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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
691

Design lehkého zemědělského traktoru / Design of Light Agricultural Tractor

Oulehla, Jakub January 2019 (has links)
The subject of this diploma is the design of a versatile light agricultural tractor. The design of the tractor will focus on timeless design. The proposed tractor will also differ from the current competition in the field of light agricultural tractors. The resulting tractor will also be usable outside agriculture, in horticulture or communal services.
692

Effects of Sudangrass Cover Crop and Soil Solarization on Weed and Pathogen Management in Organic Strawberry Production

Jacobs, Timothy 01 August 2019 (has links)
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 solarization temperatures differed between different species. Cool-season annuals annual sowthistle and bristly oxtongue were more susceptible to heat treatments than warm-season annuals common purslane, redroot pigweed and nettleleaf goosefoot. Hard seeded weed species little mallow and redstem filaree were the least susceptible to heat treatments. Annual sowthistle, bristly oxtongue and nettleleaf goosefoot were affected at all temperatures. Redroot pigweed and little mallow were not affected by temperatures below 40°C. Common purslane was not affected by temperature below 45°C and redstem filaree was not affect by any temperatures tested. Hours of exposure and percent mortality of weed seeds were used to create thermal death models for weed seeds. Field experiments were conducted at the Cal Poly Organic Farm in San Luis Obispo, CA testing the effects of soil solarization and sudangrass residues on weeds, Verticillium dahliae populations, plant health, and yields in organic strawberry production. Using a split plot design, sudangrass was grown, mowed and then developed into two treatments: surface mulch or incorporated into the soil. The sudangrass treatments and a control were tested with and without soil solarization (n=4). Maximum soil temperatures in solarized treatments were 53°C at a soil depth of 5 cm and 42°C at a soil depth of 15 cm. Solarization reduced weed biomass between 49.8 and 95.2% during the first 3.5 months after tarp removal (p=0.03), reduced Verticillium dahliae populations by 80.7% (p=0.01), reduced plant mortality by 54.9% (pV. dahliae populations (p=0.33) or yields (p=0.25). However, mulched treatments reduced weed biomass between 45.0 and 61.3% (p=0.03) compared to other sudangrass treatments. Results indicate solarization can be used in central coast organic strawberry production to reduce hand-weeding, disease incidence, and increase yields.
693

Not All Pollinator Gardens are Created Equally: Determining Factors Pertinent to Improving Pollinator Garden Effectiveness

Watson, Travis 01 May 2021 (has links)
Increasing evidence documenting the decline of insect populations, resulting from increasing human disturbances has resulted in efforts to establish pollinator gardens to provide additional resources for insect populations. However, our understanding of biotic and abiotic garden characteristics important for attracting and sustaining pollinator diversity is limited. Here, we evaluated 17 pollinator gardens to evaluate the effect of five biotic and three abiotic garden characteristics on pollinator species richness, abundance, and proportional representation of four pollinator functional groups. Plant species richness positively influenced pollinator richness and negatively influenced flower visitation. Bombus proportional abundance responded to several variables (distance to vegetation, plant species richness, floral symmetry, floral native status, habitat type), and decreases in their proportional representation were accompanied by increasing proportions of other insect groups. Our results suggest any size, diverse, native pollinator gardens can improve pollinator diversity, and small-scale pollinator gardens should favor functional groups adapted for the habitat type.
694

Phytoplasmen im sächsischen Obstbau

Herzog, Utta, Wiedemann, Wolfram, Trapp, Alfred 19 November 2012 (has links)
Untersucht wurde die Verbreitung der meldepflichtigen Krankheiten Apfeltriebsucht und Birnenverfall in Anlagen mit integrierter und ökologischer Produktion. Anhand der Krankheitssymptome wurde der Einfluss auf Ertrag und Fruchtqualität erfasst, die Populationsentwicklung der Phytoplasma übertragenden Blattsauger und die Wirkung von Insektiziden beurteilt. In älteren Apfel- und Birnenanlagen waren bis zu 20% der Bäume erkrankt. Die Äpfel der erkrankten Bäume der Sorte Jonagored hatten ein deutlich geringeres Einzelfruchtgewicht und schlechter ausgefärbte Früchte. Die Übertragung der Apfeltriebsucht durch den Vektor Cacopsylla picta fand von Ende Mai bis Anfang Juli statt. Spritzungen im April mit den Insektiziden Calypso und Spruzit reduzierten deutlich die Population der Blattsauger.
695

Landwirtschaft in Sachsen hat Zukunft: Ackerbau und Gartenbau

January 2012 (has links)
Die vorliegende Broschüre gehört zu einer Trilogie im Rahmen des Dialogprozesses »Landwirtschaft in Sachsen hat Zukunft«, der im Jahr 2007 von Akteuren aus den verschiedensten Bereichen der sächsischen Landwirtschaft mit Vertretern der Forschung und der Verwaltung ins Leben gerufen wurde. Ziel war es, Strategien zu finden, wie sich Unternehmen der Branche an absehbare Veränderungen von natürlichen, wirtschaftlichen und gesellschaftlichen Rahmenbedingungen anpassen können. In acht Fachforen erfolgte über eine Analyse von bestehenden Rahmenbedingungen die Ableitung von Handlungserfordernissen für den einzelnen Betrieb, aber auch für Politik und branchenübergreifend den gesamten Sektor. Verschiedene Lösungsmöglichkeiten wurden im Rahmen von Projekten gesucht. Die Ergebnisse der Arbeit bis 2012 werden in den drei Broschüren vorgestellt.
696

Genetic Analysis of Black Raspberry Breeding Germplasm

Willman, Matthew 24 October 2019 (has links)
No description available.
697

Seeding Multi-omic Improvement of Apple

Bilbrey, Emma A. January 2020 (has links)
No description available.
698

Exploring metabolic and genetic diversity in tomato secondary metabolites

Dzakovich, Michael Paul January 2020 (has links)
No description available.
699

Designing Roofs to Support Native Plants in the Great Lakes Region

Blackson, Meghan Michelle 29 April 2021 (has links)
No description available.
700

We Are Earth

Timmerman, Kelsey Wilt 19 July 2022 (has links)
No description available.

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