Agricultural Science Commons^™

Effects Of Micro-Rates Of 2,4-D And Dicamba On Lettuce And Pumpkin In Nebraska, Xinzheng Chen

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

Off-target herbicide injury from dicamba and 2,4-D is an increasingly common problem for specialty crop growers in the Midwestern United States. Both lettuce (Lactuca sativa L.) and pumpkin (Cucurbita spp.) are common specialty crops grown in Nebraska, and their proximity to corn and soybean production makes these crops susceptible to herbicide drift injury and yield loss. The objectives of this thesis research was to quantify crop injury and yield loss in greenhouse- and field-grown lettuce and field-grown pumpkins at different growth stages after exposure to sub-lethal doses of dicamba or 2,4-D. Dose response curves were generated to determine effective dose …

Predicting Non-Native Insect Impact: Focusing On The Trees To See The Forest, Ashley N. Schulz, Angela M. Mech, Matthew P. Ayres, Jamal J.K. Gandhi, Nathan P. Havill, Daniel A. Herms, Angela M. Hoover, Ruth A. Hufbauer, Andrew M. Liebhold, Travis D. Marsico, Kenneth F. Raffa, Patrick C. Tobin, Daniel R. Uden, Kathryn A. Thomas

Department of Agronomy and Horticulture: Faculty Publications

Non-native organisms have invaded novel ecosystems for centuries, yet we have only a limited understanding of why their impacts vary widely from minor to severe. Predicting the impact of non-established or newly detected species could help focus biosecurity measures on species with the highest potential to cause widespread damage. However, predictive models require an understanding of potential drivers of impact and the appropriate level at which these drivers should be evaluated. Here, we used non-native, specialist herbivorous insects of forest ecosystems to test which factors drive impact and if there were differences based on whether they used woody angiosperms or …

The Effects Of Gibberellic Acid, Smoke Water, And Cold Stratification On The Germination Of Native Perennial Seed, Zyreasha Tippins

Electronic Theses and Dissertations

In this study, I evaluated the germination rates of twenty native plant species and their response to cold stratification as well as four chemical solution treatments—water (control), gibberellic acid, smoke water, and gibberellic acid with smoke water. Seeds were evaluated and counted twice a week. Of the twenty evaluated species, sixteen had germination rates over 3% or 1 seed out of 30. Stratification increased germination by 54% when compared to the control. For chemical treatments, gibberellic acid and gibberellic acid with smoke water were significantly different from the control and increased germination by an average of 47% and 48%, respectively. …

Primary Industries Development Research Highlights 2021, Department Of Primary Industries And Regional Development, Tim Scanlon

Books & book chapters

The Primary Industries Development Research Highlights 2021 showcases the breadth and depth of the Department of Primary Industries and Regional Development’s research and development activities over the past several years.

Stories featured in Research Highlights 2021 stem from about 60 (of 140) current and recently-completed projects undertaken by the Department of Primary Industries and Regional Development’s (DPIRD) 1100 scientists, technical experts and economists throughout the State.

Explore our Research Highlights 2021.

The publication demonstrates the innovative and applicable research that DPIRD and its collaborators and investment partners deliver to Western Australia.

Download the Research Highlights 2021 here. Alternatively, …

Impact Of Cover Crop Monocultures And Mixtures On Organic Carbon Contents Of Soil Aggregates, Daphne Topps, Imam Ul Khabir, Hagir Abdelmagid, Todd Jackson, Javed Iqbal, Boakai K. Robertson, Zahida Hassan Pervaiz, Muhammad Saleem

Department of Agronomy and Horticulture: Faculty Publications

Cover crops are considered an integral component of agroecosystems because of their positive impacts on biotic and abiotic indicators of soil health. At present, we know little about the impact of cover crop types and diversity on the organic carbon (OC) contents of different soil aggregate-size classes. In this study, we investigated the effect of cover plant diversity on OC contents of different soil aggregates, such as macro- (<2000–500 µm), meso- (<500–250 µm), and micro-aggregates (<250 µm). Our experiment included a total of 12 experimental treatments in triplicate; six different monoculture treatments such as chickling vetch (Vicia villosa), crimson clover (Trifolium incarnatum), hairy vetch (Vicia villosa), field peas (Pisum sativum), oilseed radish (Raphanus sativus), and mighty mustard (Brassica juncea), and their three- and six-species mixture treatments, including one unplanted control treatment. We performed this experiment usingdeep pots that contained soil collected from a corn-soybean rotation field. At vegetative maturity of cover plants (about 70 days), we took soil samples, and the soil aggregate-size classes were separated by the dry sieving. We hypothesized that cover crop type and diversity will improve OC contents of different soil aggregate-size classes. We found that cover plant species richness weakly positively increased OC contents of soil macro-aggregates (p = 0.056), whereas other aggregate-size classes did not respond to cover crop diversity gradient. Similarly, the OC contents of macroaggregates varied significantly (p = 0.013) under cover crop treatments, though neither monoculture nor mixture treatments showed significantly higher OC contents than the control treatment in this short-term experiment. Interestingly, the inclusion of hairy vetch and oilseed radish increased and decreased the OC contents of macro- and micro-aggregates, respectively. Moreover, we found a positive correlation between shoot biomass and OC contents of macroaggregates. Overall, our results suggest that species-rich rather than -poor communities may improve OC contents of soil macroaggregates, which constitute a major portion of soil systems, and are also considered as important indicators of soil functions.

Tandem Duplicate Expression Patterns Are Conserved Between Maize Haplotypes Of The Α-Zein Gene Family, Preston Hurst, James C. Schnable, David R. Holding

Department of Agronomy and Horticulture: Faculty Publications

Tandem duplication gives rise to copy number variation and subsequent functional novelty among genes as well as diversity between individuals in a species. Functional novelty can result from either divergence in coding sequence or divergence in patterns of gene transcriptional regulation. Here, we investigate conservation and divergence of both gene sequence and gene regulation between the copies of the α-zein gene family in maize inbreds B73 and W22. We used RNA-seq data generated from developing, self-pollinated kernels at three developmental stages timed to coincide with early and peak zein expression. The reference genome annotations for B73 and W22 were modified …

Enhancing Our Understanding Of Plant Cell-To-Cell Interactions Using Single-Cell Omics, Sandra Thibivilliers, Marc Libault

Department of Agronomy and Horticulture: Faculty Publications

Plants are composed of cells that physically interact and constantly adapt to their environment. To reveal the contribution of each plant cells to the biology of the entire organism, their molecular, morphological, and physiological attributes must be quantified and analyzed in the context of the morphology of the plant organs. The emergence of single-cell/nucleus omics technologies now allows plant biologists to access different modalities of individual cells including their epigenome and transcriptome to reveal the unique molecular properties of each cell composing the plant and their dynamic regulation during cell differentiation and in response to their environment. In this manuscript, …

Correlation, Regression Analysis Of Seed Oil Contents In Relation To Morphological Characters In Cotton, Hafiz Muhammad Awais, Sarmad Frogh Arshad, Wajad Nazeer, Muhammad Usman, Abdul Latif Khan Tipu, Muqarrab Ali, Asif Saleem, Hasan Junaid Arshad, Asma Shah Rukh

Journal of Bioresource Management

Cotton is the backbone of Pakistan’s economy. More than half of the export of Pakistan depends on cotton and cotton-based products. Morphological quantitative traits are important for estimation of cotton yield. In this regard, a study was conducted to evaluate the morphological responses on cotton crop at experimental farm of MNS-University of Agricultural Multan during the year 2019-2020. Four cotton varieties with different time windows (early, normal and late) were sown in a randomized complete block design (RCBD) in a split plot arrangement. Correlation and regression studies of cultivars of Gossypium and Malvaceae were analyzed for quantitative characters. Result revealed …

International Rice Outlook: International Rice Baseline Projections 2020-2030, A. Durand-Morat, S. Bairagi

Research Reports and Research Bulletins

The coronavirus (COVID-19) pandemic and subsequent lockdowns impacted all economies worldwide and created an economic recession far graver than the Great Recession, contracting the global growth of gross domestic product (GDP) nearly by 4.0% in 2020, compared to -2.0% in 2009 (IHS Markit database). COVID-19 disrupted global and local food supply chains, and resulted in a significant increase in food prices (FAO, 2021). Both global and domestic rice prices increased, driven primarily by temporary export restrictions imposed by several leading rice exporters, such as Vietnam and Myanmar. The market uncertainty also created in panic-buying and hoarding; consequently, the rice demand …

Yield And Economic Performance Of Crop Rotation Systems In South Dakota, Hanxiao Feng, Tong Wang, Shannon L. Osborne, Sandeep Kumar

Economics Faculty Publications

Crop yield and economic profitability, both highly dependent on local crop management, soil characteristics, and weather conditions, are among the most influential factors to consider when considering a cropping system. The objective of this study was to compare the economic returns of three different 4-yr diverse crop rotations with that of a 2-yr traditional crop rotation in eastern South Dakota. The rotations included were (a) corn (Zea mays L.)–soybean [Glycine max (L.) Merr.]–spring wheat (Triticum aestivum L.)–pea (Pisum sativum L.) (CSSwP), (b) corn–pea–winter wheat–soybean (CPWwS), (c) corn–oat (Avena sativa L.)–winter wheat–soybean (COWwS), and (d) corn–soybean …

Establishing Regenerative Pasture Systems Using Management Intensive Grazing In The Ozarks, Shelbi M. Mundy

MSU Graduate Theses

Soil carbon and soil health are important topics relating to how climate change is impacting agriculture, and how agriculture can in turn impact climate change. The agriculture industry, particularly beef production, has a large opportunity to use conservation agriculture techniques, such as rotational grazing, to offset some of the industry’s impact on carbon emissions, erosion, water pollution, and other environmental issues. This study is the beginning of a long-term project exploring regenerative pasture systems in the Ozarks. The project takes place in a rotational grazing system with 12 paddocks. The objectives of this study are to characterize soil types by …

Evaluating Evapotranspiration And Management Of Glyphosate-Resistant Palmer Amaranth (Amaranthus Palmeri S. Watson), Jasmine Mausbach

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

Palmer amaranth (PA) is the most problematic weed in agronomic cropping systems in the United States. Acetolactate synthase (ALS) inhibitor-/glyphosate-resistant (GR) PA has been confirmed in Nebraska and is widespread in several counties. Soybean resistant to isoxaflutole/glufosinate/glyphosate has been developed to provide additional herbicide sites of action for control of herbicide-resistant weeds. The objectives of this study were to evaluate herbicide programs for control of ALS inhibitor/GR PA and their effect on PA density and biomass, as well as soybean injury and yield in isoxaflutole/glufosinate/glyphosate-resistant soybean. A PRE herbicide fb glufosinate controlled PA 80%–99% 21 d after late-POST in 2018 …

Quantifying The Combined Effect Of Abiotic Factors On The Decomposition Of Organic Matter In Semiarid Grassland Soils, Elnazsadat Hosseiniaghdam

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

Grassland ecosystems play a critical role in the global carbon cycle, and their cumulative carbon dioxide (CO2) emissions can be affected by animal grazing where litter (i.e., dead plant material) is trampled into the soil. However, the subsequent effects of trampling on litter decomposition are not well understood. Meanwhile, abiotic factors, especially temperature and soil moisture, are known to strongly affect litter decomposition. Due to the very small number of published studies that have considered litter placement, either litter on top of soil or litter mixed with soil as a factor in litter decomposition under different temperature and soil moisture …

Effects Of Cultivars And Nitrogen Management On Wheat Grain Yield And Protein, Deepak Ghimire, Saurav Das, Nathan D. Mueller, Cody F. Creech, Dipak Santra, P Stephen Baenziger, Amanda C. Easterly, Brian Maust, Bijesh Maharjan

Department of Agronomy and Horticulture: Faculty Publications

Low grain protein in hard red winter (HRW) wheat (Triticum aestivum L.) is a serious challenge for rainfed wheat growers, particularly in years with elevated grain yield. Proper nitrogen (N) management with adequate N rate and application timing is critical for optimizing grain yield and protein content. This 2-yr experiment evaluated the effects of different N rates and application timings (fall, spring, and split) on grain yield and protein of two HRW wheat cultivars. Field studies were conducted at four different sites across Nebraska under rainfed conditions in 2018/2019 (Year 1) and 2019/2020 (Year 2). A split plot randomized complete …

Management Of Glyphosate-Resistant Palmer Amaranth (Amaranthus Palmeri S. Watson) In Dicamba/Glyphosate-Resistant Soybean, Shawn Mcdonald

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

While not a historically problematic weed in Nebraska, Palmer amaranth has become increasingly problematic in many agronomic cropping systems. Throughout the state, several cohorts of Palmer amaranth have been found resistant to several different sites of action. Of major concern is a population found resistant to glyphosate the most common post-emergence herbicide in Nebraska. As chemical control methods are the most common forms of weed control throughout the state methods alternatives or enhancements are highly desired. Two field experiments were conducted in 2018 and 2019 at a grower’s field near Carleton, Nebraska with the objectives to evaluate the effects of …

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 …

An Assessment Of The Factors Influencing The Prediction Accuracy Of Genomic Prediction Models Across Multiple Environments, Sarah Widener, George Graef, Alexander E. Lipka, Diego Jarquin

Department of Agronomy and Horticulture: Faculty Publications

The effects of climate change create formidable challenges for breeders striving to produce sufficient food quantities in rapidly changing environments. It is therefore critical to investigate the ability of multi-environment genomic prediction (GP) models to predict genomic estimated breeding values (GEBVs) in extreme environments. Exploration of the impact of training set composition on the accuracy of such GEBVs is also essential. Accordingly, we examined the influence of the number of training environments and the use of environmental covariates (ECs) in GS models on four subsets of n = 500 lines of the soybean nested association mapping (SoyNAM) panel grown in …

Veganic Agriculture In The United States: Opportunities For Research, Outreach, And Education, Alisha Utter, Mona Seymour

The Journal of Extension

A growing number of farmers are excluding animal inputs from crop production, an approach commonly referred to as veganic or stockfree organic agriculture. This research-based article discusses the soil health and fertility strategies reported by a sample of U.S. veganic farmers. These approaches may be relevant beyond the veganic community to farmers seeking innovative methods for produce safety and nutrient cycling. Agricultural outreach professionals (AOPs), including Extension personnel, play a critical role in supporting veganic practices by serving as cross-pollinators between farmers and research institutions. Thus, the article endeavors to expand AOP familiarity with veganic practices and benefits.

The Analysis Of Ginsenosides In Ginseng Garden Soil, Karina Marie Kaberi

Electronic Thesis and Dissertation Repository

American ginseng (Panax quinquefolius L.) produces natural products called ginsenosides. The biggest challenge Ontario commercial ginseng farmers face is ginseng replant disease. To understand the function of ginseng root exudates, ginsenoside accumulation and persistence over time were investigated. Currently, no reliable ginsenoside specific extraction method, characterizing the changes in soil chemistry exists. Ginsenoside extraction protocol optimization was required to determine how ginsenoside composition changed over time. Overall, protocol optimization resulted in a 30% increase in yield of ginsenosides compared to previous extraction protocols. In the ginseng gardens, ginsenoside accumulation occurs slowly and did not reach significantly measurable amounts until the …

Generalist Bird Exhibits Site-Dependent Resource Selection, Samantha M. Cady, Craig A. Davis, Samuel D. Fuhlendorf, Rheinhardt Scholtz, Daniel R. Uden, Dirac Twidwell

Department of Agronomy and Horticulture: Faculty Publications

Quantifying resource selection (an organism's disproportionate use of available resources) is essential to infer habitat requirements of a species, develop management recommendations, predict species responses to changing conditions, and improve our understanding of the processes that underlie ecological patterns. Because study sites, even within the same region, can differ in both the amount and the arrangement of cover types, our objective was to determine whether proximal sites can yield markedly different resource selection results for a generalist bird, northern bobwhite (Colinus virginianus). We used 5 years of telemetry locations and newly developed land cover data at two, geographically distinct but …