Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 13 of 13

Full-Text Articles in Life Sciences

Effects Of Sudangrass Cover Crop And Soil Solarization On Weed And Pathogen Management In Organic Strawberry Production, Timothy Jacobs Aug 2019

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

Master's Theses and Project Reports

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 ...


Leaf Functional Traits As Predictors Of Drought Tolerance In Urban Trees, Sophia Huang Jun 2019

Leaf Functional Traits As Predictors Of Drought Tolerance In Urban Trees, Sophia Huang

Master's Theses and Project Reports

The services that urban trees provide to human society and the natural environment are widely recognized, but urban trees are in jeopardy due to climate change and urban stressors. With drought as a major threat in many areas, it is important for the future of urban forestry to select species composition based upon performance under water stress. Certain leaf functional traits can help horticulturalists more accurately predict water usage of urban trees. Comprehension through rigorous experimentation is lacking, partly due to the thousands of mostly exotic species. Previous studies suggest that species whose leaves have a denser arrangement of smaller ...


Effect Of Evapotranspiration Rate On Almond Yield In California, Dafne Isaac Serrano Oct 2018

Effect Of Evapotranspiration Rate On Almond Yield In California, Dafne Isaac Serrano

Master's Theses and Project Reports

Since 2011, California has been under drought conditions. These conditions have not only affected water availability for farmers, but also production. California’s second most valuable crop, almonds, has been affected by drought conditions. This study used three models (Model 1-3) to describe almond yield variability from year to year and almond yield variability within a year in Kern County, CA. The study evaluated 185 almond farms that were classified in three locations (east side, west side and north west side). The years of the study were 2011 (wet year) and 2013-2015 (drought condition years). Model 1 determined a functional ...


Araucaria In The Urban Landscape: A Novel Leaning Pattern And Evidence Of Cultivated Hybridization, Jason W. Johns Jan 2017

Araucaria In The Urban Landscape: A Novel Leaning Pattern And Evidence Of Cultivated Hybridization, Jason W. Johns

Master's Theses and Project Reports

Our understanding of the natural world is constantly evolving and strengthening as more observations are made and experiments are performed. For example, we understand that tree stems grow toward the light (positive phototropism; Darwin 1880, Loehle 1986, Christie et al. 2013) and against gravity (negative gravitropism; Knight 1806, Hashiguchi et al. 2013). We also know that plants respond to mechanical stimulus and perturbation (thigmotropism; Braam 2005). Genes and their resulting proteins have been described to uncover some of the mechanisms for these environmental responses, but relatively speaking, we have just scratched the surface (Wyatt et al. 2013). While the discovery ...


The Effects Of Foliar Nutrient Applications On Split, Yield, And Internal Fruit Quality Of 'Wonderful' Pomegranate (Punica Granatum L.), John Matthew Chater Dec 2015

The Effects Of Foliar Nutrient Applications On Split, Yield, And Internal Fruit Quality Of 'Wonderful' Pomegranate (Punica Granatum L.), John Matthew Chater

Master's Theses and Project Reports

Fruit split is the most important physiological disorder in pomegranate production, causing devastating crop losses worldwide. Foliar nutrient applications have been used experimentally to mitigate pomegranate fruit split but none have been conducted using the industry standard cultivar, Wonderful, and little is known about the effects of foliar nutrient applications on pomegranate. Additionally, investigations into putative health benefits of pomegranate fruit have increased interest in its production but limited evidence exists regarding effects of agricultural practices such as foliar fertilizer applications on internal fruit quality. ‘Wonderful’ pomegranate trees at 2 commercial orchards were treated with foliar applications of ZnSO4 ...


Studies To Characterize Heavy Metal Content And Migration From Recycled Polyethyleneterephthalate, Michael John-Ross Whitt Dec 2014

Studies To Characterize Heavy Metal Content And Migration From Recycled Polyethyleneterephthalate, Michael John-Ross Whitt

Master's Theses and Project Reports

Packaging Materials account for 31% of the world’s municipal solid waste. Agencies like the Environmental Protection Agency (EPA) and the Agency for Toxic Substances and Disease Registry (ATSDR) are pushing for the increased use of recycled thermoplastic materials. Polyethylene terephthalate (PET) is a commonly recycled thermoplastic which is used to package ready-to-eat fruits and vegetables. Most recycled polyethylene terephthalate (RPET) packaging materials contain heavy metal catalysts, the most common being antimony. The recent increased use of recycled plastic materials has been suspected as the source of increased human heavy metal exposure. In this study, cadmium, chromium, nickel, lead and ...


A Comparative Study Of Three Growing Media And Four Plant Groups Under Extensive Green Roof Conditions In San Luis Obispo, Ca, Todd Alan Nelson Jul 2010

A Comparative Study Of Three Growing Media And Four Plant Groups Under Extensive Green Roof Conditions In San Luis Obispo, Ca, Todd Alan Nelson

Master's Theses and Project Reports

ABSTRACT A Comparative Study of Three Growing Media and Four Plant Groups Under Extensive Green Roof Conditions in San Luis Obispo, California Todd A. Nelson Green roof growing media and plant species are critical factors when deciding on the best materials for a project. Growing media must be chosen in accordance with load bearing capacities of structures and water requirements of the plant material. Plant species must be able to thrive in the climate of the green roof and withstand a green roof’s harsh environment. The objectives of this research were: (1) to determine which of three extensive green ...


Effects Of Recycled Water On Landscape Plants, Casey R. Miranda Jun 2010

Effects Of Recycled Water On Landscape Plants, Casey R. Miranda

Master's Theses and Project Reports

ABSTRACT EFFECTS OF RECYCLED WATER ON LANDSCAPE PLANTS Casey Ray Miranda Recycled water is water that has been previously used, has suffered a loss of quality, and has been properly treated for redistribution (Wu et al. 2001). The use of recycled water as an alternative to fresh water in the landscape can have positive and negative effects. Experimentation on 40 different plant species during a 32 week period (2 phases of 16 weeks), was conducted to analyze the effects of recycled water irrigation on the appearance of landscape plants. Each species of plant was planted into 10 individual number 2 ...


Establishing Buffalograss In Fine Fescue Turfgrass On The Central Coast Of California, Brittani Jean Axtell May 2010

Establishing Buffalograss In Fine Fescue Turfgrass On The Central Coast Of California, Brittani Jean Axtell

Master's Theses and Project Reports

Buffalograss [Buchloe dactyloides (Nutt.) Engelm.] is a warm season, perennial grass native to the Great Plains from southern Canada to Mexico (Beetle, 1950). This newly developed, low input, turf-type grass is recommended for use on low maintenance sites (Falkenberg-Borland and Butler, 1982; Pozarnsky, 1983; Wu and Harivandi, 1989; Shearman et al., 2005). Recently, the use of buffalograss as a turfgrass has increased due to its drought tolerance, low nutrient requirements, and low growing height (Harivandi and Wu, 1995; Frank et al., 2004). It is an excellent choice in California where water use is limited. Unsightly winter dormancy of buffalograss can ...


No-Till Tomato Production, Bradley L. Booker Nov 2009

No-Till Tomato Production, Bradley L. Booker

Master's Theses and Project Reports

Tillage increases erosion rates and diminishes the quality of soils but has traditionally been a way to manage weeds and prepare a seedbed. No-till vegetable production can ameliorate the ill-effects of tillage in an economically effective way but has not been studied much in California. The objective of this thesis was to determine the viability of no-till vegetable cropping on the Central Coast of California. Tomatoes were grown in no-till and conventionally tilled treatments. Total yield, fruit weight, weed emergence, soil bulk density, soil aggregate stability, and soil organic carbon content were measured and compared. Yields and soil tests in ...


Impact Of Weed Management Practices On Grapevine Growth, Yield Components, Plant And Arthropod Abundance, And Carabid Seed Predation In Paso Robles Vineyard, Paolo Sanguankeo Sep 2009

Impact Of Weed Management Practices On Grapevine Growth, Yield Components, Plant And Arthropod Abundance, And Carabid Seed Predation In Paso Robles Vineyard, Paolo Sanguankeo

Master's Theses and Project Reports

In the Central Coast of California, USA, wine grape growers are making efforts to identify weed control practices that promote biodiversity in their vineyards while maintaining yields. A field study was conducted in Paso Robles, CA in 2006 and 2007 evaluating the effect on Zinfandel grape-vine growth and production, groundcover plant, and ground dwelling arthropod communities of five weed control practices: 1) flumioxazin, 2) simazine, 3) cultivation, 4) cover crop, and 5) untreated control.

The herbicide treatments had the lowest weed biomass followed by the cultivation, being approximately 10 and 2 times lower than the weed biomass of either the ...


Evaluation Of Herbicide Efficacy As Influenced By Adjuvant And Nozzle Type, Catherine L. (Grissom) Ansolabehere May 2009

Evaluation Of Herbicide Efficacy As Influenced By Adjuvant And Nozzle Type, Catherine L. (Grissom) Ansolabehere

Master's Theses and Project Reports

White clover (Trifolium repens) is a common and difficult weed to control in turfgrass as it is a highly visible and unsightly weed that disrupts the uniformity of the turfgrass surface. This weed is a serious problem in the turfgrass industry in California and there is a need for better methods of control. With more regulations on pesticides and less information about efficient application techniques, controlling white clover with available herbicides can be difficult.

Compatibility trials were conducted during the summer of 2005 to determine the compatibility of the herbicides and adjuvants planned for use in subsequent greenhouse and field ...


Temperature Influence And Heat Management Requirements Of Microalgae Cultivation In Photobioreactors, Thomas Hagen Mehlitz Feb 2009

Temperature Influence And Heat Management Requirements Of Microalgae Cultivation In Photobioreactors, Thomas Hagen Mehlitz

Master's Theses and Project Reports

Microalgae are considered one of the most promising feedstocks for biofuel production for the future. The most efficient way to produce vast amounts of algal biomass is the use of closed tubular photobioreactors (PBR). The heat requirement for a given system is a major concern since the best algae growth rates are obtained between 25-30 °C, depending on the specific strain. A procedure to determine temperature influence on algal growth rates was developed for a lab-scale PBR system using the species Chlorella. A maximum growth rate of 1.44 doublings per day at 29 °C (optimal temperature) was determined. In ...