Weed Science Commons^™

Trace Element Imbalance In Vegetation As A Threat To Free Ranging Cattle In The Gilgel Gibe Valley, Ethiopia, Thomas Van Hecke, Veronique Dermauw, Kechero Yisehak, Gijs Du Laing, Luc Duchateau, Geert P. J. Janssens

IGC Proceedings (1977-2023)

As in many tropical countries, natural pastures are the main source of nutrients for cattle in Ethiopia. However, there is limited information available with regard to trace element concentrations in Ethiopian forages. In this study, 58 plants were sampled in the Gilgel Gibe valley based on the observed ingestion by zebu cattle (Bos indicus) herds, grazing at different elevation and soil types, and analysed for copper (Cu), cobalt (Co), iron (Fe), molybdenum (Mo), manganese (Mn), sulfur (S), selenium (Se) and zinc (Zn). The effect of elevation, soil type and plant type on the above trace element concentrations was …

Variations An Α-Tocopherol And Β-Carotene Concentrations In Forage Legumes And Grasses Harvested At Different Sites And Maturity Stages, Elisabet Nadeau, Hanna Lindqvist, Søren Krogh Jensen, Nilla Nilsdotter-Linde, Anne-Maj Gustavsson

IGC Proceedings (1977-2023)

Forage is a major source of natural α-tocopherol and β-carotene for dairy cows. This study examined vitamin concentrations of birdsfoot trefoil (Bft), red clover (Rc), timothy (Ti) and meadow fescue (Mf) at different sites, years and cutting dates. Mixtures of Bft+Ti, Rc+Ti and Rc+Mf were established at Skara (58°21’N; 13°08’E) and Umeå (63°45’N; 20°17’E) in Sweden. First-year leys were cut on three occasions in spring (Umeå 2005, Skara 2005 and 2007); one week before heading of timothy, at heading and one week after heading. Birdsfoot trefoil had higher α-tocopherol concentration at Skara than at Umeå in the first two cuts …

Comparing Drying Protocols For Perennial Ryegrass Samples In Preparation For Chemical Analysis, Marion Beecher, Deirdre Hennessy, Tommy M. Boland, Michael O’Donovan, Eva Lewis

IGC Proceedings (1977-2023)

Diet formulation for animals requires accurate estimation of feed nutritive value. In order to determine the nutritive value of grass, the moisture in the samples must be removed, with minimum damage to cell structure, and then the dried samples milled, prior to chemical analysis. Generally samples are oven dried. The aim of this study was to verify if differing drying protocols gave diverging results when drying grass samples. The drying protocols investigated were 40°C for 48 hours, 60°C for 48 hours and 95°C for 15 hours in forced convection ovens. Four perennial ryegrass samples were cut to 4 cm from …

Remote Sensing Of Pasture Quality, Reddy R. Pullanagari, Robyn A. Dynes, Warren M. King, Ian Yule, Susanne Thulin, Nichola M. Knox, Abel Ramoelo

IGC Proceedings (1977-2023)

Worldwide, farming systems are undergoing significant changes due to economic, environmental and social drivers. Agribusinesses must increasingly deliver products specified in terms of safety, health and quality. Increasing constraints are being placed on them by the market, the community and by government to achieve a financial benefit within social and environmental limits (Dynes et al. 2003).

In order to meet these goals, producers must know the quantity and quality of the inputs into their feeding systems, be able to reliably predict the products and by-products being generated, and have the skills to be able to manage their business accordingly. …

Infrastructure To Improve Beef Business Outcomes In The Queensland Gulf, Kiri C. Broad, Bernie H. English, Rebecca A. Gunther, Emma S. Hegarty, Joe W. Rolfe, Steven G. Bray

IGC Proceedings (1977-2023)

There are significant economic and environmental issues impacting on the short and long term viability of family-run breeding enterprises in the Queensland Gulf. Falling cattle prices and increased business costs threaten the social and financial well-being of many beef producers. Set stocking and overgrazing combine to reduce native 3P (productive, palatable and perennial) grass frequency and herd productivity. The Ryan family on Greenhills Station at George-town in the Queensland Gulf embarked on a 5 year water and fencing infrastructure development program aiming to improve pasture utilisation, land condition and long term carrying capacity.

A Technique For Measurement Of Cattle Form Using A Trail 3d Digital Camera, Tamaki Kida, Shigeki Tejima, Toshitaka Uchino, Fumihiko Tanaka

IGC Proceedings (1977-2023)

Measurement of weight and form are important for the management of grazing cattle; however, form measurement is seldom carried out. Recently, use of 3D digital cameras has been increasing, and 3D-technology for reconstruction of 3D pictures has been developed. The measurement of withers and hip height of cattle from 3D pictures using the image-analysis technique has been reported (Kida et al. 2012). However, time and effort are required to obtain 3D images of grazing cattle in pastures.

Here, we examined an automatic photographic technique using a sensor camera.

Modelling Complex Sheep Systems Using Ausfarm, Susan M. Robertson, Michael A. Friend

IGC Proceedings (1977-2023)

Simulation modelling can be a valuable method for extrapolating experimental findings to different weather or management conditions. However, most of the decision support tools which are available for sheep grazing systems, for example GrassGro® (Donnelly et al. 1997), are limited to modelling of relatively simple sheep management. This makes validation of simulations against experimental results difficult where management changes from year to year, and where more complex sheep management is used. This study evaluated the use of the AusFarm® decision support tool (Moore et al. 2007) to model a split-joined sheep system, using different ram breeds against experimental …

Does Targeted Short-Term Grazing Of Lucerne Increase Twinning Rates In Unsynchronised Merino Ewes?, Jessica M. Rummery, Susan M. Robertson, Belinda J. King, Michael A. Friend

IGC Proceedings (1977-2023)

Reproduction is one of the key profit drivers in the sheep industry and increased reproductive output is needed to address the decline in sheep numbers in Australia to maintain supply to export markets (Curtis 2009). Increased nutrition around mating, or ‘flushing’, is a well-known means of increasing twinning rates. Studies using synchronisation methods have shown that short-term (acute) supplementation can increase prolificacy if targeted at days 9-14 of the oestrous cycle (Stewart and Oldham 1986). However, synchronisation involves increased chemical and labour costs, so may not suit extensive production systems. This study aimed to test whether an increase in twinning …

Evaluating Rangeland's Grazing Capacity For Livestock And Wild Herbivores Using The Delta Diet Tool And Gis Technology, Sandra A. Santos, Arnaud L. J. Desbiez, Humberto L. Perotto-Baldivieso, Juliana M. Alvarez

IGC Proceedings (1977-2023)

Rangelands are dynamic and complex systems requiring appropriate adaptive decision-making to calculate grazing capacity integrating livestock and herbivore wildlife. This work describes the development and application of an integrated framework using the microhistological analysis (DeltaDiet tool) to identify key forage used by different herbivores from the same area associated with GIS technology to mapping landscape containing forage productivity and quality information. This study was conducted in a management unit, representative of the Nhecolândia sub-region landscape, Pantanal. During the dry period, representative fecal samples were collected from cows, capybaras and deer grazing in the same management unit for diet analysis, using …

Ms Environmental Biology Capstone Project, Alexandra Sorenson

Regis University Student Publications (comprehensive collection)

• Chapter 1. Literature Review: Invasive Plant Considerations in Alpine Restoration Project Planning
• Chapter 2. Grant Proposal: Success Rates of Native See Germination on Esplanade-Treated Plots
• Chapter 3. Journal Manuscript: Meta-Analysis of Cheatgrass (Bromus Tectorum) Control with Three Commonly Used Herbicides
• Chapter 4. Stakeholder Analysis: Stakeholder Analysis: Recommendation for Herbicide Use at Lippincott Ranch

Captive Ring-Necked Pheasant Response To Very High Experimental Doses Of Lead, Travis J. Runia, Alex J. Solem

The Prairie Naturalist

Ingestion of spent lead pellets is a well-documented source of lead exposure in free-ranging birds, although the consequence of lead ingestion varies widely among avian guilds. Ring-necked pheasants (Phasianus colchicus) appear to be less susceptible to lead poisoning than other game birds. Our objectives were to determine survival, liver lead accumulation, and body mass change of 129 captive-raised pheasants in response to being gavage-fed 5, 10, 20, or 40 lead pellets. All pheasants survived the 21-day experiment. Liver-lead levels were positively correlated with the number of lead pellets retained and negatively correlated with beginning body mass. Change in percent body …

Evaluation Of Four Larval Fish Sampling Methods In A Large Midwestern River, Nathan J. Lederman, Anthony R. Sindt, Douglas J. Dieterman, John D. Krenz, Shannon J. Fisher

The Prairie Naturalist

Understanding limitations of larval fish capture gears is critical for developing appropriate sampling protocols and interpreting catch data. We evaluated genera richness, genera diversity, assemblage similarities, abundance indices (i.e., density or catch per unit effort [CPUE]), and sample size requirements between a surface slednet and glow-stick light traps used in 2014 and 2015 and a benthic slednet and light-emitting diode light (LED) traps used in 2015 in the Minnesota River. The surface slednet captured the greatest number of larval fish genera (15) while the LED light trap captured the fewest (1). Similarities of assemblages sampled was highest between surface and …

Comparing Native Bee Communities On Reconstructed And Remnant Prairie In Missouri, Joseph Larose, Elisabeth B. Webb, Deborah Finke

The Prairie Naturalist

The tallgrass prairie of North America is an imperiled ecosystem that has been the subject of considerable restoration effort and research in the past two decades. While native prairie plant species are purposely introduced during restoration, prairie invertebrates, including native bees (Anthophila), are not and must colonize from surrounding remnants. Prairie restorations may not support the same bee communities as remnant prairies because of habitat differences and dispersal limitations. We sampled native bees on reconstructed and remnant prairies in Missouri in the summers of 2016 and 2017 and compared the communities by evaluating species richness, diversity, and community composition. We …

Greater Prairie-Chickens And Sharp-Tailed Grouse Have Similarly High Nest Survival In The Nebraska Sandhills, Larkin Powell, Walter Schacht, Julia P. Ewald, Kathryn R. Mccollum

The Prairie Naturalist

The ranges of two native galliform species overlap in the Nebraska Sandhills, the largest contiguous grassland in North America. We monitored nests of greater prairie-chickens (Tympanuchus cupido) and sharp-tailed grouse (Tympanuchus phasianellus) in Cherry County, Nebraska, in 2015 and 2016. Our objectives were to 1) compare daily probability of nest survival between species, 2) evaluate vegetation structure at nests for potential effects on nest survival, 3) compare nest site topography between species, and 4) use a simple model of breeding season success to evaluate the potential for stable populations at our study sites. We captured and …

Glyphosate Plus Dicamba Spray Solution Deposition, Coverage, And Efficacy As Influenced By Spray Nozzle Design And Weed Density, Madison Dru Kramer

Theses and Dissertations--Plant and Soil Sciences

Dicamba injury to sensitive soybean and other broadleaf crops due to drift is a major issue and label restrictions have been created to mitigate dicamba drift. One restriction is the mandated use of low drift nozzles to spray dicamba; these nozzles produce larger droplets and minimize the production of driftable fines. Experiments were conducted to evaluate herbicide coverage, deposition, and efficacy. Three spray nozzle designs and different weed densities were the main factors in the analysis. Dicamba plus glyphosate was applied to 5 to 10 cm tall weeds with a Turbo TeeJet (TT11005) nozzle and two drift reduction nozzles approved …

Distribution Of Invasive Plant Species On Debris Cones At Mount Rainier National Park, Shaun Morrison

All Master's Theses

Invasive plant populations within Mount Rainier National Park are a biological and ecological threat to the unique mountain landscape. A better understanding of their distribution and transport within the landscape is needed to improve invasive species monitoring for National Park Service management. This study investigates how invasive plant populations in Stevens Canyon are utilizing the debris cone disturbances and associated geomorphic processes to facilitate movement within the park. Vegetation transects were performed along Stevens Canyon Road (to observe the roadside community composition) and on the debris cone features (to observe species movement from the roadside). These vegetation observations are presented …

Improving The Biological Control Of Persicaria Perfoliata (Polygonaceae) Using Rhinoncomimus Latipes Korotyaev (Coleoptera: Curculionidae), Jaewon Kim

Graduate Theses, Dissertations, and Problem Reports (ETD)

Persicaria perfoliata (L.) H. Gross (Polygonaceae; Mile-a-minute weed) is a rapid-growing invasive vine introduced from eastern Asia to northeastern United States in the 1930s. This vine has been invaded in disturbed areas and reforestation sites in 15 states in the U.S. and forms dense, monocultural patches that may inhibit natural forest regeneration. To control this weed, a host-specific biocontrol agent, Rhinoncomimus latipes Korotyaev (Coleoptera: Curculionidae) has been released in the P. perfoliata invaded states in the U.S. during the past 15 years. Currently, R. latipes is released by hand to the invaded area where the presence of the weed is …

Local Binary Pattern Based Algorithms For The Discrimination And Detection Of Crops And Weeds With Similar Morphologies, Vi Nguyen Thanh Le

Theses: Doctorates and Masters

In cultivated agricultural fields, weeds are unwanted species that compete with the crop plants for nutrients, water, sunlight and soil, thus constraining their growth. Applying new real-time weed detection and spraying technologies to agriculture would enhance current farming practices, leading to higher crop yields and lower production costs. Various weed detection methods have been developed for Site-Specific Weed Management (SSWM) aimed at maximising the crop yield through efficient control of weeds. Blanket application of herbicide chemicals is currently the most popular weed eradication practice in weed management and weed invasion. However, the excessive use of herbicides has a detrimental impact …

Evaluation Of The Influence Of Dicamba Exposure On Crop Injury And Canopy Closure Of Glufosinate Resistant Soybean, Zachary K. Perry

Theses and Dissertations--Plant and Soil Sciences

Dicamba-resistant soybean along with lower volatility dicamba formulations have been introduced in an attempt to control herbicide resistant weeds such as Amaranthus palmeri. This introduction has increased the amount of dicamba being applied later in the growing season increasing the prevalence of dicamba off-target movement. Dicamba damage was simulated by applying low rates of dicamba directly on soybeans at rates (0.5 g ae ha^-1, 1 g ae ha^-1 and 5 g ae ha^-1 dicamba) and five-exposure timings from June 1 to July 10. The experimental design was a randomized complete block with four replications at …

Wood Frogs (Rana Sylvatica) In Southwestern Roberts County And Western Grant County, South Dakota, Dennis R. Skadsen, Drew R. Davis

The Prairie Naturalist

Historically, only six records of Wood Frogs (Rana sylvatica) existed from South Dakota, all represented by museum specimens. A single specimen was collected from Hartford Beach on Big Stone Lake, Roberts County in 1922 (National Museum of Natural History, Smithsonian Institution [USNM] 65452) and five Wood Frogs were collected near the outlet of Blue Dog Lake, Day County in 1929 (USNM 312618– 312622; Fig. 1). After the 1920s, no other Wood Frogs were reported in South Dakota for the next six decades, and the species was presumed extirpated. Over (1923, 1943) reported the species was common in the …

Trends In A Greater Prairie Chicken Population Established By Translocation In North Dakota, Gary Huschle, John E. Toepfer

The Prairie Naturalist

In 1992, an effort was undertaken by the North Dakota Game and Fish Department (NDGFD), U.S. Fish and Wildlife Service, and North Dakota Chapter of the Wildlife Society to reestablish a viable population of greater prairie chickens (Tympanuchus cupido pinnatus; hereafter prairie chickens) in northeast North Dakota. The release area was centered on the Prairie Chicken Wildlife Management Area located 22.5 km northwest of Grand Forks, North Dakota, in the northern part of Grand Forks County. Topography consists of poorly drained, saline flats and swells separated by poorly drained swales and sloughs in the Red River Valley (Beringer 1995). Permanent …

Factors Associated With Larval Freshwater Drum Annual Peak Density In A Nebraska Irrigation Reservoir, Brett T. Miller, Brian C. Peterson, Keith D. Koupal, Casey W. Schoenebeck

The Prairie Naturalist

Freshwater drum (Aplodinotus grunniens) represent one of the most widely distributed fish species in North America. Identifying biotic and abiotic factors that influence larval freshwater drum densities can improve understanding of early life history. Our objective was to investigate correlations between annual peak density of larval freshwater drum and combinations of five variables (chlorophyll a, growing degree days [GDD], reservoir discharge, turbidity, and cladoceran density) from a longterm (2003–2017) monitoring program in a Nebraska irrigation reservoir. Twenty-eight a priori candidate models were assessed to determine the relative support of explanatory variables associated with annual peak density of larval freshwater drum …

Small Mammal Communities In Grasslands At The Grand Forks Air Force Base, North Dakota, Usa, Lynda R. Lafond, Elizabeth H. Rave, Kathryn A. Yurkonis

The Prairie Naturalist

Small mammals are important in grasslands but are often overlooked in management and reconstruction efforts. We sampled small mammals in three sites on the Grand Forks Air Force Base (GFAFB) located in central Grand Forks County, North Dakota, USA. The study sites varied in their management history and represented the three major types of grasslands (reconstructed prairie, old field, and hay field) within Grand Forks County. We captured 463 individuals of six species with Sherman live traps in summer (June, July, August) 2014 and 2015. We captured the most individuals and species (295 individuals of 5 species), including all shrews …

Patterns And Potential Causes Of Changing Winter Bird Distributions In South Dakota, David L. Swanson, Reza Goljani Amirkhiz, Mark D. Dixon

The Prairie Naturalist

Average winter temperatures in the north-central United States have been increasing since the 1970s, and this warming might influence winter distributions of birds in the region. Species potentially influenced by such winter warming include short-distance migrants for which the northern boundary of the winter range is influenced by temperature, such as hermit thrush (Catharus guttatus), yellow-rumped warbler (Setophaga coronata), and fox sparrow (Passerella iliaca). We examined winter records during 1974–2017 from a citizen-science bird observation database for South Dakota to determine recent trends in winter records for these three species. We compared their occurrence patterns with those for three benchmark …

Application Of Advanced Algorithms And Statistical Techniques For Weed-Plant Discrimination, Saman Akbar Zadeh

Theses: Doctorates and Masters

Precision agriculture requires automated systems for weed detection as weeds compete with the crop for water, nutrients, and light. The purpose of this study is to investigate the use of machine learning methods to classify weeds/crops in agriculture. Statistical methods, support vector machines, convolutional neural networks (CNNs) are introduced, investigated and optimized as classifiers to provide high accuracy at high vehicular speed for weed detection.

Initially, Support Vector Machine (SVM) algorithms are developed for weed-crop discrimination and their accuracies are compared with a conventional data-aggregation method based on the evaluation of discrete Normalised Difference Vegetation Indices (NDVIs) at two different …

Managing Forest Disturbances: Effects On Mule Deer And Plant Communities In Montana's Northern Forests, Teagan Ann Hayes

Graduate Student Theses, Dissertations, & Professional Papers

Mule deer (Odocoileus hemionus) are frequently the focus of population and habitat management in the western United States. Land and wildlife managers use disturbance to reset forests to earlier successional stages and improve the quality and quantity of forage available to mule deer. However, the effects of management practices on nutrition and selection vary widely, so the implementation of management practices raises ecological as well as management-related concerns. This work investigated how disturbance from wildfire, prescribed fire, and timber harvest influences the spatial and temporal distribution of nutritional resources in mule deer summer range, and therefore, how the …

The Effects Of Woody Vegetation Encroachment And Removal Within A Coastal Fen, Joseph Saler

Cal Poly Humboldt theses and projects

Early successional wetland habitat is being lost in temperate regions worldwide as a result of changes in disturbance regimes that allow for the establishment and dominance of woody species. In particular, this phenomenon is pronounced in fens, which harbor high numbers of rare herbaceous species that require early successional habitat. I investigated the relationship between woody vegetation encroachment and herbaceous species diversity within a Northern California coastal fen that has been undergoing encroachment by woody vegetation for ca. 80 years by recording species richness and cover data from 338 permanent plots throughout the fen. I also investigated the effect of …