Plant Biology Commons^™

Light Interception And Dry Matter Yield In Grass/Legume Mixtures, H. A. Jönsson

IGC Proceedings (1977-2023)

The influence of grass variety on light interception and dry matter yield in a grass/clover mixture was studied. Two varieties of timothy (Phleum pratense L.) and five varieties of ryegrass (Lolium spp) as components in a mixture were compared during the spring period up to the first cut of the third harvest year. By replacing the timothy variety in the mixture both light interception and dry matter yield were significantly affected. The leaf orientation was thought to be a contributing factor with erect leaves intercepting less light. There were no significant differences neither in light interception nor …

Photosynthetic Light Response Of Tanzania Grass Under Four Levels Of Leaf Temperature, A. C. L. De Mello, P. M. Santos, Carlos G. S. Pedreira, M. Corsi, C. T. Dos S. Dias

IGC Proceedings (1977-2023)

The purpose of this paper is to establish photosynthetic light response curves for Tanzania grass (Panicum maximum Jacq.) under four leaf temperature levels. Photosynthetic rate was measured as a response to levels of photosynthetic photon flux density (PPFD) on the youngest fully expanded leaves of 12 representative tillers with an infra red gas analyzer. The effect of PPFD was tested for each leaf temperature level in a randomized complete block design. Photosynthetic light response curves were adjusted for each leaf temperature using a non-linear hyperbolic model. The maximum photosynthetic response was 25,59; 31,43; 34,57 and 27,53 µmol CO_{2 …}

Nonstructural Carbohydrate Reserves Of Temperate Perennial Grasses In Autumn Early Growth, Y. Tamura, K. Matoba, A. Fushimi, M. Moriyama

IGC Proceedings (1977-2023)

The objective of this study was to determine levels of nonstructural carbohydrate reserves of four temperate perennial grasses: Orchardgrass (Dactylis glomerata L.), Timothy (Phleum pratense L.), Perennial ryegrass (Lolium perenne L.), and Reed canarygrass (Phalaris arundinacea L.) in their early growth stages during the cool autumn temperatures in northern Japan. At the time of sampling, all grasses were in their vegetative stage, and Reed canarygrass was not forming rhizomes. Fructosan concentration in reed canarygrass roots (8.04%) was 22 times that of the leaf blade (0.36%) and twice that of the stem (3.40%); the concentration in reed …

Effect Of Cutting Height On Tiller Population Density And Herbage Biomass Of Buffel Grass, L. S. Beltrán, P. J. Pérez, G. A. Hernández, M. E. García, S. J. Kohashi, H. J. G. Herrera

IGC Proceedings (1977-2023)

The aim of this trial was to investigate the effect of different cutting heights on tiller population density and herbage biomass of Buffel grass (Cenchrus ciliaris L) grown in miniature swards in a greenhouse. Four treatments with five replicates: five cm, ten cm, and 20 cm cutting height, and control (without cut) were randomly allocated. Intensity of defoliation affected the cumulative herbage harvested; the ten cm cutting height was greater (404.1 g DM m^-2) than 5 cm (317.6 g DM m^-2) and 20 cm (263.9 g DM m^-2), respectively. Cumulative herbage harvested in …

Leaf Appearance Rate In Brachiaria Decumbens Grown In Nitrogen And Potassium Rates, M. D. C. Ferragine, F. A. Monteiro, S. C. Da Silva

IGC Proceedings (1977-2023)

A greenhouse experiment was carried out with Brachiaria decumbens Stapf. cv. Basilisk grown in nutrient solution. Five nitrogen rates (42; 140; 238; 336 and 434 mg/L) and three potassium rates (78; 234 and 390 mg/L) were studied in a factorial experiment, in a randomized complete block design, with four replications. Green leaf number was evaluated in six times in the first period of growth (27, 30, 33, 36, 39 and 42 days after transplanting) and nine times in the second period (45, 48, 51, 54, 57, 60, 63, 66 and 69 days after transplanting). Data was registered in three plants …

Morphogenesis And Defoliation Frequency Of Italian Ryegrass (Lolium Multiflorum) And Paspalum Urvillei In Lowland Under Three Levels Of P And K, Fernando L. F. De Quadros, A. G. S. Pigatto, D. G. Bandinelli, E. Marchezan, Marta G. Da Rocha

IGC Proceedings (1977-2023)

This trial was conducted to evaluate growth dynamics and defoliation frequency of Italian ryegrass (Lolium multiflorum) and Paspalum urvillei in a lowland area under three levels of P and K. Using randomization tests we observed that, in a general way, fertilizer treatments were not the determinant factors of leaf appearance and elongation rates for both species. Only the leaf appearance rate of Paspalum urvillei at 100 % of recommendation level and the elongation rate for Italian ryegrass, in the same treatment, was different. Probably other factors, like drainage, are contributing to these results. I. ryegrass phyllochron ranged from …

Variability In Herbage Mass And Chemical Composition Within A Timothy Sward, O. Niemeläinen, E. Miettinen, P. Virkajärvi, L. Alakukku, K. Hakala

IGC Proceedings (1977-2023)

Variability in herbage mass (HM) and chemical composition of timothy (Phleum pratense L.) sward was studied in a three-hectare field. The field, which was flat, was divided into twelve sections and a sampling site was randomly selected in each. The study was carried out in Sotkamo (64^o 01’N, 28^o22’E) research station in Finland. Snow depth and frost conditions were measured in winter and soil water content was monitored in the growing season at each sampling site. Observations on the crop included assessment of herbage ground cover and winter damage percentage, stand height and HM and analysis …

Effects Of Temperature, Nitrogen Fertilisation And Leaf And Tiller Age On Specific Leaf Area Of Brachiaria Decumbens, J. Busqué, M. Herrero

IGC Proceedings (1977-2023)

Signal grass (Brachiaria decumbens Stapf) micro-swards were grown under controlled environmental conditions at different temperatures and nitrogen fertilisation rates. Specific leaf area was responsive both to temperature and nitrogen, but did not change with the level of insertion of the leaf in the tiller. Senescing leaves had higher specific leaf area than old extended green leaves and these had higher values than new extended green leaves. Changes in specific leaf area were more related to changes in leaf area and more exactly to changes in leaf width.

Mutations In Several Auxin Biosynthesis Genes And Their Effects On Plant Phenotypes In Arabidopsis, Gabriela Hernandez, Lauren Huebner, Bethany Karlin Zolman

Undergraduate Research Symposium

Auxins are important hormones in plants that regulate growth and development. Disruptions in the auxin biosynthesis pathway result in morphological changes in phenotypes in the model plant Arabidopsis thaliana, including differences in root and leaf formation. Mutations in the Tryptophan Aminotransferase of Arabidopsis (TAA1) and YUCCA (YUC4) genes interfere with the plant's ability to synthesize Indole-3-acetic acid (IAA), the primary auxin involved in plant development. IBR1 and IBR3 act in the multistep conversion of indole-3-butyric acid (IBA) to IAA. ILL2, IAR3, and ILR1 hydrolyze IAA-amino acid conjugates into free IAA. The goal of …

The Use Of Cover Crops After A Maize Crop In The North Of Spain, D. Báez, M. Pinto, M. Rodríguez, G. Besga, J. M. Estavillo

IGC Proceedings (1977-2023)

This work intends to study N leaching losses in a field assay when crimson clover (Trifolium incarnatum) and italian ryegrass (Lolium multiflorum) was incorporated into the soil and quantify the their effect on N₂O, N total gaseous losses under controlled soil moisture and temperature conditions. Field assay: A split-plot design where main plot was the cover crop and the subplot was the rate of fertilizer (0 and 150 kg N ha^-1) applied to the subsequent maize crop. Laboratory assay: Residues of italian ryegrass and crimson clover were mixed with soil in containers, …

Multi-Year Application Of Dairy Slurry On Grassland: Effects On Crop, Soil Biota, Soil Nutrients, And N2O Emission, Shabtai Bittman, C. G. Kowalenko, D. E. Hunt, N. Patni, J. Paul, D. Raworth, J. Hountin, T. A. Forge, C. M. Monreal, O. Schmidt

IGC Proceedings (1977-2023)

The long-term effects of using manure as the principal nutrient source in intensive crop production systems are not well known. This paper reports on the effects of multi-year application of fertilizer or dairy slurry on a tall fescue (Festuca arundinacea Schreb.) sward. Slurry sustained greater grass yield than chemical fertilizer. Unlike fertilizer, slurry supplied 70 to 120 kg N/ha one year after application but little after one year; 4-years of manure applications built up the stable organic matter pool in the soil. Manure-N was less prone to leaching but more prone to N₂O emissions than fertilizer-N. Manured …

Sewage Sludge As An Alternative Fertilizer For Tropical Pasture Grasses, M. B. Adjei, J. E. Rechcigl

IGC Proceedings (1977-2023)

This study was conducted to determine the effects of source (Liquid sludge at pH 7 (LS7) or pH 11 (LS11), cake biosolid (CB) or ammonium nitrate (AM)) by rate (0, 80 or 160 kg ha^-1) of N application on bahiagrass forage yield, quality and tissue composition. Same plots were fertilized in March 1998 and 1999. Forage yield was measured at 30 d intervals from May through November and subsamples were dried and ground for quality analyses. The 2-year mean forage yield was similar for AM, LS7 and LS 11 fertilizer applications. Forage yield from CB application was 30% …

Phosphorus Fertilizer And Stocking Rate Effects On Soil Microbial Biomass Of A Long-Term Dairy Farmlet Experiment, S. R. Aarons, C. R. O’Connor, C. J. P. Gourley

IGC Proceedings (1977-2023)

The effects of a range of P fertilizer rates and dairy cow stocking rates on microbial biomass carbon and phosphorus were compared in a long-term farmlet trial in southeastern Australia. Pastures were stocked at 2, 3, or 4 cows/ha and received fertilizer at rates of 0, 35, 70 or 140 kgP/ha. There was no effect of either P fertilizer rate or stocking rate on microbial biomass C from 1995 to 1998. Increasing P application rate significantly increased the chloroform-released microbial P flush measured, but stocking rate had no effect on microbial P. There were significant temporal changes, with the seasonal …

Dry Matter Accumulation And Partitioning Between Vegetative And Reproductive Organs In Alfalfa (Medicago Sativa L.), E. D. Bolaños-Aguilar, Christian Huyghe, B. Julier, C. Ecalle

IGC Proceedings (1977-2023)

This work investigated the partitioning of dry matter between vegetative and reproductive plant organs in alfalfa during the reproductive period under field conditions. Two French varieties (Europe and Magali) were studied. Both varieties showed similar growth pattern of the different plant organs in 1998 and 1999. The mean dry matter of vegetative organs (shoots and leaves) over the two years was higher in Europe (567g/m²) than Magali (470g/m²). No vegetative growth was observed during the reproductive period. The root organs (measured to a depth of 0.20 m) and the reproductive organs showed an increase in dry …

Herbage Seed Production Possibilities In Finland, O. Niemeläinen, M. Kinnari

IGC Proceedings (1977-2023)

In the seed production variety experiments in Finland from 1977 to 1992 the mean seed yield of timothy (Phleum pratense) cultivar Alma was 717 kg ha^-1, of meadow fescue (Festuca pratensis) cv. Boris 622 kg ha^-1, of tall fescue (Festuca arundinacea) cv. Retu 350 kg ha^-1, of perennial ryegrass (Lolium perenne) cv. Riikka, of cocksfoot (Dactylis glomerata) cv. Haka 295 kg ha^-1, and red clover (Trifolium pratense) cv. Hankkijan Venla 403 kg ha^-1. From 1988 to 1998 annual …

Center For Grassland Studies, September 2021

Center for Grassland Studies: Newsletters

Contents

Nebraska Grazing Conference Recap by Daren Redfearn

Center for Grassland Studies Policy Advisory Committee

Director's Column by Walt Schacht (Interim Director)

Land Use and Property Taxes by Jordan Johnson

Congratulations August 2021 Graduates

Wildfires are Changing the Future of Nebraska’s Woodland-Grassland Complexes by Amanda Hefner

PGA WORKS Scholarship Recipients Announced by PGA Reach

Grazing Livestock Systems Internships Provide Diverse Experience by Bryan Reiling

Jim Choquette Receives Lifetime Achievement Award

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 …

Arkansas Wheat Performance Tests 2020-2021, J. F. Carlin, R. D. Bond, D. E. Moon, R. B. Morgan

Arkansas Agricultural Experiment Station Research Series

Wheat variety performance tests are conducted each year in Ark- ansas by the University of Arkansas System Division of Agriculture’s Arkansas Agricultural Experiment Station, Department of Crop, Soil, and Environmental Sciences. The tests provide informa- tion to companies developing varieties and marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating variety recommendations for small-grain producers. The tests are conducted at the Northeast Research and Extension Center at Keiser, the Vegetable Substation near Kibler, the Lon Mann Cotton Research Station near Marianna, the Jackson County Extension Center near Newport, the Pine Tree Research Station near Colt, …

Genetic Diversity And Population Structure Of Sugarcane (Saccharum Officinarum L.) Collected From Seven Philippine Regions For Use As Breeding Stocks For Crop Improvement, Jan Leandro Acedera, Jhun Laurence Rasco, Jemimah Banganan, Antonio Lalusin

The Philippine Agricultural Scientist

Selection of parents for hybridization relies on the information on their genetic relationship and diversity which are essential in any breeding program. This study aimed to estimate the extent of genetic diversity and population structure of 76 sugarcane accessions from seven regions in the Philippines using 57 morphological characters and 50 microsatellite markers. The sugarcane collections exhibited moderate to high diversity with mean of H’ = 0.72 for qualitative and H’ = 0.75 for quantitative morphological characters, respectively. This is corroborated by the analysis of variance (ANOVA) of agronomic parameters, except for stalk length. Unweighted Pair Group Method with Arithmetic …

Three Lc-Ms Plant Metabolomics Studies Of Hop (Humulus) Species: Wild H. Neomexicanus, Drought Stress, And Agricultural Terroir, Taylan Morcol

Dissertations, Theses, and Capstone Projects

The hop plant (Humulus L., Cannabaceae) is a dioecious, perennial, twining vine with a long history of human use. Nowadays, hop plants are generally grown for their inflorescences (“cones”), which are used in brewing for their phytochemical metabolites. Many of these metabolites are involved in plant stress response and communication. Genetics and environment are two major factors that affect plant metabolism. In three separate metabolomics studies, this project examined the effects of both genetic and environmental factors on hop phytochemistry.

In the first study, 23 hop genotypes were grown in two different locations in the Pacific Northwest region of …

A Susceptible Exposed Infected Recovered Susceptible (Seirs) Model For The Transmission Of Tuberculosis, Latifat M Erinle-Ibrahim, Waheed O Lawal, Olukayode Adebimpe, Gbemisola R Sontan

Tanzania Journal of Science

In this paper, a deterministic mathematical model was proposed and analyzed to understand the dynamics of tuberculosis based on the SEIRS model. The disease-free equilibrium, the endemic equilibrium, and their stabilities were examined. The R0 (basic reproduction number) was derived using the Next Generation Matrix method and its sensitivity analysis showed that the birth rate and infectious rate were the most sensitive parameters of R0. The behaviour of exposed individuals at the latent period with varied treatment rates were examined through numerical simulation. From the analysis carried out, the effect of variations of the treatments of latent TB shows that …

Mathematical Programming Model For The Two-Level Facility Location Problem: The Case Of Tanzanian Emergence Maize Distribution Network For 2004–2010 Maize Data, Said A. Sima

Tanzania Journal of Science

A two-level facility location problem (FLP) has been studied in the transportation network of emergence maize crop in Tanzania. The facility location problem is defined as the optimal location of facilities or resources so as to minimize costs in terms of money, time, distance and risks with the relation to supply and demand points. Distribution network design problems consist of determining the best way to transfer goods from the supply to the demand points by choosing the structure of the network such that the overall cost is minimized. The three layers, namely production centres (PCs), distribution centres (DCs) and customer …

Evaluation Of Antibacterial Activities Of Tanzanian Moringa Oleifera Extracts Against Escherichia Coli And Klebsiella Pneumonia Clinical Isolates, Sartaz Begum, Jenipher S. Asenga, Valence M.K. Ndesendo, Baraka L. Ngingo

Tanzania Journal of Science

In vitro antibacterial activities of methanolic leaf and seed extracts of Moringa oleifera grown in Dodoma, Tanzania were evaluated using standard microdilution and disc diffusion methods against extended spectrum beta lactamase producing Gram negative bacteria (Escherichia coli and Klebsiella pneumoniae). Microdilution method showed no activity at concentration of 20 mg/mL for all the extracts except leaf extract which exhibited minimum inhibition at concentration of  2.5 µg/mL for E. Coli but when high concentrations of the extracts were used in the disc diffusion method then the results exhibited the highest killing susceptibility at concentration of 0.4 g/mL with zone of inhibition …

Antimicrobial Activities Of Endophytic Fungal Crude Extracts Isolated From Cashew Tree (Anacardium Occidentale), Nana Amiri, Donatha D Tibuhwa

Tanzania Journal of Science

This study presents the antimicrobial activities of endophytic fungal crude extracts isolated from leaves, stems and roots of cashew trees (Anacardium occidentale) which showed disease symptoms and those resistant from Fusarium wilt in Mtwara region. Sections of the cashew trees were made and cultured to isolate endophytes. Eight endophytes were isolated and characterized by using morphological and molecular markers. Neopestalotiopsis, Penicillium, Lasidioplodia and Daldinia sp isolated from resistant tree and Auxarthron and Aspergillus sp from diseased tree. Antimicrobial activities of the isolated endophytic fungal crude extracts were done against pathogenic Fusarium oxysporum and three human pathogens namely, Staphylococcus aureus, Escherichia …

Nutritional Composition, Sensory Profile And Consumer Acceptability Of Wheat-Jackfruit Seed Composite Buns, Sarah S Ngwere, Richard J Mongi

Tanzania Journal of Science

Jackfruit seeds flour is very rich in nutrients and may be incorporated into wheat flour to develop nutrient dense baked products. Consumption of these products may improve the nutrition status of the people, hence fulfill sustainable development goal number two. In this study, nutritional composition, sensory profile, and consumer acceptability of wheat-jackfruit seeds composite buns (Mandazi) were investigated. Jackfruit seeds flour (JSF) was developed and incorporated into wheat flour (WF) at 10, 20, and 30% to produce composite flour used for bun preparation. Flours and buns were subjected to proximate, mineral, and sensory analyses with WF serving as a control …

Insecticidal Activities Of Aqueous Extracts Of Five Nigerian Aromatic Spices Against Garden Eggplant Defoliators And Fruit Borer Leucinodes Orbonalis Guenee: Lepidoptera: Crambidae, Juliana A. Ugwu, Kehinde T. Kareem, Julius O. Aluko

Tanzania Journal of Science

The study evaluated the prospects of aqueous extracts of five Nigerian spices against garden eggplant defoliators and fruit borer (Leucinodes orbonalis) in the field. The treatments consisted of Piper guineense (black pepper), Aframomum melegueta (aligator pepper), Eugenia aromatica (cloves), Zingiber officinale (ginger), Capsicum annum (chilli pepper) and untreated check (control). All the aqueous extracts evaluated reduced leaf damaged by defoliators on garden eggplant compared to control. P. guineense, with mean value of 11.02 number of perforations, was the most effective against defoliators, followed by E. aromatica (12.97) reducing leaf damage by 39.64 and 28.74%, respectively. However, their efficacies against defoliating …

Potency Of Dioscorea Sansibarensis (Dioscoreaceae) Leaf Eluates On Callosobruchus Chinensis, Linnaeus 1758 (Coleoptera: Bruchidae) In The Protection Of Phaseolus Vulgaris (Fabaceae), Godfrey O. Mauti

Tanzania Journal of Science

Post-harvest losses of stored Phaseolus vulgaris to the bean weevil Callosobruchus chinensis have reached levels of significant concern. Governments and health organisations propose the discovery of reliable,  healthy and biodegradable pesticides with higher selectivity and a broad spectrum. This study presents investigations on the activities of Dioscorea sansibarensis leaf extracts on the mortality of C. chinensis and reduction of their egg-laying ability. Laboratory experiments under Completely Randomized Design (CRD) were carried out to determine the mortality and anti-oviposition activity of the vacuum liquid chromatography (VLC) eluates of n-hexane (HE), chloroform (CE), ethyl acetate (EE), n-butanol (BE) and methanol (BE) at …

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 …

Effect Of Fungicide Application On Seed Yield Of Perennial Ryegrass, Piotr Goliński

IGC Proceedings (1977-2023)

In four plot experiments established according to random blocks, application effectiveness of propiconazol + carbendazim (Tilt), propiconazol + fenpropimorph (Archer), flusilazol + carbendazim (Alert) and epoxiconazol + crezoxim-metil (Juwel) pesticides regarding the infection by fungal diseases of plant inflorescence structure, biological floret site utilisation, thousand seed weight and harvested seed yield of perennial ryegrass cv. Anna (2n) and cv. Maja (4n) was analysed. The Archer preparation was found to be the most effective, both in the case of Anna and Maja cultivars. Its application was found to increase seed yield in Anna and Maja cultivars by, respectively, 21,5% and 14,5%. …

Genetic Control Of Parthenogenesis In Kentucky Bluegrass: Results From A Sexual X Apomictic Cross, E. Albertini, G. Barcaccia, A. Porceddu, D. Rosellini, Mario Falcinelli

IGC Proceedings (1977-2023)

Apomixis, as it exists in Poa pratensis L., permits to combine genotype fixation with propagation by seed. The process of apomictic seed production involves the formation of embryo sacs without meiotic reduction (apospory) and embryos without egg cell fertilization (parthenogenesis). Further information on the genetic control of apomixis was obtained by analyzing aposporous parthenogenesis and the segregation of molecular markers in a progeny resulting from a “sexual” (S) x “apomictic”(A) cross. Data from the 35 F₁ plants examined so far have shown that parthenogenesis segregated 1:1, confirming control by a dominant gene, simplex in the parthenogenetic parent. Analysis of …