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Why Organic Resources And Current Fertilizer Formulations In Southern Africa Cannot Sustain Maize Productivity: Evidence From A Long-Term Experiment In Zimbabwe, Tongai J. Mtangadura, Florence Mtambanengwe, Hatirarami Nezomba, Jairos Rurinda, Paul Mapfumo

All Peer-Reviewed Publications

Sustainability of maize-based cropping systems is a major challenge for southern Africa, yet the demand for maize as staple food and animal feed in the region continues to increase. A study was conducted on a sandy clay loam (220 g clay kg-1 soil) at Domboshawa in Zimbabwe to investigate the long-term effects of organic resource quality and application rate, and nitrogen (N) fertilization on soil chemical properties and maize (Zea mays L.) productivity. Crotalaria juncea (high quality), Calliandra calothyrsus (medium quality), cattle manure (variable quality), maize stover and Pinus patula sawdust (both low quality) were incorporated into soil at 4.0 …

Evaluating Methods For Quantifying Evapotranspiration In Arkansas Rice, Colby Reavis

Graduate Theses and Dissertations

The goal of this study was to evaluate different methods for quantifying evapotranspiration (ET) in commercial rice fields using different irrigation regimes. The rice fields were located in south central Arkansas. The different irrigation regimes were alternate wetting and drying (AWD) and continuous flooding (CF). Alternate wetting and drying and conventional flooding estimates of ET were 602 mm and 570 mm, respectively, based on field observations using eddy covariance. Models used to estimate ET estimated values between 498 and 653 mm for the 2015 growing season. The Penman Monteith actual evapotranspiration model (PM AET) performed best when compared to the …

Application Of X-Ray Imaging As A Technique For Fissure Detection In Rough Rice Kernels, Zephania R. Odek

Graduate Theses and Dissertations

Fissured rice kernels break during milling, leading to head rice yield (HRY) reductions. Conventional fissure detection instruments cannot be used to observe fissures in rough rice kernels, the form in which rice in normally dried and stored. X-rays can penetrate hulls allowing visualization of the internal structure of a rough rice kernel. This study evaluated the capability of X-ray imaging to adequately detect fissures in rough rice and established a correlation between HRY and the fissured kernel percentage (FKP) in a rough rice sample. Fifteen long-grain rice cultivars, harvested in Arkansas in 2015 and 2016 were dried using heated air …

The Role Of Co-Opted Escrt Proteins And Lipid Factors In Protection Of Tombusviral Double-Stranded Rna Replication Intermediate Against Reconstituted Rnai In Yeast, Nikolay Kovalev, Jun-Ichi Inaba, Zhenghe Li, Peter D. Nagy

Plant Pathology Faculty Publications

Reconstituted antiviral defense pathway in surrogate host yeast is used as an intracellular probe to further our understanding of virus-host interactions and the role of co-opted host factors in formation of membrane-bound viral replicase complexes in protection of the viral RNA against ribonucleases. The inhibitory effect of the RNA interference (RNAi) machinery of S. castellii, which only consists of the two-component DCR1 and AGO1 genes, was measured against tomato bushy stunt virus (TBSV) in wild type and mutant yeasts. We show that deletion of the co-opted ESCRT-I (endosomal sorting complexes required for transport I) or ESCRT-III factors makes …

Volume 2, Chapter 16-1: Birds And Bryophytes Intersect, Janice M. Glime

Bryophyte Ecology Subchapters

No abstract provided.

Synergistic Use Of Remote Sensing And Modeling To Assess An Anomalously High Chlorophyll-A Event During Summer 2015 In The South Central Red Sea, Wenzhao Li, Hesham El-Askary, K. P. Manikandan, Mohamed A. Qurban, Michael J. Garay, Olga V. Kalishnikova

Mathematics, Physics, and Computer Science Faculty Articles and Research

An anomalously high chlorophyll-a (Chl-a) event (>2 mg/m3) during June 2015 in the South Central Red Sea (17.5° to 22°N, 37° to 42°E) was observed using Moderate Resolution Imaging Spectroradiometer (MODIS) data from the Terra and Aqua satellite platforms. This differs from the low Chl-a values (<0.5 mg/m3) usually encountered over the same region during summertime. To assess this anomaly and possible causes, we used a wide range of oceanographical and meteorological datasets, including Chl-a concentrations, sea surface temperature (SST), sea surface height (SSH), mixed layer depth (MLD), ocean current velocity and aerosol optical depth (AOD) obtained from different sensors and models. Findings confirmed this anomalous behavior in the spatial domain using Hovmöller data analysis techniques, while a time series analysis addressed monthly and daily variability. Our analysis suggests that a combination of factors controlling nutrient supply contributed to the anomalous phytoplankton growth. These factors include horizontal transfer of upwelling water through eddy circulation and possible mineral fertilization from atmospheric dust deposition. Coral reefs might have provided extra nutrient supply, yet this is out of the scope of our analysis. We thought that dust deposition from a coastal dust jet event in late June, coinciding with the phytoplankton blooms in the area under investigation, might have also contributed as shown by our AOD findings. However, a lag cross correlation showed a two- month lag between strong dust outbreak and the high Chl-a anomaly. The high Chl-a concentration at the edge of the eddy emphasizes the importance of horizontal advection in fertilizing oligotrophic (nutrient poor) Red Sea waters.

Resistance To Xylem Cavitation In Evergreen Ferns Correlates With Seasonal Dehydration Levels, Not Mechanical Strength, Helen I. Holmlund, Kaitlyn E. Sauer, Breahna M. Gillespie, Jarmila Pittermann, Stephen D. Davis

Biology

Ferns in the Santa Monica Mountains of southern California display a range of responses to severe drought. In this study, we further characterized the traits that may contribute to fern survival in a mediterranean-type climate. Due to anatomical differences between ferns and angiosperms, we predicted that ferns would exhibit no correlation between stipe mechanical strength and vulnerability to water stress-induced cavitation of stipe xylem. However, we predicted that ferns would show a correlation between seasonal water stress (minimum water potential) and cavitation resistance. Our results support these hypotheses; however, we must increase our sample size of evergreen fern species in …

Molecular And Culture-Based Assessment Of Root/Crown Rot Fungal/Oomycete Complex Of Bean In Mozambique, Suzana Vanessa Ismael Fernandes

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

Dry edible beans (Phaseolus vulgaris) play an important role in food security, alleviating hunger and malnutrition and adding value to the economy in Mozambique. Recently, root/crown rot (RCR) has caused yield losses in bean fields in Mozambique. A diverse taxa of fungi and oomycetes have been associated with RCR. However, in Mozambique little information on root rot is available. The purpose of this study is to use Illumina sequencing platform, polymerase chain reaction (PCR) and culture-based methods to identify the primary pathogens associated with RCR in Mozambique. A total of 88 plants showing symptoms of RCR disease were …

The Impact Of Climate And Elevation On The Growth And Mortality Of Piñon Pine, Alice M. Fretz

Biology ETDs

The Southwestern United States is currently experiencing severe drought, resulting in the mortality of many tree species. Piñon-juniper woodlands are an extensive biome in the Southwest, and are highly vulnerable to extended periods of drought that lead to tree mortality. Specifically, Pinus edulis populations are decreasing due to increasingly arid conditions. I used dendrochronology to investigate how tree growth rings of Pinus edulis reflect severe drought in living and dead trees. I also investigated how severe drought affects Pinus edulis along an altitudinal gradient. Tree core samples were taken from currently living and dead trees, as well as from trees …

Effects Of Climate Warming On Net Primary Productivity In China During 1961–2010, Fengxue Gu, Yuandong Zhang, Mei Huang, Bo Tao, Rui Guo, Changrong Yan

Plant and Soil Sciences Faculty Publications

The response of ecosystems to different magnitudes of climate warming and corresponding precipitation changes during the last few decades may provide an important reference for predicting the magnitude and trajectory of net primary productivity (NPP) in the future. In this study, a process-based ecosystem model, Carbon Exchange between Vegetation, Soil and Atmosphere (CEVSA), was used to investigate the response of NPP to warming at both national and subregional scales during 1961–2010. The results suggest that a 1.3°C increase in temperature stimulated the positive changing trend in NPP at national scale during the past 50 years. Regardless of the magnitude of …

Inferring Foliar Water Uptake Using Stable Isotopes Of Water, Gregory R. Goldsmith, Marco M. Lehmann, Lucas A. Cernusak, Matthias Arend, Rolf T.W. Siegwolf

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

A growing number of studies have described the direct absorption of water into leaves, a phenomenon known as foliar water uptake. The resultant increase in the amount of water in the leaf can be important for plant function. Exposing leaves to isotopically enriched or depleted water sources has become a common method for establishing whether or not a plant is capable of carrying out foliar water uptake. However, a careful inspection of our understanding of the fluxes of water isotopes between leaves and the atmosphere under high humidity conditions shows that there can clearly be isotopic exchange between the two …

Positioning Of The Scrambled Receptor Requires Udp-Glc:Sterol Glucosyltransferase 80b1 In Arabidopsis Roots, Victoria G. Pook, Meera Nair, Kookhui Ryu, James C. Arpin, John Schiefelbein, Kathrin Schrick, Seth Debolt

Horticulture Faculty Publications

The biological function of sterol glucosides (SGs), the most abundant sterol derivatives in higher plants, remains uncertain. In an effort to improve our understanding of these membrane lipids we examined phenotypes exhibited by the roots of Arabidopsis (Arabidopsis thaliana) lines carrying insertions in the UDP-Glc:sterol glucosyltransferase genes, UGT80A2 and UGT80B1. We show that although ugt80A2 mutants exhibit significantly lower levels of total SGs they are morphologically indistinguishable from wild-type plants. In contrast, the roots of ugt80B1 mutants are only deficient in stigmasteryl glucosides but exhibit a significant reduction in root hairs. Sub-cellular investigations reveal that the plasma membrane …

Cellular And Molecular Targets Of Menthol Actions, Murat Oz, Eslam El Nebrisi, Keun-Hang Susan Yang, Frank Christopher Howarth, Lina T. Al Kury

Mathematics, Physics, and Computer Science Faculty Articles and Research

Menthol belongs to monoterpene class of a structurally diverse group of phytochemicals found in plant-derived essential oils. Menthol is widely used in pharmaceuticals, confectionary, oral hygiene products, pesticides, cosmetics, and as a flavoring agent. In addition, menthol is known to have antioxidant, anti-inflammatory, and analgesic effects. Recently, there has been renewed awareness in comprehending the biological and pharmacological effects of menthol. TRP channels have been demonstrated to mediate the cooling actions ofmenthol. There has been new evidence demonstrating thatmenthol can significantly influence the functional characteristics of a number of different kinds of ligand and voltage-gated ion channels, indicating that at …

Potential Recovery From Drought-Induced Dieback In A Keystone Chaparral Species, Malosma Laurina, Guinevere X. Mesh, Natalie M. Aguirre, Stephen D. Davis

Featured Research

After five years of protracted drought and water-related dieback and mortality, the coastal chaparral ecosystems of the Santa Monica Mountains have finally received increased precipitation. As a co-dominant plant species in this region, Malosma laurina (common name Laurel Sumac), provides an important indication of environmental change. This study examines the effect of the increased precipitation of the 2016-2017 rainy season on potential recovery from drought-induced dieback in M. laurina. This study shows a significant increase in tissue hydration levels and photosynthetic production of dieback plants during post-drought recovery (2017) and between irrigated control sites and dieback sites.

Life Behind The Wall: Sensing Mechanical Cues In Plants, Olivier Hamant, Elizabeth S. Haswell

Biology Faculty Research

There is increasing evidence that all cells sense mechanical forces in order to perform their functions. In animals, mechanotransduction has been studied during the establishment of cell polarity, fate, and division in single cells, and increasingly is studied in the context of a multicellular tissue. What about plant systems? Our goal in this review is to summarize what is known about the perception of mechanical cues in plants, and to provide a brief comparison with animals.

Effect Assessment Of Tio2 Nanoparticles Exposure On Medicago By Monitoring Morphophysiology, Charles Towey

Mahurin Honors College Capstone Experience/Thesis Projects

In recent years titanium dioxide nanoparticles (TiO₂NPs) have been ingredients in everything from paints to cosmetics, and even in some kinds of food. This growth in use has resulted in a substantial increase in the amount of titanium released into the environment, which could have detrimental effects on nearby plant and animal life. Currently, the number of studies conducted on the effects of TiO₂NPs is quite small, especially when it comes to edible crops. Because of this lack of research data, this study has been designed to assess the effect of TiO₂ NPs exposure on …

Hydrogenation Of Organic Matter As A Terminal Electron Sink Sustains High Co2:Ch4 Production Ratios During Anaerobic Decomposition, Rachel M. Wilson, Malak M. Tfaily, Virginia I. Rich, Jason K. Keller, Scott D. Bridgham, Cassandra Medvedeff Zalman, Laura Meredith, Paul J. Hanson, Mark Hines, Laurel Pfeifer-Meister, Scott R. Saleska, Patrick Crill, William T. Cooper, Jeff P. Chanton, Joel E. Kostka

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Once inorganic electron acceptors are depleted, organic matter in anoxic environments decomposes by hydrolysis, fermentation, and methanogenesis, requiring syntrophic interactions between microorganisms to achieve energetic favorability. In this classic anaerobic food chain, methanogenesis represents the terminal electron accepting (TEA) process, ultimately producing equimolar CO₂ and CH₄ for each molecule of organic matter degraded. However, CO₂:CH₄ production in Sphagnum-derived, mineral-poor, cellulosic peat often substantially exceeds this 1:1 ratio, even in the absence of measureable inorganic TEAs. Since the oxidation state of C in both cellulose-derived organic matter and acetate is 0, and CO₂ has …

Soybean Cyst Nematode Hatching Behavior, Aaron K. West, Sita Thapa, Nathan E. Schroeder

PRECS student projects

The ability of soybean cyst nematodes (SCN. Heterodera glycines) to lay dormant as eggs within a cyst for up to 11 years, has made this parasite a principal target for soybean crop pest management. Research on SCN hatching will improve understanding of SCN biology will uncover new mechanisms for their control. This poster summarizes three experiments using hatching stimulants, soybean root exudate (SRE) zinc chloride, testing whether it affects post hatch development.

The Interacting Roles Of Climate, Soils, And Plant Production On Soil Microbial Communities At A Continental Scale, M. P. Waldrop, J. M. Holloway, D. B. Smith, M. B. Goldhaber, Rebecca E. Drenovsky, K. M. Scow, R. Dick, D. Howard, B. Wylie, J. B. Grace

2017 Faculty Bibliography

Soil microbial communities control critical ecosystem processes such as decomposition, nutrient cycling, and soil organic matter formation. Continental scale patterns in the composition and functioning of microbial communities are related to climatic, biotic, and edaphic factors such as temperature and precipitation, plant community composition, and soil carbon, nitrogen, and pH. Although these relationships have been well explored individually, the examination of the factors that may act directly on microbial communities vs. those that may act indirectly through other ecosystem properties has not been well developed. To further such understanding, we utilized structural equation modeling (SEM) to evaluate a set of …

Foliar Mineral Accumulation Patterns Of Gypsophiles And Their Relatives From The Usa And Spain, Clare Muller

Masters Theses

Gypsum endemism in plants (gypsophily) is common on gypsum outcrops worldwide, but little is known about the functional ecology of Chihuahuan Desert gypsophiles. We investigated whether leaf chemistry of gypsophile lineages from the northern Chihuahuan Desert are similar to leaves of related non-endemic (gypsovag) species relative to their soil chemistry. We expected widely-distributed gypsophiles, hypothesized to be older lineages on gypsum, would have distinct leaf chemistry from narrowly-distributed, relatively younger lineages endemic to gypsum and gypsovags, reflecting adaptation to gypsum. We collected leaves from 23 gypsophiles and related non-endemic taxa growing on non-gypsum soils. Soils and leaves were analyzed for …

A Revision Of Prespelea Park (Staphylinidae, Pselaphinae), Michael S. Caterino, Laura M. Vásquez-Vélez

Publications

We revise the genus Prespelea Park, redefining and redescribing the two previously known species, P.copelandi Park and P. quirsfeldi Park, and adding ten new species: P. parki Caterino & Vásquez-Vélez, sp. n., P.minima Caterino & Vásquez-Vélez, sp. n., P. morsei Caterino & Vásquez-Vélez, sp. n., P. divergens Caterino & Vásquez-Vélez, sp. n., P. carltoni Caterino & Vásquez-Vélez, sp. n., P. myersae Caterino & Vásquez-Vélez, sp. n., P. georgiensis Caterino & Vásquez-Vélez, sp. n., P. enigma Caterino & Vásquez-Vélez, sp. n., P. wagneriCaterino & Vásquez-Vélez, sp. n., and P. basalis Caterino …

Determining Effects Of Heat Stress On Illinois Soybeans, Ava Alford, Charles Burroughs, Lisa Ainsworth

PRECS student projects

Rising global temperatures affect our food supply. Heat stress could negatively affect photosynthesis, plant development, and flower and pod production. The research summarized in this poster aims to better understand which physiological processes in soybeans are negatively affected by heat stress in order to identify targets for future soybean production. Using infrared heat arrays, two different cultivars of Illinois soybeans are continually heated. Throughout the experiment, data is collected on photosynthesis, leaf area index, and overall productivity of the plant. At the end of the growing season, all of the soybean plants will be harvested and their biomass will be …

Effectiveness Of Indoor Plants For Passive Removal Of Indoor Ozone, Omed A. Abbass, David J. Sailor, Elliott T. Gall

Mechanical and Materials Engineering Faculty Publications and Presentations

Indoor vegetation is often proposed as a passive approach for improving indoor air quality. While studies of outdoor environments indicate that vegetation can be an important sink of outdoor ozone, there is scant data in the literature concerning the dynamics of ozone uptake by indoor plants. This study determined ozone deposition velocities (v_d) for five common indoor plants (Peace Lily, Ficus, Calathia, Dieffenbachia, Golden Pothos). The transient v_d was calculated, using measured leaf areas for each plant, for exposures mimicking three diurnal cycles where ozone concentrations in chamber tests were elevated for 8 h followed by …

Nebline, July 2017

NEBLINE Newsletter Archive from Nebraska Extension in Lancaster County

Feature: The Road to Great (and Safe!) Grilling

Food & Health

Farm & Acreage

Pests & Wildlife

Horticulture

Early Childhood

4-H & Youth

and other extension news and events

Induction And Suppression Of Antiviral Rna Silencing By Tomato Spotted Wilt Virus, Sergio M. Gabriel Peralta

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

Tomato spotted wilt virus (TSWV) is an emerging pathogen with wide host range and one of the most important viruses of plants. Information regarding processing of negative single stranded RNA viruses such as TSWV in the RNA silencing pathway remains limited. In nature TSWV is only transmitted by thrips as vectors and since infection occurs in both thrips and plants, an experimental system to transmit using thrips and the detection of TSWV were established. In order to understand the processing of TSWV in the RNA silencing pathway, Arabidopsis thaliana as a model plant was used in the genetic analysis against …

Dissecting The Genetic Basis Of Salt Tolerance In Rice (Oryza Sativa), Malachy Thomas Campbell

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

Excessive salt is a major factor limiting crop productivity. Rice is an important food crop worldwide, and provides a major source of calories for billions of people in tropical and subtropical developing countries. In many regions throughout Southeast Asia, rice is grown in low-lying coastal regions, which are prone to ingress by seawater. Rice is highly sensitive to salt stress, with mild salinity resulting in large reductions in yield. Improving salt tolerance in rice is essential for ensuring food security for many individuals throughput the developing world.

In this work, the overall goals were to characterize a diverse collection of …

Population-Level Coordination Of Pigment Response In Individual Cyanobacterial Cells Under Altered Nitrogen Levels, Jaclyn Murton, Aparna Nagarajan, Amelia Y. Nguyen, Michelle Liberton, Harmony A. Hancock, Himadri B. Pakrasi, Jerilyn A. Timlin

Biological Sciences Faculty Publications

Cyanobacterial phycobilisome (PBS) pigment-protein complexes harvest light and transfer the energy to reaction centers. Previous ensemble studies have shown that cyanobacteria respond to changes in nutrient availability by modifying the structure of PBS complexes, but this process has not been visualized for individual pigments at the single-cell level due to spectral overlap. We characterized the response of four key photosynthetic pigments to nitrogen depletion and repletion at the subcellular level in individual, live Synechocystis sp. PCC 6803 cells using hyperspectral confocal fluorescence microscopy and multivariate image analysis. Our results revealed that PBS degradation and re-synthesis comprise a rapid response to …

Growing South Dakota (Summer 2017), College Of Agriculture &. Biological Sciences

Growing South Dakota (Publication of the College of Agriculture, Food and Environmental Sciences)

This issue contains the 2016 SDSU Extension Annual Report.

Page] 2 From the Director
[Page] 3 WaterTouches Everything, Multi-State Network Strives to Enhance Water Stewardship
[Page] 6 From RubbleTo Renewal, Unique Art Project Helps Delmont Community Heal
[Page] 7 Future Focused, Community Development Program Helps Harness Ideas Into Action
[Page] 8 Health Help, Statewide Program Strives To Help Individuals Better Manage Chronic Health Condition
[Page] 10 Making An Impact, Master Gardener Program Helps Individuals & Communities Flourish
[Page] 12 Statewide Highlights & Happenings
[Page] 14 Outreach to Youth, Programs Foster Engagement With Diverse Youth Audiences
[Page] 17 A Look At …

The Yield Gap: Closing The Gap By Widening The Approach, Katherine A. Snyder, Sriyanie Miththapala, Rolf Sommer, Juliet Braslow

All Peer-Reviewed Publications

The yield gap has arisen again as a focus for agricultural research to ensure food security and economic growth for farmers around the world. To examine this renewed interest, we carried out a review of key literature in the field of yield gap analysis to identify important gaps in research and analysis. In so doing, both the complexities in yield gap studies emerged along with some significant omissions. Much of the literature and research on the yield gap has been framed by larger concerns and initiatives to raise agricultural productivity. This focus has led to an emphasis on technical solutions …

Conservation Farming And Changing Climate: More Beneficial Than Conventional Methods For Degraded Ugandan Soils, Drake N. Mubiru, Jalia Namakula, James Lwasa, Godfrey A. Otim, Joselyn Kashagama, Milly Nakafeero, William Nanyeenya, Mark S. Coyne

Plant and Soil Sciences Faculty Publications

The extent of land affected by degradation in Uganda ranges from 20% in relatively flat and vegetation-covered areas to 90% in the eastern and southwestern highlands. Land degradation has adversely affected smallholder agro-ecosystems including direct damage and loss of critical ecosystem services such as agricultural land/soil and biodiversity. This study evaluated the extent of bare grounds in Nakasongola, one of the districts in the Cattle Corridor of Uganda and the yield responses of maize (Zea mays) and common bean (Phaseolus vulgaris L.) to different tillage methods in the district. Bare ground was determined by a supervised multi-band …