Plant Pathology Commons^™

Effects Of Thinning Density On Soil Water Content Of Alfalfa And David Peach Intercropping In The Hilly Loess Plateau, China, Z. X. Chen, X. L. Yang, G. H. Wang, Yuying Shen

IGC Proceedings (1977-2023)

Intercropping alfalfa (Medicago sativa) between the four meters inter-row spacing of David peach (Amygdalus davidiana) is one of replantation practices at the Longtan catchment in Gansu province of the western Loess Plateau in the early 1980’s. However, both alfalfa and David peach are deep-rooted species and their intercropping results in excessive consumption of soil water in the hilly Loess Plateau. To alleviate this, we set up four density/intercrop treatments, which includes: David peach+alfalfa (PA), David peach (P), 60% David peach+alfalfa (60% P+A) and 60% David peach (60% P). TRIME was used to quantify the soil water …

Exploring Drivers Of Invasiveness Of The Plant Species Senna Obtusifolia In Rangelands To Secure Forage Production In West Africa, O. Ouédraogo, A. Zaré, C. Bougma, S. Kambou, A. Linstädter

IGC Proceedings (1977-2023)

Rangelands in Sahelian countries are continuously over-grazed decreasing forage resources and causing rapid environmental changes. Senna obtusifolia is a less palatable plant species that becomes increasingly invasive. This research explored drivers of its invasiveness in the perspective to propose solutions to secure forage production in the pastoral reserves. Species composition and herbaceous aboveground biomass were assessed in rangelands with different levels of invasion of Senna obtusifolia along a climatic and land-use pressure gradient. A greenhouse experiment was conducted to test the competitiveness of this species. The development of Senna obtusifolia in rangelands affected significantly forage quantity. Indeed the biomass of …

Enhanced Grazing Management Assessment Using Drone-Based Lidar Measurements, V. W. Temu, W. C. Hession, P. Sforza, H. Wang

IGC Proceedings (1977-2023)

Globally, there is an urgent need of research-based technologies for small ruminant producers to benefit from rapidly growing market demands for ruminant meat and related food products from forage-based operations. However, effective forage-based animal production requires a rapid assessment, and monitoring of grazing management needs to adjust stocking rates and/or spatial animal distribution in a timely manner. Applicability of unmanned aerial vehicles (drones) for grazing management offers opportunities to rapidly estimate biomass build-ups, ground coverage, and monitor animal behaviour. The reliability of drone-based laser scanning (DLS) for monitoring warm-season grass responses to simulated grazing intensities was assessed at Virginia State …

Effects Of Parthenium Hysterophorus On Grassland Community In Nyando Sub-County, Kisumu County, Kenya, B. M. Mutua, W. Chiuri

IGC Proceedings (1977-2023)

Parthenium hysterophorus is an invasive alien species native to South and Central America. The plant is ranked as one of the most dreaded weeds of the world. Parthenium hysterophorus affects grassland community through the release of allelochemicals that inhibit the germination and growth of grass species. However, little is known about its effects on native grassland community in Nyando sub-county of Kenya. Therefore, this study sought to investigate the effects of P. hysterophorus on grass species, livestock production and its control. A total of 121 farm household heads were interviewed using semi-structured interview schedules. Descriptive analysis and the T-test at …

Ecorestore: Decision Support System To Restore The Productivity Of Degraded Rangelands In Southern Africa, Klaus Kellner, Dirk Pretorius, C. Marais

IGC Proceedings (1977-2023)

Land degradation is a multifaceted problem that affects the agricultural productivity of land due to a loss of vegetation cover and can often be ascribed to bush encroachment in savanna and grassland rangelands. Bush encroachment entails the increase in abundance and density of indigenous and alien woody vegetation (i.e. shrub thickening), which has a negative impact on the tree-grass ratio, biodiversity, as well as on a range of ecosystem services that affect the well-being of land users, often causing an increase in poverty and the introduction of non-sustainable land management practices, especially in arid- and semi-arid regions mostly affected by …

Rangeland Management In A Changing World – Active And Passive Restoration Case Studies From Ethiopia, Tanzania, And South Africa, A. C. Treydte, S. A. Baumgartner, S. K. Tuffa, A. A. Abdeta

IGC Proceedings (1977-2023)

Rangelands cover almost 50% of the earth’s land surface and are often found in marginal areas that often face climate extremes. The production of herbaceous biomass has strongly declined over the last decades due to overgrazing and adverse climatic conditions such as frequent droughts and flooding. While different rangeland restoration methods are being used, their effect on vegetation quality and quantity over time has rarely been experimentally tested and monitored. Our research comprises experiments of various rangeland restoration tools we have used across eastern and southern Africa. We conducted passive restoration through exclosure experiments and compared vegetation in and outside …

Counteracting Green Alder Shrub Expansion By Low-Input Grazing, M. K. Schneider, T. Zehnder, J. Berard, C. Pauler, M. Staudinger, Michael Kreuzer, A. Lüscher

IGC Proceedings (1977-2023)

In the past decades, the decline of traditional agriculture has caused an abandonment of marginal pastures in many mountain areas of Europe. In the Swiss Alps, green alder (Alnus viridis) is the most abundant successional shrub. A survey of 24 pasture-shrub gradients showed that the encroachment by green alder, in contrast to other shrubs, is associated with a substantial decline in plant species richness. The understorey of alder is primarily populated by very few, broad-leaved herbaceous species benefitting from the atmospheric nitrogen fixed by actinomycetes in symbiosis with green alder. However, the understory vegetation also provides an underestimated …

Characterization Of Degree Of Eco-Restoration By Tree-Grass Interaction In Degraded Lands Of Semi-Arid Tropics, R. V. Kumar, A. Ghosh, A. K. Singh, Sunil Kumar, A. K. Roy, Kamini Gautam

IGC Proceedings (1977-2023)

Land degradation majorly declines soil health. Eco-restoration through tree-grass interaction provides a perfect solution to restore degraded lands. The study was carried out at Jhansi district of India during 2010 to 2019 with three fodder trees viz namely, Ficus infectoria, Morus alba, and Acacia nilotica and a shrub Leucaena leucocephala (along with three grasses (Cenchrus ciliaris, Chrysopogon fulvus and Panicum maximum). The main objectives of these study were to a) assess the changes in soil organic carbon pools and responses of soil enzymes as impacted by different eco-restoration strategies involving trees and grasses; and b) …

Bee-Friendly Beef: Developing Biodiverse Pastures To Increase Ecosystem Services, J. Wagner, S. Ghajar, M. O’Rourke, B. Tracy

IGC Proceedings (1977-2023)

The capacity of grasslands to provide ecosystem services, such as pollinator resources, is often limited by lack of plant biodiversity. This is true of grasslands in the eastern US that are dominated by tall fescue (Festuca arundinacea) a non-native, cool-season grass that is typically toxic to cattle. This paper summarizes a research project in Virginia, USA exploring the idea that ecosystem services provided by tall fescue-dominated grasslands can be improved by increasing the plant biodiversity available to beef cattle and bees. Within three 6.5 ha tall fescue grasslands, we established 0.8 ha plots with a 17 species mix …

Rangeland In Marajó Island, Brazilian Amazon, A Long History Of Commons For Small-Breeders, T. Barbosa, M. Opplert, R. Folhes, S. Carvalho, Jean François Tourrand

IGC Proceedings (1977-2023)

Rangelands cover almost one third of the earth's surface and are characterized by a low productivity and high sociocultural value. But the lack of recognition of the environmental, social and economic values of rangelands, along with the expansion of agribusiness, tourism and urban sprawl give rise to a rangeland dilemma. This dilemma is found in various regions of the world, where this set of factors leads to the generally irreversible destruction of the rangeland. The process is recent in the Amazon rangeland, such as the eastern part of Marajó Island and the Low Amazon wetlands. A survey conducted on 90 …

Effects Of Herding On Rangeland Use Efficiency In Kenya, A. Seidel, F. Asch, B. Warth

IGC Proceedings (1977-2023)

Within each foraging itinerary, herders can intervene in the forage selection process, encouraging herds to use highly palatable and less palatable rangeland resources. Such a herding strategy could prevent rangeland degradation and increase livestock productivity. The objectives of this study were to examine forage availability and identify factors influencing stocking rates around night resting places on a ranch in Laikipia County, Kenya.

Forage availability was measured along six regularly spaced transects around night resting places corralling one herd of camels, one mixed herd of goats and sheep, and two herds of cattle, with biomass sampling points at 50-, 150-, 250-, …

Identifying Land Use Options For Networked Māori Owned Land Blocks To Deliver On Collective Aspirations In New Zealand, N. Mccrossin, F. A. Walker, M. E. Wedderburn, R. Mato, W. Mcmillan

IGC Proceedings (1977-2023)

Māori (the indigenous people of New Zealand) have many opportunities and challenges to realise the potential provided by their whenua (land), wai (water) and tangata (people) to deliver to their goals and aspirations. The challenges are old and new, including environmental constraints, governance, geographic isolation, fragmented land ownership, access to finance, and lack of appropriate skills, knowledge, and networks. Extension programmes aimed at the general primary production sector have failed to attract or retain any or many Māori participants. Landowner to landowner learning built around landowner aspirations along with collective action has the potential to inform an extension approach of …

Livestock Policy In Special Areas, Alberta, Canada, P. L. Strankman

IGC Proceedings (1977-2023)

Special Areas, Alberta, Canada, is a rural municipality of 2.1 million hectares (about 5 million acres) in south-eastern Alberta. It is home to almost 5000 residents, with a unique governance arrangement in Alberta. Most of the farms and ranches utilize a mix of crop and livestock primarily annual cereal and oil seed cultivation and beef cattle. These production units are usually a mosaic of privately-owned land and Crown land leased from the government.

It provides an interesting case study for the local, and national challenges facing western Canadian agriculture. It also provides an opportunity to contrast with different bioclimatic and …

Collaborative Construction Of A Method That Contributes To Improve The Decision Making In Associative Ranches By Controlling The Grass Allowance In A Context Of Climate Variability, Emilio Duarte Esteves, Rómulo Cesar, Javier Fernández, Marcelo Ghelfi, Valentina Herrera, Virginia Caravia, Rodrigo Iribarne, Federico De Brum, Héctor Rodríguez, Marcelo Pereira Machín

IGC Proceedings (1977-2023)

Pasture management and the particular conditions of each year are responsible for productive results, farm income, and condition of the pasture. A simple and robust method that relates the available grass and the required grass was built in a participatory manner, and contributes to a critical reflection process among the group of decision-making, adapting to their context. In 17 farms from the Basalt region in Uruguay, grass and animals were monitored seasonally. A simple method was developed with farmers, and from de offer needed to meet production targets (KgMS/KgPV) the amount of grass requires was calculated. The grass height was …

C3 Perennial Grass Dominates Mixed C3/C4 Grasslands After Invasion By A C3 Woody Sprouter, C. E. Cooper, R. J. Ansley, T. J. Steffens, D. B. Murray, T. Zhang

IGC Proceedings (1977-2023)

Honey mesquite (Prosopis glandulosa) encroachment has resulted in decreased C₄ mid-grass production and increased C₃ mid-grass in the Southern Great Plains of the US. Woody legumes have had similar effects in Africa, Australia, and South America. Prosopis initially facilitates Texas wintergrass (Nassella leucotricha) growth under canopies, in part because N-fixation by this woody legume enriches subcanopy soils, favoring C₃ species. As stand density increases, Nassella extends into interspaces between trees as well. Here we report Nassella responses in several studies that either reduced Prosopis to indirectly impact Nassella or treated Nassella directly. In …

Transcriptomics Reveals The Putative Mycoparasitic Strategy Of The Mushroom Entoloma Abortivum On Species Of The Mushroom Genus Armillaria, Rachel A. Koch, Joshua Herr

Department of Plant Pathology: Faculty Publications

During mycoparasitism, a fungus—the host—is parasitized by another fungus—the mycoparasite. The genetic underpinnings of these relationships have been best characterized in ascomycete fungi. However, within basidiomycete fungi, there are rare instances of mushroom-forming species parasitizing the reproductive structures, or sporocarps, of other mushroom-forming species, which have been rarely investigated on a genetic level. One of the most enigmatic of these occurs between Entoloma abortivum and species of Armillaria, where hyphae of E. abortivum are hypothesized to disrupt the development of Armillaria sporocarps, resulting in the formation of carpophoroids. However, it remains unknown whether carpophoroids are the direct result of a …

Increase Of Genetic Variability Of Forage Arachis By Intra And Interspecific Hybridization, J. M. F. Valls, C. M. Castro, M. A. P. Oliveira, C. C. Teixeira

IGC Proceedings (1977-2023)

This study was conducted to examine the potencial to increase the genetic variability of forage Arachis species, involving crosses between accessions of same species and crosses between different species, mostly of distinct taxonomic sections. Hybrids were produced between creeping, stoloniferous accessions belonging to section Caulorrhizae, Arachis pintoi x A. pintoi and A. pintoi x A. repens. Additional crosses involved section Caulorrhizae versus representatives of Erectoides (A. hermannii and A. paraguariensis) and Procumbentes (A. appressipila, A. kretschmeri, A. lignosa and A. vallsii). In intersectional crosses, the stoloniferous accessions were used as male parents. …

Searching For Molecular Markers For Salt Tolerance In Rhodes Grass (Chloris Gayana Kunth), E. Taleisnik, M. Salgado, M. D. Bonafede, L. E. Manghers, H. Pérez, L. García Seffino, A. Castagnaro, D. G. Díaz

IGC Proceedings (1977-2023)

Rhodes grass (Chloris gayana Kunth), a C4 forage grass, is regarded as salttolerant and exhibits intra- and inter-cultivar variability for this trait. Plants of cv Boma were selected for salt tolerance at the seedling and adult stages, cloned and characterized by RAPD and AFLP amplification patterns. Both techniques were equally efficient for fingerprinting these clones. More bands were obtained by AFLP but the ratio of polymorphic bands and the proportion present only in tolerant clones were the same by both methods. These bands, along with those exclusive for sensitive clones could be useful as markers for assisted selection.

Biotechnological Improvement In Timothy Breeding, S. Pulli, Y. D. Guo

IGC Proceedings (1977-2023)

Biotechnological improvements in timothy breeding by androgenic and somatic cell culture and molecular identification were achieved. The doubled haploid (DH) plants were obtained via anther and microspore culture. A series of factors which affect androgenic embryogenesis and green plant regeneration have been evaluated. The PG-96 induction media which sharply promote androgenic embryogenesis have been established. Over 400 DH plants of timothy were obtained. Timothy somatic callus induction was successfully established using immature inflorescences and seedling stems. Suspension cultures were initiated from friable nodule-forming callus. More than 100 regenerated green plants were obtained from somatic callus and suspension clumps. DNA-based fingerprinting …

Evolutionary Recurrent Selection Develops Adapted Annual Ryegrass, G. M. Prine

IGC Proceedings (1977-2023)

Seed companies find having their own annual ryegrass breeding program in the southeastern USA, unprofitable. The annual ryegrass breeding program at the University of Florida provides new annual ryegrass (Lolium multiflorum) cultivars with disease resistance and adaption. The evolutionary recurrent selection breeding uses large nurseries, roguing of diseased and unthrifty plants and selection of best plants to provide seed for the next generation. Current commercial cultivars developed are named along with some of their characteristics.