Agronomy and Crop Sciences Commons^™

4-Hydroxyphenylpyruvate Dioxygenase (Hppd)-Inhibiting Herbicides: Past, Present, And Future, Amit J. Jhala, Vipan Kumar, Ramawatar Yadav, Prashant Jha, Mithila Jugulam5, Martin M. Williams Ii, Nicholas E. Hausman, Franck E. Dayan, Paul M. Burton, Richard P. Dale, Jason K. Norsworthy

Department of Agronomy and Horticulture: Faculty Publications

The 4-hydroxyphenylpyruvate dioxygenase (HPPD)-inhibiting herbicides are primarily used for weed control in corn, barley, oat, rice, sorghum, sugarcane, and wheat production fields in the United States. The objectives of this review were to summarize (1) the history of HPPD-inhibitor and their use in the United States, (2) HPPD-inhibitor resistant weeds, their mechanism of resistance, and management, (3) interaction of HPPD-inhibitor with other herbicides, and (4) the future of HPPD-inhibitor-resistant crops. As of 2022, three broadleaf weeds (Palmer amaranth, waterhemp, and wild radish) have evolved resistance to the HPPD-inhibitor. The predominance of metabolic resistance to HPPD-inhibitor was found in aforementioned three …

Limited Irrigation For Managing Declining Water Resources In The Us High Plains, Bijesh Maharjan, Gary Hergert, Saurav Das

Department of Agronomy and Horticulture: Faculty Publications

The US High Plains region has a semiarid climate receiving between 330 and 455 mm of rainfall annually. In the Nebraska Panhandle of the High Plains, 30-year average rainfall is 394 mm, and one-fourth of agriculture is under irrigation. In addition to concerns about water quality, there is a growing concern over water quantity for ground- and surface-water resources that producers use for irrigation. Wisely managing limited water resources for irrigation can help maintain crop productivity and profitability. Deficit irrigation research for 13 years (2005–2017) was conducted in the Nebraska Panhandle to study effects of limited irrigation on maize ( …

Monitoring Environmental Policy Process: Indicators To Evaluate Performance, Stella Namanji, Charles A. Francis, Charles Ssekyewa, Geir Hofgaard Lieblein

Department of Agronomy and Horticulture: Faculty Publications

The complexity of environmental policy development was examined in relation to sustainability, holistic and systems-thinking perspectives. We studied potential application of systems principles of coordination, representation, collaboration, participation and teamwork to improve policy effectiveness at formulation, communication, implementation, and operationalisation of the environment policy in Uganda. The research unveiled the ineffectiveness of the Uganda National Environment Management Policy. We applied systems theory to develop a mechanism for monitoring effectiveness of environmental policies at national level, with the goal to identify key monitoring indicators. We used the soft systems methodology to identify occurring environmental problems causing forest loss. Results suggest that …

Charles A. Francis, Abstracts And Publications [1969--2022], December 2022, Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

Contents

I. Journal articles (218), p.1

II. Book reviews (60), p. 18

III. Published abstracts (213), p. 23

IV. Books (23), p. 40

V. Chapters in books (81), p. 42

VI. Symposium or workshop proceedings (127), p. 50

VII. Symposia or extension publications edited (31), p. 62

VIII. Miscellaneous (522), p. 65

Modeling The Evolution Of Herbicide Resistance In Weed Species With A Complex Life Cycle, K. Harrison Holmes, John L. Lindquist, Richard Rebarber, Rodrigo Werle, Melinda K. Yerka, Brigitte Tenhumberg

Brigitte Tenhumberg Papers

A growing number of weed species have evolved resistance to herbicides in recent years, which causes an immense financial burden to farmers. An increasingly popular method of weed control is the adoption of crops that are resistant to specific herbicides, which allows farmers to apply the herbicide during the growing season without harming the crop. If such crops are planted in the presence of closely related weed species, it is possible that resistance genes could transfer from the crop species to feral populations of the wild species via gene flow and become stably introgressed under ongoing selective pressure by the …

An Evaluation Of Eragrostis Tef For Future Cultivar Development, Eric Wayne Luteyn

Theses and Dissertations--Plant and Soil Sciences

The many benefits of utilizing teff (Eragrostis tef) as small grain is well documented in journal publications. Over time the domestication of this species has become essential to the diets of the local population and the livestock living in the African highlands. Current research points to a high diversity of trait characteristics found in many teff populations and the potential utilization of these traits to increase desirable characteristics in both grain and forage varieties. With the overarching goal of adding to what is already known about teff, this study evaluates the different traits that are of interest to …

Intercropping Grain Sorghum Into Established Rhizoma Peanut: Greenhouse And Field Studies, Erika Hm Cooperman

Graduate Theses/Dissertations

Land degradation and urbanization are among the top factors pushing the Kenyan Maasai community into an unstable future, with food insecurity and poverty amidst the most fragile components. Implementing conservation agricultural techniques into the Maasai nomadic lifestyle could potentially lead to a diversification of finances and food security. Intercropping is one technique of conservation agriculture that could provide the Maasai both. The main objective of this study is to evaluate the effects of creating an intercropped environment between rhizoma peanut and grain sorghum. A greenhouse study was conducted from late 2020 to 2021 in an effort to investigate the effects …

Effect Of Essential Oils In The Control Of Fungal Diseases In Small Grains, Esneider Mahecha Bojaca

Electronic Theses and Dissertations

Spring wheat (Triticum aestivum L.) and oats (Avena sativa L.) are important crops due to their high consumption in our daily diet worldwide. They are the main food of consumption per capita due to the high amino-acid content as well of vitamins. However, grain production is limited due to the negative impact of the diseases that cause significant yield loss. Diseases in oats, such as crown rust caused by Puccinia coronata f. sp. avenae (Pca), and in wheat such as Fusarium head blight (FHB) caused by the fungus Fusarium graminearum. Foliar diseases such as tan spot incited by the fungi …

Phomopsis Stem Canker Of Sunflower (Helianthus Annuus L.): Etiology And Epidemiological Conditions Affecting Endophytic Population Of Diaporthe Spp., And Fungicide Efficacy, Nabin Kumar Dangal

Electronic Theses and Dissertations

Phomopsis stem canker (PSC), caused by species of Diaporthe, is a major disease of sunflower (Helianthus annuus L.) in the U.S., which can cause yield loss over 40%. The disease prevalence increased since 2010 in the major sunflower producing U.S. states of Nebraska, Minnesota, North Dakota, and South Dakota. Previous studies on the use of foliar fungicides in managing Phomopsis stem canker indicated mixed results on their efficacy in disease reduction and yield gain. Additionally, we do not have sufficient information on asymptomatic colonization by endophytic Diaporthe on sunflower tissue and how foliar fungicide and weather parameters affect the prevalence …

Study Of Root System Architectural Traits Of Oat And Response To Endophyte Inoculation And Drought Stress, Krishna Ghimire

Electronic Theses and Dissertations

Oat is an important cereal crop grown worldwide. Oats have the potential to contribute to human health due to their unique nutritional attributes. Developing oat cultivars with efficient root systems able to extract heterogeneously distributed soil resources can help maintain yield under drought conditions and in nutrient poor soil. Various root traits determine the soil volume that is explored by the root system for resource acquisition. Knowledge about the genetic control of oat root traits and response to biotic and abiotic environmental factors is lacking. Identifying quantitative trait loci associated with root traits and understanding the response of roots to …

Keeping What You Sow: Intellectual Property Rights For Plant Breeders And Seed Growers, Paulina B. Jenney

Graduate Student Theses, Dissertations, & Professional Papers

Over the last 150 years, the food system in the present-day United States has undergone a transformational restructuring, from a diversified, decentralized, network of farmers and seed growers, to one in which the majority of crop production is controlled by a few industrial corporations. The consolidation of power has been under-girded by the application of intellectual property rights (IPR)—especially utility patents—to plant varieties and genetic traits, which are leveraged to exclude small-scale seed growers from accessing quality germplasm. Patents and restrictive licensing agreements recapitulate colonial structures by appropriating common and traditionally community-held resources for profit, and by creating reliance on …

Minimum Dataset And Metadata Guidelines For Soil-Test Correlation And Calibration Research, Nathan A. Slaton, Sarah E. Lyons, Deanna L. Osmond, Sylvie M. Brouder, Steve W. Culman, Gerson L. Drescher, Luciano C. Gatiboni, John Hoben, Peter J.A. Kleinman, Joshua M. Mcgrath, Robert O. Miller, Austin Pearce, Amy L. Shober, John T. Spargo, Jeff J. Volenec

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Soil-test correlation and calibration data are essential to modern agriculture, and their continued relevance is underscored by the expansion of precision farming and the persistence of sustainable soil management priorities. In support of transparent, science-based fertilizer recommendations, we seek to establish a core set of required and recommended information for soil-test P and K correlation and calibration studies, a minimum dataset, building on previous research. The Fertilizer Recommendation Support Tool (FRST) project team and collaborators are developing a national database that will support a soil-test-based nutrient management decision aid tool. The FRST team includes over 80 scientists from 37 land-grant …

Changes In The Barley Stem Proteome In Response To Drought During Grain Filling, Mohammed Al Slamh

Dissertations and Theses @ UNI

Drought is the major environmental factor that limits crop yield worldwide. Crops are particularly vulnerable to drought at the reproductive stage. In cereals, grain filling during drought depends on the contribution of current photosynthesis products from the leaf and spike and carbohydrates stored mainly in the stem and remobilized to the grain. Even though stem reserve is an important source for grain filling, changes in the proteome of barley stem under drought have not been studied. Also, the molecular events associated with differential stem reserve remobilization under drought are not well understood. In this study, barley plants were exposed to …

Rice Tolerance To Multiple Applications Of Florpyrauxifen-Benzyl Alone And Followed By Benzobicyclon, James Winston Beesinger, Jason K. Norsworthy, Thomas R. Butts, Trenton Roberts

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Varying levels of sensitivity to florpyrauxifen-benzyl and benzobicyclon applications among rice (Oryza sativa L.) cultivars have been observed. The safe use of florpyrauxifen-benzyl and benzobicyclon in the same herbicide program could provide broad-spectrum weed control and delay resistance in weed species. Two experiments were conducted in 2019 and 2020 near Stuttgart, AR, to test cultivars' sensitivity to multiple rates of florpyrauxifen-benzyl and applications of florpyrauxifen-benzyl followed by benzobicyclon. The first experiment was designed to determine the sensitivity of the rice cultivars `XP753', 'CL XL745', 'Gemini 214CL', 'Titan', and 'Diamond' to applications of florpyrauxifen-benzyl at 0.03 and 0.06 lb acid …

Getting To The Root Cause: The Genetic Underpinnings Of Root System Architecture And Rhizodeposition In Sorghum, Farren Smith

Graduate Theses, Dissertations, and Problem Reports (ETD)

Plants are some of the most diverse organisms on earth, consisting of more than 350,000 different species. To understand the underlying processes that contributed to plant diversification, it is fundamental to identify the genetic and genomic components that facilitated various adaptations over evolutionary history. Most studies to date have focused on the underlying controls of above-ground traits such as grain and vegetation; however, little is known about the “hidden half” of plants. Root systems comprise half of the total plant structure and provide vital functions such as anchorage, resource acquisition, and storage of energy reserves. The execution of these key …

Long Term Observation Of The Grassland Vegetation Used Intensively Or Extensively And Ecologically, H.-D. Matthes, J. Matthes, W. Jentsch, V. Pastushenko

IGC Proceedings (1977-2023)

The aim of the present paper was to study alterations of the grassland flora from 55 plots following a more extensive management under long term observation within 6 years. Extensification of grassland use leads to an increase of the numbers of plant species by 32%, “Red-list-species” included. The moisture number of the soils slightly increased and the reaction and nitrogen numbers decreased. Results are presented for different vegetation units.

Influence Of Extensive Management On Botanical Composition Of Permanent Meadow Sward, K. Mlynarczyk, E. Korona, E. Marks

IGC Proceedings (1977-2023)

The aim of undertaken investigations was to find the possibilities of grassland management with special respect to the biodiversity and the landscape conservation. Changes in botanical composition of the meadow sward against a background of different mowing utilization were examined on the semi-natural meadows situated on the peat-mursh soil in Masurian Landscape Park (north-east Poland). The areas mown with biennial pause and completely turned off from uses followed gradual simplifying of species composition and increasing of bog species participation. Results show on advisability of passing one harvest each year or with one-year pauses.

Vegetation Changes In Sown Grassland In The Uk After Nine Years Of Extensive Grazing Management, C. A. Marriott, G. T. Barthram

IGC Proceedings (1977-2023)

The effect of extensive grazing management with sheep on vegetation change in sown pastures (initially containing Lolium perenne and Trifolium repens) in the uplands of Scotland was investigated from 1990-1999. One treatment was representative of current more intensive management systems; it was fertilized, and maintained at a sward surface height of 4 cm. Two treatments were unfertilized and were maintained at sward surface heights of 4 cm or 8 cm; the ewe numbers carried on these treatments averaged 74% and 44%, respectively, of those on the fertilized treatment. In all treatments the sheep were Scottish Blackface ewes. Their single …

The Influence Of Rising Atmospheric Co2 On Grassland Ecosystems, J. A. Morgan, P. C. D. Newton, J. Nösberger, C. E. Owensby

IGC Proceedings (1977-2023)

Increasing atmospheric CO₂ concentrations and climatic change will have significant effects on the ecology of grasslands. This paper evaluates results from four CO₂ enrichment studies in contrasting grasslands. A Swiss study investigates the effects of elevated CO₂ (600 μL L^-1 CO₂) on perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L), a New Zealand study examines how elevated CO₂ (475 μL L^-1 CO₂) affects a botanically diverse pasture, and studies in the Kansas tallgrass prairie and the Colorado shortgrass steppe investigate the effects of an approximate …

Elevated Co2 Enhances Productivity And The C/N Ratio Of Grasses In The Colorado Shortgrass Steppe, J. A. Morgan, A. R. Mosier, D. R. Lecain, W. J. Parton, D. G. Milchunas

IGC Proceedings (1977-2023)

Atmospheric CO₂ concentrations have been increasing since the industrial revolution, and are projected to double within this century over today's concentration of 360 µmol mol^-1 . This study used six open-top chambers in the Colorado, USA shortgrass steppe to investigate how increasing CO₂ will affect productivity and C and N status of indigenous perennial grasses and forbs. From March until October, chambers were placed on two plots in each of the three blocks. In each block, one chamber was assigned an ambient CO₂ treatment (~360 µmol mol^-1), the other an elevated CO₂ treatment …

Rangeland Desertification In China, Wang Tao

IGC Proceedings (1977-2023)

Land desertification is one of the most serious environmental and social-economic problems in the North China. The processes of desertification mainly have being controlled by the interaction of human activities and fragile eco-environment, that means the pattern and intension of landuse are major factors for development or reverse of desertification. Because of the increasing pressure of population, the rangeland in the North China has being cultivated decade by decade, which changed landuse from grassing to cropping in a large area and destroyed the natural vegetation cover. The result is to let the wind erosion become easier and the desertification has …

Grasslands, Communicating The Benefits, D. Keeney

IGC Proceedings (1977-2023)

The multiple benefits of perennial agriculture , including forages and grasslands, for building soil quality, protection of natural resources, enhancement of biodiversity and wildlife, are well known to us, but little understood by the public. This is not a situation where “more education” would necessarily increase recognition. Rather, we must build in the public a desire for the enhancement of green space, clean water and air, and diverse landscapes that multiple purpose agriculture can bring. We seek such environments intuitively and now that much of the world’s people are “trapped” in urban settings of steel and concrete, this desire is …

Agropastoral Systems An Alternative To Revert Pasture Degradation In The Cerrados Of Brazil: Preliminary Results, Manuel C. M. Macedo, J. A. M. Bono, A. H. Zimmer, F. P. Costa, Tsutomu Kanno, Cesar Heraclides Behling Miranda, A. N. Kichel

IGC Proceedings (1977-2023)

A long term experiment was set to test the hypothesis that agropastoral systems could improve crop and animal production, being more profitable and sustainable relative to economical, biological and environmental aspects, than continuous and traditional crop and grazing pasture systems. Five farming systems are being tested: two traditional (continuous soybean annual cropping and continuous pasture cropping) and three agropastoral systems (two combinations of four by four years of rotational crop-pasture systems and one by three years of crop-pasture rotation). Animal production in continuous pasture cropping measured as liveweight gain/ha (LWG) are declining along the years in the sub-treatment without fertilizer …

Evaluation Of A Number Of Grass Species For Restoring Degraded Semi-Arid Rangelands In Southern Africa, K. Kellner, S. De Wet

IGC Proceedings (1977-2023)

The biophysical environment is an important determinant of land degradation in both commercial and communal land tenure systems in South Africa. According to a recent study on the status of land degradation, approximately 25% of the total land cover in South Africa is degraded. Several technologies exist to restore the soil and vegetation degraded areas in natural pastures. To improve the production and biodiversity potential for agricultural and conservation uses in these rangelands, a common restoration technology includes the cultivation the eroded and compacted soil surfaces by rip- ploughing and the re-vegetation with high productive, palatable and perennial species. Five …

Water-Use Efficiency And Infiltration Under Different Rangeland Conditions And Cultivation In A Semi-Arid Climate Of South Africa, Hennie A. Snyman

IGC Proceedings (1977-2023)

The objective of this study was to determine the impact of rangeland in different botanical composition classes (good, moderate and poor), on water-use efficiency (WUE: crude protein produced per unit of evapotranspiration) and soilwater content. The same measurements were also made on an undisturbed bare soil surface and soil cultivated twice per annum. Evapotranspiration was determined by quantifying the soil-water balance equation with the aid of runoff plots and soil-water content measurements done by a neutron hydroprobe. Water-use efficiency declined significantly (P ≤ 0.01) with rangeland degradation. Rangeland in good condition averaged a WUE of 0.28 kg crude protein ha …

Community Structure Of Serrated Tussock (Nassella Trichotoma) Infested Grasslands, Warwick B. Badgery, David R. Kemp, D. L. Michalk, W. Mcg. King

IGC Proceedings (1977-2023)

Serrated tussock (Nassella trichotoma) is the most serious perennial grass weed in southeastern Australia, extending over more than a million hectares. Previous control techniques using herbicides and oversowing with competitive pastures are no longer feasible in many of the lower fertility, infested areas. New management solutions need to be found, based upon a better understanding of the ecology of this species. A survey was done to determine the community structure of serrated tussock infested grasslands. Winter growing C3 grasses were closely associated with serrated tussock, while C4 perennial grasses appeared not to be. It is not known if …

Valuing The Pasture Resource - Importance Of Perennials In Higher Rainfall Regions Of South Eastern Australia, P. M. Dowling, R. E. Jones, David R. Kemp, D. L. Michalk

IGC Proceedings (1977-2023)

The premature decline of perennial grass based pastures in southern temperate Australia results in poor productivity and unstable pastures that allow invasion by less desirable weedy species and the potential for soil degradation. The loss of perennial species is attributed to overgrazing arising from an undervaluation of the pasture resource. Resowing pastures is largely uneconomic so maintenance of, or increasing the perennial, is dependent on improved grazing and pasture management practices. A key to changing perceptions is valuing the true worth of the perennial component. Results are presented from a model that takes into account the seasonality of production of …

Using ‘Traps’ (Transect Recording And Processing System) In Woody Weed Control Studies In Australia, P. V. Back

IGC Proceedings (1977-2023)

The ‘TRAPS’ (Transect Recording And Processing System) methodology has proven to be a powerful and versatile tool for studying the effects of various woody weed control strategies in studies carried out in Queensland, Australia. ‘TRAPS’ allows the tracking of individual woody plants even when destructive control techniques such as bulldozing, ploughing and burning are used. This methodology also allows the investigator to discriminate between plants present before any treatment is imposed and plants recruited after the treatment.

Importance Of Haresfoot Clover (Trifolium Arvense) As A Nitrogen Fixer In Semi-Arid Grasslands Of New Zealand, C. C. Boswell, W. L. Lowther, P. R. Espie

IGC Proceedings (1977-2023)

The aim of the study was to determine the distribution of annual haresfoot clover (Trifolium arvense) in a depleted indigenous short tussock grassland catchment in the dry subhumid MacKenzie Basin, South Island, New Zealand. Haresfoot clover was present on all landscapes, and widely distributed on lower sunny aspects, suggesting that it is an important component of the nitrogen cycle in these environments even in the absence of fertiliser application. The study was conducted during an atypically moist summer when a bloom of the annual clover occurred. Nitrogen inputs will vary with landscape and spring/summer rainfall and it is …

The Future For Savanna And Tropical Grasslands: A Latin American Perspective, R. R. Vera

IGC Proceedings (1977-2023)

The objective of the paper is to briefly review the main trends in the tropical lowlands of Latin America and the Caribbean (LAC) with particular emphasis in the neotropical savannas. These tropical native grasslands cover occupy approximately 210 million hectares, and constitute major portions of the territory of Bolivia, Brazil, Colombia, Guyana and Venezuela. Many analysts consider that intensification of their use is a valid alternative to the expansion of the livestock and crop industries into the rainforest.

The evidence reviewed shows that since the late 1980s, the LAC agricultural sector has shown dynamism not seen for many years. Despite …