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Weed-Induced Crop Yield Loss: A New Paradigm And New Challenges, David Horvath, Sharon A. Clay, Clarence J. Swanton, James V. Anderson, Wun S. Chao

Agronomy, Horticulture and Plant Science Faculty Publications

Direct competition for resources is generally considered the primary mechanism for weed-induced yield loss. A re-evaluation of physiological evidence suggests weeds initially impact crop growth and development through resource-independent interference. We suggest weed perception by crops induce a shift in crop development, before resources become limited, which ultimately reduce crop yield, even if weeds are subsequently removed. We present the mechanisms by which crops perceive and respond to weeds and discuss the technologies used to identify these mechanisms. These data lead to a fundamental paradigm shift in our understanding of how weeds reduce crop yield and suggest new research directions …

Belowground Plant Communities: Seed Bank Dynamics And Relationship To Aboveground Vegetation In Grazing Allotment Of Klamath County, Oregon, Dellaina C. Morse, Scott M. Estepa

Environmental Science & Management Senior Capstones

Seed banks are valuable resources for restoration but are understudied. The species present in the aboveground composition influence the seed bank through seed inputs. Land managers utilize herbicides to selectively reduce certain species in the above- and belowground composition. The aim of this paper is to observe and assess the species present in a seed bank post-herbicide application, and to discuss the seed bank potential for future restoration at the specific site in Klamath County, Oregon. Soil core samples were collected in the field and brought to the lab where they were processed and prepared for germination. We watered and …

Opportunities And Challenges In Augmenting Honey Bee Forage Resources With Pasture Legumes In Southern Australia, M. Kratz, M. Brown, M. T. Newell, R. C. Hayes

IGC Proceedings (1977-2023)

More than 80% of Australian honey is produced from native tree and shrub species. However, with increasing demands on public lands along with production risks posed by drought, floods and wildfires, there is a need to identify alternative forage resources to augment Australian honey production. With over 30 pasture legumes now available for agriculture in southern Australia, opportunity exists to increase the utilisation of some species with co-benefits to multiple production industries. However, there is little understanding of the potential value of most pasture legumes for honey production, and side by side comparisons are complicated by factors such as differences …

Data Curation For Modeling Tall Fescue Biomass Dynamics With Dssat-Csm, M. B. Hanson, P. D. Alderman, T. J. Butler, A. Caldeira Rocateli

IGC Proceedings (1977-2023)

While models for predicting forage production are available to aid management decisions for some forage crops, there is limited research for a yield model designed specifically for tall fescue (Schedonorus arundinaceus). Therefore, our objective was to adapt an existing perennial forage model, the Decision Support System for Agrotechnology Transfer Cropping Systems Model (DSSAT-CSM) for predicting forage biomass of tall fescue in the southern Great Plains. To evaluate model performance, there must first be a high level of data manipulation and cleaning. In this project, a cohesive dataset combining biomass, weather, soil, and management data were structured into DSSAT …

Can Changing Breeding Structure Serve As A Climate Adaptation Strategy? Evidence From A Comparative Study Of China And Mongolia, Y. Zhang, Z. Huang, J. Wang, Y. Huang, T. Hao, G. Xu

IGC Proceedings (1977-2023)

Under the influence of climate change, the vulnerability of grassland ecosystems in the Mongolian Plateau has increased. Correspondingly, herdsmen need to adopt more livelihood adaptation strategies to cope with changes in climate and grassland environment. The purpose of this study is to analyze the impact of breeding structure on grassland quality in Mongolian plateau. We select 20 border provinces/banners of Mongolia and Inner Mongolia Autonomous Region for research, and combined statistical data with remote sensing data of 2007-2016. The Normalized Difference Vegetation Index (NDVI) is used to quantify the grassland vegetation quality. Results show that there are differences in livestock …

Impact Of Eastern Redcedar Encroachment On Water Resources In The Nebraska Sandhills, Yaser Kishawi, Aaron R. Mittelstet, Troy E. Gilmore, Dirac Twidwell, Tirthankar Roy, Nawaraj Shrestha

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Worldwide, tree or shrub dominated woodlands have encroached into herbaceous dominated grasslands. While very few studies have evaluated the impact of Eastern Redcedar (redcedar) encroachment on the water budget, none have analyzed the impact on water quality. In this study, we evaluated the impact of redcedar encroachment on the water budget in the Nebraska Sand Hills and how the decreased streamflow would increase nitrate and atrazine concentrations in the Platte River. We calibrated a Soil and Water Assessment Tool (SWAT model) for streamflow, recharge, and evapotranspiration. Using a moving window with a dilate morphological filter, encroachment scenarios of 11.9%, 16.1%, …

Understanding The Basis For Increased 2,4-D Tolerance In Red Clover (Trifolium Pratense): Field Evaluations, Metabolism, And Gene Expression, Lucas Pinheiro De Araujo

Theses and Dissertations--Plant and Soil Sciences

Incorporation of red clover (Trifolium pratense L.) into grass pastures offers several benefits. However, red clover cultivars available for Kentucky producers are highly susceptible to synthetic auxin herbicides, such as 2,4-D (2,4-dichlorophenoxy acetic acid), used for pasture broadleaf weed control. To overcome this problem, UK2014 red clover was bred for increased tolerance to 2,4-D. We compared the field performance of UK2014 to Kenland, a standard cultivar grown in the transition zone of the United States. UK2014 and Kenland were seeded in the springs of 2017 and 2018. Single applications of 0, 1.12, or 2.24 kg ae ha^-1 2,4-D …

Forage Grass Growth Habit And Allelopathy In Birdsfoot Trefoil Germination And Establishment, Nathan El Blake

Graduate Theses, Dissertations, and Problem Reports (ETD)

Birdsfoot trefoil (Lotus corniculatus L.) (BFT) is a high quality, tanniniferous forage legume that has been shown to mitigate gastrointestinal nematode (GIN) infection in sheep. Reliable establishment of birdsfoot trefoil in existing pastures is difficult due to BFT’s poor seedling vigor, susceptibility to crown and root rot, and, perhaps chiefly, competition from other pasture plants. Most existing pastures in the Northeastern United States are primarily composed of cool-season grasses, many of which can be highly competitive. A common form of interplant competition is allelopathy, which occurs when secondary metabolites produced by a plant inhibit a necessary growth process of …

Establishment Of The Invasive Cactus Moth, Cactoblastis Cactorum (Berg) (Lepidoptera: Pyralidae) In Pakistan: A Potential Threat To Cultivated, Ornamental And Wild Opuntia Spp. (Cactaceae), Muhammad Ather Rafi, Harry Pavulaan, Muhammad Islam, Muhammad Ashfaq, Haseeb Kamran, Walija Fayaz, Gul Naz Parveen, Riffat Sultana, Ahmad Zia, Waqar Ahmed, Qudrat Ullah, Muhammad Qasim, Falak Naz, Nazeer Ahmed, Muhammad Tariq Khan, Muhammad Saeed, Jalal Hayat Khan

The Taxonomic Report of the International Lepidoptera Survey

Subsequent to the significant accomplishment of biological control of Opuntia weeds in Australia, the larvae of the cactus moth, Cactoblastis cactorum (native to parts of South America), were released in many countries for the biological control of native Opuntia species (Simmonds and Bennett, 1966). Inauspiciously, larvae were also released in the Caribbean, where the moth spread naturally and by the human support all over the region (García-Turudi et al., 1971). Its enhanced dissemination rate and the biological potential for invasiveness, suggests that the cactus moth is likely to become an invasive pest of Opuntia in the Southeast United States, Mexico, …

Studi Pendahuluan Regenerasi Eksplan Teh Sebagai Upaya Percepatan Penyediaan Bibit Unggul Secara In Vitro, Intan Ratna Dewi Anjarsari, Erni Suminar, Murgayanti

Jurnal Kultivasi

Pembiakan generatif tanaman teh yang dilakukan dengan biji, sementara secara vegetatif dengan setek tunas yang mempunyai kelemahan, antara lain jumlah bibit yang dihasilkan terbatas, perlu waktu lama untuk menyeleksi pohon induk, dan bibit yang dihasilkan kurang optimal dalam penyerapan air dan unsur hara karena perakarannya dangkal sehingga kurang toleran terhadap kekeringan. Kultur jaringan menjadi salah satu alternatif dalam perbanyakan teh memperoleh klon teh unggul, seperti klon Seri Gambung 1-11, dalam jumlah banyak dan sifatnya yang seragam. Penelitian pendahuluan ini dilaksanakan di Laboratorium Kultur Jaringan Departemen Budidaya Pertanian Fakultas Pertanian UNPAD, mulai bulan Juni hingga Desember 2021. Penelitian terdiri dari dua …

Resistensi Gulma Echinochloa Crusss-Galli Terhadap Herbisida Berbahan Aktif Metamifop Di Areal Persawahan Sulawesi Selatan, Annisa Nadiah Aprilia, Denny Kurniadie, Uum Umiyati

Jurnal Kultivasi

Barnyardgrass [Echinochloa cruss-galli (L.) P. Beauv.] diakui sebagai gulma paling bermasalah di areal persawahan Provinsi Sulawesi Selatan, Indonesia. Herbisida metamifop sudah lama digunakan untuk mengendalikan gulma tersebut pada areal pertanaman padi sawah di Sulawesi Selatan dengan intensitas aplikasi yang cukup tinggi. Hal tersebut menimbulkan E. cruss-galli yang sulit dikendalikan dan diperkirakan resisten terhadap herbisida metamifop. Namun demikian, kasus resistensi gulma terhadap herbisida metamifop di Indonesia belum banyak dilaporkan dan diteliti. Penelitian ini bertujuan untuk mengetahui (1) adanya resistensi gulma E. cruss-galli terhadap metamifop, (2) tingkat resistensi yang terjadi pada gulma E. cruss-galli terhadap metamifop. Penelitian dilakukan di rumah kaca Fakultas …

Demonstration Farm Provides Educational Opportunity For Ipm, Nick Volesky, Mair Murray

Outcomes and Impact Quarterly

The mission of USU Extension’s Integrated Pest Management (IPM) program is to increase the use of sustainable pest management practices within urban and rural landscapes to provide economic, human, and environmental health in Utah. In the spring of 2022, the IPM program established a vegetable farm to test and demonstrate IPM practices. The farm served as an experiential learning classroom for almost 50 farmers and home gardeners.

Nitrification Inhibitor, Nitrogen Source, And Herbicide Effects On Soil Nitrogen Transformations And Corn Yield, William Neels

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

Nitrogen fertilizer management continue to be challenging due to potential nitrogen losses under variable weather conditions. The objective of this was to evaluate the performance of nitrification inhibitors, nitrogen sources and herbicides on in-season nitrogen availability and agronomy indicators. A two site-year field experiment was conducted in silty clay loam soil in corn phase of the corn-soybean rotation at Central Nebraska. The treatments included three herbicide (no pre-emergence, Acuron, Resicore) and five nitrogen treatments: 1) control, 2) anhydrous ammonia, 3) anhydrous ammonia without nitrification inhibitor, 4) urea with nitrification inhibitors, and 5) urea without nitrification inhibitors. Results indicated that nitrogen …

Effects Of Disturbance (Mowing) On Florivory And Floral Defenses In Solanum Elaeagnifolium, A Noxious And Worldwide Invasive Weed, Alejandro Rafael Vasquez Marcano

Theses and Dissertations

Chapter 1: Literature Review- In this literature review we have examined weed management as it concerns urban and agricultural ecosystems, as well as the need for mowing assessments as it relates to floral traits and defense against herbivory.

Chapter 2: Experiments- In the experiments we examined the role of mowing on floral growth traits, floral defense traits, and their effect on Manduca sexta specialist herbivores.

Chapter 3: Results- In the results we found SLN flowers to have larger diameters than unmowed flowers; however, flower mass was in line with our predictions as unmowed flowers were heavier in high mowing frequency …

Effects Of Sowing Date And Phosphorus Fertiliser Application On Winter Survival Of Lucerne Cv. Aohan In The Northern Semi-Arid Region Of China, Z. L. Wang, Q. Zh. Sun, Y. W. Wang, Zh. Y. Li, Sh. F. Zhao

IGC Proceedings (1977-2023)

In the northern semi-arid region of China, winter survival is always a limiting factor for lucerne production, because low temperatures and a dry climate in winter (Zhou et al., 1993; Ma, 2000; Sun & Gui, 2001; Sun et al., 2003). An experiment was conducted to find an appropriate sowing date and P application rate in order to improve lucerne winter survival.

Ear Emergence Of Different Grass Species Under Finnish Growing Conditions, M. Niskanen, O. Niemeläinen, L. Jauhiainen

IGC Proceedings (1977-2023)

Timothy is the most commonly cultivated grass species in Finland. Swards cultivated for silage of hay are of pure timothy or timothy is the dominant species of the mixture. Successful timing of harvesting of the primary growth is very critical in Northern latitudes where the stand develops very rapidly at daylengths of above 18 hours with a daily mean temperature close to 20 °C. The primary growth has to be harvested within a very short period to obtain a yield of high and uniform quality. Short harvesting periods require high capacity harvest machinery which lead to high costs. If it …

Reasons For The Premature Decline In Astragalus Adsurgens Stands In Kerqin Sandy Land, Q. Zh. Sun, Z. L. Wang, J. G. Han, Y. W. Wang, G. R. Liu

IGC Proceedings (1977-2023)

Diseases partly account for reductions in Astragalus adsurgens, stand longevity. The effect of some cultural practices on the control of pests and diseases have been reported (Hou, 1986; Nan, 1996), but few reports have detailed the relationship among soil fertiliser status, diseases and premature stand decline. This study was conducted to investigate these relationships in order to extend the longevity of Astragalus adsurgens stands.

The Influence Of Fertiliser Application To Strip-Sown Grasslands On Herbage Production And Quality, A. Kohoutek, P. Komárek, V. Odstrčilová, P. Nerušil

IGC Proceedings (1977-2023)

To increase the productivity of dairy cattle in the Czech Republic requires an improvement in herbage quality and an increase in the net energy of herbage. The decrease in cattle numbers by 50 % and the expansion of the grassland area both result in a surplus of feedstuffs of low quality. Introduction of strip-seeding of legumes and grasses into grasslands in interaction with fertilisation provides a possible solution to this problem.

Range-Based Livestock Production In Turkmenistan, R. H. Behnke, G. Davidson

IGC Proceedings (1977-2023)

Turkmenistan retains a centralized system of livestock production in which many critical assets are owned by the state. Though technically in the temperate zone, the country's climate is harsh and unstable. Groundwater resources are unevenly distributed, leaving many potential grazing areas seasonally inaccessible due to lack of drinking water for livestock. This paper summarizes the results of a three-year study of rangelands, livestock production, flock economics and land tenure at two study sites, one in central and the other in eastern Turkmenistan. The results of this study suggest that pastoral communities in Turkmenistan have coped remarkably well with the institutional …

Green Dairy, A Project For Environmental Friendly And Sustainable Dairy Systems In The Atlantic Area, H. Chambaut, A. Pflimlin, C. Raison

IGC Proceedings (1977-2023)

Green Dairy is an European Interreg III B project which runs over 3 years. It brings together 10 research and development partners from 5 countries and 11 regions of the Atlantic Area which range from Scotland to Portugal. It aims to provide a better understanding of the impact of intensive dairy systems on the quality of the environment in order to develop ways of improving practices in the different regions. This is expected to encourage more rapid responses to the problems of deteriorating water and air quality and a more appropriate response within or between regional contexts that could be …

Rangeland Ecological Management Counter-Measures Study Of Xinjiang, H. X. Cui, J. Li, S. Asiya, J. L. Zhang, Jialin

IGC Proceedings (1977-2023)

Xinjiang is located in the hinterland of the Asian-Euro continental area and far from the ocean. It is surrounded by mountains and forms a physiognomic landscape of two basins located in three mountains. This results in an extremely droughty continental climate and a harsh environment in the Temperate Zone. However, the geographical environment is diverse in the Xinjiang Autonomous region, the three high mountains and complicated geographical structure results in changes in ecological conditions with altitude and a diverse ecological environment. Because of the drought characteristics the desert area has developed different types of vegetation, and the complexity of the …

Management Options To Reduce N-Losses From Ploughed Grass-Clover, J. De Wit, G. J. Van Der Burgt, N. Van Eekeren

IGC Proceedings (1977-2023)

Nitrate (NO₃ -) leaching from grassland can be kept at acceptable levels, but is often high after ploughing for grassland renewal or for silage maize/grain production. In on-farm research with several organic farmers, management options are being explored to save scarce organic manure and to reduce N-losses.

Mechanical Aeration And Liquid Dairy Manure: Application Impacts On Grassland Runoff Water Quality And Yield, T. J. Basden, S. B. Shah, J. L. Miller

IGC Proceedings (1977-2023)

Wet weather on heavy soils reduces oxygen availability in the root zone and reduces forage yields. Mechanical aeration can improve forage yield in these soil conditions. Research has shown that under certain conditions, mechanical aeration can increase yield by improving drainage and aeration (Davies et al., 1989); aeration can also increase depression, storage and infiltration thus reducing surface runoff and improving nutrient distribution in the root zone. Aeration on sloping, fertilised grassland can provide environmental (Douglas et al., 1995) and agronomic benefits. The objectives of this study were to evaluate the runoff water quality and agronomic impacts of …

Nitrogen Dynamics Following The Break-Up Of Grassland On Three Different Sandy Soils, Manfred Kayser, K. Seidel, J. Müller

IGC Proceedings (1977-2023)

Nitrogen (N) is accumulated under grassland depending on factors such as soil type, management, and fertiliser input. Break-up of grassland stimulates mineralisation of organic N and may lead to increased soil mineral N and leaching losses (Lloyd, 1992). The objective of this study was to find out how site factors, e.g. soil, previous management and sward age, the following crop and the new level of N fertiliser affect the amount of inorganic N in autumn and the preceding mineralisation processes when grassland is ploughed in spring.

Fine Colloids ‘Carry’ Diffuse Water Contaminants From Grasslands, P. M. Haygarth, A. L. Heathwaite

IGC Proceedings (1977-2023)

The transport of diffuse pollutants from grassland has traditionally been described by the operationally defined threshold of greater, or smaller than a nominated membrane filter size. Most commonly this has been a 0.45 μm threshold to define ‘solute’ and ‘particulate’ transport. In this paper we shall use phosphorus (P) to help provide an example of the importance of colloid-facilitated transport.

Leaching Losses Of N, P And K From Grazed Legume Based Swards: Some Preliminary Results, E. R. Dixon, A. C. Stone, D. Scholefield, D. J. Hatch

IGC Proceedings (1977-2023)

There is increasing interest in sustainable agricultural systems because of environmental concerns. Animal production which utilises mixed grass and legume swards could be an effective measure in increasing the efficiency of nutrient utilisation, and investigation into different legume species is necessary. Leaching losses of N, P and K from 3 legume species under grazing by sheep were measured using Teflon-coated suction cups. The experiment took place on the UK site of the EU-funded, multi-site experiment – LEGGRAZE.

Soil Aggregate Dynamics, Particulate Organic Matter And Phosphate Under Dryland And Irrigated Pasture, J. T. Scott, L. M. Condron, R. W. Mcdowell

IGC Proceedings (1977-2023)

Soil aggregate formation and turnover affects the rate of occlusion or release of soil organic matter and therefore the availability for mineralisation or stabilisation of soil carbon (C) and phosphorus (P). Furthermore, differences in soil type, management and the quantity and quality of organic inputs can affect aggregate turnover rates (Six et al., 2000). Under pastoral farming the ratio of coarse particulate organic matter (inter-POM) inside macroaggregates but outside microaggregates to fine POM (intra-POM) within microaggregates may provide an indication of physical processes influencing mineralisation and stabilisation of soil C and organic P (Po). Our aim was to determine …

Fire And Nutrient Cycling In Shortgrass Steppe Of The Southern Great Plains, Usa, P. L. Ford, C. S. White

IGC Proceedings (1977-2023)

Fire in semi-arid grasslands releases nutrients bound up in organic matter and accelerates the rate of decomposition in the soil. This research experimentally tested effects of season and frequency of fire on nutrient cycling dynamics in shortgrass steppe. The objective was to identify if fire treatments have the ability to increase potential grassland productivity relative to untreated ‘reference condition’ grassland. Many such studies focus on short-term, direct effects of fire. However, this study is part of a long-term, 18-year study examining both direct, and indirect effects of fire in the growing vs. dormant season at return intervals of 3, 6 …

Maximising Slurry Crop Available Nitrogen Utilisation In Grassland Systems, J. R. Williams, E. Sagoo, B. J. Chambers, J. Laws, D. R. Chadwick

IGC Proceedings (1977-2023)

In the UK, approximately 90 million tonnes of animal manure containing ca 450,000 tonnes of nitrogen (N) are recycled to agricultural land each year. The efficient utilisation of manure N can save farmers money and reduce diffuse air (ammonia) and water (nitrate) pollution. For slurries, bandspreading techniques (e.g. trailing shoe and trailing hose) can improve N utilisation by reducing ammonia volatilisation losses compared with conventional broadcast applications. They also provide increased spreading opportunities in spring/summer as slurry is placed in a band on the soil surface limiting herbage contamination, which can reduce the need to apply slurry in the autumn/early …

Phosphorus Transfer To River Water From Grassland Catchments In Ireland, H. Tunney, P. Jordan, G. Kiely, R. Moles, G. Morgan, P. Byrne, W. Menary, K. Daly

IGC Proceedings (1977-2023)

In Ireland it is estimated that at least half of phosphorus (P) loss to water is from agricultural sources and National and European Union policy and legislation aim at reducing phosphorus (P) loss to water in order to reduce eutrophication. In Ireland, the average soil test P (STP) levels increased ten-fold, from less than 1 to over 8 mg Morgan P per l soil over the past 50 years, reflecting increased P inputs in fertiliser and animal feed. One of the main objectives of this three-year research programme, started in 2001, was to investigate P loss to water in grassland …