Agronomy and Crop Sciences Commons^™

Improved Drought Stress Tolerance Of White Clover Through Hybridisation With Trifolium Uniflorum L., Shirley N. Nichols, Rainer W. Hofmann, Isabelle M. Verry

IGC Proceedings (1977-2023)

The objective of this study was to determine the effect of hybridisation with Trifolium uniflorum L. on drought resistance of Trifolium repens L. (white clover). Shoot dry weight of backcross 1 (BC1) hybrids was reduced less by water stress than for backcross 2 (BC2) hybrids and white clover, as were key morphological traits such as leaf area. Under water stress, important differences for the BC1 generation compared to white clover also included lower senescence, higher stolon density, increased root dry weight, and a higher maximum nodal root diameter. Drought decreased the net photosynthetic rate by up to 48% in BC2 …

Designing Resilient And Sustainable Grasslands For A Drier Future: Adaptive Strategies, Functional Traits And Biotic Interactions, Florence Volaire, Karim Barkaoui, Mark Norton

IGC Proceedings (1977-2023)

In many regions of the world, such as Southern Europe and most Mediterranean areas, the frequency and magnitude of droughts and heat waves are expected to increase under global warming and will challenge the sustainability of both native and sown grasslands. To analyze the adaptive strategies of species, genotypes and cultivars, we aim both: (1) to understand the composition and functioning of natural grasslands; and (2) to propose ideotypes of cultivars and optimal composition for mixtures of species/genotypes under water deficit and high temperatures. This review presents a conceptual framework to analyze adaptive responses of perennial herbaceous species, starting from …

Australian Grasslands Research At The Crossroads, Alan Robson

IGC Proceedings (1977-2023)

Grasslands research in Australia is at a crossroad. There are several difficulties. First, the decline of sheep production and dairying within Australia and increased cropping has focused attention on crop research rather than pasture research. Second, enrolments in agricultural and related education have declined, and graduate numbers are insufficient to meet demand for expertise. Third, there has been a move towards specialisation in research and there are relatively few generalist agricultural scientists able to integrate research results into agricultural ecosystems. There remain very many challenges. Adapting grassland production to minimize the emission of carbon dioxide and methane is a major …

International R D & E Investment: Revitalising The Skill Base In Grassland Research And Practice, Ralph Von Kaufmann

IGC Proceedings (1977-2023)

Grasslands make up about 40.5% of the world’s land surface, and almost everywhere they make vital contributions to food supplies, livelihoods, watersheds, conservation of biodiversity and to ameliorating climate change through carbon sequestration. However, grasslands are under-represented in discussions on food security and livelihoods. Despite large investments in building human capacity, improving production systems and in research, grasslands are continuing to degrade and there is no let-up in sight for the consequent strife, famines and conflicts among the pastoral and other communities that depend on them. This review of grassland issues identified many critical skills that are lacking but it …

Drivers Of Change For Grassland And Forage Systems: A Case Study Of China, Yingjun Zhang, L. Z. Zhang, M. L. Wang, X. L. Li, Q. C. Yang, J. Hanson, M. A. Jorge

IGC Proceedings (1977-2023)

Grassland and forage systems have changed dramatically across the world. This paper describes some of the key drivers of change of grassland and forage systems using examples from China as a case study. The key drivers of change for grassland and forage systems include political, economic, social, technical and environmental factors and their impact on changes in grasslands ecosystems in China is discussed. There are interactions among the drivers and their impact is similar in many developing countries.

Legumes, Livestock And Livelihoods In The Australian Mixed Farming System, E. C. Wolfe

IGC Proceedings (1977-2023)

This Howard Oration describes the pathway that I have taken towards my specialisation in ‘big picture’ agriculture. A simple protocol is presented for the analysis of agricultural systems by using descriptive or quantitative indicators of five system properties: productivity, sustainability, profitability, social wellbeing and political acceptability. These properties are further illustrated by considering four important issues in the Australian sheep-wheat belt, a distinctive world food production system. The issues are the supply of and demand for legume nitrogen for crops, reconciling agricultural and natural resource objectives, the low profitability of farms in relation to production and marketing risks, and the …

Does Intensification Of Grassland And Forage Use Lead To Efficient, Profitable And Sustainable Ecosystems?, Oene Oenema, Cecile De Klein, Marta Alfaro

IGC Proceedings (1977-2023)

The increasing demand for safe and nutritional dairy and beef products in our globalizing world, together with the needs to increase resource use efficiency and to protect biodiversity, provide strong incentives for intensification of grassland and forage use. This paper addresses the question in the title. Firstly, we present some notions about ‘intensification of agricultural production’. Secondly, we discuss the intensification of grassland-based dairy production in The Netherlands (NL), Chile and New Zealand (NZ). Finally, we arrive at some conclusions. External driving forces and ‘the law of the optimum’ provide strong incentives for intensification, i.e., for increasing the output per …

New Frontiers And Perspectives In Grassland Technology, Jürgen Schellberg, E. Verbruggen

IGC Proceedings (1977-2023)

Grassland scientists and farmers are increasingly faced with emerging new technologies and in-formation systems that have been primarily developed by engineering sciences in particular: precision agriculture, remote sensing, geographic localization and biotechnology. Whether the implementation of any of these technologies may be beneficial in economic and ecological respect is a challenging judgment call, especially for those who have to carry over that decision on their farm. Compared to arable land, new technologies have been applied on grassland only partially and with some delay. However, as we will demonstrate, there is place for a successful implementation of new technologies in various …

Diversity, Trends, Opportunities And Challenges In Australian Grasslands–Meeting The Sustainability And Productivity Imperatives Of The Future?, Lindsay W. Bell, Richard C. Hayes, Keith G. Pembleton, Cathy M. Waters

IGC Proceedings (1977-2023)

Grassland production systems contribute 40% to Australia’s gross agricultural production value and utilise over 50% of its land area. Across this area a broad diversity of systems exist, but these can be broadly classified into four main production systems: 1. Pastoral grazing of mainly cattle at low intensity (i.e. < 0.4 DSE/ha) on relatively unimproved native rangelands in the arid and semi-arid regions of northern and central Australia; 2. Crop-livestock systems in the semi-arid zone where livestock graze a mixture of pastures and crops which are often integrated; 3. High rainfall permanent pasture zone in the coastal hinterland and highlands and; 4. Dairy systems covering a broad range of environments and production intensities. A notable trend across these systems has been the replacement of wool sheep with beef cattle or meat sheep breeds, which has been driven by low wool prices. Although there is evidence that most of these systems have lifted production efficiencies over the past 30 years, total factor productivity growth has failed to match the decline in terms of trade. This has renewed attention on how research and development can help increase productivity. In addition, these industries are facing increasing scrutiny to improve their environmental performance and develop sustainable production practices. We propose several areas in which grasslands research and development might help provide gains in system productivity and sustainability. In particular, pasture productivity might be improved by filling gaps in the array of pastures available either through exploring new species or improving the adaptation and agronomic characteristics of species currently sown. Meanwhile there is a need to maintain efforts to overcome persistent and emerging constraints to pasture productivity. Improving livestock forage feed systems and more precise and lower cost management of grasslands would translate into improved utilisation and conversion of forage produced into livestock products. There is significant scope to capture value from the ecological services grasslands provide and mitigate greenhouse gas emissions from livestock production. Multi-purpose grasslands provide not only grazing for livestock but produce other food products such as grain which may also have potential to integrate livestock with cropping. However, reduced human research capacity in pasture science will challenge our ability to realise these potential opportunities unless efforts are made to attract and support a new generation of pasture scientists.

Managing Grassland Systems In A Changing Climate: The Search For Practical Solutions, Jean-François Soussana, Luis Gustavo Barioni, Tamara Ben Ari, Rich Conant, Pierre Gerber, Petr Havlik, Alexandre Ickowicz, Mark Howden

IGC Proceedings (1977-2023)

By the end of the XXI^st century, a global temperature rise between 1.5 and 4°C compared to 1980-1999 and CO₂ concentrations in the range 550-900 ppm are expected, together with an increased frequency of extreme climatic events (heat waves, droughts, and heavy rain) that is likely to negatively affect grassland production and livestock systems in a number of world regions. Grassland management has a large potential to mitigate livestock greenhouse gas emissions at a low (or even negative) cost, by combining a moderate intensification, the restoration of degraded pastures and the development of silvo-pastoral systems. Climate change vulnerability …

Feeding The World In 2050: Trade-Offs, Synergies And Tough Choices For The Livestock Sector, Jimmy Smith, Shirley Tarawali, Delia Grace, Keith Sones

IGC Proceedings (1977-2023)

Feeding the World in 2050 is a major challenge at the forefront of the global development agenda. The importance of agriculture in addressing this challenge has re-emerged in recent years as food security issues are considered in a more holistic manner. The role of livestock as part of the solution is, however, often not considered. This article presents a brief overview of the global food security challenge, and considers the increased focus on holistic food systems. It contends that animal agriculture is relevant to this complex, multifaceted and dynamic global challenge. However, if livestock-based solutions are to become a reality …

Front Matter [22nd International Grassland Congress Proceedings], Organizing Committee, International Grassland Congress

IGC Proceedings (1977-2023)

No abstract provided.

Improving The Efficiency Of Soybean Breeding With High-Throughput Canopy Phenotyping, Fabiana Freitas Moreira, Anthony Ahau Hearst, Keith Aric Cherkauer, Katy Martin Rainey

Purdue University Libraries Open Access Publishing Fund

Background: In the early stages of plant breeding programs high-quality phenotypes are still a constraint to improve genetic gain. New field-based high-throughput phenotyping (HTP) platforms have the capacity to rapidly assess thousands of plots in a field with high spatial and temporal resolution, with the potential to measure secondary traits correlated to yield throughout the growing season. These secondary traits may be key to select more time and most efficiently soybean lines with high yield potential. Soybean average canopy coverage (ACC), measured by unmanned aerial systems (UAS), is highly heritable, with a high genetic correlation with yield. The objective of …

Evaluation Of Soil Type And Seeding Rate On Winter Cover Crop Species In A Soybean Production System, Donna S. Morgan

LSU Doctoral Dissertations

The integration of winter annual cover crops into a cropping system can potentially improve soil health and crop production, however, the impact of variables such as seeding rates, across two very different soil types, has not been well documented. A two-year study was conducted at the Dean Lee Research Station and Extension Center in Alexandria, Louisiana to evaluate the effects of cover crop seeding rate and soil type on cover crop biomass, weed suppression, soil fertility, and soybean (Glycine max L) growth and yield. Analysis of potential economic impacts was also performed to estimate financial net returns for three …

Evaluation Of A Global Spring Wheat Panel For Stripe Rust: Resistance Loci Validation And Novel Resources Identification, Ibrahim Elbasyoni, Walid M. El-Orabey, Sabah Morsy, P. S. Baenziger, Zakaria Al Ajlouni4, Ismail M. Dweikat

Department of Agronomy and Horticulture: Faculty Publications

Stripe rust (incited by Puccinia striiformis f. sp. tritici) is airborne wheat (Triticum aestivum L.) disease with dynamic virulence evolution. Thus, anticipatory and continued screening in hotspot regions is crucial to identify new pathotypes and integrate new resistance resources to prevent potential disease epidemics. A global wheat panel consisting of 882 landraces and 912 improved accessions was evaluated in two locations in Egypt during 2016 and 2017. Five prevalent and aggressive pathotypes of stripe rust were used to inoculate the accessions during the two growing seasons and two locations under field conditions. The objectives were to evaluate the panel for …

Metabolic Dynamics Of Developing Rice Seeds Under High Night-Time Temperature Stress, Balpreet K. Dhatt, Nathan Abshire, Puneet Paul, Kalani Hasanthika, Jaspreet Sandhu, Qi Zhang, Toshihiro Obata, Harkamal Walia

Department of Agronomy and Horticulture: Faculty Publications

High temperature stress during rice reproductive development results in yield losses. Reduced grain yield and grain quality has been associated with high temperature stress, and specifically with high night-time temperatures (HNT). Characterizing the impact of HNT on the phenotypic and metabolic status of developing rice seeds can provide insights into the mechanisms involved in yield and quality decline. Here, we examined the impact of warmer nights on the morphology and metabolome during early seed development in six diverse rice accessions. Seed size was sensitive to HNT in four of the six genotypes, while seed fertility and seed weight were unaffected. …

Legacy Effects Of Biodegradable Mulch And Soil Amendments On Vegetable Crops And The Soil, Elise V. H. Reid

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

Plastic film mulches are used in horticulture to manage weeds, improve water retention, and increase soil temperature. Bioplastics and biofabrics are potentially sustainable alternatives to plastic film; however, they have different rates of in soil degradation. Polylactic acid (PLA) is a 100% biobased polymer that degrades slowly, but could fulfill organic certification to be soil incorporated. Mater-Bi is a commercially available biodegradable plastic (bioplastic), which degrades quickly, but cannot be incorporated in organic systems. Our objectives were to determine the individual and combined effects of soil amendments and residual mulch on vegetable crop yield and soil fertility. In a two-year …

Organic Agriculture Teaching And Learning In 2025: Transforming The Future Learning Landscape, Randa Jabbour, Charles A. Francis, Mary Barbercheck, Katharina S. Ullman

Department of Agronomy and Horticulture: Faculty Publications

University instructors are compelled to anticipate future changes in farming and food systems that will impact their students. Sixteen educators met in 2018 to envision the future of organic agriculture courses needed by 2025. Likely future global issues include food access, especially for people of limited economic means; climate change; and fossil fuel costs. Changes that will impact education are increasing demand for quality food, more organic production, and globalization of food systems due to consolidation. Probable course content changes are increasing focus on whole farm systems; designing for resilience in changing physical, economic, environmental, and political climates; and increasing …

Ghd8 Controls Rice Photoperiod Sensitivity By Forming A Complex That Interacts With Ghd7, Peng Wang, Rong Gong, Ying Yang, Sibin Yu

Department of Agronomy and Horticulture: Faculty Publications

Background: Flowering time is one of the most important agronomic characteristics that ultimately determine yield potential and eco-geographical adaptation in crops. Ghd8 and Ghd7, two major flowering genes, have similar functions and large pleiotropic effects in controlling the heading date, plant height and grain yield of rice. However, these gene interactions at the genetic and molecular levels have not been determined to date.

Results: In this study, we investigated the genetic interaction between Ghd8 and Ghd7 by using a set of near-isogenic lines and a panel of natural germplasm accessions in rice. We found that Ghd8 affected multiple agronomic traits …

Understanding Nitrogen Limitation In Soybean, Nicolas Cafaro La Menza

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

Meeting soybean demand on existing cropland area for a global population of 9.7 billion people by the year 2050 requires narrowing the existing gap between average producer yield and yield potential. Soybean relies on two sources on nitrogen (N): biological N₂ fixation and indigenous soil N supply. As soybean yield continues to increase, it seems critical to know if there is a yield level at which potential contribution of indigenous nitrogen sources and fixation becomes insufficient to meet crop N requirements for high yields, while still maintaining or increasing protein and oil concentration. This study evaluated N limitation across …

Exploitation Of Wastelands For Fodder Production And Agroforestry, Gurbachan Singh

IGC Proceedings (1977-2023)

Natural resources degradation for agricultural production and environmental protection has been a matter of concern for future food, nutrition, environment and livelihood security. As per current estimates, 120.7 million hectare (mha) is under degraded or wastelands. These lands provide ample opportunity for growing fodder trees and grasses to bridge the gap between demand and supply of green and dry fodder.Several species of fodder trees and grasses have been identified and their agro-techniques standardized for raising in different categories of wastelands such as affected by soil and wind erosion, salinity, acidity and mining etc. A brief account of such plants is …

Application Of Autofluorescence For Confocal Microscopy To Aid In Archaeoparasitological Analyses, Johnica Jo Morrow, Christian Elowsky

Department of Agronomy and Horticulture: Faculty Publications

Confocal laser scanning microscopy (CLSM) was used to examine archaeoparasitological specimens from coprolites associated with La Cueva de los Muertos Chiquitos (CMC) located near present-day Durango, Mexico. The eggs for 4 different types of parasites recovered from CMC coprolites were imaged using CLSM to assist with identification efforts. While some of the parasite eggs recovered from CMC coprolites were readily identified using standard light microscopy (LM), CLSM provided useful data for more challenging identifications by highlighting subtle morphological features and enhancing visualization of parasite egg anatomy. While other advanced microscopy techniques, such as scanning electron microscopy (SEM), may also detect …

Analysis Of Mutations In West Australian Populations Of Blumeria Graminis F. Sp. Hordei Cyp51 Conferring Resistance To Dmi Fungicides, Madeline A. Tucker, Francisco J. Lopez-Ruiz, Hans J. Cools, Jonathon G L Mullins, Kithsiri W. Jayasena, Richard P. Oliver

Biosecurity Research Articles

BACKGROUND

Powdery mildew caused by Blumeria graminis f. sp. hordei (Bgh) is a constant threat to barley production but is generally well controlled through combinations of host genetics and fungicides. An epidemic of barley powdery mildew was observed from 2007 to 2013 in the West Australian grain belt.

RESULTS

We collected isolates across Australia, examined their sensitivity to demethylation inhibitor (DMI) fungicides and sequenced the Cyp51B target gene. Five amino acid substitutions were found, of which four were novel. The most resistant haplotypes increased in prevalence from 0% in 2009 to 16% in 2010 and 90% in 2011. …

Grains, Seeds And Hay Industry Funding Scheme Annual Report 2018/2019, Department Of Primary Industries And Regional Development, Western Australia

Biosecurity published reports

The Grains, Seeds and Hay Industry Funding Scheme (IFS) has been operating since 2010 to address biosecurity threats relevant to Western Australia’s (WA) grains, seeds and hay industry. The Scheme was established under the Biosecurity and Agriculture Management Act 2007 to enable growers to identify the pest and disease priorities at a whole-of-industry level and raise funds for activities to address these priorities.

There are currently three Industry Funding Schemes in operation. In addition to the Grains, Seeds and Hay IFS, there is a Cattle IFS and a Sheep and Goat IFS. The three IFSs operate in a similar manner. …

Canavalia And Dolichos Extracts For Sustainable Pest Biocontrol And Plant Nutrition Improvement In El Salvador, Carlos Martinez

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

Botanical repellents and pesticides are now being rediscovered as new tools for integrated pest management in order to reduce the use of toxic chemicals in crop production. Canavalia gladiata and Dolichos lablab are two Fabaceae very well adapted to farmlands of El Salvador, effective as living barriers and mostly as cover crops, however, they are not yet very well disseminated. This document describes the potential for using the liquid extracts and the dry flour of raw seeds of those plants for economic benefit and practical convenience for pest management in Salvadorian agriculture under field conditions. Seed extracts were useful when …

Challenges And Opportunities For Weed Control In Nebraska Popcorn, Ethann R. Barnes

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

Weed control in popcorn is challenging with limited herbicide options and popcorn’s perceived sensitivity to herbicides. Understanding the impact of weeds maximizes yield and profit. New herbicide-resistant crops increase chances of drift or misapplication into popcorn, which doesn’t have herbicide-resistant traits. Herbicides that are labeled in popcorn are often only conditionally labeled with reduce rates, warnings, or limited popcorn types. Dent-sterility in popcorn is contingent on the Ga1 gene (Ga1-s), but this system is at risk from Ga1-m field corn introduced from Mexico because it overcomes dent-sterility. This risk is under-assessed as Ga1-m carriers are undocumented and Mexican germplasm usage …

Arkansas Corn And Grain Sorghum Performance Tests 2019, J. F. Carlin, R. D. Bond, J. A. Still

Arkansas Agricultural Experiment Station Research Series

Corn and grain sorghum performance tests are conducted each year in Arkansas by the University of Arkansas System Division of Agriculture. The tests provide information to companies marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating recommendations for producers. The 2019 corn performance tests contained 74 hybrids and were conducted at the Northeast Research and Extension Center (NEREC) at Keiser, the Lon Mann Cotton Research Station (LMCRS) near Marianna, the Bell Farming Company near Des Arc, the Rohwer Research Station (RRS) near Rohwer and the Rice Research and Extension Center (RREC) near Stuttgart. The 2019 …

Silicon Fertilization In Rice And Wheat: Dynamics With Trace Elements And Effect Of Silicate Slag Granular Size On The Release Pattern Of Monosilicic Acid In Soil, Wooiklee S. Paye

LSU Doctoral Dissertations

Studies were conducted to evaluate the impact of silicon (Si) fertilization on the uptake of harmful trace elements in Louisiana rice production system, and document the effect of silicate slag granular size on its ability to supply Si in wheat. The influence of silicate slag and lime on the uptake and translocation of harmful trace elements in rice grain was determined. Results showed that both slag and lime had similar effects on pH at five of the nine sites investigated. Soil Si was significantly (P <0.001) increased with application of silicate slag at all sites. Lime and silicate slag had no effect on the concentration of trace elements in soil. However, increasing Si rates were negatively correlated with arsenic (As) and cadmium (Cd) concentration in rice grain. The release pattern of monosilicic acid (H₄SiO₄) from wollastonite and silicate slag was compared in a wheat greenhouse …

United States Midwest Soil And Weather Conditions Influence Anaerobic Potentially Mineralizable Nitrogen, Jason D. Clark, Kristen S. Veum, Fabian G. Fernandez, James J. Camberato, Paul R. Carter, Richard B. Ferguson, David W. Franzen, Daniel E. Kaiser, Newell R. Kitchen, Carrie A.M. Laboski, Emerson D. Nafziger, John E. Sawyer, John F. Shanahan

Agronomy, Horticulture and Plant Science Faculty Publications

Nitrogen provided to crops through mineralization is an important factor in N management guidelines. Understanding of the interactive effects of soil and weather conditions on N mineralization needs to be improved. Relationships between anaerobic potentially mineralizable N (PMN_an) and soil and weather conditions were evaluated under the contrasting climates of eight US Midwestern states. Soil was sampled (0–30 cm) for PMN_an analysis before pre-plant N application (PP_0N) and at the V5 development stage from the pre-plant 0 (V5_0N) and 180 kg N ha⁻¹ (V5_180N) rates and incubated for 7, 14, …

Measuring Bird Damage To Three Fruit Crops: A Comparison Of Grower And Field Estimates, Julie L. Elser, Catherine A. Lindell, Karen M. M. Steensma, Paul D. Curtis, Deanna K. Leigh, William F. Siemer, Jason Boulanger, Stephanie A. Shwiff

Biology Faculty Publications

Birds are common pests in fruit orchards. They frequently consume and damage fruit resulting in decreased yields for growers. The true extent of damage is difficult to measure. Producer surveys are often implemented to estimate damage, but the accuracy of these estimates is uncertain. We compared damage estimates obtained through field studies with estimates from a producer survey for three fruit crops: wine grapes, sweet cherries, and ‘Honeycrisp’ apples. We also analyzed relationships between use of various damage management methods and levels of bird damage. We found wine grape and sweet cherry growers accurately assessed bird damage, while ‘Honeycrisp’ apple …