Plant Pathology Commons^™

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 …

Effects Of Sudangrass Cover Crop And Soil Solarization On Weed And Pathogen Management In Organic Strawberry Production, Timothy Jacobs

Master's Theses

Field and lab experiments were conducted to determine the efficacy of sudangrass (Sorghum X drumondii (Nees ex Steud.) Millsp. & Chase) cover crop management techniques and soil solarization on important agricultural weeds and pathogens in organic strawberry production in Central California. Lab experiments assessed the time needed to kill weed seeds at temperatures typically achieved during soil solarization (40°C, 45°C, 50°C, 55°C, and 60°C) in California. Seeds tested included little mallow, redstem filaree, bristly oxtongue, annual sowthistle, common purslane, nettleleaf goosefoot, and redroot pigweed. Efficacy of simulated …

B.R. Wells Arkansas Rice Research Studies 2018, R. J. Norman, K. A.K. Moldenhauer

Arkansas Agricultural Experiment Station Research Series

No abstract provided.

Effect Of Soil-Applied Protoporphyrinogen Oxidase Inhibitor Herbicides On Soybean Seedling Disease, Nicholas J. Arneson

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

Seedling disease is one the most economically important diseases of soybean in the United States. It is commonly caused by Fusarium spp., Rhizoctonia solani, Pythium spp., and Phytophthora sojae, alone, or together as a disease complex. Fungicide seed treatments continue to provide the most consistent management of seedling diseases. Soil-applied protoporphyrinogen oxidase (PPO) inhibitor herbicides are used preemergence in soybean production to manage several broadleaf weeds. Applications of PPO-inhibitors can result in phytotoxic injury to soybean when environmental conditions are not favorable for soybean growth. These environmental conditions can favor seedling disease development as well. In this thesis, two …

Integrated Management Of Phytophthora Stem And Root Rot Of Soybean And The Effect Of Soil-Applied Herbicides On Seedling Disease Incidence, Vinicius Castelli Garnica

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

Soybean seedling diseases and Phytophthora stem and root rot (PSRR; caused by Phytophthora sojae) are two of the most economically important diseases in North Central U.S. Remarkable differences in disease incidence occur each year, which demonstrate that abiotic and biotic factors must interact for disease onset and development. During 2017 and 2018, field studies were conducted to (i) address the efficacy of seed treatment and genetic resistance for PSRR management on soybean population, canopy coverage (CC), and yield, and (ii) investigate potential interactions between pre-emergence (PRE) herbicides and the incidence of seedling diseases in alluvial soils in Nebraska.

Despite …

Science Communication In Agriculture: The Role Of The Trusted Adviser, Lee Galen Briese

Doctor of Plant Health Program: Dissertations and Student Research

Agronomy is not simply the selling of agricultural products to farmers, nor is it the process of solving singular production problems. Agronomy is defined as the integrated, holistic perspective of agriculture (ASA, 2019) and “agronomists are specialists in crop and soil sciences, as well as ecology” (ASA, 2019). While scientific investigation and discovery are essential to understanding systems function, the tangible benefits from our knowledge stems from the application to solve problems. Clear communication is vital to successfully help stakeholders understand the importance of the science and help scientists understand the challenges stakeholders face. However, to successfully put science into …

Impact Of Roadside Maintenance Practices On Larinus Minutus (Gyllenhal), A Biological Control Agent Of Spotted Knapweed, Mary Elizabeth Ferguson

Graduate Theses and Dissertations

Spotted knapweed, Centaurea stoebe, is an invasive weed found throughout much of the United States. Spotted knapweed is a rangeland weed where it was originally introduced into western North America in the 1880s.Where spotted knapweed spread to the southeastern U.S., it is found mostly along roadsides. It has been the focus of a biological control program beginning in the 1960s, with 12 insects established, with the final introductions occurring in the 1990s. After the success observed in the western U.S. and Canada with one of these insects, Larinus minutus, this weevil was established in northwestern Arkansas. It is too early …

Characterization Of Multiple-Herbicide-Resistant Echinochloa Colona From Arkansas, Christopher Edward Rouse

Graduate Theses and Dissertations

Echinochloa species are highly adaptive weeds that have the potential to impact crops in a variety of environments. This has positioned them as the most problematic weeds in a number of USA cropping systems with some species having the distinction of the 'worst herbicide-resistant weeds' in the world. Recent evidence has positioned Echinochloa colona (junglerice) as the most dominant in Arkansas and throughout the Mid-South, USA, especially in rice (Oryza sativa L.) and soybean (Glycine max L.) production fields. A history of extensive herbicide-use for management and a lack of integrated or diverse approaches to management have led to rampant …

Over-Summering Ecology Of The Wheat Curl Mite (Aceria Tosichella Keifer), Anthony J. Mcmechan

Department of Entomology: Dissertations, Theses, and Student Research

The wheat-mite-virus complex is a consistent and significant threat to winter wheat production in the western Great Plains. This complex consists of three viruses (Wheat streak mosaic virus, Triticum mosaic virus, and Wheat mosaic virus that are transmitted by the wheat curl mite (Aceria tosichella Keifer). Yield impacts from this complex are typically associated with the presence of volunteer wheat that emerges prior to harvest as a result of hail occurring during the heading stages of wheat in early summer. Historical literature on pre-harvest germination has been primarily focused on accelerating breeding programs; however, critical gaps in knowledge exist on …

Canola: A Modern Crop For A Modern Era, Kenneth J. Roché

Doctor of Plant Health Program: Dissertations and Student Research

The University of Nebraska-Lincoln Doctor of Plant Health program is a professional doctorate program with a comprehensive approach to plants and agriculture. The program emphasizes a broad interdisciplinary education across all plant-related disciplines, practical learning, research, and experience through internships. For my final required internship, I worked as a senior agricultural research intern with Research Designed for Agriculture (RD4AG) in Montana. RD4AG is a contract research organization based in Yuma, AZ with over thirty-years of experience. During my three month internship at RD4AG in Montana, a large portion of my responsibilities centered on managing regulated canola trials that were undertaken …

Productivity And Biological Nitrogen Fixation Of Different Species Of Vetches (Vicia Spp.) Under The Rainfed Conditions Of West Asia, Ali Abd El Moneim, Mohan C. Saxena

IGC Proceedings (1977-2023)

The low rainfall areas of West Asia are characterized by pastoral production system primarily based on small ruminants (sheep and goats). Rangelands serve as the main source of feed. With increasing population, the demand for livestock products has increased. As a consequence, the stocking rates have soared, increasing the pressure on rangelands. Rangeland degradation has therefore been increasing threatening the sustainability of livestock production system and the livelihood of the people dependent on it. Production of additional feed is essential to reduce the pressure on rangelands. Vetches (Vicia spp.) are endemic in the area and can be potential source …

Livestock Production From Grasslands With Improved Management Compared To Traditional Management, Florian Leiber

IGC Proceedings (1977-2023)

The value of traditional versus improved management systems for grassland is discussed. The set target is the persistence of the ecological, economic and social multifunctionality of grasslands and the increase of food output from these areas without increasing parallel requirements for arable crop or energy inputs. Based on the fact that historically traditional systems were stable and sustainable in many cases, while severe damage is faced nowadays, it is argued that lot of improvement should be based on the acknowledgment of successful traditional practises. The challenge might rather be to define improvement as a contemporary development of traditional techniques. The …

Potential Of Forages In Crop Diversification And Crop Rotation, Martin H. Entz, Joanne Thiessen Martens

IGC Proceedings (1977-2023)

Redesign of agricultural systems according to ecological principles has been proposed for the development of sustainable systems. We review a wide variety of ecologically-based crop production practices that focus on forage crops in farming systems and discuss their potential role in enhancing the profitability, environmental sustainability and resilience. Crop-livestock systems that most closely mimic natural systems through appropriate integration of diverse components appear to offer the greatest potential benefits. These systems are more energy efficient and combine high productivity with low ecological footprint. Greater understanding of ecological relationships within crop-livestock systems are required to purposefully and proactively redesign agricultural systems …

Forage Seed Quality: Dormancy, Standards And Quarantine, John G. Hampton

IGC Proceedings (1977-2023)

There are many dimensions to the concept of seed quality. Viable seed which will not germinate when provided with all the requirements for germination is dormant. Forage grasses mostly exhibit non-deep physiological dormancy (PD), while physical dormancy (PY) is common in forage legumes where imbibition is prevented by the seed coat’s impermeability to water (hard seed). Methods for breaking PD and PY to allow germination testing and/or crop establishment are discussed.

In the seed industry seed quality standards are an important feature of quality assurance and may apply for seed production contracts, seed certification, seed sale and seed importing. Standards …

Quality Seed Production And Effective Marketing Systems For Development Of Grasslands, M. Philip Rolston

IGC Proceedings (1977-2023)

Seed quality is defined as (i) maintaining genetic purity using seed certification principles (generation system; isolation; previous cropping history); (ii) achieving high levels of physical purity (especially low weed seed levels) by in field weed control and seed cleaning; (iii) achieving high levels of seed germination at harvest and maintaining germination through the seed supply chain. Seed production systems must not only produce high quality seed but also achieve economic seed yields. Seed crops have to be profitable (by being high yielding) to justify the investment of time and input costs to achieve quality. This in turn requires supporting research …

Scouting Benefits And Developing Innovations In Temperate Grassland To Sustainable Agriculture Production, Walter Ayala, Ethel Barrios, Ignacio Macedo, Jorge Sawchik, José A. Terra

IGC Proceedings (1977-2023)

Agricultural intensification raises concern about land use and future effects to natural resources. The world demand for grain, meat and forest products is increasing constantly. Changes are occurring at large scale, being a compromise for policy makers to contribute to identify opportunities to readdress the productive scenario. There is available technology to reduce impacts, without restricting necessarily productivity. Grasslands provide a large series of economical and ecological benefits to the agricultural systems, being the literature exhaustive in examples. Ley-farming and cover crops technologies are good examples of environmentally sound soil management practices. The society is also worried about an improper …

Evergraze: A Partnership Between Researchers, Farmers And Advisors To Deliver Effective Grassland Management, Warwick B. Badgery, Kate Sargeant, Michael A. Friend, Scott Glyde, Paul Sanford, Ralph Behrendt, Meredith L. Mitchell, Sean Murphy, Angela Avery

IGC Proceedings (1977-2023)

The profitable and sustainable management of livestock production from grassland systems is challenging and it can be difficult to develop a research structure that addresses farmer’s needs and has acceptable rigour and on-ground impact. This paper describes the attributes of research, development and extension (RD&E) programs that are required for a successful partnership between researchers, farmers and advisors. Insights are provided from the EverGraze program that designed, tested and implemented farming systems based on perennial pastures across southern Australia. With this project farmers and advisors were involved in setting research direction, designing experiments, providing strategic guidance over the management of …

Ecologically And Socially Sustainable Livestock Development In Marginal Areas, Ilse Köhler-Rollefson

IGC Proceedings (1977-2023)

“Marginal areas” are perceived as difficult and unproductive landscapes, always under the threat of drought, desertification and poverty. Yet, both dryland and high altitude marginal areas have an extraordinary output of livestock products; in the efficiency of producing human-edible protein they far surpass more fertile areas. This productivity under adverse climatic conditions rests on sophisticated strategies and social institutions developed by pastoral communities to deal with variability in the availability of resources. It depends on the use of animal genetic resources that are adapted to make best use of local vegetation and can cope with seasonal variations in availability. Livestock …

Valuing Variability--New Perspectives On Climate Resilient Dryland Development, Saverio Kratli

IGC Proceedings (1977-2023)

Valuing Variability is a challenge to the view of the drylands as naturally vulnerable to food insecurity and poverty. It argues that improving agricultural productivity in dryland environments is possible by working with climatic uncertainty rather than seeking to control it – a view that runs contrary to decades of development practice in arid and semi-arid lands.

Participatory And Holistic Approaches With Grassland Farmers And Development Of Policies, Alain Peeters

IGC Proceedings (1977-2023)

The world is changing rapidly. Grassland farmers and ruminant livestock breeders will have to adapt to these changing environmental, social and economic conditions. Research can help them at the condition that linear ‘top-down’ technology transfer methods are abandoned for the benefit of participatory and holistic approaches. These approaches classified in the generic term of ‘Farming System Research’ consider farmers as real research partners, and they merge farmer’s and scientist’s ideas with those of other stakeholder types. They combine scientist’s and farmer’s knowledge for creating fast innovations, easily adopted by farmers since farmers themselves contribute to their design and their development. …

Sustainable Grasslands: Resolving Management Options For Livelihood And Environmental Benefits, David R. Kemp, Warwick B. Badgery, David L. Michalk

IGC Proceedings (1977-2023)

To help solve the major issues of improving livelihoods and environmental services, grassland research needs to be evaluated within the context of relevant farm systems. Treatments need to show that they not only have significant effects but that they have effects that are meaningful in the context of the relevant farm system. Research often defines an optimum criterion for management that is a single point, but that is difficult to achieve in practice, especially when there are several components in a grassland system that need to be optimised. It is argued that an appropriate criterion for optimising management is a …

Climate Change Impact And Adaptation In Temperate Grassland And Livestock Industries, Afshin Ghahramani, Andrew D. Moore

IGC Proceedings (1977-2023)

Climate is projected to have negative impact on temperate grassland and livestock productions across the globe. Moderately elevated atmospheric CO₂ in the near future is expected to increase plant photosynthetic rates but this is likely to be limited by soil nitrogen deficits. However, in Australia at least it is unlikely that positive effect of elevated CO₂ on plant production be able to offset the negative impacts of climate change. Currently there is a considerable gap between actual and achievable production and profit in Australian grazing systems and many management and genetic improvements for climate adaptation would operate by …

Climate-Smart Brachiaria For Improving Livestock Production In East Africa: Emerging Opportunities, Sita R. Ghimire, Donald M. G. Njarui, Mupenzi Mutimura, Juan A. Cardoso, Linda Johnson, Elias M. Gichangi, Suliana Teasdale, Kennedy Odokonyero, John Caradus, Idupulapati M. Rao, Appolinaire Djikeng

IGC Proceedings (1977-2023)

Brachiaria grass is an important tropical forage of African origin with desirable attributes of agricultural and environmental significance. Brachiaria has been extensively cultivated as a pasture across the tropics except in its endemic provenance of Africa. In 2013, a collaborative research program was initiated in Kenya and Rwanda with the aim of improving the availability of quality livestock feeds adapted to drought and low fertility soils using Brachiaria. The outcomes sought were increased livestock productivity leading to improved farmer income and the development of seed production opportunities. The program has identified five preferred cultivars, and four of them are currently …

Tropical Grassland Ecosystems And Climate Change, C. R. Babu, Vivek Kr. Choudhary, Vijay Kumar

IGC Proceedings (1977-2023)

Grasses are unique group of flowering plants that form the foundation for the trophic structure in terrestrial communities. The grasses are found in every conceivable habitat where plants can thrive – from sea to deserts and from wetlands to peaks of highest mountains. The grasses form a distinct biome – a major ecological formation in the global classification of vegetation.

Recent Trends In Breeding Of Tropical Grass And Forage Species, J. S. Sandhu, Dinesh Kumar, Vijay Kumar Yadav, Tejveer Singh, R. P. Sah, Auji Radhakrishna

IGC Proceedings (1977-2023)

Germplasm enrichment in major tropical grasses and their characterization for emerging environmental challenges have been major focussed area in the recent past. Breeding efforts in tropical grasses are still limited to few selected species viz. Panicum spp, Cenchrus spp, Pennisetum spp and Bracharia spp and all other grasses use of land races for varietal development through selection have been major source of improvement. The pace of breeding efforts in the tropical grasses have been slowed because of many inherent characteristics viz. apomixis, poor seed set, high photo and thermo sensitivity often creating problem in designing and implementing an effective breeding …

Sustainability, Biodiversity And Environmental Issues: A Global Perspective For Livestock Production, David L. Michalk

IGC Proceedings (1977-2023)

To meet world food demand through the 21st century, agricultural production needs to increase, but this needs to be done sustainably through increasing efficiency, optimising sufficiency and achieving consistency, such that resource use is optimised, waste reduced and environmental benefits gained. These strategies need to be developed against changing food patterns, especially a decline in per capita consumption of cereals and an increase in meat consumption as household incomes increase. Grasslands are collectively the larger group of land-based ecosystems on the planet. Their values are not always recognised, often being seen as ‘reserves’ for exploitation for urban expansion, …

Wastelands Of The Mind: The Identity Crisis Of India’S Savanna Grasslands, Abi Tamim Vanak

IGC Proceedings (1977-2023)

The idea that wastelands are unproductive continues to be pervasive and is used by various agencies to gain control over marginal landscapes and remake them for productive purposes with dire results.

Grassland And Livestock Production: The East African Case, David Miano Mwangi

IGC Proceedings (1977-2023)

Grasslands cover over 26% of the world land mass and about 80% of the agricultural area. They are the source of a livelihood for about 1 million people in the developing countries. Livestock contributes 40% of the global value of agricultural outputs. Approximately 60% of rural households keep livestock. In East Africa there are a number of grasslands. The most extensive of these are the Acacia based Savanna grasslands. Others include the sudd flooded grasslands of South Sudan and the Miobo woodlands of Tanzania. More than 60% of the livestock and wildlife in this region are found on these grasslands. …

Three Is Company: Fixing The Grazing-Land Business Conundrum, Ralph Von Kaufmann

IGC Proceedings (1977-2023)

Grazing-lands have the largest footprint on the world’s land surface area but this is not reflected in the amount of business conducted on them. The most common land use systems are very land intensive, i.e., they use a lot of land to produce not very much and few jobs. The health of the planet depends on having healthy grazing-lands but there is a perfect storm brewing in which the demand from expanding pastoral communities for more food and jobs cannot be met just by applying good grazing-land management practices. Compatible businesses must be found that can create jobs without increasing …

Tropical Grasslands--Trends, Perspectives And Future Prospects, Panjab Singh

IGC Proceedings (1977-2023)

This paper attempts a rapid summary of the present day state of tropical grassland and livestock based production systems globally, especially in tropics, in relation to recent trends, future assessment, grassland rehabilitation and management strategies, future perspectives of grassland science and development including policy imperatives.