Agronomy and Crop Sciences Commons^™

Evaluation Of Biological And Chemical Seed Treatments For Management Of Rice Diseases, Sherif Adam Sharfadine

Graduate Theses and Dissertations

Rice is the primary staple for more than half of the global population and is the second most important cereal worldwide. In the US, rice is primarily grown in the southern states, with Arkansas leading production and responsible for 47% of the total rice production in the country. Diseases cause significant yield losses in rice. Sheath blight, rice blast and bacterial panicle blight are the main diseases in rice and cause significant yield losses. Sheath blight alone could cause up 50% yield loss in heavily damaged fields with highly susceptible cultivars. Additionally, rice seed and seedling diseases primarily caused by …

Successful Creation Of Seedless (Sterile) Leucaena Germplasm Developed From Interspecific Hybridisation For Use As Forage, Daniel Real, Clinton K. Revell Dr, Yong Han, Chengdao Li, Marieclaire Castello, C. D. Bailey

Grain and Other Field Crops Research Articles

Context: The legume shrub/tree leucaena (Leucaena leucocephala (Lam.) de Wit.) is highly regarded as a cattle fodder, although it is considered an environmental weed in many parts of Australia.

Aims: We investigated the feasibility of developing a forage variety of triploid leucaena through interspecific hybridisation that is sterile (without seeds) as a strategy to mitigate its weed risk.

Methods: A conventional breeding strategy was used to create triploid hybrids from hand-crosses between tetraploid and diploid species of leucaena. Molecular markers were developed to confirm successful crosses and flow cytometry was used to confirm the ploidy level. The plants are being …

Rice Tolerance To Acetochlor With A Fenclorim Seed Treatment, Tristen H. Avent, Jason K. Norsworthy, Thomas R. Butts, Trenton Roberts, Nicholas R. Bateman

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Rice producers in the United States need effective herbicides to control problematic weeds. Previous research has demonstrated that acetochlor can provide in-season weed control in rice; however, undesirable injury is common. Thus, trials were initiated in 2020 and 2021 to evaluate 1) rice cultivar tolerance to microencapsulated (ME) acetochlor with the use of a fenclorim seed treatment at 2.5 g ai kg⁻¹ of seed; 2) a dose-response of a fenclorim seed treatment with ME acetochlor; and 3) rice tolerance to fenclorim and ME acetochlor under cool, wet conditions. For all trials, acetochlor was applied delayed-preemergence (4 to 7 d …

A Glass Bead Semi-Hydroponic System For Intact Maize Root Exudate Analysis And Phenotyping, Martha G. Lopez-Guerrero, Peng Wang, Felicia Phares, Daniel P. Schachtman, Sophie Alvarez, Karin V. Van Dijk

Department of Agronomy and Horticulture: Faculty Publications

Background: Although there have been numerous studies describing plant growth systems for root exudate collection, a common limitation is that these systems require disruption of the plant root system to facilitate exudate collection. Here, we present a newly designed semi-hydroponic system that uses glass beads as solid support to simulate soil impedance, which combined with drip irrigation, facilitates growth of healthy maize plants, collection and analysis of root exudates, and phenotyping of the roots with minimal growth disturbance or root damage. Results: This system was used to collect root exudates from seven maize genotypes using water or 1 mM CaCl2, …

Nitrogen Management In Rice Under Suboptimal Soil Conditions, Payton Suzanne Rhea

Graduate Theses and Dissertations

In Mid-South rice (Oryza sativa, L.) production, nitrogen (N) fertilizer management for pureline varieties is most often recommended as a single preflood (SPF) or two-way split (2WS) application in a direct-seeded, delayed-flood system. Most of the N fertilizer is typically applied at the four- to six-leaf stage onto dry soil, and the second application, if necessary, into the floodwater during early reproductive growth stages (referred to as midseason). Environmental factors frequently prohibit growers from applying early N fertilizer under optimal dry soil conditions. A study was conducted to determine the best N fertilization management practices to utilize in rice when …

Germination And Early Seedling Growth Attributes Of Rice (Oryza Sativa L.) Cultivars Under Different Salinity (Nacl) Stresses [Research Note], Shahid Hussain, Shuli Liu, Rui Zhang, Yinglong Chen, Altaf Adil, Qigen Dai

The Philippine Agricultural Scientist

This study investigated the impact of different salinity stresses [0, 6.4, 12.8, 19.2, and 25.6 dS/m (NaCl)] on the final germination percentage, speed of germination, germination capacity, shoot and root length, seedling vigor index, and total plant dry weight of ten rice cultivars at germination and early seedling stages. Salinity stress significantly decreased the final germination percentage, speed of germination, germination capacity, shoot and root length, and seedling dry weight in all cultivars, with the most severe effects from level 19.2 and 25.6 dS/m NaCl. Rice cultivars were classified as tolerant, moderately tolerant, moderately susceptible, and susceptible based on reduction …

Insights On The Behavior Of Nano-Copper In The Agroecosystem: Mycorrhizal Associations With Spearmint (Mentha Spicata), Suzanne Annette Apodaca

Open Access Theses & Dissertations

Nanotechnology offers significant potential benefits to our society, including the agriculture sector. With the advancement of nano-enabled agrochemicals towards sustainable and efficient agricultural practices, it is essential to address environmental issues associated with the use of nanoscale materials. The same properties that give promise to applications of nanotechnology in modern agriculture could have unintended consequences on ecosystem dynamics. A point of concern for risk management is the impact of engineered nanomaterials (ENMs) to beneficial microbial communities, which support a variety of ecosystem services.

Use of copper (Cu) products in agriculture are based on their abundance, role as a micronutrient, and …

Flowering Habit And Photoperiodic Flowering Response Of Stevia (Stevia Rebaudiana Bertoni) In The Philippines, Kennilyn May Balbin-De Luna, Bong Salazar

The Philippine Agricultural Scientist

Stevia is a perennial shrub commercially cultivated for the sweet-tasting compounds known as steviol glycosides (SVglys). SVglys are extracted from the green leaves, thus maintenance of vegetative growth is critical in stevia production. This study was conducted to describe the flowering habit and response of potted stevia plants to different photoperiods under Philippine conditions. Photoperiodic treatments (10, 11, 12, 13, and 14 h) were provided using light chambers. Stevia has both terminal and axillary flowering habits. It has five white florets enclosed in a capitulum and exhibits an opposite branching pattern. Results showed that stevia is a facultative short-day plant …

Determination Of Some Seed Characteristics Of False Flax (Camelina Sativa L. Crantz) Genotypes Grown Under Semi-Temperate Conditions, İlhan Subaşı, Yusuf Arslan, Tamer Eryigit, Vahdettin Çiftçi, Mahmut Çamlıca

The Philippine Agricultural Scientist

Camelina is an alternative low-input oil plant grown in marginal areas in Turkey. This study aimed to determine some quality characteristics of 39 camellia genotypes in ecological conditions in Bolu, Turkey. The field experiments were carried out in an augmented design with randomized blocks. In this work, some important properties such as thousand seed weight, oil content, fatty acid composition, and protein ratio were investigated. Results showed that mean data for thousand seed weight, oil ratio, and protein ratio were 0.63 – 1.5 g, 26.69 – 39.17%, and 21.81 – 29.81%, respectively. Considering the oil content of the genotypes used …

Evaluation Of Triticale Lines Compared To Wheat Cultivars In Terms Of Agronomic Traits Using Supervised Learning Methods And Multivariate Statistics, Sara Farokhzadeh, Hossein Shahsavand Hassani

The Philippine Agricultural Scientist

The first man-made cereal grain triticale merges the yield and quality potential of wheat with tolerance of rye against environmental stresses. To find the traits with the greatest impact on the superiority of triticale over wheat, four promising triticale lines and six bread wheat varieties were evaluated in a randomized complete block design (RCBD) with three replications in the field of the Agricultural Research Station of Shiraz University, Iran. Attribute weighting algorithms revealed main leaf width (MLW), grain number per spike (GN/S), spikelet number per spike (SN/S), 1000-grain weight (TGW), plant height (PHT), main leaf length (MLL), and grain yield …

Applying A Material Science Approach To Improve Rice Processing Performance, Michelle Oppong Siaw

Graduate Theses and Dissertations

Rice is typically consumed as whole kernel, which makes the economic value of whole kernels twice that of brokens. Macro-structural defects such as fissures and chalkiness have been recognized to weaken kernel mechanical strength, and thereby increase breakage during milling. However, high percentages of brokens are sometimes recorded even though these defects are controlled prior to milling. It was hypothesized that rice milling characteristics are influenced by endosperm porosity from the structural arrangement of chemical components and by bran thickness and composition. Thus, this study aimed to modify chemical components by applying treatments to alter rice porosity and its associated …

Nitrification Inhibitor, Nitrogen Source, And Herbicide Effects On Soil Nitrogen Transformations And Corn Yield, William Neels

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Nitrogen fertilizer management continue to be challenging due to potential nitrogen losses under variable weather conditions. The objective of this was to evaluate the performance of nitrification inhibitors, nitrogen sources and herbicides on in-season nitrogen availability and agronomy indicators. A two site-year field experiment was conducted in silty clay loam soil in corn phase of the corn-soybean rotation at Central Nebraska. The treatments included three herbicide (no pre-emergence, Acuron, Resicore) and five nitrogen treatments: 1) control, 2) anhydrous ammonia, 3) anhydrous ammonia without nitrification inhibitor, 4) urea with nitrification inhibitors, and 5) urea without nitrification inhibitors. Results indicated that nitrogen …

Addressing Challenges Of Dryland Production Of Sunflowers And Corn In The Semi-Arid High Plains Of Nebraska, Zhan Orazov

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Corn and sunflower are value crops for America. Cultivation of corn and sunflower often vary depending on growing environment. Selecting appropriate planting dates, hybrids and plant density frequently concerns farmers. This concern is understandable because the decision made directly impacts final income. The objectives were to evaluate interaction of corn and sunflower planting dates and hybrid maturity and evaluate interaction of corn flex hybrids and plant density under conditions of western Nebraska. Nine corn hybrids with relative maturity ranging from 86 to 105 days were sown between early May and late June in first and between late April and early …

Deciphering The Genetic Architecture Of Key Female Floral Traits For Hybrid Wheat Seed Production, Juan David Jimenez

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Wheat (Triticum aestivum L.) is a staple cereal that provides 20% of the calories and proteins in human intake (Ray et al., 2013). Global population is projected to increase to 9.7 billion by 2050. Food production must increase by 70% to feed this future population. Wheat production is in crisis due to political and environmental challenges and is projected to decline by 0.8% in 2022 (FAO, 2022). To ensure food security yield genetic gain must increase by around 1.4% annually. Taking advantage of heterosis, hybrid wheat has the potential to boost grain yield. However, hybrid wheat seed production systems …

Micronutrient Concentration Effects On Lettuce Growth And Susceptibility To Pythium, Kalyn M. Helms

Graduate Theses and Dissertations

In hydroponic production waterborne pathogens such as Pythium are ubiquitous and continually threaten a wide range of Controlled Environment Agriculture (CEA) crops in hydroponic production, including but not limited to: lettuce, spinach, basil, arugula, cucumber, tomato, sweet pepper, roses, chrysanthemums, and cannabis (Sutton et al., 2006; Gull, 2002; McGehee and Raudales, 2021; Gillespie, 2020). Despite extensive sanitation measures, disease control in hydroponics is fallible and requires constant surveillance and management to minimize outbreaks (Sutton et al., 2006). A potential disease suppression strategy is to increase micronutrient concentrations within hydroponic systems to naturally strengthen plant defenses against pathogens such as Pythium. …

Comparative Genomics Of Five Valsa Species Gives Insights On Their Pathogenicity Evolution, Guangchao Sun, Shichang Xie, Lin Tang, Chao Zhao, Mian Zhang, Lili Huang

Department of Agronomy and Horticulture: Faculty Publications

Valsa is a genus of ascomycetes within the Valsaceae family. This family includes many wood destructive pathogens such as the well known Valsa mali and Valsa pyri which cause canker diseases in fruit trees and threaten the global fruit production. Lack of genomic information of this family is impeding our understandings about their evolution and genetic basis of their pathogenicity divergence. Here, we report genome assemblies of Valsa malicola, Valsa persoonii, and Valsa sordida which represent close relatives of Valsa mali and Valsa pyri with different host preferences. Comparative genomics analysis revealed that segmental rearrangements, inversions, and translocations …

Understanding The Potential Utility Of Tamarktm Grain Sorghum, Jacob Alan Fleming

Graduate Theses and Dissertations

Herbicide-resistant crops have been commonly used in corn, cotton, and soybean since the 1990s to control numerous different grass and broadleaf weeds. However, this technology has not been available for grain sorghum producers whom have faced challenges controlling grass weeds. Recently a collaboration between the University of Arkansas and Texas A&M University has resulted in a new bred line of grain sorghum, TamArkTM, which is resistant to ACCase inhibitor herbicides which have been previously used to control grass weeds in broadleaf crops. Multiple studies were conducted to determine the sensitivity of TamArkTM and problematic grass weeds to ACCase inhibitor herbicides, …

Arkansas Soybean Research Studies 2021, Jeremy Ross

Arkansas Agricultural Experiment Station Research Series

Arkansas is the leading soybean-producing state in the mid-southern United States. Arkansas ranked 11th in soybean production in 2021 compared to the other soybean-producing states in the U.S. The state represented 3.49% of the total U.S. soybean production and 3.49% of the total acres planted in soybean in 2021. The 2021 state soybean average yield was 52.0 bushels per acre, setting a new state record and surpassing the previous yield record of 51.5 bushels per acre set in 2020. The top five soybean-producing counties in 2021 were Mississippi, Phillips, Crittenden, Poinsett, and Arkansas (Table 1). These five counties accounted for …

Comparative Genome Analysis Of Plant Ascomycete Fungal Pathogens With Different Lifestyles Reveals Distinctive Virulence Strategies, Yansu Wang, Jie Wu, Jiacheng Yan, Ming Guo, Lei Xu, Liping Hou, Quan Zou

Department of Agronomy and Horticulture: Faculty Publications

Background: Pathogens have evolved diverse lifestyles and adopted pivotal new roles in both natural ecosystems and human environments. However, the molecular mechanisms underlying their adaptation to new lifestyles are obscure. Comparative genomics was adopted to determine distinct strategies of plant ascomycete fungal pathogens with different lifestyles and to elucidate their distinctive virulence strategies. Results: We found that plant ascomycete biotrophs exhibited lower gene gain and loss events and loss of CAZyme-encoding genes involved in plant cell wall degradation and biosynthesis gene clusters for the production of secondary metabolites in the genome. Comparison with the candidate effectome detected distinctive variations between …

Biobased Sprayable Mulch Films Suppressed Annual Weeds In Vegetable Crops, Eliott Gloeb, Sibel Irmak, Loren Isom, John L. Lindquist, Samuel E. Wortman

Department of Agronomy and Horticulture: Faculty Publications

Biobased sprayable mulch (BSM) films are a potential alternative to herbicides, polyethylene plastic mulch film, and hand weeding for specialty crops. We developed a series of BSM films using locally available biomaterials [including corn (Zea mays) starch, glycerol, keratin hydrolysate, corn gluten meal, corn zein, eggshells, and isolated soy (Glycine max) protein] and tested their effects on weeds and crop yield during a total of seven greenhouse or field trials between 2017 and 2019 in Nebraska, USA. Application rates of BSM films applied in pots (greenhouse), planting holes in plastic film (field), or bed tops (field) …

Quizalofop-Resistant Rice Response To Quizalofop When Exposed To Low Rates Of Glyphosate And Imazethapyr, Navdeep Godara, Jason K. Norsworthy, Thomas R. Butts, Trenton L. Roberts, Edward E. Gbur

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Injury to quizalofop-resistant rice was reported in some fields following postemergence applications of quizalofop. Glyphosate-resistant (GR) corn, cotton, and soybean, and imidazolinone-resistant rice are grown near quizalofop-resistant rice. Herbicide drift from glyphosate and imazethapyr and the resulting crop injury and potential yield loss is a cause of concern for producers. Field experiments conducted near Colt, and Keiser, AR, in 2021 evaluated whether low rates of glyphosate or imazethapyr interact with sequential quizalofop applications to exacerbate injury to quizalofop-resistant rice compared to quizalofop applications alone. Herbicide treatments consisted of a low rate of glyphosate (90 g ae ha(-1)) or imazethapyr (10.7 …

Evaluation Of Rice Tolerance And Weed Control With Acetochlor And Fenclorim, Tristen H. Avent, Jason K. Norsworthy, Thomas R. Butts, Trenton L. Roberts, Nicholas R. Bateman

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Many problematic weeds have evolved resistance to herbicides in mid-southern U.S. rice fields. With the lack of new effective herbicides, rice producers seek alternatives that are currently not labeled for rice production. Inhibitors of very-long chain fatty acid elongase (VLCFA) are currently not labeled for use with U.S. rice crops but are labeled for use in other U.S. row cropping systems and rice production in Asia. Previous research has demonstrated the utility of VLCFA inhibitors for weed control in rice; however, these herbicides induce variable amounts of injury to the crop when applied early in the growing season. Experiments were …

Nitrogen Use Efficiency Of Pretassel Nitrogen Applications In Corn, Robyn Brittlee Mulloy

Graduate Theses and Dissertations

Corn (Zea mays L.) production continues to be a critical component of row-crop production systems within Arkansas and is seeing a resurgence in recent years. Nitrogen (N) is critical for corn growth and is often one of the single largest input costs associated with corn production. Research objectives for this study were to determine the nitrogen use efficiency (NUE) of late season N applications as influenced by sidedress N rate and timing of pretassel application and to quantify the nutrient uptake and partitioning in modern era corn hybrids within a furrow-irrigated production system. Research was conducted at the Milo J. …

Diagnosing Excess Nitrogen In Rice Using Post-Season Tissue Samples, Kyle Hoegenauer

Graduate Theses and Dissertations

Proper nitrogen (N) management in rice production can be difficult to achieve without the aid of tools such as soil and tissue tests. There are no tests currently available to rice producers that determine whether N has been managed properly throughout the season or that detect instances of over fertilization. Rice stalk samples were collected from N response trials within 3 days of harvest from the primary Arkansas rice growing region in 2016-2018. Stalk samples were analyzed for N concentration through a KCl extraction and spectrofluorometric quantification. Samples analyzed with leaf material intact contained statistically different N concentrations than samples …

A Non-Destructive Approach For Measuring Rice Panicle-Level Photosynthetic Responses Using 3d-Image Reconstruction, Jaspinder Singh Dharni, Balpreet Kaur Dhatt, Puneet Paul, Tian Gao, Tala Awada, Harel Bacher4, Zvi Peleg, Paul E. Staswick, Jason Hupp, Hongfeng Yu, Harkamal Walia

Department of Agronomy and Horticulture: Faculty Publications

Background: Our understanding of the physiological responses of rice inflorescence (panicle) to environmental stresses is limited by the challenge of accurately determining panicle photosynthetic parameters and their impact on grain yield. This is primarily due to the lack of a suitable gas exchange methodology for panicles and non-destructive methods to accurately determine panicle surface area.

Results: To address these challenges, we have developed a custom panicle gas exchange cylinder compatible with the LiCor 6800 Infra-red Gas Analyzer. Accurate surface area measurements were determined using 3D panicle imaging to normalize the panicle-level photosynthetic measurements. We observed differential responses in …

Bison Movements Change With Weather: Implications For Their Continued Conservation In The Anthropocene, Nicholas A. Mcmillan, Samuel D. Fuhlendorf, Barney Luttbeg, Laura E. Goodman, Craig A. Davis, Brady W. Allred, Robert G. Hamilton

Department of Agronomy and Horticulture: Faculty Publications

Animal movement patterns are affected by complex interactions between biotic and abiotic landscape conditions, and these patterns are being altered by weather variability associated with a changing climate. Some animals, like the American plains bison (Bison bison L.; hereafter, plains bison), are considered keystone species, thus their response to weather variability may alter ecosystem structure and biodiversity patterns. Many movement studies of plains bison and other ungulates have focused on point-pattern analyses (e.g., resource-selection) that have provided information about where these animals move, but information about when or why these animals move is limited. For example, information surrounding the …

The Effects Of Tillage And Cover Crops On Crop Yield And Soil Properties In Wheat Double-Cropping Systems, Peters E. Egbedi

LSU Doctoral Dissertations

This three-year study was conducted on a commerce silt loam soil at the Northeast Research and Experiment Station near St. Joseph, Louisiana to evaluate the following objectives: 1) evaluate crop yield response to tillage, winter, and summer cover crops in wheat double-cropping systems. 2) evaluate the effects of tillage, winter and summer cover crops on soil properties under different cropping systems. 3) quantify the economic benefits of double-cropping, cover cropping and monoculture systems under conventional and no tillage practices. A winter cover crop (WCC) mix (winter wheat (Triticum aestivum and Austrian winter pea (Pisum sativum) and summer …

The Genome Of Orychophragmus Violaceus Provides Genomic Insights Into The Evolution Of Brassicaceaepolyploidizationandits Distinct Traits, Kang Zhang, Yinqing Yang, Xin Zhang, Lingkui Zhang, Yu Fu, Zhongwei Guo, Shumin Chen, Jian Wu, James C. Schnable, Keke Yi, Xiaowu Wang, Feng Cheng

Department of Agronomy and Horticulture: Faculty Publications

Orychophragmus violaceus, referred to as ‘‘eryuelan’’ (February orchid) in China, is an early-flowering ornamental plant. The high oil content and abundance of unsaturated fatty acids in O. violaceus seeds make it a potential high-quality oilseed crop. Here, we generated a whole-genome assembly for O. violaceus using Nanopore and Hi-C sequencing technologies. The assembled genome of O. violaceus was ~1.3 Gb in size, with 12 pairs of chromosomes. Through investigation of ancestral genome evolution, we determined that the genome of O. violaceus experienced a tetraploidization event from a diploid progenitor with the translocated proto-Calepineae karyotype. Comparisons between the reconstructed subgenomes …

Novel Single-Nucleotide Variants For Morpho-Physiological Traits Involved In Enhancing Drought Stress Tolerance In Barley, Ibrahim S. Elbasyoni, Shamseldeen Eltaher, Sabah Morsy, Alsayed M. Mashaheet, Ahmed M. Abdallah, Heba G. Ali, Samah A. Mariey, P. Stephen Baenziger, Katherine Anna Frels

Department of Agronomy and Horticulture: Faculty Publications

Barley (Hordeum vulgare L.) thrives in the arid and semi-arid regions of the world; never-theless, it suffers large grain yield losses due to drought stress. A panel of 426 lines of barley was evaluated in Egypt under deficit (DI) and full irrigation (FI) during the 2019 and 2020 growing seasons. Observations were recorded on the number of days to flowering (NDF), total chlorophyll content (CH), canopy temperature (CAN), grain filling duration (GFD), plant height (PH), and grain yield (Yield) under DI and FI. The lines were genotyped using the 9K Infinium iSelect single nucleotide polymorphisms (SNP) genotyping platform, which …

Effects Of Sowing Date And Phosphorus Fertiliser Application On Winter Survival Of Lucerne Cv. Aohan In The Northern Semi-Arid Region Of China, Z. L. Wang, Q. Zh. Sun, Y. W. Wang, Zh. Y. Li, Sh. F. Zhao

IGC Proceedings (1977-2023)

In the northern semi-arid region of China, winter survival is always a limiting factor for lucerne production, because low temperatures and a dry climate in winter (Zhou et al., 1993; Ma, 2000; Sun & Gui, 2001; Sun et al., 2003). An experiment was conducted to find an appropriate sowing date and P application rate in order to improve lucerne winter survival.