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Halosulfuron Plus Prosulfuron And Propanil Interactions For Weed Control In Louisiana Rice Production, John A. Williams Mar 2024

Halosulfuron Plus Prosulfuron And Propanil Interactions For Weed Control In Louisiana Rice Production, John A. Williams

LSU Master's Theses

A greenhouse study was conducted on November 18, and December 2, 2020 at Louisiana State University in Baton Rouge, Louisiana to evaluate the interaction between a pre-packaged mixture of halosulfuron plus prosulfuron mixed with propanil for alligatorweed control. Antagonism occurred when halosulfuron plus prosulfuron at 55 g ha-1 was mixed with propanil at 2,242 g ha-1 at all evaluation dates and antagonism was also observed with halosulfuron plus prosulfuron at 83 g ha-1 mixed with propanil at 2,242 g ha-1 at all evaluation dates except 14 DAT with observed controls of 69 to 77% compared with expected controls of 94 …


The Ecological Responses To Hydroperiod Of Wetland Plant Species Determined By Manipulated Soil Surface Elevation (Marsh Organs), Brandon Wolff Jan 2024

The Ecological Responses To Hydroperiod Of Wetland Plant Species Determined By Manipulated Soil Surface Elevation (Marsh Organs), Brandon Wolff

LSU Master's Theses

As sea level rise, subsidence, and abandonment of natural deltaic processes due to a highly engineered Mississippi River continue to threaten Louisiana’s coastal wetlands, the need for a system-wide understanding of natural wetland land-building and preservation processes has never been greater. A key component of any wetland is the ever-changing water environment that periodically floods and dries the marsh platforms. The flooding depth, duration, and frequency, known as the hydroperiod, along with salinity and soil fertility are key determining factors of vegetation and marsh types at a particular location. Different types of vegetation will have different growth characteristics such as …


Machine Learning-Based Soybean Yield Prediction And Optimizing Lidar-Mounted Uav Efficiency, Leticia Santos Jan 2024

Machine Learning-Based Soybean Yield Prediction And Optimizing Lidar-Mounted Uav Efficiency, Leticia Santos

LSU Master's Theses

The first chapter of this thesis explores the predictive capabilities of random forests algorithm on datasets obtained from field plot experiments on crop management systems in soybean. Furthermore, the chapter presents a complementary analysis of model performance according to dataset sizes and two techniques on how to impute and deal with missing data. Random forests are being compared with standard statistical techniques such as linear regression on a well-structured, information-rich agronomic experiment. The key findings of this chapter includes the best hyperparameters adjustment and the identification of the dataset threshold for optimal algorithms performance. The second chapter has a research …


Containerized Satsuma Mandarin Production Under Protective Screens As A Management Strategy, Anna Timmerman Nov 2023

Containerized Satsuma Mandarin Production Under Protective Screens As A Management Strategy, Anna Timmerman

LSU Master's Theses

Many of the world’s citrus growing regions are experiencing challenges related to citrus greening, also known as Huanglongbing (HLB) caused by the presumed bacterial agent Candidatus Liberibacter spp. HLB is vectored by the Asian citrus psyllid (Diaphorina citri) and through propagation of infected citrus material. HLB impacts tree health as well as fruit development, ripening, and quality of the resulting citrus fruit, often leading to an unmarketable product. Producers are growing citrus in high density orchards underneath protective screening material that excludes the Asian citrus psyllid, preventing new HLB infections. Four ultra-high containerized tree spacings of 2 feet …


Effects Of Fertigation Versus Palletized Fertilizer On Height And Caliper Growth In Oaks, Zachary M. Davis Oct 2023

Effects Of Fertigation Versus Palletized Fertilizer On Height And Caliper Growth In Oaks, Zachary M. Davis

LSU Master's Theses

The Covid-19 pandemic and ensuing lockdowns led to an increase in revenue and production for green industry products in early 2020. In Study 1. an evaluation of fertigation (liquid feed, quick release) and controlled release fertilizers (CRFs, slow release) were applied to container-grown (7 gallon) live oak (Quercus virginiana) and Nutall oak (Quercus nuttallii) trees (100% Liquid feed, 0% CRF, 67% Liquid feed, 33% CRF, 33% Liquid feed, 67% CRF, 100% Liquid feed, 0% CRF). Live oak trees fertilized with CRFs had increased stem calipers (>30%). Nuttall stem caliper and height were significantly increased by …


Black Experiences With Community Gardening In Southeast Louisiana, Kiarah Craft Aug 2023

Black Experiences With Community Gardening In Southeast Louisiana, Kiarah Craft

LSU Master's Theses

Community gardens have been rising in popularity over the past few years (Mayers, 2023). In response to the COVID-19 pandemic, many people across the United States have decided that it is crucial to grow their own food and develop sustainability within their community. Historically, Black communities have been underserved and ignored, especially in relation to food security and community safety (White, 2019, Penniman, 2018). The purpose of this study was to collect information about the effects of community-based gardening programs on Black people in Southeast Louisiana. Additionally, the researcher would like to gain knowledge regarding the reasons that Black people …


Molecular Identification Of Oomycete Species Associated With Woody Plants In Louisiana And Survey Of Oomycete Species Associated With Live Oak Trees Planted On The Louisiana State University Campus, Hamilton Crockett Jul 2023

Molecular Identification Of Oomycete Species Associated With Woody Plants In Louisiana And Survey Of Oomycete Species Associated With Live Oak Trees Planted On The Louisiana State University Campus, Hamilton Crockett

LSU Master's Theses

Three Oomycetes genera, Phytophthora, Phytopythium and Pythium, contain many important plant pathogens. Historically, Phytophthora infestans, responsible for the great Irish potato famine, and Phytophthora ramorum, causal agent of sudden oak death disease, are the two better-known high impact pathogens. The LSU AgCenter Plant Diagnostic Center (PDC) has been isolating putative Phytophthora and related species from combined root and soil samples collected from various woody ornamentals and trees for over a decade. In August of 2016, Louisiana received torrential rains, which resulted in historic flooding in several southern parishes. During subsequent years, the PDC staff isolated a …


Evaluating Form And Function Of Groundcovers And Their Environmental Impacts In Louisiana Landscapes, Thomas Maxwell Mckeown Apr 2023

Evaluating Form And Function Of Groundcovers And Their Environmental Impacts In Louisiana Landscapes, Thomas Maxwell Mckeown

LSU Master's Theses

Increasing environmental concerns are encouraging the adoption of sustainable landscapes that have environmental, social, and financial benefits. Ornamental groundcover systems are touted as sustainable landscape features due to the associated decreased demand of water, fertilizer, pesticide, and maintenance; however, limited research exists on soil property effects, planting density, weed density, or consumer preferences of groundcovers. This study was aimed to gain a more thorough understanding of ornamental groundcovers systems and their environmental impacts. The effects of groundcover growth habit (matting; bunching) and irrigation delivery (micro spray; overhead) on soil temperature, volumetric water content (VWC), and electric conductivity (EC) along with …


Louisiana Resident Perceptions On Invasive Aquatic Plant Species And Their Management, Anna Ribbeck Mar 2023

Louisiana Resident Perceptions On Invasive Aquatic Plant Species And Their Management, Anna Ribbeck

LSU Master's Theses

Determining the public perception of invasive species in Louisiana is an important tool to help shape and develop future management decisions, educational material and ultimately public policy. Therefore, the primary purpose of this study was to determine the perceptions of adult Louisiana residents regarding invasive aquatic plant species and their management. An online survey was used to collect data on registered Louisiana residential boaters’ perceptions towards invasive aquatic plants and their management. A postcard with a quick response code leading to the survey was mailed to 6,000 randomly selected Louisiana registered residential boaters. Of the 230 Louisiana registered boaters that …


Effect Od Different Sources And Application Rates Of Sulfur On Corn And Soybean Production Systems In Louisiana, Diego Mayorga Valladares Jan 2023

Effect Od Different Sources And Application Rates Of Sulfur On Corn And Soybean Production Systems In Louisiana, Diego Mayorga Valladares

LSU Master's Theses

Sulfur (S) is a structural component of amino acids such as cysteine and methionine and is involved in important functions within the plant like photosynthesis, carbon and nitrogen metabolism, protein synthesis of oils, and detoxification mechanisms. Sulfur deficiency in crops has intensified around the world. Some of the reasons are improvement in controlling SO2 emissions from industries, growing usage of high analysis S-free fertilizers and augmented cropping intensity. Sulfur fertilization has become an important factor in crop production systems and fertilization guidelines for S need to be up-to-date to improve use efficiency and compensate for rising prices of fertilizers. …


Population Genomic Characterization Of Cercospora Janseana On Rice In The Southern United States, Jacob Searight Nov 2022

Population Genomic Characterization Of Cercospora Janseana On Rice In The Southern United States, Jacob Searight

LSU Master's Theses

Cercospora janseana is the causative agent of narrow brown leaf spot (NBLS). Effort had been undertaken since the 1940’s to control this disease through resistance breeding in the Southern United States. However, a severe epidemic of NBLS in 2006 inspired renewed focus on managing this disease. One tool for managing this disease has been identified among resistant cultivars, the CRSP-2.1 resistance locus to NBLS. One thing limiting the investment and deployment of CRSP-2.1, and other unknown resistance genes, is the historical observation that resistance to NBLS rapidly breaks-down in the field. Together, the rapid breakdown of resistance to NBLS …


Paraquat-Resistant Italian Ryegrass (Lolium Multiflorum) Confirmed In Louisiana, Alphonse B. Coco Iii Nov 2022

Paraquat-Resistant Italian Ryegrass (Lolium Multiflorum) Confirmed In Louisiana, Alphonse B. Coco Iii

LSU Master's Theses

Paraquat is the only herbicide labeled for postemergence control of Italian ryegrass in sugarcane. In 2017, sugarcane farmers in Louisiana reported Italian ryegrass control failures with paraquat applications. Seeds were collected from sugarcane fields in White Castle, St. Gabriel, and Bunkie, Louisiana where control was not achieved (reduced susceptibility). Additionally, Italian ryegrass seeds were collected from a sugarcane field in Welcome, LA with a history of paraquat use and with no reported control issues (susceptible population). A dose-response study was conducted at the Louisiana State University Agricultural Center’s Sugar Research Station in February 2021 and was repeated in November 2021. …


Effects Of Pesticides On Red Rot Of Sugarcane, Kezia Cristina Da Silva Reis Aug 2022

Effects Of Pesticides On Red Rot Of Sugarcane, Kezia Cristina Da Silva Reis

LSU Master's Theses

Red rot disease of sugarcane, caused by Colletotrichum falcatum, can be an important constraint to crop production. In Louisiana, red rot primarily affects seed-cane and is more severe when billets (stalk sections) are planted rather than whole-stalks. At planting application of seed-treatment chemicals, particularly a combination of fungicide and thiamethoxam insecticide, has improved stand establishment and increased yields in billet plantings in Louisiana. However, information has been lacking on the effect of the treatments on disease development. Greenhouse experiments were conducted in 2020 and 2021 to evaluate stalk rot symptom severity and initial plant growth for billets dip-treated with …


Application Of Organic Fertilizers For Lawn Establishment And Maintenance In Louisiana, Matthew Lambert Aug 2022

Application Of Organic Fertilizers For Lawn Establishment And Maintenance In Louisiana, Matthew Lambert

LSU Master's Theses

Landscape contractors are increasingly interested in organic products for Louisiana's residential and commercial turfgrass areas. However, the use, motivations, and barriers to adopting organic practices in the commercial turfgrass and landscape industry are undocumented. A survey with Louisiana Turfgrass Association (LTA) members to gauge their perceptions on current and future use of organic products in Louisiana was performed; and a field trial was conducted to evaluate organic fertilizers during turfgrass establishment. Substantial majorities of turfgrass professionals are currently applying organic fertilizers and believe organic product use will increase due to consumer demands, potential governmental regulation, and the belief that they …


Identifying The Components Of A Hemp (Cannabis Sativa L.) (Rosales: Cannabaceae) Integrated Pest Management Program In Louisiana, Nathan C. Arey Jul 2022

Identifying The Components Of A Hemp (Cannabis Sativa L.) (Rosales: Cannabaceae) Integrated Pest Management Program In Louisiana, Nathan C. Arey

LSU Master's Theses

Hemp, Cannabis sativa (L.) (Rosales: Cannabaceae), is defined as a plant in the genus Cannabis with a delta-9 3 tetrahydrocannabinol (THC) concentration of not more than 0.3% on a dry weight basis. Domestic acreage of this crop has increased in response to the ratification of the Agricultural Act of 2014 and the Agricultural Improvement Act of 2018. In 2021, 21,915 hectares of hemp were planted in the United States with a production value of $712 million. There is a current lack of literature on insect related research in this reemerging crop system in the state of Louisiana. Therefore, this present …


Screening Soybean Cultivars For Resistance To Aerial Blight Caused By Rhizoctonia Solani Ag1-Ia, Kensy D. Rodriguez-Herrera Jul 2022

Screening Soybean Cultivars For Resistance To Aerial Blight Caused By Rhizoctonia Solani Ag1-Ia, Kensy D. Rodriguez-Herrera

LSU Master's Theses

Aerial blight, caused by the fungus Rhizoctonia solani AG1-IA, is an economically important soybean disease in the mid-South. The same pathogen also infects other crops commonly rotated with soybeans like rice, corn, and grain sorghum. Rhizoctonia solani AG1-IA is difficult to manage because of its soilborne nature and the production of long-term survival structures, sclerotia. Management has relied on fungicide applications during the season. Still, there is an increasing prevalence of resistance to commonly used strobilurin fungicides and an urgent need to identify soybean cultivars resistant to aerial blight. Since the patchy distribution of the pathogen complicates field cultivar screening, …


Cover Cropping: Sensor-Based Estimations Of Biomass Yield And Nutrient Uptake And Its Impact On Sugarcane Productivity, Hector H. Fajardo Duran Jul 2022

Cover Cropping: Sensor-Based Estimations Of Biomass Yield And Nutrient Uptake And Its Impact On Sugarcane Productivity, Hector H. Fajardo Duran

LSU Master's Theses

Sugarcane in Louisiana can be harvested for up to three years from one planting. Soil cultivation along sides of established beds is done for weed control and improve fertilizer use efficiency which increases the risk of soil degradation and yield decline. Planting cover crops (CC) is a soil conservation practice and an effective strategy to improve soil health and nutrient recycling. Limited work has been done on remote sensor-based evaluation of the potential nutrient benefits from cover crops and its effect on nutrient cycling on sugarcane systems. This study was conducted to evaluate the effect of two planting methods (broadcast …


Evaluating The Effect Of Coated Urea And Urea-Ammonium-Nitrate Solution On Cane Tonnage, Sugar Yield, And Leaf-Soil Nitrogen Content Under Louisiana Sugarcane Production System, Hector J. Mendoza Lagos May 2022

Evaluating The Effect Of Coated Urea And Urea-Ammonium-Nitrate Solution On Cane Tonnage, Sugar Yield, And Leaf-Soil Nitrogen Content Under Louisiana Sugarcane Production System, Hector J. Mendoza Lagos

LSU Master's Theses

Nitrogen (N) is a crucial nutrient for proper plant growth and development. N deficiency results in poor tillering and thin, short internode stem production for sugarcane production, thus resulting in low cane tonnage. Therefore, proper N fertilizer management is essential for a sustainable sugarcane production system. This research was conducted at the LSU AgCenter Sugar Research Station in St. Gabriel, LA, from 2019 to 2020 at three Sites (Site 1, 2, and 3). The treatments consisted of different N rates (0, 45, 90, and 135 kg N ha-1) and sources (urea-ammonium-nitrate solution [UAN]-32%, 30-day [Coated Urea 1], 45-day …


Examination Of Pre-Emergence Control Of Johnsongrass In Sugarcane Seedlings, Carleton Baucum Apr 2022

Examination Of Pre-Emergence Control Of Johnsongrass In Sugarcane Seedlings, Carleton Baucum

LSU Master's Theses

Sugarcane is susceptible to many diseases and insect pests; therefore, to maintain high sugar yield new varieties must be developed. Producing new varieties contributes to the overall crop success through enhanced yield, insect and/or disease resistance, cold tolerance, and ratooning ability. However, unlike conventional sugarcane, which is vegetatively propagated, new sugarcane varieties are produced from true seed. These seedlings are more susceptible to herbicidal injury and weed competition than conventional sugarcane. For sugarcane seedlings to succeed, weeds must be controlled therefore, the most effective herbicide program with regards to seedling safety must be implemented. The objectives of this research were …


Marker-Trait Association Mapping Of Sorghum Mosaic Virus Resistance In Sugarcane, Chenie Zamora Apr 2022

Marker-Trait Association Mapping Of Sorghum Mosaic Virus Resistance In Sugarcane, Chenie Zamora

LSU Master's Theses

Mosaic is a potentially devastating disease of sugarcane that had severe economic impact on Louisiana’s sugarcane industry in the 1920’s and has caused periodic problems ever since. The disease is vectored by migrating aphids that transmit Sugarcane mosaic virus (SCMV) and Sorghum mosaic virus (SrMV) in a non-persistent manner. Mosaic in Louisiana is currently caused by strains of SrMV. Mosaic has been controlled primarily by developing resistant cultivars. Recently, mosaic was detected in some near-commercial clones in the cultivar selection program. This prompted extensive screening of breeding program parent populations that detected infiltration of susceptibility and revealed the need for …


Re-Evaluation Of Late Season Action Thresholds And The Effect Of Seed Treatments On Early Season Colonization Of Threecornered Alfalfa Hopper, Spissistilus Festinus (Say), In Louisiana Soybean, Glycine Max (L) Merr, Tyler Ray Tagle Musgrove Apr 2022

Re-Evaluation Of Late Season Action Thresholds And The Effect Of Seed Treatments On Early Season Colonization Of Threecornered Alfalfa Hopper, Spissistilus Festinus (Say), In Louisiana Soybean, Glycine Max (L) Merr, Tyler Ray Tagle Musgrove

LSU Master's Theses

Soybean, Glycine max (L.) Merr, is considered the most economically important oil and feed crop in the US and is grown on nearly 35,000,000 ha on an annual basis. Factors that limit yield include weed pressure, disease infection, and of particular interest to entomologists, insect herbivory. Soybean is targeted by a range of above and below ground pests which are primarily controlled by insecticides. Neonicotinoids are a recently popularized insecticide class that when applied as a seed treatment, can provide protection from early season pests. The most economically significant early season pest is threecornered alfalfa hopper, Spissistilus festinus (Say), whose …


Development Of Alternative Materials And Strategies For Enhancing Rice Health, Jobelle S. Bruno Apr 2022

Development Of Alternative Materials And Strategies For Enhancing Rice Health, Jobelle S. Bruno

LSU Master's Theses

Bacterial panicle blight (BPB) and sheath blight (ShB) are economically important diseases of rice (Oryza sativa) in Louisiana and other rice-growing regions around the world. However, there are challenges in the current disease management practices for these diseases. Thus, the main goal of this study is to identify new materials and their application methods that effectively suppress BPB and ShB. To achieve this goal, we evaluated the effect of various materials and application methods against the rice diseases. In 2020 and 2021, various materials, such as ascorbic acid (AA), N-acetylcysteine, chitosan, the avirulent strain of Burkholderia glumae 257sh-1 …


Genetic Characterization Of Resistance To Bacterial Panicle Blight And Sheath Blight In Rice Using Qtl Linkage Analysis And Qtl-Seq, John Christian E. Ontoy Apr 2022

Genetic Characterization Of Resistance To Bacterial Panicle Blight And Sheath Blight In Rice Using Qtl Linkage Analysis And Qtl-Seq, John Christian E. Ontoy

LSU Master's Theses

Bacterial panicle blight (BPB) and sheath blight (SB) are major diseases of rice causing significant yield reduction in conducive conditions. Few cultivars have shown reliable resistance to these diseases. In this study, a recombinant inbred line (RIL) population derived from the U.S. cultivars Jupiter (moderately resistant) and Trenasse (susceptible) was investigated to identify genomic regions associated with BPB and SB resistance. Phenotypes in BPB and SB, as well as days to heading (DH), of the RIL population were evaluated in the field. DH was found to be correlated to BPB and SB diseases. BPB was also positively correlated to SB. …


Hemp Microgreen Mineral Content, Cannabinoids, Total Phenolics, And Antioxidants, Cheston T. Schayot Nov 2021

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 Nov 2021

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 …


Corn Nitrogen Management Under Different Tillage Systems, Akshara Athelly Nov 2021

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 ( …


Using Uav Technology Paired With Multispectral Cameras To Assess Crown Rust Epidemics In Oats, Turner A. Graham Nov 2021

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 Nov 2021

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 …


Influence Of Planting Date, Maturity Group, Harvest Aids And Fungicide Application On Soybean (Glycine Max (L.) Seed Quality, Ana Priscila Campos Sep 2021

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 Aug 2021

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 …