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Full-Text Articles in Horticulture

Light-Emitting Diodes As An Alternative Supplemental Lighting Source For Greenhouse Tomato Propagation And Production, Celina Gomez Vargas Oct 2014

Light-Emitting Diodes As An Alternative Supplemental Lighting Source For Greenhouse Tomato Propagation And Production, Celina Gomez Vargas

Open Access Dissertations

Intensive year-round local production of greenhouse-grown tomatoes (Solanum lycopersicum L.) requires the use of supplemental lighting (SL) to complement solar radiation in light-limited seasonal climates. However, SL represents a large expense to greenhouse-vegetable production. Currently, energy is second only to labor as the most expensive indirect cost of production. Thus, the greenhouse industry is interested in cost-effective, energy-efficient sources of supplemental photosynthetic light to sustain steady supplies of high-quality produce during the off-season. Overhead (OH) high-pressure sodium (HPS) lamps are considered the industry standard in greenhouse SL because of their capability to deliver adequate photosynthetically active radiation (PAR …


Defining Management Strategies To Maximize Net Soil Carbon And Nitrogen Retention In Turfgrass Systems, Quincy D. Law Oct 2014

Defining Management Strategies To Maximize Net Soil Carbon And Nitrogen Retention In Turfgrass Systems, Quincy D. Law

Open Access Theses

Soil carbon (C) sequestration has been proposed as a method to reduce atmospheric carbon dioxide (CO2 ). Managed turf areas are both a source and a sink for greenhouse gases (GHGs) including CO 2 , methane (CH4 ), and nitrous oxide (N2 O), among others. Management practices, including turfgrass selection and mowing, influence the amount of C and N stored in the soil, as well as the direct and indirect GHG emissions. Thus, the objective of this research was to determine how turfgrass selection (both species and cultivar) and mowing practices (such as frequency and grass clipping management) influence the …


Identification And Characterization Of Factors Involved In Dna Demethylation And Anti-Silencing In Arabidopsis, Zhaobo Lang Oct 2014

Identification And Characterization Of Factors Involved In Dna Demethylation And Anti-Silencing In Arabidopsis, Zhaobo Lang

Open Access Dissertations

DNA methylation is a key epigenetic mark for transcriptional gene silencing in many eukaryotes. DNA methylation status can be dynamically controlled by methylation and active demethylation processes. Compared to the well-known mechanisms of DNA methylation, the mechanisms of DNA demethylation and its regulation are poorly understood. In order to better understand the DNA demethylation pathway, we developed two genetic screening systems in Arabidopsis to identify new components involved in the DNA demethylation. In the first system, which is based on 35S promoter driven SUC2 (sucrose transporter 2) transgene, a mutant (91-1) was isolated and map-based cloning identified the …


Using Energy-Efficient Technologies To Produce Bedding Plants And Microgreens In Protected And Controlled Environments, Joshua R. Gerovac Oct 2014

Using Energy-Efficient Technologies To Produce Bedding Plants And Microgreens In Protected And Controlled Environments, Joshua R. Gerovac

Open Access Theses

Gerovac, Joshua R. M.S., Purdue University, December 2014. Using Energy-Efficient Technologies to Produce Bedding Plants and Microgreens in Protected and Controlled Environments. Major Professor: Roberto G. Lopez. Production of bedding plants in commercial greenhouses (GHs) located in northern latitudes begins in late winter and continues through late spring when low outdoor temperatures generally necessitate active heating to maintain temperatures suitable for growth and development. Meanwhile, year-round production of microgreens using multi-layer systems requires sole-source (SS) photosynthetic lighting for production. Energy used to provide active heating in commercial GHs or SS lighting in multi-layer systems is second only to labor as …


Using Stable Isotopes To Quantify Nitrogen Fates In Container Plants, Sam Raimann, Greg Michalski, Michael V. Mickelbart Aug 2014

Using Stable Isotopes To Quantify Nitrogen Fates In Container Plants, Sam Raimann, Greg Michalski, Michael V. Mickelbart

The Summer Undergraduate Research Fellowship (SURF) Symposium

Currently, in the agriculture field, it is not yet known the accurate amount of Nitrogen in fertilizer that plants take up. This statistic, known as the Nitrogen Use Efficiency is currently known to be within the 30-50% range (Lea-Cox and Ross, 2001). This is very important figure to know and it is a figure that can be improved, and therefore much time, energy, and resources can be saved. This research project will use concepts involving stable isotopes to examine red maple plant material and the soilless media that the plants were grown in. Three different isotope-labelled fertilizer treatments will be …


Abcb11 Functions With B1 And B19 To Regulate Rootward Auxin Transport, Jesica Elyse Reemmer Jul 2014

Abcb11 Functions With B1 And B19 To Regulate Rootward Auxin Transport, Jesica Elyse Reemmer

Open Access Theses

Auxin transport is essential for the architecture and development of erect plants. In a network of transporters directing auxin flows, ATP-Binding Cassette (ABC) transporters are a ubiquitous family of proteins that actively transport important substrates, including auxins, across the plasma membrane. ABCB1 and ABCB19 have been shown to account for the majority of rootward auxin transport, but residual fluxes to the root tip in Arabidopsis b1b19 double mutants implies the involvement of at least one additional auxin transporter in this process. Of specific interest, the severe dwarfism seen in abcb1abcb19 is strikingly reminiscent of that seen in mutants defective in …


Supplemental, End-Of-Day, And Sole-Source Lighting From Light-Emitting Diodes Influences Growth, Morphology, And Quality Of Annual Bedding Plant Seedlings, Wesley C. Randall Jul 2014

Supplemental, End-Of-Day, And Sole-Source Lighting From Light-Emitting Diodes Influences Growth, Morphology, And Quality Of Annual Bedding Plant Seedlings, Wesley C. Randall

Open Access Theses

Annual bedding plants make up the largest sector of the U.S. floriculture industry. High-quality annual bedding plant seedlings are compact, fully rooted transplants with a large stem caliper and high root dry mass. However, production usually occurs in late winter or early spring when the daily light integral (DLI) is as low as 1 to 5 mol·m–2·d –1 in northern latitudes. Therefore, supplemental lighting (SL) is often used to increase the DLI to a recommended 10 to 12 mol·m –2·d–1. The objectives of this study were to: 1) quantify the effects of SL from three …


Biochar And Vermicompost Amendments In Vegetable Cropping Systems: Impacts On Soil Quality, Soil-Borne Pathogens And Crop Productivity, Nathan Lee Shoaf Apr 2014

Biochar And Vermicompost Amendments In Vegetable Cropping Systems: Impacts On Soil Quality, Soil-Borne Pathogens And Crop Productivity, Nathan Lee Shoaf

Open Access Theses

Amending soils with biochar and vermicompost has the potential to provide multiple benefits for specialty crops including pathogen suppression and increased crop productivity. Oomycete pathogens such as Phytophthora capsici can devastate crop fields and they are difficult to control presenting significant management challenges for Midwestern growers. Soils amended with a microbially-inoculated softwood biochar increased carrot root growth relative to the control and corn stover biochar in 2011, while the corn stover biochar also increased carrot root growth relative to the control, but only in two varieties. Neither biochar treatment influenced carrot growth in 2012. In greenhouse trials, vermicompost amendments provided …


Lettuce Cultivar Observation Trial — 2013, Elizabeth Maynard Jan 2014

Lettuce Cultivar Observation Trial — 2013, Elizabeth Maynard

Purdue Fruit and Vegetable Research Reports

Lettuce is one of several cool-season crops that Indiana growers produce to meet market demands for local produce early and late in the season. It is grown in the field as well as in unheated and heated structures. Growers who responded to a survey in 2013 indicated that important characteristics for lettuce varieties include slow bolting, good eating quality, and disease resistance. Numerous varieties are available and it is important to identify which perform well in Indiana. We report here characteristics of 38 lettuce cultivars grown in an unreplicated field trial at the Pinney-Purdue Agricultural Center in Wanatah, Indiana.


Lettuce Cultivar Observation Trial — 2013, Elizabeth Maynard Jan 2014

Lettuce Cultivar Observation Trial — 2013, Elizabeth Maynard

Midwest Vegetable Trial Reports

Lettuce is one of several cool-season crops that Indiana growers produce to meet market demands for local produce early and late in the season. It is grown in the field as well as in unheated and heated structures. Growers who responded to a survey in 2013 indicated that important characteristics for lettuce varieties include slow bolting, good eating quality, and disease resistance. Numerous varieties are available and it is important to identify which perform well in Indiana. We report here characteristics of 38 lettuce cultivars grown in an unreplicated field trial at the Pinney-Purdue Agricultural Center in Wanatah, Indiana.