Weed Science Commons^™

Effect Of Soil Nitrogen And Water Content On The Establishment Of A Lolium Perenne L. And Trifolium Repens L. Pasture, M. F. Alonso, Oscar A. Balocchi, I. Calvache, O. Martínez

IGC Proceedings (1977-2023)

Climate change has decreased rainfall in Southern Chile affecting the productivity of the grasslands that sustain the dairy and beef cattle industries. These grasslands are mainly mixtures of Lolium perenne L. and Trifolium repens L. Thus, we study the response on the establishment of a mixture of these two species to three levels of soil water content and two levels of nitrogen (N) fertilization. The trial was carried out in containers sowed in a complete randomized block´s design. Soil moisture measurements were taken daily. N fertilizations was applied at the establishment and every 60 days. Leaf appearance rate was measured …

Impact Of Level Of Use On Plant Vigor And Weight Of Festuca Humilior And Calamagrostis Vicunarum, T. Edson, L. Aguirre, E. R. Flores

IGC Proceedings (1977-2023)

Tussock grasslands of Festuca humilior and Calamagrostis vicunarum cover a significant extension of the central Andes of Peru, constituting a plant association highly appreciated by cattle ranchers. The objective of this research was to estimate the cumulative impact of the level of use of the key grasses Festuca humilior and Calamagrostis vicunarum on plant height, vigor, and weight. This study was conducted in a humid grassland of regular condition located at 4186 masl in the Puna ecoregion. The variables evaluated were: plant height, basal and canopy diameter and plant weight. The experiment lasted two years in which individual plants from …

Containerized Satsuma Mandarin Production Under Protective Screens As A Management Strategy, Anna Timmerman

LSU Master's Theses

Many of the world’s citrus growing regions are experiencing challenges related to citrus greening, also known as Huanglongbing (HLB) caused by the presumed bacterial agent Candidatus Liberibacter spp. HLB is vectored by the Asian citrus psyllid (Diaphorina citri) and through propagation of infected citrus material. HLB impacts tree health as well as fruit development, ripening, and quality of the resulting citrus fruit, often leading to an unmarketable product. Producers are growing citrus in high density orchards underneath protective screening material that excludes the Asian citrus psyllid, preventing new HLB infections. Four ultra-high containerized tree spacings of 2 feet …

Protecting Wa Crops Issue 35 - November 2023, Department Of Primary Industries And Regional Development, Western Australia

Protecting WA Crops

Protecting WA Crops Issue 35 - November 2023 contents:

• Modelling to increase understanding of Ascochyta blight aggressiveness in chickpea crops
• Meet Crop Protection team member – Dr Rodrigo Pires

Protecting Wa Crops Issue 34 - October 2023, Department Of Primary Industries And Regional Development, Western Australia

Protecting WA Crops

Protecting WA Crops Issue 34 - October 2023 contents:

• Does electric weed control work on herbicide resistant weeds?
• Meet Crop Protection team member – Miranda Slaven

Fauna As Fieldworkers: An Analysis On The Use Of Animals As A Form Of Organic Weed And Pest Management In Modern Viticulture, Mariana Del Carmen Campano

Independent Study Project (ISP) Collection

Recent data on the current state of pesticide use in global agriculture suggests serious concerns over significant overuse and negative effects on both environmental and human health, and current trends only suggest continued increases in future global pesticide use. Without prompt, large-scale intervention, this global abuse of chemical pesticides spells significant threats of not only continued harm to global health and environmental quality, but also to the long term viability of agricultural lands and the growing threat of pesticide resistant insects and weeds. Various methods have been explored in the realm of integrated pest management (IPM), but a current lack …

Herbicide And Additive Impacts On Bradyrhizobium Japonicum Growth In Solution, Joy Amajioyi, Thandiwe Nleya, Senthil Subramanian, Sharon A. Clay

Agronomy, Horticulture and Plant Science Faculty Publications

Plant biostimulants include beneficial fungi and bacteria, and are often applied to foliage to improve crop growth, yield, and/or crop quality. Crop improvements due to biostimulant addition may be modest; therefore, solo applications may not be economical or climate smart. However, biostimulants combined with other postemergence treatments, such as herbicides, may provide an alternative application method, if mixtures do not harm the living organism(s). The growth of Bradyrhizobium japonicum, as a biostimulant surrogate, was assessed in solutions of glyphosate [N-(phosphonomethyl)glycine] and dicamba (3,6-dichloro-2-methoxybenzoic acid), with and without common spray additives (ammonium sulfate [AMS] and nonionic surfactant) in laboratory studies over …

Protecting Wa Crops Issue 33 - September 2023, Department Of Primary Industries And Regional Development, Western Australia

Protecting WA Crops

Protecting WA Crops Issue 33 - September 2023 contents:

• Aphid and Turnip Yellows Virus Management: Research Highlights
• Meet Crop Protection team member – Janette Pratt

Evaluation Of Organic And Synthetic Herbicides Applications On Indicators Of Soil Health And Weed Suppression In A Conventional Cropping System In Louisiana, Caitlin Denux

LSU Doctoral Dissertations

Synthetic herbicides, with their varying modes of action, are well known for their efficiency in the suppression and control of weed species in U.S. agriculture. However, the consequences of using synthetic herbicides without attention to the surrounding environment can produce chemical run-off, changes in soil health and soil health conditions, and create herbicide-resistant weeds. These consequences have encouraged growers to find alternatives in their weed management programs. In this study, organic and synthetic herbicides were assessed on how well they performed in weed suppression surveys, and their potential effects on soil health indicators. Commonly used indicators include soil pH, β-glucosidase …

Soil Seed Bank Composition And Spatial Distribution In A Cheatgrass (Bromus Tectorum L.)–Dominated Rangeland In Colorado, Usa, Ryan W. R. Schroeder, Jayne L. Jonas, M. Nikki Grant-Hoffman, Mark W. Paschke

Western North American Naturalist

Invasion by nonnative annual plants that form prolific seed banks, including Bromus tectorum L. (cheatgrass), throughout western North America is a major natural resource concern. Even with known economic and ecological implications, soil seed banks and their potential to impact ecological restoration in arid and semiarid ecosystems are poorly understood. Quantifying the regenerative potential of the soil seed bank—the living seeds in the soil profile and on the soil surface—can help natural resource managers make decisions to increase the likelihood of restoration success. We analyzed the germinable soil seed bank composition and distribution of a rangeland site in western Colorado …

Scaling Up Of Site Carbon Dynamics To Predict The Carbon Dynamics In Kazakhstan, Central Asia, B. K. Wylie, Tagir Gilmanov, S. L. Stensaas, N. Z. Saliendra, D. A. Johnson, K. Akshalov, S. B. Frank, L. Zhang, R. F. Doyle, E. A. Laca, Montague W. Demment

IGC Proceedings (1977-2023)

Climate and management determine whether rangelands are net carbon sources or carbon sinks. Regional carbon dynamics of the Kazakh Steppe has not previously been documented. The objective of this study is to quantify the regional carbon flux dynamics of these extensive steppes.

A New System For Plant Experiments On Biodiversity Or Multi-Species Competition, John Connolly, L. Kirwan

IGC Proceedings (1977-2023)

Considerable discussion in recent years has focused on the design of competition and biodiversity experiments (Connolly et al., 2001a; Allison, 1999). Few agronomic experiments with >2 plant species have been conducted in greenhouse conditions (Gibson et al, 1999) or in the field (Connolly et al., 2001b). In many experiments the effects of density and initial species size have been confounded. The effects of species richness and evenness also are confounded frequently. The proposed system provides a framework of design and analysis, in which to address questions of function at community level and of structure and competition at …

Native Grasses Seeded Into A Cool-Season Pasture Encouraged By Low Resource Availability, J. E. Doll, R. L. Cates, R. D. Jackson

IGC Proceedings (1977-2023)

Native prairie of the Upper Midwest, which was dominated by warm-season (C₄) grasses, now exists as relatively small relict and restored patches (Curtis 1959). Re-introduction of natives into grazed agroecosystems would promote genetic, species, and landscape diversity. Extensive re-introduction of C₄ grasses will require a shift away from the paradigm of maximizing production because C₄ grasses have higher C:N ratios than C₃ grasses rendering them inferior forage species. Nonetheless, there is great interest amongst the grazing community of the Upper Midwest in establishing native grasses as a means of improving wildlife habitat and increasing belowground …

The Ag-Biota Project: A Preliminary Assessment Of Potential Indicators Of Biodiversity In Agricultural Grasslands, Gordon Purvis, A. Anderson, A. J. Helden, L. Kirwan

IGC Proceedings (1977-2023)

In compliance with European commitments to the Convention on Biological Diversity, the conservation and enhancement of biodiversity within agricultural land is a primary objective of current agri-environmental measures. However, there is a widespread lack of information concerning the effectiveness of agri-environmental schemes in Europe, (Kleijn & Sutherland, 2003). In large part, this is due to uncertainties about selection of appropriate biological indicators of biodiversity (Buchs, 2003; Duelli & Obrist, 2003).

Effects Of Plant Species Diversity In Multifunctional Grasslands On Avian Communities, K. K. Bakker, K. F. Higgins

IGC Proceedings (1977-2023)

Grasslands, planted or native sod, can provide multiple simultaneous functions (e.g., hay-forage production, biomass fuel products, bird nesting cover, soil and water conservation). Bird use of and abundance in grasslands is dependent on vegetation structure, size, and surrounding landscape (Bakker et al., 2002) but little is known about avian relationships to plant species diversity. We evaluated the relationship between plant species diversity and avian community structure in 5 grassland types. The results have application to grazing, haying, burning, and conservation practices applied to native and sown grassland stands and to conservation strategies for declining grassland bird populations.

Diversity And Adaptation Of Perennial Plants From North Africa: Legumes And Grasses, Aissa Abdelguerfi, M. Laouar, K. Abbas, M. M'Hammedi Bouzina

IGC Proceedings (1977-2023)

A variety of climates, soil types and reliefs characterise North Africa (Algeria, Morocco, and Tunisia). These natural conditions have produced a large diversity of environments, landscapes, plant formations and flora. Several factors have contributed to the spread of a wide floristic variety: the influence of the Mediterranean in the north and in the north-east, the Atlantic in the west, and the Sahara in the south, as well as the presence of mountain ranges, particularly the Rif, the Tell Atlas, the Sahara Atlas, the Middle Atlas, the High Atlas, and the Anti-Atlas. This diversity of landscapes, environments and ecosystems has generated …

Comparison Of Compositional Changes In Multi-Species Grass/Legume Mixture Experiments Across Three Nordic Countries (Iceland, Sweden And Finland) Over Two Years, Caroline Brophy, Anne-Maj Gustavsson, A. Helgadottir, Oiva Nissinen, J. Connolly

IGC Proceedings (1977-2023)

A multi-site experiment was established at 39 sites across Europe, Australia and Canada within COST Action 852 to: (1) assess the benefits of grass/legume mixtures over monocultures, (2) test the stability of mixtures and (3) evaluate the consistency of the observed patterns over broad environmental gradients. This paper compares the results from 3 Nordic sites using the same plant species: Korpa Experimental Station in Iceland, Lapland Research Station in Finland and Piteå in Sweden to investigate if compositional changes in mixtures are consistent across the sites.

Site Effects On The Composition Of Multi-Species Grass/Legume Mixtures During Sward Establishment, Rosemary P. Collins, M. Fothergill, John Connolly

IGC Proceedings (1977-2023)

Under the auspices of COST Action 852, a multi-site experiment investigated issues of community structure, function and their interrelationships in multi-species grass/legume mixtures (Collins et al., 2004; Sebastià et al., 2004). We describe the effects of 2 contrasting sites on forage yield and species composition during sward establishment.

Unplanned Fires And Sustainability Of A Semi-Arid Rangeland In South Africa, Hennie A. Snyman

IGC Proceedings (1977-2023)

Whether due to lightning or human negligence, large-scale unplanned fires affect large areas of the semi-arid southern African rangelands during the dormant winter (June-August) period (Everson 1999). These fires cause enormous fodder flow problems, and also influence ecosystem functioning (Snyman 2003). The short-term impact (2 years) of an unplanned fire on the sensitivity of above- and belowground productivity of a semi-arid rangeland was therefore investigated.

Effects Of Burning On Grassland Vegetation Cover On The Northeastern Side Of The Alborz Ranges In Iran, F. Amiri, M. R. Chaichi, A. Atrakchali

IGC Proceedings (1977-2023)

Golestan National Park is located on the northeastern side of the Alborz ranges, Golestan province, Iran. Because of the special vegetation cover and being located close to two wet and dry weather areas, this park is vulnerable to fire hazards. Between 1957 and 2004 more than 67 fires have been reported in the park. The international importance of the park requires a careful study on fire effects on vegetation cover, phytomass production, grass diversity and successional process after fires.