Agricultural Science Commons^™

Pestfacts Wa Issue 07 - June 2022, Alan Lord, Dusty Severtson, Cindy L. Webster, Svetlana Micic, Kithsiri Jayasena, Geoff J. Thomas, Ciara Beard, Andrea Hills, Jean Galloway

PestFacts WA

PestFacts WA Issue 07 - June 2022 contents:

• Native budworm moths and caterpillars are being found early
• 2022 winter spring insecticide spray guide is now available
• Monitor barley crops for net blotches
• Powdery mildew in barley and wheat
• Sclerotinia apothecia
• Spartacus leaf tipping

Water Quality, Carrier Volume And Droplet Size Effects On Herbicide Efficacy And Drift Potential, Barbara Houston

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

Herbicide performance is directly related to the amount of active ingredient that has been deposited on the plant. Hence, spray solution characteristics and application parameters are crucial in determining the efficacy of an herbicide application. To maximize the effectiveness of chemical control, methods to deliver full chemical dose must be utilized: allowing the active ingredient to be readily absorbed once added to the carrier and mitigating off-target movement and low herbicide doses. Water is the most frequently used carrier in herbicide applications. Chemical parameters, such as water hardness and pH, can have a critical role in herbicide performance. It is …

Developing A Miniature Smart Boat For Marine Research, Michael Isaac Eirinberg

Computer Engineering

This project examines the development of a smart boat which could serve as a possible marine research apparatus. The smart boat consists of a miniature vessel containing a low-cost microcontroller to live stream a camera feed, GPS telemetry, and compass data through its own WiFi access point. The smart boat also has the potential for autonomous navigation. My project captivated the interest of several members of California Polytechnic State University, San Luis Obispo’s (Cal Poly SLO) Marine Science Department faculty, who proposed a variety of fascinating and valuable smart boat applications.

Recombination Hotspots In Soybean [Glycine Max (L.) Merr.], Samantha J. Mcconaughy

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

Recombination allows for the exchange of genetic material between two parents which plant breeders exploit to make new and improved varieties. This recombination is not distributed evenly across the chromosome. In crops, it mostly occurs in the euchromatic regions of the genome and even then, recombination is focused into recombination hotspots flanked by recombination cold spots. Understanding the distribution of these hotspots along with the sequence motifs associated with them may lead to methods that enable breeders to better exploit recombination in breeding.

In chapter 1 background information on recombination, recombination hotspots detection methods, landscape of recombination (describe recombination patterns …

Pestfacts Wa Issue 06 - June 2022, Cindy L. Webster, Svetlana Micic, Alan Lord, Benjamin S. Congdon, Steve Collins

PestFacts WA

PestFacts WA Issue 06 - June 2022 contents:

• African black beetle
• Aphid and turnip yellows virus update
• Cutworm caterpillars
• European earwigs are damaging canola
• Other recent insect activity
• New PestFacts WA Reporter app available for apple devices

Plant Growth And Defense Traits In Sorghum Bicolor’S Response To Chilo Partellus In The Tropics, Adekunle W. Adesanya, Maria Isabel Gomez, Kimberly Morrell, Charles Midega, Zeyaur Khan, André Kessler, Katja Poveda

All Peer-Reviewed Publications

In order to meet the increasing demands from an exploding human population, sustainable agriculture relies on the availability of crop varieties with high yields and optimal defenses to pests. However, ample work has suggested that domesticated plants could have reduced defenses at the expense of increased biomass or yield, and these potential trade-offs can vary among plant species and genotypes. Herbivory coping mechanisms such as tolerance and resistance can be expressed differently among plant genotypes, with variable relationships and inherent fitness costs. Knowledge of the connection between growth and defense mechanisms in cultivated plants is still limited, especially in tropical …

The Plant And The Pathogen: Elucidating The Relationship Between Root-Knot Nematodes, Ph Levels, And Arabidopsis Thaliana Development, Rachel Garnett

Undergraduate Theses and Capstone Projects

Root-knot nematodes (RKNs) within the Meloidogyne genus are considered one of the largest threats to plant health and subsequent crop yield and profit (Forghani and Hajihassani 2020; Bernard et al. 2017). As a pest that presents global consequences, its mitigation through sustainable interventions may confer results for the treatment of similar plant pathogens. A member of the Brassicaeae family, Arabidopsis thaliana, was chosen for this study to determine how this model plant responds to RKN-standard pH media. pH was varied between control and experimental groups, and the phenotypic variables of primary root length and plant height were observed and analyzed. …

Progress In Research On Site-Specific Nutrient Management For Smallholder Farmers In Sub-Saharan Africa, P. Chivenge, S. Zingore, K. S. Ezui, S. Njoroge, M. A. Bunquin, A. Dobermann, K. Saito

All Peer-Reviewed Publications

Increasing fertilizer access and use is an essential component for improving crop production and food security in sub-Saharan Africa (SSA). However, given the heterogeneous nature of smallholder farms, fertilizer application needs to be tailored to specific farming conditions to increase yield, profitability, and nutrient use efficiency. The site-specific nutrient management (SSNM) approach initially developed in the 1990 s for generating field-specific fertilizer recommendations for rice in Asia, has also been introduced to rice, maize and cassava cropping systems in SSA. The SSNM approach has been shown to increase yield, profitability, and nutrient use efficiency. Yield gains of rice and maize …

Lintul-Cassava-Npk: A Simulation Model For Nutrient-Limited Cassava Growth, J. G. Adiele, A. G.T. Schut, K. S. Ezui, K. E. Giller

All Peer-Reviewed Publications

A solid understanding of the dynamics of plant nutrient requirements and uptake from the soil is needed to provide robust fertilizer recommendations, timing of applications and nutrient use efficiency. Our objective was to develop and test the ability of the crop model LINTUL-Cassava-NPK to simulate biomass growth and yield of cassava under nutrient-limited conditions. We used experimental data from six fields located in three different agro-ecologies in Nigeria: Rainforest Zone– Ogoja and Ikom (Cross River), Rainforest Transition Zone – Ekpoma (Edo) and Guinea Savanna Zone – Otukpo (Benue) over two consecutive growing seasons from 2016 to 2018. Nutrient stress in …

Grain-Filling Rate Improves Physical Grain Quality In Barley Under Heat Stress Conditions During The Grain-Filling Period, Hamid Shirdelmoghanloo, Kefei Chen, Blakely Paynter, Tefera Angessa, Sharon Westcott, Hammad Aziz Khan, Camilla Beate Hill, Chengdao Li

Grain and Other Field Crops Research Articles

Heat stress is a primary constraint to Australia's barley production. In addition to impacting grain yield, it adversely affects physical grain quality (weight and plumpness) and market value. The incidence of heat stress during grain filling is rising with global warming. However, breeding for new superior heat-tolerant genotypes has been challenging due to the narrow window of sensitivity, the unpredictable nature of heat stress, and its frequent co-occurrence with drought stress. Greater scientific knowledge regarding traits and mechanisms associated with heat tolerance would help develop more efficient selection methods. Our objective was to assess 157 barley varieties of contrasting genetic …

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 …

Water Use Efficiency In Western Australian Cropping Systems, Martin Harries, Ken C. Flower, Michael Renton, Geoffrey C. Anderson

Grain and Other Field Crops Research Articles

Rotations and associated management practices in rainfed farming systems of southwest Australia have shifted towards intensified cropping. Survey data from 184 fields spanning 14 Mha of southwest Australia were used to document water use efficiency (WUE) and water-limited yield potential (WLYP) of commercial crops and crop sequences and identify biophysical variables influencing WUE. WUE achieved in commercial wheat crops was 10.7 kg grain/ha.mm. Using a boundary function Ywl = 25 × (WU − 45), farmers achieved 54% of WLYP. Climate variables affected WUE more than management and biotic variates, the highest latitude region having WUE of 9.0 kg grain/ha.mm, compared …

Investigating The Mechanics And Chemistry Of Sickle Polish Development, Justin Jared Dubois

Graduate Theses and Dissertations

This series of experiments is designed to understand the development and chemistry of sickle gloss. Sickles are common in the archaeological record and have long been studied for their eponymous “sickle gloss”. There is debate as to how this gloss is formed. Five experimental sickles containing flint and novaculite blades were used to harvest high and low moisture content rye and common fescue and associated field weeds. The differences in the development of sickle gloss were examined. High moisture content plants create thick, smooth fields of polish with undulating, billowing margins at a higher developmental speed. Low moisture content plants …

Pestfacts Wa Issue 05 - May 2022, Jean Galloway, Cindy L. Webster, Steve Collins

PestFacts WA

PestFacts WA Issue 05 - May 2022 contents:

• Blackleg and the risk of sowing canola on canola
• Meet PestFacts WA team member – Steve Collins

Pestfacts Wa Issue 04 - May 2022, Svetlana Micic, Benjamin S. Congdon, Cindy L. Webster, Andrea Hills, Ravjit Khangura

PestFacts WA

PestFacts WA Issue 04 - May 2022 contents:

• Grasshoppers are hatching
• Aphid activity and turnip yellows virus detections
• Downy mildew and damping off in canola
• Nodorum blotch in wheat
• Plant disease webinar recording can now be viewed online

Agricultural Practices And Nitrogen Cycling Microbes: The Impact Of Sustainable Farming Practices On Nutrient Movement In Indianapolis Urban Farms, Margaret Davis

Undergraduate Honors Thesis Collection

As population movement to urban centers and decreased availability of fresh foods becomes more common, the prevalence of food deserts is becoming far greater. Urban farming can potentially help address these issues by bringing healthy and fresh food sources directly to these areas that lack access to quality food. Urban farming is reliant on the implementation of sustainable practices, like the use of cover crops, to increase the amount of nutrients that are accessible to plants from the soil. Nitrogen is a vital nutrient but cannot be readily produced by plants, so it must be obtained by either an external …

Economic Viability Of Weed Management Strategies In High-Tunnel Tomato, Gracie Morrison

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

Cost-effective weed suppression is an important consideration for tomato growers. Growers often choose methods which minimize hand labor, as hand weeding can be prohibitively expensive. This project determined economic viability of high tunnel tomatoes treated with several methods of weed control, both organic and chemical. These methods included: 2-week hand weeding, 1-week hand weeding, preemergent, straw, landscape fabric, and untreated weedy control plots. These treatments were applied to randomized blocks in a high-tunnel. Weeding, planting, and harvest were all timed to determine labor and material costs of weed management strategy implementation. After harvest, marketable yield was weighed to determine revenue. …

Dicamba Tank Mixtures And Formulations And Their Effects On Sensitive Crops During Cleanout Procedures, Vinicius Velho

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

The introduction of dicamba-tolerant (DT) soybeans (Glycine max L. Merr) and cotton (Gossypium hirsutum L) in 2017 provided an additional tool for herbicide resistant weeds management. In the subsequent years, off-target movement of dicamba allegedly caused damage to sensitive crops and vegetation.

Possible causes of off-target movement include tank contamination, physical drift, and volatility. Additional products, such as herbicides to control grass, are often added to tank with dicamba, which is used to control broadleaf weeds, to increase the spectrum of control and application efficiency. Dicamba products registered for DT crops require the use of drift reducing …

The Synchronization Of Nocturnal Pollinator Behavior And Apple Flower Nectar Production, Madison Jennings

Biological Sciences Undergraduate Honors Theses

Insects perform an essential ecological service by facilitating the pollination of crops for food production worldwide. Recent declines in diurnal bee populations threaten food security and has led to growing concerns about existent pollination methods. Pollination contributions by native nocturnal insects have been documented to occur in a variety of systems, thought to be supported by the plant’s attractant and reward system. If this is the case, pollination of flowers by nocturnal vectors may be influenced by circadian cycles of nectar production and insect activity. To test this hypothesis, we recorded insect abundance of nocturnal pollinators periodically throughout the night …

Winter Cover Crop Impacts On Weed Dynamics In Eastern And Central Nebraska, Elizabeth Ann Oys

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

Reducing tillage in cropping systems causes weed management to be dependent on chemical and cultural methods for weed control. Over time, herbicide-resistant weeds have developed due to the continuous selection pressures from herbicides, particularly in the Midwest Corn Belt. Integrated weed management strategies, such as cover crops, can be used to mitigate some of these issues. Cover crops are primarily known for their soil health benefits, but there is evidence that cover crops can suppress weeds. However, less research has been done at the field-scale level to address cover crop impacts on the weed seedbank and aboveground weeds during the …

Regional Plant Community Differences In The Nebraska Sandhills, Travis Millikan

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

The Nebraska Sandhills is very valuable to the state of Nebraska, representing one of the most in-tact and largest grassland ecosystems in temperate regions in the world. Rangeland managers must understand plant community dynamics across the Sandhills to better inform management decisions. The first objective of this study was to evaluate plant community variability on upland Sands ecological sites across different precipitation zones in the Nebraska Sandhills. The second objective of our study was to utilize the Rangeland Analysis Platform (RAP) to examine spatial and temporal variability in biomass production and cover on pastures of ranches analyzed in the first …

Exploration Of Genes Controlling Grain Yield Heterosis In Hybrid Wheat (Triticum Aestivum L.) Utilizing 3ʹ Rna Sequencing, Nichole Lynn Miller

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

The implementation and future success of hybrid wheat (Triticum aestivum L.) is impacted by breeders’ inability to create consistent high yielding, high heterosis hybrids. This research addresses this problem by conducting an exploration of transcriptomes from hybrids and parent lines to determine what genes are active in heterotic or non-heterotic hybrids and how their level of expression can explain the phenotype of grain yield heterosis. Using hybrids that showed positive mid-parent heterosis (MPH), classified as heterotic in our study, and negative or no difference MPH hybrids, classified as non-heterotic, differentially expressed genes (DEGs) potentially related to heterosis and hybrid …

Pestfacts Wa Issue 03 - May 2022, Svetlana Micic, Dustin Severtson, Jean Galloway, Cindy L. Webster

PestFacts WA

PestFacts WA Issue 03 - May 2022 contents:

• Seeing chewing damage in sprayed canola crops but can’t find the culprit?
• Mites and lucerne flea are active
• Slaters
• Meet PestFacts WA team member – Svetlana Micic
• Field pea blackspot forecasts for WA are available online
• PestFacts WA podcast

Wayne E. Sabbe Arkansas Soil Fertility Studies 2021, Nathan A. Slaton

Arkansas Agricultural Experiment Station Research Series

Rapid technological changes in crop management and production require that the research efforts be presented in an expeditious manner. The contributions of soil fertility and fertilizers are major production factors in all Arkansas crops. The studies described within will allow producers to compare their practices with the university’s research efforts. Additionally, soil-test data and fertilizer sales are presented to allow comparisons among years, crops, and other areas within Arkansas.

Oestrogenic Subterranean Clover Guide. Identification And Remediation, Kevin J. Foster, Megan H. Ryan, Daniel R. Kidd

Bulletins 4000 -

Subterranean clover (subclover, Trifolium subterraneum L.) is an annual pasture legume that provides high quality feed for livestock. It is estimated to be sown over 30 million hectares across southern Australia, with cultivars developed for the low, medium and high rainfall zones. Unfortunately, some older cultivars contain high levels of phytoestrogen which can affect the reproductive system of sheep and cause other health issues. This became a significant issue for sheep producers from the 1940s as new land was cleared and sheep grazed subclover-dominant pastures. There was a collection of livestock issues observed and these were grouped together under the …

Chromosome-Level Thlaspi Arvense Genome Provides New Tools For Translational Research And For A Newly Domesticated Cash Cover Crop Of The Cooler Climates, Adam Nunn, Isaac Rodríguez-Arévalo, Zenith Tandukar, Katherine Anna Frels, Adrián Contreras-Garrido, Pablo Carbonell-Bejerano, Panpan Zhang, Daniela Ramos Cruz, Katharina Jandrasits, Christa Lanz, Anthony Brusa, Marie Mirouze, Kevin Dorn, David W. Galbraith, Brice A. Jarvis, John C. Sedbrook, Donald L. Wyse, Christian Otto, David Langenberger, Peter F. Stadler, Detlef Weigel, M. David Marks, James A. Anderson, Claude Becker, Ratan Chopra

Department of Agronomy and Horticulture: Faculty Publications

Thlaspi arvense (field pennycress) is being domesticated as a winter annual oilseed crop capable of improving ecosystems and intensifying agricultural productivity without increasing land use. It is a selfing diploid with a short life cycle and is amenable to genetic manipulations, making it an accessible field-based model species for genetics and epigenetics. The availability of a high-quality reference genome is vital for understanding pennycress physiology and for clarifying its evolutionary history within the Brassicaceae. Here, we present a chromosome-level genome assembly of var. MN106-Ref with improved gene annotation and use it to investigate gene structure differences between two accessions (MN108 …

Using Thermal Units To Predict Biomass Accumulation And Total Nitrogen Uptake For Cover Crops In Arkansas, Mila Victório Pessotto

Graduate Theses and Dissertations

Including cover crops in agricultural production systems is an important management practice. Cover cropping can improve soil health, increase plant-available nitrogen (N), provide surface residue to prevent erosional soil loss, increase water infiltration, and increase weed suppression. Cover crops growth can be predicted using thermal days or growing degree days [GDD] similar to commodity crops such as corn (Zea mays L.) or rice (Oryza sativa). Growing degree day calculations are a well-known tool to predict crop growth stage or development stage and can be adapted for use in any plant species, including cover crops. Identifying and developing the relationship between …

Breeding Soybean [Glycine Max (L) Merr.] Under Reduced Irrigation, Francia Seconde Ravelombola

Graduate Theses and Dissertations

Soybean [Glycine max (L) Merr.], a legume species native to East Asia in the Fabaceae family, ranks among the most important food crops in the world. It is widely grown and known for its high protein and oil concentration. Soybean is valuable because its seeds have multiple applications in food, feed, pharmaceutical, and industrial enterprises. Even though seed yield is the most important trait, breeders have recently given a significant attention to quality traits, such as high protein or modified oil concentration. Soybean seed protein inheritance has been extensively studied; however, genetics of high-protein ‘BARC-7’ soybean are still unknown.On the …

Climate Change And Maize Productivity In Uganda: Simulating The Impacts And Alleviation With Climate Smart Agriculture Practices, Alex Zizinga, Jackson Gilbert Majaliwa Mwanjalolo, Britta Tietjen, Bobe Bedadi, Himanshu Pathak, Geofrey Gabiri, Dennis Beesigamukama

All Peer-Reviewed Publications

CONTEXT: Climate change continues to affect maize production, food security and livelihoods of smallholder farmers in most of the developing countries. Climate smart agriculture (CSA) practices can enhance agricultural production by alleviating adverse climate effects on maize productivity through improved soil moisture storage, water use efficiency, increased soil carbon (C) and nutrient supply with long-term resilience to climate change. OBJECTIVE: This study investigated the effectiveness of CSA practices (mulching at 0, 2, 4 and 6 cm thicknesses), permanent planting basins (20 and 30 cm deep), and halfmoon pits as a mitigation and adaptation strategy for improving maize productivity in rainfed …

Evaluation, Characterization, And Utilization Of Weed-Suppressive Sweetpotato Cultivars For Sustainable Weed Management, Isabel Schlegel Werle

Graduate Theses and Dissertations

Sweetpotato (Ipomoea batatas L.) is a low-technology, subsistence crop that enhances food and nutrition security particularly in developing nations. Weed interference with the crop can reduce sweetpotato storage root yields and product quality. Current weed management practices in sweetpotato include PRE or POST herbicides application, cultivation, mowing, or handweeding. Unlike row crops, herbicide options for sweetpotato are few; therefore, alternative weed control practices are needed. The overall objective of this research was to determine the weed suppressive ability of several sweetpotato cultivars. This research also provides information about cover crop use for weed suppression in sweetpotato production in Arkansas. Field …