Life Sciences Commons^™

Impact Of New Technologies On Weed Control In Louisiana Rice Production, David C. Walker

LSU Doctoral Dissertations

Field studies were conducted in 2018-2021 at the LSU Agricultural Center’s H.R. Caffey Rice Research Station (RRS) near Crowley, LA, and the Dean Lee Research and Extension Center (DLREC) near Alexandria, LA to evaluate off-target florpyrauxifen movement on soybean. Soybean was treated with florpyrauxifen at the V4-V5 or R1-R2 growth stages. Soybean injury was evaluated at 1, 7, 14, and 28 days after treatment (DAT) and soybean plant height (cm) was recorded at 7, 14, and 28 DAT. At soybean maturity, yield and individual yield components were subjected to regression analysis to describe the relationship between florpyrauxifen rate and soybean …

Characterization Of Genetic Sources Associated With Restorability And Seed Dimension In Arkansas Restorer Rice Lines, Ozgur Azapoglu

Graduate Theses and Dissertations

Hybrid rice (Oryza sativa L.) breeding offers a significant opportunity to enhance rice production, and the cultivation of a male sterile line is the most important factor in the success of cross-breeding. One of the key elements of hybrid rice production is to develop a restorer line that is assigned as the male parent. The restorer lines provide viable pollen for fertilization of the male sterile plant due to the presence of a restorer gene (Rf) in their genomes. Any superior restorer line applied to hybrid rice production must contain genes/quantitative trait loci (QTL) associated with the desirable agronomic traits …

Mining For Biological Control Agents Against B. Glumae, The Causal Agent Of Bacterial Panicle Blight Of Rice., Katherine Anne Wilkinson

Graduate Theses and Dissertations

Burkholderia glumae is the causal agent of the emerging disease, Bacterial Panicle Blight of rice, a serious disease that can significantly decrease yield and poses a threat to rice production worldwide. This thesis is concerned with searching for a biological control agent to control this disease. Plant associated microbes are a good source of beneficial bacteria which can be exploited for use as a biological control agent. It is possible that the microbiomes of cultivars which are known to be more resistant to plant pathogens may contain more microbes which inhibit those pathogens and therefore could be used as biological …

Strategies To Overcome Antagonism Of Quizalofop-P-Ethyl When Applied In Mixture With Other Herbicides, Lucas C. Webster

LSU Master's Theses

A field study was conducted in 2017 and 2018 at the LSU Agricultural Center H. Rouse Caffey Rice Research Station (RRS) near Crowley, LA. to evaluate the influence of different adjuvants in overcoming the antagonism of quizalofop when mixed with bispyribac in Louisiana rice production. The antagonism of quizalofop mixed with bispyribac plus HCOC at 14 DAIT was overcome with a neutral interaction observed at 28 DAIT for barnyardgrass control with an observed control of 91%, compared with an expected control of 97%. The addition of COC, SNS or HCOC into a mixture of quizalofop plus bispyribac provided synergistic or …

The Tripartite Interaction Between Arbuscular Mycorrhizal Fungi, Rice, And Insects, Lina Bernaola Alvarado

LSU Doctoral Dissertations

Losses caused by pests remain an important limitation to achieving high rice yields in the United States. Arbuscular mycorrhizal fungi (AM fungi) are able to modify plant physiology by increasing plant growth or inducing defense responses against insect herbivores. However, studies of the role of AM fungi in agroecological factors, including natural occurrence, plant resistance, soil dependency, and plant tolerance, with specific regards to pests that feed on rice plants have not been conducted before. A three-year study revealed natural occurring colonization by AM fungi on rice roots sampled in four rice-producing areas in the southern United States. Overall, rice-AM …

Evaluation Of Rice Stink Bug, Oebalus Pugnax (F.), Damage And Monitoring Techniques In Rice, Oryza Sativa L., And Grain Sorghum, Sorghum Bicolor (L.), Aaron Joseph Cato

Graduate Theses and Dissertations

Rice stink bug, Oebalus pugnax (F.), is a serious pest of headed rice, Oryza sativa L. and an occasional pest of heading grain sorghum in the Mid-south. Work from this dissertation focuses on resolving gaps in and knowledge of rice stink bug sampling and management, and attempts to create a basis for rice stink bug damage assessment in future studies.

Field experiments were conducted from 2016-2018 to asses variation in sweep net sampling by observing producers, researchers, extension personnel, consultants and their workers. Large levels of variation were found in sweep lengths between observed sweepers and reliability of smaller sweep …

The Effect Of Preflood Nitrogen And Flood Establishment Timing On Rice Development, Nitrogen Uptake And Grain Yield, Tyler Richmond

Graduate Theses and Dissertations

Urea-N fertilizer is typically applied at the 5-leaf stage to rice (Oryza sativa L.) grown in a dry-seeded, delayed-flood production system. How long the preflood-N can be delayed without adverse effects on yield potential is poorly understood. The research objective was to determine the effects of preflood-N application and flood establishment timing on aboveground-N content, 50% heading, yield components, and grain yield. Trials were established on silt loam soils at the Pine Tree Research Station (PTRS) and Rice Research and Extension Center (RREC) during 2015 and 2016. Urea-N was applied at 0, 45, 90, 135, and 180 kg N ha-1 …

Disaggregating The Effect Of Drought And Heat Stress During Flowering On Spikelet Fertility In Rice, Lisa Straussberger

Graduate Theses and Dissertations

Due to rice’s wide geographic distribution, extending from 50°N to 35°S, rice is

forecasted to be the most vulnerable crop to warming global climates. Previous studies have

predicted lower rice yields and increasing rice yield variability due to higher frequencies of heat

stress events, and a higher variability in precipitation patterns due to global warming. As such,

understanding the effects of drought and heat stress intensity and frequency on rice yields is of

upmost importance to feeding the growing global population.

Given that drought and high-temperature stress often occur together, it is essential to

disaggregate the two individual stressors and …

The Role Of Oswrky71 And Its Interacting Proteins In Seed Germination And Early Growth Of Cereal Grains, Margaret Ja Shin

UNLV Theses, Dissertations, Professional Papers, and Capstones

During seed germination and early seedling growth, complex molecular and physiological events occur in rice (Oryza sativa) and other cereal grains. As the seed transitions to vegetative tissue, it responds to both favorable and unfavorable environmental conditions and is vulnerable to attack by predation and disease. Although seeds are relatively small and tender in size, extensive and sophisticated molecular networks enables the immobile seed to grow, survive and adapt in its environment. One of the networks I am interested in is in the crosstalk between the gibberellin (GA) and abscisic acid (ABA) signaling pathways. These pathways are interesting because they …

False Smut Of Rice: Histological Analysis Of Infection, Liem Thi Thanh Nguyen

Graduate Theses and Dissertations

False smut of rice, caused by Ustilaginoidea virens (Cooke) Takahashi (Teleomorph: Villosiclava virens), has become a common disease in most major rice growing regions throughout the world. Considerable confusion exists regarding the infection process and the disease cycle. Therefore, a clearer understanding of pathogenesis caused by Ustilaginoidea virens is critical for future efforts to develop genetic and chemical tools to manage false smut in Arkansas and other regions of the world. The overall goal of this research was to clarify the infection process underlying false smut, with emphasis on comparing and contrasting the histological basis of root and foliar infections. …