchafalaya Bay, that is still in the active phase of delta cycle resulting in the growth of the Wax Lake, …
Silicate-Solubilizing Bacteria In Louisiana Soils: Identification, Profiling, And Functions In Crop Production, Jayvee A. Cruz
Silicate-Solubilizing Bacteria In Louisiana Soils: Identification, Profiling, And Functions In Crop Production, Jayvee A. Cruz
LSU Doctoral Dissertations
Studies were conducted to determine the potential of silicate-solubilizing bacteria (SSB) as biostimulant in Louisiana rice (Oryza sativa L.) production systems. Isolation and profiling of SSB in Louisiana soils; evaluation on its effects on the silicon (Si) uptake and productivity of rice using various carriers derived from slag, rice hull, and sugarcane (Officinarum spp.) bagasse; and development of a feasible approach of incorporating SSB to the rice production system were conducted. Results showed that numerous bacteria isolated from Louisiana soils can solubilize silicate and produce multiple plant growth-promoting compounds. These potential SSBs were identified into four genera: Aeromonas, …
Silicon Fertilization In Rice And Wheat: Dynamics With Trace Elements And Effect Of Silicate Slag Granular Size On The Release Pattern Of Monosilicic Acid In Soil, Wooiklee S. Paye
Silicon Fertilization In Rice And Wheat: Dynamics With Trace Elements And Effect Of Silicate Slag Granular Size On The Release Pattern Of Monosilicic Acid In Soil, Wooiklee S. Paye
LSU Doctoral Dissertations
Studies were conducted to evaluate the impact of silicon (Si) fertilization on the uptake of harmful trace elements in Louisiana rice production system, and document the effect of silicate slag granular size on its ability to supply Si in wheat. The influence of silicate slag and lime on the uptake and translocation of harmful trace elements in rice grain was determined. Results showed that both slag and lime had similar effects on pH at five of the nine sites investigated. Soil Si was significantly (P <0.001) increased with application of silicate slag at all sites. Lime and silicate slag had no effect on the concentration of trace elements in soil. However, increasing Si rates were negatively correlated with arsenic (As) and cadmium (Cd) concentration in rice grain. The release pattern of monosilicic acid (H4SiO4) from wollastonite and silicate slag was compared in a wheat greenhouse …
Effect Of Increasing Levels Of Monosilicic Acid On Arsenic And Phosphorus Sorption In Soil, Flávia Bastos Agostinho
Effect Of Increasing Levels Of Monosilicic Acid On Arsenic And Phosphorus Sorption In Soil, Flávia Bastos Agostinho
LSU Doctoral Dissertations
Arsenic (As) accumulation in rice (Oryza sativa) grains has increased human’s daily intake. Studies have shown that arsenite is taken up through known silicon (Si) transporters in rice. Moreover, the availability of As in soil is affected by chemically similar ligands that have high affinity to oxides surfaces, such as Si and phosphorus (P). Studies were conducted to: (I) investigate the role of elevated levels of Si on the concentration of different As fractions in soil and on As uptake by rice; (II) evaluate the effect of increasing monosilicic acidconcentrations on As sorption and kinetics in soil; and …
Impact Of Sorghum Cultivar, Phenology, Nitrogen, And Silicon Fertilization On Melanaphis Sacchari Biology, Luna Lama
LSU Master's Theses
The sugarcane aphid, Melanaphis sacchari (Zehntner) (Hemiptera: Aphididae), is an invasive pest of grain sorghum, Sorghum bicolor (L.) Moench. Since its first outbreak in sorghum in 2013, severe infestations have spread throughout the southern U.S. causing high economic losses. While insecticidal control has mitigated some of the impacts of this pest, a sustainable ecology-based management program is needed to reduce reliance on chemical control. We studied the effects of silicon (rates equivalent to 0 and 3360 kg Si/ha) and nitrogen (rates equivalent to 0, 110, and 220 kg N/ha) on M. sacchari growth and reproduction on resistant (DKS 37-07) and …
Effects Of Silicon And Nitrogen Fertilization On Growth, Yield, And Leaf Rust Disease Development In Wheat, Maryamossadat Shahrtash
Effects Of Silicon And Nitrogen Fertilization On Growth, Yield, And Leaf Rust Disease Development In Wheat, Maryamossadat Shahrtash
LSU Master's Theses
There are so many people who have helped me throughout my graduate studies and for whom I am grateful. I would like to take this opportunity to first and foremost thank God for his always guidance throughout my life and giving me the wisdom and the patience I needed to finish my thesis. I would like to thank Dr. Brenda Tubana for taking me in and providing me with guidance and knowledge. I also would like to thank my committee members, Prof. Brian D. LeBlanc who guided me, encouraged me and provided me with knowledge about sustainable agriculture and Dr. …
Influence Of Silicon On The Development Of Anthracnose Of Grain Sorghum, Sanjay Pokhrel
Influence Of Silicon On The Development Of Anthracnose Of Grain Sorghum, Sanjay Pokhrel
LSU Master's Theses
To study the effect of Silicon (Si) with and without a fungicide on anthracnose development of sorghum, several experiments were conducted in the greenhouse and field. In the initial study, different Si rates [0 (control), 0 (lime control), 200, 400, 600, 800 kg Si/ha] were used in a low-Si Alfisol to determine if inoculum densities were affected by Si levels. No differences were observed between inoculum densities of 1*105 and 1*106 conidia/ml in affecting anthracnose development in the greenhouse. Anthracnose severity was found to be lowest in plants treated with 800 kg Si/ha, regardless of inoculum density. In another study, …
Silicon Fertilization In Rice:Establishment Of Critical Silicon Level And Its Impact On Availability Of Nutrients In Soils Of Louisiana, Wooiklee Sundayboy Paye
Silicon Fertilization In Rice:Establishment Of Critical Silicon Level And Its Impact On Availability Of Nutrients In Soils Of Louisiana, Wooiklee Sundayboy Paye
LSU Master's Theses
While silicon (Si) fertilization is widely practiced in paddy rice production, the establishment of critical soil Si levels has remained understudied. This study was undertaken to: 1) determine the critical soil Si level for rice production in Louisiana using different extraction procedures, and 2) document the relationship between plant-available Si and select essential plant nutrients in soil and their uptake by rice. Field trials were established at 12 sites across Louisiana from 2013 to 2015. Si was applied as silicate slag (SiO3, 14% Si) at the rates of 0, 1, 2, 4, 6, and 8 Mg ha-1. Agricultural lime was …
Surface Functionalization Of Crystalline Silicon Substrates, Sri Sai Vegunta
Surface Functionalization Of Crystalline Silicon Substrates, Sri Sai Vegunta
LSU Doctoral Dissertations
In this work, various chemical and electrochemical methods were demonstrated to attach application-specific organic monolayers to crystalline silicon substrates. In one study, alkyl monolayers were anodically electrografted or thermally grafted onto planar (100) silicon substrates using Grignard precursors. The results show electrografted methyl monolayers provide a stable Si-C termination, resisting oxidation on (100) surfaces for approximately 55 days in air. The alkyl termination could provide a potential alternative to defective native oxides and kinetically unstable hydride surfaces. A mechanism involving two electron transfers per grafting event was established for both the thermal and electrochemical routes. In another study, unsaturated organic …
Assessing The Silicon Status Of Rice (Oryza Sativa), Joseph Eugene Kraska
Assessing The Silicon Status Of Rice (Oryza Sativa), Joseph Eugene Kraska
LSU Master's Theses
Low silicon (Si) content in rice, sugarcane and other Si-accumulating crops can adversely affect crop performance due to reduced tolerance to both abiotic and biotic stresses. This research had two specific objectives relative to Si in Louisiana rice: develop a digestion procedure for Si tissue analysis that is robust, accurate, precise, and requires equipment commonly found in most agricultural laboratories; and survey the Si status of rice plants at mid-tiller (Y-leaf) and after harvest (straw) throughout the rice-growing regions of Louisiana. Assessing the Si status of a crop typically depends upon accurately measuring Si accumulation in plant tissue. While wet-digestion …