Open Access. Powered by Scholars. Published by Universities.®

Agricultural Science Commons

Open Access. Powered by Scholars. Published by Universities.®

10,672 Full-Text Articles 11,103 Authors 1,709,746 Downloads 89 Institutions

All Articles in Agricultural Science

Faceted Search

10,672 full-text articles. Page 7 of 203.

Achieving Full-Season Waterhemp Control In Soybean, Robert G. Hartzler, Meaghan Anderson 2019 Iowa State University

Achieving Full-Season Waterhemp Control In Soybean, Robert G. Hartzler, Meaghan Anderson

Integrated Crop Management News

Although there are many ways weeds escape control in crop fields, one of the leading causes of waterhemp control failures is emergence of plants following postemergence herbicide (POST) treatments. Waterhemp requires more than twice as many growing degree days to reach 50% emergence as giant foxtail or velvetleaf (Figure 1), resulting in much of the population emerging after mid-June.


Evaluation Of Stabilized Fertilizer And Crop Canopy Sensors As Next-Generation Nitrogen Management Technologies In Irrigated Corn, Leonardo Mendes Bastos 2019 University of Nebraska-Lincoln

Evaluation Of Stabilized Fertilizer And Crop Canopy Sensors As Next-Generation Nitrogen Management Technologies In Irrigated Corn, Leonardo Mendes Bastos

Theses, Dissertations, and Student Research in Agronomy and Horticulture

Nitrogen (N) is often the most limiting nutrient to corn. Once applied to the field, N can be lost through different pathways, which contributes to low N use efficiency (NUE) by plants. Increases in NUE and decreases in N losses can be potentially achieved by using management options that allow a better synchrony between N supply and demand, such as stabilized fertilizers, and spatially-variable sensor-derived in-season N application. Three studies were conducted in order to assess the effects of different stabilized fertilizers and crop canopy sensors on irrigated corn yield. The first study evaluated the effect of urease inhibitor on ...


2018 Insecticide Evaluation For Soybean Aphid, Erin W. Hodgson 2019 Iowa State University

2018 Insecticide Evaluation For Soybean Aphid, Erin W. Hodgson

Integrated Crop Management News

Plots were established at two locations in 2018 (ISU Northwest Research Farm and ISU Northeast Research Farm). Syngenta NK S24-K2 brand soybean was used at both locations. Seven insecticidal groups/subgroups were evaluated in 2018. Seed did not have a pesticidal seed treatment unless specifically stated. At both locations, soybean aphid peaked in August (four perplant at Northeast Research Farm and 22 perplant at Northwest Research Farm). The economic threshold was not reached at either location in 2018; however, all plots were sprayed mid-August.


Understanding Greenhouse Gases, Julie M. Mueller, Laura Edwards, Madhav P. Nepal, Larry B. Browning, Matthew L. Miller, P. Troy White 2019 Garretson Public School, Garretson, South Dakota

Understanding Greenhouse Gases, Julie M. Mueller, Laura Edwards, Madhav P. Nepal, Larry B. Browning, Matthew L. Miller, P. Troy White

iLEARN Teaching Resources

Students will conduct hands-on experiments to see how greenhouse gases interact with the Earth’s atmosphere and how greenhouse gases affect temperature. This lesson introduces National Geographic’s Geo-Inquiry Process, where students will identify a Geo-inquiry question, collect data, and create a project around the answer to their question. Students will then present their findings to their peers and evaluate their Geo-Inquiry process.


2018 Scn-Resistant Variety Trial Results Show Yield Effects And Scn Buildup, Greg Tylka 2019 Iowa State University

2018 Scn-Resistant Variety Trial Results Show Yield Effects And Scn Buildup, Greg Tylka

Integrated Crop Management News

Iowa State University annually evaluates the agronomic performance and nematode control of hundreds of soybean varieties that are resistant to the soybean cyst nematode (SCN). A limited number of SCN-susceptible soybean varieties are included in the research to serve as a reference point for comparison. The work is supported by the soybean checkoff through the Iowa Soybean Association. The experiments are conducted in each of Iowa’s nine crop reporting districts.


Long-Term Land Management Practices And Their Effect On Soil Health And Crop Productivity, Thomas Joseph Muratore Jr. 2019 University of Kentucky

Long-Term Land Management Practices And Their Effect On Soil Health And Crop Productivity, Thomas Joseph Muratore Jr.

Theses and Dissertations--Plant and Soil Sciences

Agricultural intensification reliant on monocrops could change soil health in a way that does not support maximum crop productivity. Twenty-nine-year-old no-till field plots at the University of Kentucky Spindletop research farm showed a significant reduction in corn yields from continuous corn plots compared to those from plots in various types of rotation. The objective of this study was to determine what role soil microbes might play in yield reduction and how management and time effects microbial community structure. Samples were collected from the following treatments: continuous corn (CC), continuous soybean (SS), a 2-year corn/soybean rotation (CCSS), Corn in rotation ...


Apple Disease Forecasting Models: When Climate Changes The Rules, Elizabeth W. Garofalo 2019 University of Massachusetts Amherst

Apple Disease Forecasting Models: When Climate Changes The Rules, Elizabeth W. Garofalo

Masters Theses

With a changing global climate, plant pathologists must understand the impact aberrant weather events may have on the development of plant diseases. Fungal plant infections are largely dependent on temperature and precipitation, climate parameters that are predicted to change more in this century. Venturia inaequalis causes apple scab, one of the most destructive apple diseases of temperate growing regions. Temperature and precipitation drive apple scab infections and forecast models, which guide growers in efficient, effective fungicide applications. In some recent years in the Northeast, these models have failed to accurately predict when ascospores of this fungus are available to cause ...


Field Evaluation Of Tobacco Engineered For High Leaf-Oil Accumulation, James Perry 2019 University of Kentucky

Field Evaluation Of Tobacco Engineered For High Leaf-Oil Accumulation, James Perry

Theses and Dissertations--Plant and Soil Sciences

The biofuel market is dominated by ethanol and biodiesel derived from cellulosic and lipid-based biomass crops. This is largely due to the relatively low costs and reliability of production. At present, production of non-food plant-derived oils for biofuel production in the U.S. is minimal. A research team from the Commonwealth Scientific and Industrial Research Organization (CSIRO), an independent Australian federal government research institution, has developed an efficient transgenic system to engineer oil production in tobacco leaves. This novel system is comprised of multiple transgenes that direct the endogenous metabolic flux of oil precursors towards triacylglycerol (TAG) production. Additional genes ...


Cover Crop Mixture Diversity, Biomass Productivity, Weed Suppression, And Stability, A. M. Florence, L. G. Higley, R. A. Drijber, C. A. Francis, J. L. Lindquist 2019 University of Nebraska - Lincoln

Cover Crop Mixture Diversity, Biomass Productivity, Weed Suppression, And Stability, A. M. Florence, L. G. Higley, R. A. Drijber, C. A. Francis, J. L. Lindquist

Agronomy & Horticulture -- Faculty Publications

The diversity-productivity, diversity-invasibility, and diversity-stability hypotheses propose that increasing species diversity should lead, respectively, to increased average biomass productivity, invasion resistance, and stability. We tested these three hypotheses in the context of cover crop mixtures, evaluating the effects of increasing cover crop mixture diversity on above ground biomass, weed suppression, and biomass stability. Twenty to forty cover crop treatments were replicated three or four times at eleven sites using eighteen species representing three cover crop species each from six pre-defined functional groups: cool-season grasses, cool-season legumes, cool-season brassicas, warm-season grasses, warm-season legumes, and warm-season broadleaves. Each species was seeded as ...


Drought Stress Tolerance In Wheat And Barley: Advances In Physiology, Breeding And Genetics Research, Ahmed Sallam, Ahmad M. Alqudah, Mona F. A. Dawood, P. Stephen Baenziger, Andreas Borner 2019 Assiut University

Drought Stress Tolerance In Wheat And Barley: Advances In Physiology, Breeding And Genetics Research, Ahmed Sallam, Ahmad M. Alqudah, Mona F. A. Dawood, P. Stephen Baenziger, Andreas Borner

Agronomy & Horticulture -- Faculty Publications

Climate change is a major threat to most of the agricultural crops grown in tropical and sub-tropical areas globally. Drought stress is one of the consequences of climate change that has a negative impact on crop growth and yield. In the past, many simulation models were proposed to predict climate change and drought occurrences, and it is extremely important to improve essential crops to meet the challenges of drought stress which limits crop productivity and production. Wheat and barley are among the most common and widely used crops due to their economic and social values. Many parts of the world ...


Beyond Bird Feed: Proso Millet For Human Health And Environment, Saurav Das, Rituraj Khound, Meenakshi Santra, Dipak K. Santra 2019 University of Nebraska - Lincoln

Beyond Bird Feed: Proso Millet For Human Health And Environment, Saurav Das, Rituraj Khound, Meenakshi Santra, Dipak K. Santra

Agronomy & Horticulture -- Faculty Publications

Domesticated in 8000–10,000 BP in northern China, proso millet (Panicum miliaceum L.) is the best adaptive rotational crop for semiarid central High Plains of the USA, where average annual precipitation is 356–407 mm. Proso millet has multiple benefits when consumed as human food. Proso millet is rich in minerals, dietary fiber, polyphenols, vitamins and proteins. It is gluten-free and therefore, ideal for the gluten intolerant people. Proso millet contains high lecithin which supports the neural health system. It is rich in vitamins (niacin, B-complex vitamins, folic acid), minerals (P, Ca, Zn, Fe) and essential amino acids (methionine ...


Developments In Agricultural Soil Quality And Health: Reflections By The Research Committee On Soil Organic Matter Management, Michelle M. Wander, Larry J. Cihacek, Mark Coyne, Rhae A. Drijber, Julie M. Grossman, Jessica L. M. Gutknecht, William R. Horwath, Sindhu Jagadamma, Daniel C. Olk, Matt Ruark, Sieglinde S. Snapp, Lisa K. Tiemann, Ray Well, Ronald F. Turco 2019 University of Illinois at Urbana-Champaign

Developments In Agricultural Soil Quality And Health: Reflections By The Research Committee On Soil Organic Matter Management, Michelle M. Wander, Larry J. Cihacek, Mark Coyne, Rhae A. Drijber, Julie M. Grossman, Jessica L. M. Gutknecht, William R. Horwath, Sindhu Jagadamma, Daniel C. Olk, Matt Ruark, Sieglinde S. Snapp, Lisa K. Tiemann, Ray Well, Ronald F. Turco

Agronomy & Horticulture -- Faculty Publications

The North Central Education and Research Activity Committee (NCERA-59) was formed in 1952 to address how soil organic matter formation and management practices affect soil structure and productivity. It is in this capacity that we comment on the science supporting soil quality and associated soil health assessment for agricultural lands with the goal of hastening progress in this important field. Even though the suite of soil quality indicators being applied by U.S. soil health efforts closely mirrors the “minimum data set” we developed and recommended in the mid-1990s, we question whether the methods or means for their selection and ...


A Key Variant In The Cis-Regulatory Element Of Flowering Gene Ghd8 Associated With Cold Tolerance In Rice, Peng Wang, Yin Xiong, Rong Gong, Ying Yang, Kai Fan, Sibin Yu 2019 Huazhong Agricultural University

A Key Variant In The Cis-Regulatory Element Of Flowering Gene Ghd8 Associated With Cold Tolerance In Rice, Peng Wang, Yin Xiong, Rong Gong, Ying Yang, Kai Fan, Sibin Yu

Agronomy & Horticulture -- Faculty Publications

Variations in the gene promoter play critical roles in the evolution of important adaptive traits in crops, but direct links of the regulatory mutation to the adaptive change are not well understood. Here, we examine the nucleotide variations in the promoter region of a transcription factor (Ghd8) that control grain number, plant height and heading date in rice. We find that a dominant promoter type of subspecies japonica displayed a high activity for Ghd8 expression in comparison with the one in indica. Transgenic analyses revealed that higher expression levels of Ghd8 delayed heading date and enhanced cold tolerance in rice ...


Climate-Smart Practices For Improvement Of Crop Yields In Mid-Hills Of Nepal, Roshan Subedi, Laxmi Dutt Bhatta, Erica Udas, Nand Kishor Agrawal, Keshab Datta Joshi, Dinesh Panday 2019 CEAPRED

Climate-Smart Practices For Improvement Of Crop Yields In Mid-Hills Of Nepal, Roshan Subedi, Laxmi Dutt Bhatta, Erica Udas, Nand Kishor Agrawal, Keshab Datta Joshi, Dinesh Panday

Agronomy & Horticulture -- Faculty Publications

Farming in Nepal mostly represents the hill farming system with the dominance of small-holder farmers. In recent days, farmers in the country are impacted by climate change. Events of surface runoff, landslides, and soil erosions, along with changes in rainfall pattern and intensity have elevated a decline in crop productivity and soil fertility. Considering the situation, a pilot project on Resilient Mountain Village was implemented in Kavrepalanchowk district of Nepal from 2014–2016 with a participatory approach to demonstrate climate-smart practices. These practices include the application of locally prepared bio-fertilizer (named as “jholmal”), green manuring in rice (Oryza sativa L ...


Engineering Linear, Branched-Chain Triterpene Metabolism In Monocots, Chase Kempinski, Zuodong Jiang, Garrett Zinck, Shirley J. Sato, Zhengxiang Ge, Thomas E. Clemente, Joseph Chappell 2019 University of Kentucky

Engineering Linear, Branched-Chain Triterpene Metabolism In Monocots, Chase Kempinski, Zuodong Jiang, Garrett Zinck, Shirley J. Sato, Zhengxiang Ge, Thomas E. Clemente, Joseph Chappell

Agronomy & Horticulture -- Faculty Publications

Triterpenes are thirty-carbon compounds derived from the universal five-carbon prenyl precursors isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP). Normally, triterpenes are synthesized via the mevalonate (MVA) pathway operating in the cytoplasm of eukaryotes where DMAPP is condensed with two IPPs to yield farnesyl diphosphate (FPP), catalyzed by FPP synthase (FPS). Squalene synthase (SQS) condenses two molecules of FPP to generate the symmetrical product squalene, the first committed precursor to sterols and most other triterpenes. In the green algae Botryococcus braunii, two FPP molecules can also be condensed in an asymmetric manner yielding the more highly branched triterpene, botryococcene. Botryococcene is ...


The Effect Of Year-To-Year Variability On Planting Date And Relative Maturity Selection For Maize, Mitch Baum 2019 Iowa State University

The Effect Of Year-To-Year Variability On Planting Date And Relative Maturity Selection For Maize, Mitch Baum

Graduate Theses and Dissertations

Current maize (Zea mays L.) planting date recommendations have not been updated in the state of Iowa since 2001. A state that produced 68.8 million tons of maize on 5.5 million hectares in 2016. It is imperative that this information be regularly updated as both climate and maize hybrid selection are constantly changing. We analyzed maize yield and phenology, from a multi-location, year, relative maturity (RM), and planting date (PD) experiment carried out in Iowa, US. The dataset was used to calibrate a site-specific model (Agricultural Production System sIMulation, APSIM) and extrapolate APSIM results across Iowa, using a ...


Uhf Band Attenuation Through A Corn Canopy With Crop Growth, Richard Jay Cirone 2019 Iowa State University

Uhf Band Attenuation Through A Corn Canopy With Crop Growth, Richard Jay Cirone

Graduate Theses and Dissertations

Soil moisture and vegetation remote sensing measurements can be inaccurate and/or misinterpreted in the US Corn Belt, specifically when considering seasonal variation in standing vegetation. A direct crop water measurement method was employed to assist in correction of satellite measurements, specifically to SMOS and SMAP. A 433 MHz radio link was installed in a central Iowa cornfield, shortly after planting, across a distance of 50 meters, for the purpose of measuring attenuation by crop water. This experiment ran until mid grain fill, development stage R3. Vegetation water column density increased from essentially 0 at planting to just above 4 ...


Segregation Strategies For Non-Gm Corn: Improving Effectiveness Through An Analytical Modeling Approach, Chad Joseph Dolphin 2019 Iowa State University

Segregation Strategies For Non-Gm Corn: Improving Effectiveness Through An Analytical Modeling Approach, Chad Joseph Dolphin

Graduate Theses and Dissertations

The open air growing environment for corn (Zea mays L.) makes it impossible to maintain genetic purity of 100%. Much debate has characterized the discussion on acceptable tolerance levels for adventitious presence to ensure coexistence between genetically modified and non-genetically modified crops. This research analyzes nine scenarios to test field, handling, and elevator-based segregation capabilities in a commodity system. Using stochastic models to model individual factors that contribute to adventitious presence in commodity maize including: impure seed, isolation distance, equipment cleanout, and elevator handling practices, Monte Carlo simulation was used to calculate the cumulative amount of adventitious presence for each ...


A Statistical Analysis Of Zea Mays Grain Yield Response To Nitrification-Inhibitor Amendments Under Field Conditions Utilizing Parametric And Non-Parametric Techniques, Elliot H. Sully 2019 Iowa State University

A Statistical Analysis Of Zea Mays Grain Yield Response To Nitrification-Inhibitor Amendments Under Field Conditions Utilizing Parametric And Non-Parametric Techniques, Elliot H. Sully

Graduate Theses and Dissertations

Nitrification is a matter of economic and ecological importance in nitrogen-tensive agricultural practices such as corn (Zea mays) grain production. When ammonium is bacterially oxidized into nitrate it becomes more susceptible to leaching and denitrification as nitrous oxide. The nitrification process not only adds to water and air pollution but also impacts on farm productivity by reducing grains yields and increasing fertilizer demands. Nitrification inhibiting fertilizer amendments can potentially improve grain yields by retarding the growth of nitrifying soil bacteria. Multiple field studies conducted across various locations and timespans have generated mixed results regarding the grain yield difference attributed to ...


Diversifying Cornfields By Interseeding Cover Crops: Practical Implications And The Response Of Invertebrate Communities, Michael Bredeson 2019 South Dakota State University

Diversifying Cornfields By Interseeding Cover Crops: Practical Implications And The Response Of Invertebrate Communities, Michael Bredeson

Electronic Theses and Dissertations

The lack of suitable habitat conditions for beneficial organisms in simplified agroecosystems leads to unstable invertebrate communities and overreliance on chemical control of herbivores. It is possible to manage pest populations without agrichemicals by manipulating farmland so that herbivores are impaired by plant-driven bottom-up and enemy-driven top-down antagonisms. Interseeding cover crops between established crop rows is a method used by farmers to improve habitat suitability for natural enemies and hinder host-finding, feeding and movement by herbivores. Here I address three important research gaps related to interseeding cover crops. A calcium carbonate seed coating, used to improve seed-broadcasting efficiency, was tested ...


Digital Commons powered by bepress