Physical Sciences and Mathematics Commons^™

Summer Dormancy In Italian Populations Of Dactylis Glomerata L., F Lorenzetti, A Panella, E Falistocco

IGC Proceedings (1977-2023)

Mediterranean types of perennial grasses are winter-growing and summer-dormant, while central and northern European types arc winter-dormant and aummer•growing. Dormancy severely limits the annual production and largely determines the seasonal distribution pattern of the perennial grass. Summer dormancy wa• studied in 81 Italian populations of Dac!)llit glomtTata. L. collected from north (48°N) to south (38°N) on the Italian pt:ninaula. Dormancy was measured at Perugia (43°O5'N) on 60 plant.'i for each population. The percentage of summer-dormant plants was negatively correlated with the mean score for summer growth (r = -0.75**). The results distinguish three main groups of populations with increasing levels …

Growth And Development Of Two Echinochloa Millet Species In A Warm Temperate Climate, D K. Muldoon

IGC Proceedings (1977-2023)

Most summer forage crops fall into either the sorghum or the millet species group. Included in the millet group are two species, Echinochloa utilis and Echinochloa frumentacea, commonly known as Japanese barnyard millet and Indian barnyard millet, respectively. These species have a negligible HCN potential and higher nutritive value than Sorghum species. However, they generally flower early, yield less than forage sorghum , and lack vigor in regrowth. In this study the pattern of growth and development of two Echinochloa millets was examined as part of a larger program of improving the production of these forage species. E. utilis …

Test Adaptation And Evaluation Trials Of Forage Plants In Major Ecological Regions Of Ethiopia And Kenya, K M. Ibrahim, A Orodho

IGC Proceedings (1977-2023)

Kenyan and Ethiopian natural grazing Ian.cl. support more than 20% of the cattle population of the African continent. Many of the natural pastures of these countries are severely overgrazed, as unfavorable grazing conditions prevail for over half the year. Objectives of adaptation trials were to evaluate and identify introduced or indigenous forage and fodder species or ecotypes having genetic potential for high production of digestible dry matter for direct pasture and range improvement and for future use in breeding programs. Over 4,000 indigenous and 3,000 introduced ecotypes were evaluated for 24 vegetative characters in six ecological regions between 1971 and …

Collections Of Western Wheatgrass And Blue Grama And Associated Nematode Genera In The Western Dakotas, R E. Barker, J D. Berdahl, J M. Krupinsky, E T. Jacobson

IGC Proceedings (1977-2023)

Western wheatgrass (Agropyron smithii Rydb.) and blue grama (Bouteloua gracilis[Willd. ex H.B.K.J Lag. ex Griffiths) are widely distributed throughout the U.S.A. They arc two of the predominant native grasses in rangelands in the northern Great Plains. Because suitable cultivars are not always available for reseeding disturbed areas, we collected plants of the two species and evaluated phenotypic variability to determine potential for breeding improvement. We also sampled the nematode popula­tion associated with the collections. Sampling sites were systematically chosen by establishing a grid pattern 19 .3 km apart in the western halves of North Dakota and South Dakota. …

Neutral Detergent Fiber And Protein Levels In Diploid And Tetraploid Ryegrass Forage, L R. Nelson, F M. Rouquette Jr

IGC Proceedings (1977-2023)

Nutritive value of 18 ryegrass (Lolium multifloriumLam.) cultivars was studied at Overton, Te1

0.42-mm screen. Plots were harvested four times during each of the first 2 years and five times in the third year. In 1977-1978 and 1978-1979, NDF and protein analyses were run on samples from 2 replications. All forage samples were analyzed for pro­tein via the micro-Kjeldahl technique. Percentages of NDF were obtained via Van Soest extraction procedures. A seasonal increase in neutral detergent fiber (NDF) content and a decrease in protein percentage was observed. Differences in NDF were observed among cultivars and were most apparent during …

Forage Quality Of Barley Straw As Influenced By Genotype, D W. Meyer, D O. Erickson, A E. Foster

IGC Proceedings (1977-2023)

Cereal straw is an untapped carbohydrate source for ruminant animal feeds, but little information is available on genotypic differences in the feeding value of barleys (Hordeum vulgare L.) commonly grown in the northern Great Plains of the U.S.A. Our objective was to determine if barley genotypes differ in straw forage quality and if straw-quality parameters are associated with agronomic characters. Straw from 37 and 31 barley genotypes was sampled in 1977 and 1978, respectively. Straw from 10 barley genotypes grown at four locations was sampled in 1979. Standard laboratory procedures were used to determine the quality parameters measured. Correlations …

Alfalfa Breeding For Forage Yield And Low Saponin Content, P Rotili

IGC Proceedings (1977-2023)

The objective of our breeding program is to build alfalfa (Medicago satia L.) varieties, having good vigor and persistence, high protein level, and low ,aponin content. The: breeding method utilizes a selfing phase combined with selection in competitive conditions. Leaf-saponin content was analyzed by the Tn'choderma viridc bioassay. Parent populations (cv. Leonicena and Cantoni), S0, S1., and S2, families :1 were evaluated 11ndcr competitive and &equcnt culling conditions. In both populations, some S1, families yield more than their respective S1 family. Vuiatioo in yield and mortality increased with the level of selfing, and 1ome S2 families showed lower minimum values …

Productivity Of Forage Legumes On Rice-Paddy Walls In Northeast Thailand, R G. Gutteridge

IGC Proceedings (1977-2023)

Rice stubble left standing in paddy fields after rice harvest is the major source of forage for livestock in the dry season in northeast Thailand. Although the quantity of thi5 1tubble is generally not limiting, its quality as a forage is very low, and substantial live-weight losses in livestock usually occur by the end of the dry season. A trial was conducted to evaluate a range of forage legumes that could be grown on rice-paddy walls to supplement rice stubble as a dry-season feed. Seven legumes were planted at two sites in villages close to Khon Kaen in northeast Thailand. …

Development Of Gama Medic {Medicago Rugosa Desr.) As An Annual Leguminous Species For Dryland Farming Systems In Southern Australia, E J. Crawford

IGC Proceedings (1977-2023)

Annual medics (Medicago spp.) are the basic legume for nitrogen fixation in the alkaline soils of southern Australia. Not all in­dividual species are well adapted to all soil types, one difficult soil being the highly alkaline clay loam where annual rainfall is less than 500 mm. The first gama medic (M. rugosa) cultivar, Paragosa, was well adapted to the clay-loam soil type but proved to be susceptible to germination after summer thunderstorms, and seedlings died in the following drought. Many gama medic accessions were then grown in an attempt to select a genotype capable of maintaining seedcoat impermeability during …

Evolution Of Selection Techniques In Breeding For Bloat-Safe Alfalfa, B P. Goplen, R E. Howarth, G L. Lees, W Majak, J P. Fay, K J. Cheng

IGC Proceedings (1977-2023)

This report summarizes the Canadian breeding program to develop a bloat-safe alfalfa (Medicago sativa L.). This program has experienced an evolution of selection methods in attempting to identify bloat-safe alfalfa genotypes. In chronological order, the methods involved selection for fraction I (18S) protein, soluble proteins, foam volume, tannins (flavolans), saponins, initial rate of digestion (IRD), sonication, purified enzymes, gas production, and leaching. Although soluble herbage protein is correlated with the occurrence of pasture bloat, we have experienced slow progress in a selection program to reduce soluble-protein concentration in alfalfa. We have found that foam volume is not correlated with …

Evaluation Of Within-Half-Sub Family Selection From Leo Birdsfoot Trefoil, D T. Tomes, O U. Onokpise, B E. Twamley

IGC Proceedings (1977-2023)

This research was undertaken to evaluate the effectiveness of within-half-sib family recurrent selection for seedling vigor, seed yield, and forage yield in birdsfoot trefoil (Lotus comiculatusL. cv. Leo). The effectiveness of selection was measured by comparing progeny performance, genetic variance, and heritability in selected and unselected populations. In addition, cx­perimc.ntal synthetic• (Syn-2 generation) from the selected population were compared to Leo for forage yield and seed yield in several trials. Seedling vigor and yield in 1979, and forage yield in 1980, of polycross progeny in the selected population were significantly higher than those of similar progeny in the unselected …

Breeding Centrosema Pubescens Better Adapted To Acid Infertile Soils Of South America, E M. Hutton

IGC Proceedings (1977-2023)

Centrosema pubescen, Benth. {centro) in tropical South America depends upon the development of lines with increased tolerance to high acidity and aluminum (Al). This study classified levels of acid tolerance among Centrosema introduc­tions and crosses of promising introductions. Initially, greenhouse and field evaluations in Carimagua oxisol (pH 4.5, 90% Al saturation) were used. Introductions of C. schottii and C. pascuorom died, while most C. virginianum and C. Uutifolium and a few C. pubescens had low acid tolerance. Most C. pubescens introductions had medium acid tolerance, whereas C. macrocarpum and C. schiedanum were highly acid tolerant. The degree of acid …

Comparison Of Italian Ryegrass And Meadow Fescue With F2, F3, F4 Hybrids Of Both Grass Species, H Kaltofen, E Wojahn

IGC Proceedings (1977-2023)

In forage-grass breeding there is an increasing interest in hybrids of Italian ryegrass (Lolium multiflorum Lam.) and meadow fescue (Festuca pratensis Huds.). The objective of this study was to investigate some agronomic properties of such Festulolium hybrids with special reference to the question of whether these hybrids change from one generation to the next. In a pot experiment with four levels of nitrogen fertilization, Italian ryegrass and meadow fescue as well as F2, F3, and F4 hybrids of the two grass species were examined for 2 years. In each year four cuts were taken. All the F2, F3, …

Effective Selection For Tolerance To Grass-Killing Herbicides In Perennial Ryegrass (Lolium Perenne L.), C E. Wright, J S. Faulkner

IGC Proceedings (1977-2023)

The aim of grassland reseeding is to establish a high-quality sward of improved herbage cultivars. To obtain the maximum value from the improved sward, weed invasion should be prevented. Herbicides are the main tool available. There are many herbicides for selectively controlling dicotyledonous, but not graminaceous, weeds. The control of graminaceous weeds would be possible in swards of grass cultivars selected for tolerance to grass-killing herbicides. Two cycles of recurrent selection for glyphosate tolerance in Lolium perenne L. were carried out by spraying large seedling populations with critical dosages in the greenhouse and intercrossing the survivors. It was found that …

Selection For Specific Leaf Weight In Reed Canarygrass And Its Effects On The Plant, I T. Carlson, D K. Christensen, R B. Pearce

IGC Proceedings (1977-2023)

Specific leaf weight (SL W, dry weight/unit leaf area) may serve as a selection criterion for forage yield through a positive rela• tionship with photosynthesis. Two cycles of phenotypic selection for high and low SLW were conducted in reed canarygrass (Phalaris anmdinacea L.) to investigate direct and correlated responses, particularly those related to yield and quality of forage. In a space-planted test, average direct responses from two cycles of selection for high and low SLW were 23% and 19%, respectively. Significant correlated responses were obtained for ten traits. Compared with the low-SLW cycle-2 population, the high SLW cycle-2 population averaged …

Value Of White Sweet Lupin In Production Of Protein Fodder And Feeding Of Animals, O Saric, I Ramosevac

IGC Proceedings (1977-2023)

The potential of white sweet lupin (Lupinus albus L.) as a grain or forage feed for livestock was investigated in a series of ex­periments. Grain yield of lupin was greater than or equal to that of soybeans (Glycine max [L.] Merrill) in most evaluations. The quality of lupin seed compared favorably with that of soybean meal and fishmeal. Lupin is capable of producing large amounts of forage in a short period, making it a good prospect for forage production in regions that have a short growing season.

Genetic Variability For Morphological And Agronomic Characters In Desmodium Uncinatum (Jacq.) D.C. And D. Intortum (Mill.) Urb., E.M P. Oliveira, P S. Martins, A B. Cruz

IGC Proceedings (1977-2023)

Objectives of this research were to study the performance of eight populations of D. unicinatum and ten populations of D. intortum, with relation to morphological and agronomic characters to estimate the genetic variation between populations and between plants within populations, and to estimate genetic and phenotypic parameters for these characters.

White Clover: An Olde Crop With A Promising Future, P B. Gibson, W E. Knight, G W. Barnett, W A. Cope, J D. Miller

IGC Proceedings (1977-2023)

White clover (Trifolium repens L.) is a widely adapted, important forage legume for grazing in the U.S. The palatability and quality of the forage, the wide adaptation of the plants to growth in different climates and under various grazing conditions and the role it plays in supplying nitrogen to pastures make white clover our finest pasture legume. The use of adapted white clover cultivars should result in large economic gains to the livestock industry in the U.S .A. Beef and dairy farmers would profit from reduced need for nitrogen fertilizer, an extended grazing season, increased forage pro­duction and quality, better …

Performance And Variability Of Agronomic Characters In Populations Of Stylosanthes Guianensis (Aubl.) Sw., P S. Martins, N A. Vello

IGC Proceedings (1977-2023)

Stylosanthes guianens-is (Aubl.) Sw. shows wide variations in morphological and physiological characteristics, and basic infor­mation on genetic variability is needed for future breeding programs. The objectives of this paper were to evaluate 25 native Brazilian populations of S. guianensis for forage characteristics · • ;10,d • to estimate genetic and phenotypic parameters for these characters. The experiment was conducted in a duplicated 5 x 5 balanced lattice design with plots that contained 4 individuals spaced on 2-m centers. The following characters were evaluated after the beginning of flowering period: days to flowering (DF), mean diameter (MD), basal area (BA), growth …

Rhizoma Peanut: Perennial Warm-Season Forage Legume, G M. Prine

IGC Proceedings (1977-2023)

Rhizoma peanut is the common name given species in section Rhizomatosae of the genus Arachis. Florigraze rhizoma peanut (A. glabrata Benth.) has been released as a cultivar by the Florida agricultural experiment stations and the USDA Soil Conserva­tion Service. Florigraze is adapted to the well-drained soils of Florida and the warm humid tropics and subtropics around the world. Rhizoma peanuts are propagated by rhizomes, which in Florida are best planted during winter. The slowness of coverage during early establishment is the biggest shortcoming of rhizoma peanuts. If they are established first, rhizoma peanuts will grow well in mixture with bermudagrass …

Hedysarum Mongolicum Turcz.: An Important Protein Resource Legume On Dry Sandy Land, Li Min, A W. Hovin

IGC Proceedings (1977-2023)

In searching for plants that can both increase the protein production and improve the sandy-soil conservation of the grassland in the arid, windy regions of North China, so far, from among many native plants, we have identified Hedysarum mongolicum Turcz. as the best species to fulfill our dual purposes. We investigated its distribution, planted its native seeds in the Maowusu desert, and studied it under its native and cultivated growing conditions from 1957 to 1964. Chinese farmers call this perennial subbrush legume of the sweetvetcb genus "Yang Cai," meaning "sheep like to eat." It can thrive in the stable or …

Adaptation And Utilization Of Three Legume In China, Huang Wenhui

IGC Proceedings (1977-2023)

China is a vast territory with extremely varied climates, soil, and topography, and it is very rich in pasture grass resources. The main legumes for forage are Alfalfa (Medicago sativa L.), yellow alfalfa (Medicago folcata L.) and shadawang (Astragalis adsurgent Pall.)

Preliminary Evaluation Of Legume Germ Plasm In The Cerrados Of Brazil, D Thomas, R P. De Andrade

IGC Proceedings (1977-2023)

In 1978 an evaluation program was initiated to select legumes that (1) grow and produce seed on acid soils under aluminum and water stress, (2) persist under grazing, and (3) tolerate pests and diseases. The work is being conducted at the Cerrados Agricultural Research Center, near Brasilia, at lat 15°S and altitude 1,000 to 1, 100 m . Annual rainfall is 1,500 mm, mostly distributed in a 6-month wet season, and mean annual temperature is 21°C. Nine hundred legume accessions from thirteen genera have now been established as spaced plants on the 2 major soil types of the region. The …

Genetics And Utilization Of Apomixis For The Improvement Of Guineagrass (Panicum Maximum Jacq.), Y H. Savidan

IGC Proceedings (1977-2023)

Natural polymorphism in guineagrass (Panicum maximumjacq.) has been stabilized in tetraploid biotypes by apomixis. Sex­ual diploids were found in East African populations. Our objective was to determine whether apomixis could be related with a simple genetic background and manipulated in an improvement program. Apomicts of guineagrass are characterized by a 4-nucleate embryo sac structure, and this trait was used in genetical analyses to differentiate apomictic from sexual hybrids. Progeny tests were also conducted as controls. Ten different types of progenies were analyzed: tetraploid sexual (from colchicine treatment of diploids) x apomictic F1 hybrids; selfed and backcrossed progenies of sexual F1 …

Breeding Challenges In Apomictic Warm-Season Grasses, E C. Bashaw, P W. Voigt, B L. Burson

IGC Proceedings (1977-2023)

Efforts to breed apomictic grasses met with little success in the past, but results of more recent research show significant progress with some species and new prospects for improving apomicts. Early research uncovered the cytological basis for apospory and diplospory, found the common apomictic mechanisms in grasses, and showed that apomixis is transmitted from pannt to offspring. Discovery of sexual or partially sexual (facultative apomicts) plants in several species formerly considered obligate apomicts allowed for hybridization and genetic studies. Results of subsequent research confirmed inheritance of apomixis, and data from the more conclusive studies indicate that method of reproduction …

A Symbolic Model Of Proof Acquisition In Act-R, Beckett Morris, Kerstin Haring

DU Undergraduate Research Journal Archive

Learning to construct mathematical proofs—formal arguments demonstrating the truth of a mathematical statement using logical deductions and previously established facts—is one of the most challenging skills in STEM education. This research aims to build the foundations for a symbolic cognitive model, using the ACT-R cognitive architecture and implementing in Python with the pyactr package, to explore how different proof strategies can be thought through with only symbols and rules. The model observes simple proofs, and its abilities are assessed based on its generalization capabilities, efficiency, and error patterns. By developing and analyzing such a model, this research provides new insights …

Visualizing Ozone Pollution In The Denver Metro Area Using A Bioindicator Garden, Ella K. Mathews, Hillary Hamann, Julie Morris, Erica L. Larson

DU Undergraduate Research Journal Archive

Since the industrial revolution, widespread fossil fuel combustion has significantly increased atmospheric pollution. The combustion of fossil fuels releases nitrogen oxides (NOx) and volatile organic compounds (VOCs), which form tropospheric (ground-level) ozone when exposed to sunlight. Ozone directly harms plants by disrupting their ability to absorb carbon dioxide, release oxygen, and carry out photosynthesis. Bioindicator species are plants that have visible responses to environmental conditions, such as ozone, and can act as “canaries in the coal mine,” indicating the health of their environment. In this study, we used a garden of ozone bioindicator species (ozone garden) as a cost-effective tool …

Generation Z And The Ai Misinformation Paradox: Understanding A New Digital Vulnerability, Cecilia Cooley, Elizabeth Sperber

DU Undergraduate Research Journal Archive

This paper asks: How and why is Generation Z more vulnerable to AI-generated misinformation and disinformation than older generations? Using a comparative review of recent empirical studies, survey data, and meta-analyses from 2019–2025, this paper synthesizes research on Gen Z’s exposure to and interaction with AI-produced content across social media platforms. Although it is commonly assumed that Gen Z ’s technological exposure and fluency make them better equipped to recognize false information, findings show the opposite: Gen Z is consistently outperformed by older cohorts in detecting AI-generated falsehoods. This vulnerability stems from three intersecting factors: (1) the sheer volume of …

Du Undergraduate Showcase Abstracts: Research, Scholarship, And Creative Works, Sophia Wismar, Henry Staats, Allison Metzler, Chloe Puckett, Rachel Levine, Christa Kilpatrick, Scott Wolf, Joe Walsh, Grace Doolittle, John Engebreston, Zoe Lopez, Christopher Aaby, Audrey Duff, Timothy Sisk, Katelyn Lamberton, Angela Narayan, Gilkah Argueta, Habiba Samir, Girena Tesfazghi, Genet Kenore, Sinit Tesfamariam, Effley Brooks, Abi Newell, Megan Doherty, Natalie Baer, Lexi Blood, Talya Riciputi, Jessica Jimenez, Devin Hernandez, Lynn Clark, Taj Kumar, Sunil Kumar, Allen Rutman, Mira Pronobis, Tess Carson, Anna Sher, Frankie Stroud, Tamra Pearson D'Estree, Alyssa Wilson, Emily Melnick, Jenalee Doom, Yihang Gao, Gwendolyn Geiger, Noah Gettle, Scott Nichols, Clare Ayoub, Cara Dienno, Sunny Walker, Zoe Hansen, Maya Wheeler, Addison Rice, Patrick Martin, Sanjana Acharya, Daniel Mcintosh, Amanda Mckellips, Calli Cain, Justin Blake, Peter Sokol-Hessner, Natalie Miller, Max Weisbuch, Sophia Dellota, John Macikas, Charlotte Snow, Mark Siemens, Zoe Lynch, Alex Huffman, Prachi Shah, Jason Roney, Halcyon Levi, Nicole Herzog, Andrea Koly, Daniel Linseman, Annie London, Xi Yang, Avery Zwisler, Jane Smith, Chaz Contag, Michael Kerwin, Lucy Rand, Grace Schroeder, Michelle Rozenman, Nissa Tapper, Guiming Zhang, Mateo Mazariego-Halpern, Keith Meyer, Julie Do, Dakota Park-Ozee, Travis Herink, Kara Neu, Jonathan Plomin, Eve-Odine Duchaufour, Debbie Gale Mitchell, Tennyson Anderson-Stricklin, Lily Treitz, Samantha Rosenberger, Sierra Griffith, Finley Joseph, Daniel Sampson, Emmy Davis, Skyler Kasnoff, Evon Lopez, Vivian Nguyen, Cassy Young, Franklin Sellner, Martin Tobon, Ila Graham, Zach Billings, Holden Hedit, Decatur Boland, Paul Kosempel, Cory Chandler, Jay Mahoney, Sam Dragan, Susan Dagget, Yarrow Ator, Heidi Vuletich, Owen Weber, Andrew Kloeppel, Petersen Gray, Mandi Schaeffer-Fry, Razleen Bassra, Bryanna Rodriguez, Christina Blue, Taubie Sanders, Rachel Epstein, Luke Milburn, Camryn Evans, Ezra Martinez, Mary Westwood, Gabri Notov, Robin Tinghitella, Lilou Cabrol, Eli Barbour, Juliet Mendik, Selma Myers, Zac Wise, Noah Fahlin, Michelle Knowles, Abigail Hopper, Michael Greenberger, Romi Laclair, Sarah Watamura, Sabrina Efroymson, Casey Barker, Sydney Seltzer, Bryn Yehle, Jennifer Hoffman, Sara Garcia, Ryuka Nagamine, Trevor Briggs, Remy Le Boeuf, Elena Krone, Eileen Farrell, Regan O'Rourke, Elena Roel, Greg Mortimer, Ali Ayoub, Stefani Langehennig, Caitlin Turk, Logan Scmid, Stefan Chavez-Norgaard, Karen Kim, Tatiana Peccedi, Courtney Cassidy, John Sebesta, Rhianna Lewis, Janice Bening-Lacek, Vivian Lawless, Mckenna Hanson, Jeffrey Amidon, Riya Joshi, Ram Ambre, Brady Worrell, Perrin Schneider, Ali Azadani, Brooke Agulnek, Lyndsie Salvagio, Elise Siemanowki, Yan Qin, Andre Allen, Melodie Nguyen, Megan Livengood, Abby Reams, Saffron Hartreeve, Bri Wylie, Sarah Brookman, Mariah Loiacono, Green Russo, Abhia Lodhi, Gabrielle Welsh, Nika Spehar, Shahked Levin, Evrim Baykal, Kimberly Chiew, Jocelyn Torres, Kailey Hicks, Mykaela Tanino-Springsteen, Audrey Bellows, Akam Chahal, Madeline Tepper, Shannon Murphy, Alexa Fonseca, Deborah Han, Cassandra Perez, Oluwatoyin Alaba, Julia Roncoroni, Vy Nguyen, Nana Burn, Sarah Sasse, Rubin Tuder, Anthony Gerber, Nancy Lorenzon, Christine Vohwinkel, Camryn Gunter, Tristan Weber, Sam Rommel, Brian Michel, Muskan Fatima, Alannah Oleson, Kira Frey, Edward Garrido, Beckett Morris, Kerstin Haring, Drew Middleton, Abigail Walpert, Liam Dee, Gabby Ishaw, Cole Carnes, Maddie Weiser, Claire Fox, Valeriia Vlasenko, Kateri Mcrae, Riley Smith, Abigail Templin, Kushani Rajapaksha

DU Undergraduate Research Journal Archive

Abstracts from the DU Undergraduate Research Showcase.

2026 May 28 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.