Digital Commons Network^™

Hemp Microgreen Mineral Content, Cannabinoids, Total Phenolics, And Antioxidants, Cheston T. Schayot

LSU Master's Theses

Hemp (Cannabis sativa) L. microgreens were grown to 7 and 12 days with and without supplemental lighting and/or fertilizer. The principal macronutrient found in hemp microgreens was nitrogen (N), followed by potassium (K), phosphorus (P), magnesium (Mg), calcium (Ca), and sulfur (S). The principal micronutrient found in hemp microgreens was iron (Fe), followed by manganese (Mn), zinc (Zn), boron (B), and copper (Cu). Hemp microgreens were similar to other commonly grown microgreen species in minerals except for P and Mg, where they could potentially be an excellent source, and Zn, where they fell below previously reported amounts. The …

Response Of Roseau Cane (Phragmites Australis) To Two Biotic Stresses: Hyalopterus Pruni And Bipolaris Yamadae, Heather E. Cizek

LSU Master's Theses

Roseau cane (Phragmites australis) is considered an invasive plant because of its ability to replace native plant species. However, in Louisiana it plays an important role protecting coastal infrastructure and being part of the marsh ecosystem in the lower Mississippi River Delta. In recent years, Roseau cane has been affected by a die-off, a problem that has also been reported in some European countries. Possible biotic and abiotic factors that have been associated with the die-off include scale insects, climate change, pollution, salinity levels, and pathogens.

In this research, the individual and combined effect of a foliar disease …

Investigation Of Arabidopsis Extremophyte Relatives, Schrenkiella Parvula And Eutrema Salsugineum Reveals Different Roads Leading To Salt Stress Tolerance, Kieu-Nga Thi Tran

LSU Doctoral Dissertations

How plants adapt to salt stress has been a central question in plant biology for decades. Yet we have not been able to fully understand the molecular networks and genetic mechanisms underlying this complex trait. Most of the genetic work on salinity stress has focused on understanding salt stress responses in the leading, yet a salt-sensitive model Arabidopsis thaliana. With the recent availability of genomes for wild-relatives of A. thaliana, we can now investigate how naturally salt adapted plants may have evolved modified or novel molecular networks to adapt to salt stress. Therefore, my research utilizes a comparative …

Corn Nitrogen Management Under Different Tillage Systems, Akshara Athelly

LSU Master's Theses

Adoption of no-tillage (NT) and cover crops (CC) significantly effect soil physicochemical properties and nutrient cycling that necessitates modified nutrient management to maximize crop yields. Two field experiments were conducted to evaluate N-sources Urea Ammonium Nitrate (UAN), urea, and urea+ N-stabilizer (urea+ stab) and N-split applications 100%N at V2 (S1), 25%N at V2+75%N at V6 (S2), 25%N at V2+ 50%N at V6+ 25%N at VT (S3) in a sandy loam soil and three CC wheat (Triticum aestivum), hairy vetch (Vicia villosa) , and radish (Raphanus sativus) and their combinations along with three N-rates ( …

Insights Into Abscisic Acid And Phosphatidic Acid Signal Transduction Dynamics In Arabidopsis Thaliana, Ruth Wanjiru Ndathe

LSU Doctoral Dissertations

Abscisic acid (ABA) is a plant hormone that triggers a signaling transduction in response to drought, salinity, and cold. The core components in the ABA signaling pathway that lead to downstream ABA responses have been identified.

Phosphatidic acid (PA) is a membrane phospholipid that is involved in the signaling pathway for ABA-induced stomatal closure. We tested whether PA is involved in the signaling pathway for ABA-induced gene expression as well, using model plant Arabidopsis thaliana. We selected the RD29A gene which is a canonical drought gene that is induced by ABA. We found that PA is not involved in …

Using Uav Technology Paired With Multispectral Cameras To Assess Crown Rust Epidemics In Oats, Turner A. Graham

LSU Master's Theses

Crown rust, caused by Puccinia cornonata f. sp. avenae, is a common disease of oats (Avena sativa) found virtually everywhere oats are cultivated. This disease has caused yield losses of 10 to 40% worldwide. Early detection is important for effective management. A more recently utilized technology in agriculture is unmanned aerial vehicles (UAVs). UAVs, or drones, equipped with cameras are now being used as a resource to take images of fields to identify pests and other issues that may be occurring. Normalized differentiated vegetative index (NDVI) is a numerical indicator used to determine the vegetative health of …

Evaluating Substrate Stratification Practices For Enhanced Water Resource Management In Nursery Production, Kristopher S. Criscione

LSU Master's Theses

The nursery and greenhouse industries have continued to increase in production and sales over the past two decades. This increase in horticultural production necessitates a greater demand for finite natural resources, specifically water. Sustainable water resource management will be critical to the success and continual growth of the nursery industry. Strategic irrigation scheduling and innovative substrate management practices can improve nursery resource efficiency. Soilless substrates were originally utilized by the industry to increase substrate air-filled porosity, to ensure adequately drained container systems. Thus, the implementation of these soilless substrates can lead to an inefficient use of water and fertilizer. Substrate …

Investigating Plant Tolerance For The Management Of Insect Pests In Rice, James Michael Villegas

LSU Doctoral Dissertations

The rice water weevil, Lissorhoptrus oryzophilus Kuschel (Coleoptera: Curculionidae), is the most destructive and widespread insect pest of rice (Oryza sativa L., Poaceae) in the USA. This insect poses a global threat to rice production, having invaded rice-producing regions of Asia and Europe. Moreover, lepidopteran stemborers, particularly the invasive Mexican rice borer, Eoreuma loftini (Dyar) (Lepidoptera: Crambidae), are increasingly becoming problematic in Louisiana rice. Although insecticidal seed treatments have been widely used against weevils and stemborers, alternative management strategies are needed. Plants possess defense-related traits that both reduce injury from herbivores (resistance) and the amount of yield loss per …

Integrated Nutrient Management And Cover Cropping Practices In Louisiana Sugarcane Production Systems, Daniel Erneso Forestieri

LSU Doctoral Dissertations

Integrating effective fertilizer management with conservation practices is essential to improve farm income and promote environment friendly sugarcane production systems. A study was conducted in multiple to document the impact of nitrogen (N) source and cover cropping on sugarcane yield and quality components. The treatment consisted of different N sources: urea, knife-in urea ammonium nitrate (UAN) solution, calcium nitrate-CaNO3, ammonium sulfate-NH4SO4, and knife-in UAN. + foliar N, applied at 90 kg ha-1 and control (0 N). The cover crops included: crimson clover (Trifolium incarnatum), hairy vetch (Vicia villosa), and oilseed radish (Raphanus sativus L.) planted at 13, 17, and 1 …

Influence Of Planting Date, Maturity Group, Harvest Aids And Fungicide Application On Soybean (Glycine Max (L.) Seed Quality, Ana Priscila Campos

LSU Master's Theses

Field studies evaluated the influence of planting date, maturity group, and harvest timing on soybean yield and seed quality at the LSU AgCenter Northeast (NERS), Macon Ridge, and Dean Lee Research Stations in 2018-2020. In addition, the influence of harvest aid and fungicide application on seed quality impact from delayed harvest and environment was investigated at NERS in 2019 and 2020 in both field and environmentally controlled growth chambers. Soybean yield was maximized when maturity group IV and V soybean varieties were planted between Mid-April and Mid-May. Earlier and later planting dates did not result in maximized yield. Planting date …

Understanding The Etiology Of Taproot Decline Of Soybean Caused By Xylaria Necrophora, José E. Ortiz Solórzano

LSU Master's Theses

Taproot decline (TRD) of soybean is caused by Xylaria necrophora. However, the mechanisms by which it infects soybean and produces symptoms are unknown. Symptoms of TRD include foliar interveinal chlorosis and necrosis and root necrosis, yet X. necrophora appears to be restricted to the roots. While Xylaria species are predominantly wood decomposers, a few are pathogens. More importantly, they produce secondary metabolites (SMs) with multiple bioactivities, including phytotoxicity and antimicrobial activity. Preliminary experiments suggested that X. necrophora was producing SMs responsible for TRD symptoms. We evaluated cell-free culture filtrates (CFs) for phytotoxicity on soybeans, testing for changes in chlorophyll …

Palynology And Paleoclimatology Of The Chicxulub Impact Crater In The Early Paleogene, Vann Smith

LSU Doctoral Dissertations

At the end of the Cretaceous Period, a large bolide impacted the Earth and formed the Chicxulub impact crater in the Yucatán Peninsula, Mexico. In 2016, International Ocean Discovery Program (IODP) Expedition 364 Site M0077 drilled into the buried peak ring of the crater, recovering a marine Paleocene to early Eocene post-impact section deposited on top of the impact breccia. Palynological analysis of 195 samples from the post-impact section has yielded the first pre-Holocene vegetational record from inside the Chicxulub impact crater and the first palynological record of the recovery of life following the end-Cretaceous mass extinction from inside the …

Degumming Of Hemp Fibers Using Combined Microwave Energy And Deep Eutectic Solvent, Bulbul Ahmed

LSU Master's Theses

Hemp is considered as one of the sustainable agricultural fiber materials. Degumming or surface modification of hemp bast is needed to produce single fibers for ensuing textile and industrial applications. The traditional degumming process necessitates a high amount of alkali, which causes detrimental environmental pollution. This study offers a new method to degum hemp fibers with reduced use of harmful alkali and precious water resources. In this work, hemp bast fibers were degummed by using combined microwave energy and deep eutectic solvent (DES). The properties of hemp fibers manufactured by this method were investigated and compared with the traditional alkali …

Effects Of Plant Spacing Variability And Non-Uniform Emergence On Corn Yield, Justin Dufour

LSU Master's Theses

Plant spacing variability and non-uniform emergence in corn (Zea mays L.) is not uncommon in Louisiana corn fields. Variation in planting depth, non-uniform surface crop residue distribution in no-tillage systems, microsite variation in the seed bed condition, and seed vigor are major factors responsible for non-uniform emergence. Also, planters with low precision in seed placement and careless planting operations can cause non-uniform spacing. Two studies were conducted to quantify the effects of plant spacing variability and non-uniform emergence on grain yield in corn. Six plant spacing treatments at 47,770 plants ha^-1 were evaluated. Uniform spacing, seed skip, double …

Evaluation Of Cool-Season Annuals Effect On Soil Health In Warm-Season Perennial Pastures In Southestern Us., Paola C. Muela Negrete

LSU Master's Theses

Perennial grass crops represent approximately 8 million hectares of the land area of the humid lower southeastern United States. These forage crops receive high rates of fertilizer, especially nitrogen (N), and near monoculture remains have often been treated with repeated applications of herbicides. Pasture management is crucial to improve soil properties in pasturelands. Common pasture management practices include introducing cool-season multispecies in warm-season pasture systems and forage harvest frequency of pasture systems. It is known that cool-season multispecies in warm-season pasture systems ensure cattle feeding during winter season and have beneficial effects on soil microbial biomass, soil organic matter (SOM), …

Effects Of Wetland Management And Associated Abiotic Factors On Rare Plant Communities Of Spring-Fed Arid Wetlands, Antonio Cantu De Leija

LSU Master's Theses

Spring-fed arid wetlands support high biological productivity and are hotspots for endemism and distribution of rare plants, making them areas of high conservation value. These systems are driven by complex interactions among groundwater discharge and the geomorphic and climatic features of the setting, which provide gradients of edaphic conditions, particularly soil moisture and salinity that influence the presence and abundance of rare plant communities. However, spring-fed arid wetlands are at particular risk of increases in salinity and drier hydrological regimes due to anthropogenic activities. Such alterations to abiotic conditions may jeopardize the distribution and abundance of rare plants by exceeding …

Understanding Potassium Toxicity Stress Responses Of The Extremophyte Schrenkiella Parvula Using Systems Biology Approaches, Pramod Pantha

LSU Doctoral Dissertations

Schrenkiella parvula is an extremophyte model closely related to Arabidopsis thaliana and Brassica crops. Its natural habitat includes shores of saline lakes in the Irano-Turanian region. It has adapted to grow in soils rich in multiple salts including Na⁺ and K⁺. I have investigated the genetic basis for high K⁺ tolerance in plants using S. parvula as a stress tolerant model compared to the premier plant model, Arabidopsis thaliana which is highly sensitive to salt stresses using physiological, ionomic, transcriptomic, and metabolomic approaches. Under high K⁺ stress, root system architecture changes significantly compared to control …

Characterization Of Resistance To Two Crambid Stem Borers Among Louisiana Sugarcane Cultivars, Leonardo D. Salgado

LSU Master's Theses

Cultivar resistance is a key management strategy for the stem borer complex (Lepidoptera: Crambidae) in Louisiana sugarcane, but mechanisms of resistance are not well understood. This research evaluated the potential mechanisms of cultivar resistance to Diatraea saccharalis and Eoreuma loftini among commercial sugarcane cultivars and experimental clones through a series of field screenings, greenhouse trials, and diet incorporation assays. The stem borer resistant standard HoCP 85-845 and cultivar L 01-299 were among the cultivars with the lowest borer injury levels in both field and greenhouse trials. Cultivars HoCP 00-950, L 12-201, and HoCP 14-885 were among the most heavily injured …

Isolation Of Foliar Fungi From Roseau Cane (Phragmites Australis) In Coastal Louisiana, David M. Galo Espinal

LSU Master's Theses

Roseau cane (Phragmites australis) is a wild plant with an extensive root system that is useful in areas vulnerable to soil erosion. In Louisiana, this plant plays an important role protecting the coastal infrastructure of the lower Mississippi River delta (MRD). Currently, P. australis growing in the MRD is being affected by a die-off, which has been associated with several biotic and abiotic factors.

Plant pathogenic fungi is a biotic factor that negatively affect plant growth. Therefore, foliar fungi were isolated from plants growing in one die-off affected area (MRD) and two non-affected areas (Pecan Island and Manchac) …

The Effect Of Fallow Season Cover Crops On Nutrient Cycling And Soil Health In Row Crop Production In The Mid-South, Kritsanee Iamjud

LSU Doctoral Dissertations

The reliance on conventional cropping has profoundly impacted agricultural sustainability and resulted in soil degradation. Winter cover crops can preserve the soil surface, recycle soil nutrients, and improve soil health. Hence, the role of cover crops in Louisiana row-crop production was examined in small-scale plots and large-scale on-farm studies at three sites in Northeast Louisiana from 2017 to 2020. Additionally, mixed cover crops degradation and nutrient release were evaluated at Macon Ridge and Dean Lee sites to determine the optimum time of nutrient availability after cover crop termination. The small-scale results showed that integrating cover crops for corn (Zea …

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, …

Zein And Lignin-Based Nanoparticles As Delivery Systems: Pesticide Release And Nanoparticle Health Impact On Soybean Plants, Fallon Polette Salinas Gonzalez

LSU Doctoral Dissertations

This research examined the effect of biodegradable, polymeric, lignin-based nanoparticles (LNPs, 113.8±3.4, negatively charged) and zein nanoparticles (ZNP, 141.6±3.9, positively charged) on soybean plant health. The LNPs were synthesized from lignin, covalently linked to poly(lactic-co-glycolic) acid by emulsion evaporation. ZNPs were synthesized by nanoprecipitation. Soybeans grown hydroponically were treated with three concentrations (0.02, 0.2, and 2 mg/ml) of NPs at 28 days after germination. The effect of ZNPs and LNPs on plant health was determined through analysis of root and stem length, chlorophyll concentration, dry biomass of roots and stem, as well as carbon, nitrogen, and micronutrient absorption after 1, …

Resistance To Aflatoxin Accumulation In Maize Mediated By Host-Induced Gene Silencing Of Aspergillus Flavus Alkaline Protease And O-Methyltransferase-A Genes, Olanike Omotola Omolehin

LSU Doctoral Dissertations

Aspergillus flavus is a soil-borne fungal pathogen that infects maize and produces aflatoxins. In the current study, portions of the alkaline protease (alk) and the O-methyl transferase (omtA) genes, which are key in A. flavus virulence and aflatoxin biosynthesis, respectively, were targeted for suppression through an RNAi (RNA interference) approach known as Host-Induced Gene Silencing (HIGS). Separate RNAi vectors were designed to carry regions of the alk and omtA gene fragments (Alk-RNAi and OmtA-RNAi) and introduced into B104 maize zygotic embryos. Eight and six transformation events were positive for the alk and omtA transgene, respectively. …