Life Sciences Commons^™

Effects Of Nitrogen Management And Cultivar On Strawberry Production Under Disease Pressure, Kamille A. Garcia-Brucher

Master's Theses

Effects of nitrogen management and cultivar on strawberry production under disease pressure

Kamille Garcia-Brucher

California strawberry growers face increasing regulatory pressures to manage nitrogen (N) applications in their production system. Standard practice in the California strawberry industry is to apply a synthetic pre-plant controlled release fertilizer (CRF) to ensure the crop has sufficient N during winter establishment. Some research from the UC Cooperative Extension suggests this practice is not efficient at delivering N to the crop since most of the N is released from CRF before strawberry crop N uptake is significant. Another concern for California strawberry growers is loss …

Climate Adaptation And Water Conservation Decision-Making In Paso Robles, California Vineyards, Christopher R. Klier

Master's Theses

This paper examines vineyard perceptions and adoption of climate change adaptation and water conservation measures in the Paso Robles American Viticultural Area (AVA). A survey was distributed to all 220 vineyards and vineyard management companies that operate in the AVA, with a 53.64% response rate. The objective of the survey was to determine vineyard manager and owner attitudes towards climate change and adaptation, as well as their perceptions of how these threats would impact their operation. A second objective was to document the current level of water conservation and climate adaptation while identifying the barriers and opportunities for further adoption …

Effects Of Compost On Soil Health And Greenhouse Gas Emissions: A Case Study In A Mediterranean Vineyard, Tsz Fai Wong

Master's Theses

Compost is commonly used as an organic amendment in cropping systems such as vineyards, and has been shown to be beneficial to carbon (C) sequestration and soil health. As perennial crops, grapevines have a larger potential for C sequestration than most crops. Yet, there is a lack of understanding regarding the relationship between compost application rate, the magnitude of C sequestration, and its environmental tradeoff in the form of greenhouse gas (GHG) emissions. In the study, we investigated the effects of compost application rate on soil C sequestration, GHG emissions, crop growth, and overall soil health after two annual compost …

Evaluation Of Masculinization Treatments To Produce Feminized Hemp Seed (Cannabis Sativa L.), Ted Fitzgerald, J. Wyatt Brown

Master's Theses

Cannabis sativa L. (hemp) develops plants with either male or female flowers, and growers of hemp greatly prefer female flowers which bear the glandular trichomes that contain cannabinoids. Feminized (all female) seeds are highly desired, which are produced by crossing a female plant with a masculinized female plant. Masculinization is achieved through the inhibition of ethylene and/or addition of gibberellins before flower initiation in female plants. The hemp industry uses silver thiosulfate (STS) to masculinize hemp, but spraying silver poses environmental concerns. This study compared STS to three other ethylene-inhibiting agents: aminoethoxyvinylglycine (AVG), cobalt nitrate (CBN), and 1-methylcyclopropene (1-MCP). Treatments …

Reciprocal Transplant And Machine Learning Study Of Oak Mistletoe On Three Host Oak Species In Santa Margarita, California, Ella Abelli-Amen

Master's Theses

At Santa Margarita Ranch, California, oak mistletoe (Phoradendron villosum) parasitizes valley oak and blue oak but cannot be found growing on coast live oak despite its abundance and ability to parasitize coast live oak in other areas. It seems as though this species of mistletoe is specializing on certain host oak trees, but the mechanisms of this specialization are unknown. In order to investigate this pattern, we utilized a type of machine learning in GIS called supervised classification as well as a reciprocal transplant study in the field. The three species of oak trees were classified with 87% accuracy using …

The Future Of Organic Insect Pest Management: Be A Better Entomologist Or Pay For Someone Who Is, David H. Headrick

Horticulture and Crop Science

Insect pest management in certified organic production systems presents considerable challenges for growers. The Federal National Organic Program (NOP) guidelines list acceptable tactics, but their effective use requires a considerable knowledgebase in entomology. The range of tactics allowed by the NOP are viewed as limiting by many growers and there are important elements missing from the list such as pest monitoring and identification. Educational programs must consider utilizing instructional methods and additional means of outreach that introduce new pest management tactics that are individualized, regionally appropriate and emphasize grower adoption and collaboration with local professionals. This review describes the challenges …

Estimating Food Waste Due To Food Safety Recalls And Investigating Ways To Minimize Negative Impacts, Mykayla Latronica

Master's Theses

For years the issue of food waste has been recognized and quantified; however, food safety issues often go unrecognized as a source of food waste. One objective of this research is to estimate quantities and monetary value of fruits and vegetables implicated in food safety recalls, and thus wasted. Using publicly available data we identified all recalls involving vegetable or fruit commodities contaminated with Listeria monocytogenes, pathogenic E. coli, or Salmonella during 2015-2018. When quantities were provided, monetary value of recalled product was calculated using USDA ERS 2016 average retail prices. Although data limitations only allowed analysis of …