Citation
Production and Performance of Gaillardia Cultivars and Ecotypes

Material Information

Title:
Production and Performance of Gaillardia Cultivars and Ecotypes
Creator:
DANIELSON, HELEN E.
Copyright Date:
2008

Subjects

Subjects / Keywords:
Blankets ( jstor )
Flowering ( jstor )
Flowers ( jstor )
Peat ( jstor )
Plant growth ( jstor )
Plant growth regulators ( jstor )
Planting ( jstor )
Plants ( jstor )
Species ( jstor )
Yard waste composts ( jstor )
Miami metropolitan area ( local )

Record Information

Source Institution:
University of Florida
Holding Location:
University of Florida
Rights Management:
Copyright Helen E. Danielson. Permission granted to the University of Florida to digitize, archive and distribute this item for non-profit research and educational purposes. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder.
Embargo Date:
12/31/2006
Resource Identifier:
496175039 ( OCLC )

Downloads

This item is only available as the following downloads:


Full Text

PAGE 1

PRODUCTION AND PERFORMANCE OF Gaillardia CULTIVARS AND ECOTYPES By HELEN E. DANIELSON A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLOR IDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE UNIVERSITY OF FLORIDA 2005

PAGE 2

Copyright 2005 by HELEN E. DANIELSON

PAGE 3

This document is dedicated to every student w ho gave up before finishing. With a little support and dedication, anything is possible.

PAGE 4

iv ACKNOWLEDGMENTS I would like to thank my professors that have inspired and taught me throughout college, especially Dr. Sandra B. Wilson for he r patience and counsel. I would also like to thank my committee members, Dr. Rick K. Schoellhorn, Dr. Jeff G. Norcini, and Dr. Debbie Miller, for their guidance and support. I also wish to express my whole-hearted gratitude to the many people at various Univ ersity of Florida cam puses, as well as to those outside of the University, who helped ma ke my studies possible. I would especially like to thank Carolyn Bartuska for he r tireless assistance with statistics.

PAGE 5

v TABLE OF CONTENTS page ACKNOWLEDGMENTS.................................................................................................iv LIST OF TABLES............................................................................................................vii LIST OF FIGURES...........................................................................................................ix ABSTRACT....................................................................................................................... xi CHAPTER 1 INTRODUCTION AND LITERATURE REVIEW....................................................1 Compost Usage in Blanket Flower Growing Medium..........................................4 Growth Regulator Use on Blanket Flower............................................................6 Landscape Evaluations of Gaillardia Cultivars and Ecotypes..............................9 Blanket Flower Ecotype Evaluations..................................................................11 2 CONTAINER AND FIELD-EVAL UATION OF BLANKET FLOWER ( Gaillardia pulchella FOUG.) PRODUCED IN COMPOST-BASED MEDIA........15 Introduction.................................................................................................................15 Abstract....................................................................................................................... 16 Materials and Methods...............................................................................................17 Plant Material and Media Composition...............................................................17 Growth and Development....................................................................................18 Statistical Analysis..............................................................................................19 Results and Discussion...............................................................................................19 Physical, Chemical, and Nutrient Characteristics of the Media...................19 Growth and Development............................................................................20 Conclusions.................................................................................................................22 3 USE OF PLANT GROWTH REGULATORS FOR PRODUCING MORE COMPACT BLANKET FLOWER ( Gaillardia pulchella FOUG.)...........................28 Introduction.................................................................................................................28 Abstract....................................................................................................................... 30 Materials and Methods...............................................................................................30 Growth Regulators...............................................................................................31

PAGE 6

vi Measurements......................................................................................................31 Statistical Design and Analysis...........................................................................31 Results and Discussion...............................................................................................32 Ethephon..............................................................................................................32 Uniconazole.........................................................................................................34 Conclusions.................................................................................................................36 4 EVALUATION OF Gaillardia CULTIVARS AND ECOTYPES FOR LANDSCAPE PERFORMANCE IN NORTH CENTRAL FLORIDA....................44 Introduction.................................................................................................................44 Abstract....................................................................................................................... 47 Materials and Methods...............................................................................................47 Plant Material and Site Conditions......................................................................47 Evaluations..........................................................................................................48 Results and Discussion...............................................................................................49 Uniformity...........................................................................................................49 Flowering.............................................................................................................49 Landscape Impact................................................................................................49 Conclusions.................................................................................................................50 5 GROWTH, FLOWERING, AND SURVIVAL OF BLANKET FLOWER ( Gaillardia pulchella FOUG.) BASED ON SEED SOURCE AND GROWING LOCATION................................................................................................................57 Introduction.................................................................................................................57 Abstract....................................................................................................................... 58 Materials and Methods...............................................................................................59 Plant Material......................................................................................................59 Site Conditions....................................................................................................59 Experimental Design...........................................................................................62 Results and Discussion...............................................................................................62 Site Conditions....................................................................................................62 Growth.................................................................................................................63 Vigor....................................................................................................................64 Flowering.............................................................................................................64 Quality.................................................................................................................65 Survival................................................................................................................65 Conclusions.................................................................................................................66 6 CONCLUSIONS........................................................................................................76 LIST OF REFERENCES...................................................................................................78 BIOGRAPHICAL SKETCH.............................................................................................85

PAGE 7

vii LIST OF TABLES Table page 2-1 Chemical and physical properties of compost and peat-based media......................23 2-2 Elemental contents of co mpost and peat-based media.............................................23 2-3 Mean plant growth, leaf color, flow ering, and dry weight of blanket flower ( Gaillardia pulchella ) grown in peat and compost-based media for 10 weeks.......24 3-1 Summary of preliminary plant growth regulator studies and resulting size comparisons of a cultivar and north Florida ecotype of Gaillardia pulchella .........37 3-2 Summary of PGR applications and resulting size comparisons for Gaillardia pulchella ‘Torch’ and a north Florida ecotype.........................................................38 3-3 Growth index, size chan ge, dry weight, compactness rating, flower number at week 3, and flower number at week 4 of Gaillardia pulchella ‘Torch’ treated with ethephon...........................................................................................................39 3-4 Anova table data for growth index at three weeks after in itial treatment for Gaillardia pulchella ‘Torch’ treated with ethephon................................................39 3-5 Anova table for flower number f our weeks after initial treatment for Gaillardia pulchella ‘Torch’ treated with ethephon..................................................................40 3-6 Growth index, size chan ge, dry weight, compactness rating, and flower number data of Gaillardia pulchella ‘Torch’ treated with uniconazole drench....................41 3-7 Anova table data for growth index at three weeks after in itial treatment for Gaillardia pulchella ‘Torch’ treated with uniconazole............................................41 4-1 List of cultivar or ecotype name, source, species name, propagation method, flower description and plant description of Gaillardia trialed in north central Florida......................................................................................................................52 4-2 Frequency table of Gaillardia trial entries with th e number of times each received a specific rating in the unif ormity, flowering, and landscape impact categories for six bi-weekly evaluations..................................................................53

PAGE 8

viii 4-3 Gaillardia cultivars and ecotypes based on landscape impact during periods of the landscape trial.....................................................................................................54 5-1 Analysis of soil from the three planting locations in Florida us ed in this study......68 5-2 Dry weight (in grams) of five blanket flower ( Gaillardia pulchella ) ecotypes planted in north, north central, and central south Florida........................................68 5-3 Growth index of fi ve blanket flower ( Gaillardia pulchella ) ecotypes planted in north, north central, and central south Florida.........................................................69 5-4 Total vigor, flowering, a nd quality ratings compiled from bi-weekly evaluations of five blanket flower ( Gaillardia pulchella ) ecotypes grown in the north, north central, and central south Florida.............................................................................70 5-5 Percent survival of surviv al of five blanket flower ( Gaillardia pulchella ) ecotypes grown in the north, north ce ntral, and central south Florida.....................71

PAGE 9

ix LIST OF FIGURES Figure page 1-1 Counties in Florida with vouchered specimens of (A) Gaillardia aestivalis and (B) Gaillardia pulchella ...........................................................................................13 1-2 States which have vouchered specimens of Gaillardia pulchella ............................14 2-1 Blanket flower ( Gaillardia pulchella ) grown in peat-based, compost-based and compost media for 10 weeks....................................................................................25 2-2 Bi-weekly plant height of blanket flower ( Gaillardia pulchella ) grown in peatbased, compost-based and compost media during container production.................26 2-3 Flowering (A) and visual qua lity (B) of blanket flower ( Gaillardia pulchella ) that were transferred to the field fo llowing greenhouse cont ainer production in peator compost-based media..................................................................................27 3-1 Gaillardia pulchella ‘Torch’ after treatment w ith ethephon. (A) Control, 500 mg·L-1 (ppm) ethephon sprayed once, 500 mg·L-1 ethephon sprayed twice, 1 week apart. (B) Control, 1,000 mg·L-1 ethephon sprayed once, 1,000 mg·L-1 ethephon sprayed twice, 1 week apart......................................................................42 3-2 Gaillardia pulchella ‘Torch’ after uniconazole soil drench. (A) Control, 6 mg·L1 (ppm) uniconazole drench once, 12 mg·L-1 uniconazole drench once, and 24 mg·L-1 uniconazole drench once. (B) Control, 16 mg·L-1 (ppm) uniconazole drench twice, 12 mg·L-1 uniconazole drench twice, and 24 mg·L-1 uniconazole drench twice, 1 week apart.......................................................................................43 4-1 Landscape impact ratings of Gaillardia cultivars and ecotypes evaluated in the study.........................................................................................................................5 5 5-1 Map of blanket flower ( Gaillardia pulchella ) ecotype planting locations and seed sources in Florida and Texas............................................................................71

PAGE 10

x 5-2 Monthly average total daily solar radiation (A), average maximum and minimum daily temperatures (B), and to tal of rainfall (C) from first planting date (5 Apr. 2005) to last evaluation da te (9 Sept. 2005) at three planting sites used in this study......................................................................................................72 5-3 Weekly vigor ratings of five blanket flower ( Gaillardia pulchella ) ecotypes (NEF=northeast Florida, CWF=central west Florida, CEF=central east Florida, SEF=southeast Florida, ET=east Texas) pl anted in three loca tions in Florida........73 5-4 Weekly flower ratings of five blanket flower ( Gaillardia pulchella ) ecotypes (NEF=northeast Florida, CWF=central west Florida, CEF=central east Florida, SEF=southeast Florida, ET=east Texas) pl anted in three loca tions in Florida........74 5-5 Weekly quality ratings of five blanket flower ( Gaillardia pulchella ) ecotypes (NEF=northeast Florida, CWF=central west Florida, CEF=central east Florida, SEF=southeast Florida, ET=east Texas) pl anted in three loca tions in Florida........75

PAGE 11

xi Abstract of Thesis Presen ted to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Master of Science PRODUCTION AND PERFORMANCE OF Gaillardia CULTIVARS AND ECOTYPES By Helen E. Danielson December 2005 Chair: Sandra B. Wilson Major Department: Environmental Horticulture Blanket flower ( Gaillardia pulchella Foug.) and related species are wildflowers native to much of the US. Cultivated varieties, as well as native ecotypes, are widely available from growers and seed companies. Horticultural grade composts of suffic ient quantity and quality are now being produced by private enterprises and public municipalities and marketed at economical values. Our study evaluated blanket flower gr own in peat or com post-based media, and found compost to be a viable a lternative to peat use in containerized nursery media, while maintaining sufficient plant growt h, development, and plant quality. Many blanket flower cultivars and ec otypes are characterized by having long internodes, thus having a leggy appearance. Plant growth regulato rs (PGRs) are often used to control internode le ngth, resulting in decreased over all plant size. The PGRs ethephon and uniconazole effec tively controlled the size of Gaillardia pulchella ‘Torch,’ but not for a north Florida Gaillardia pulchella ecotype.

PAGE 12

xii Cultivar trials are useful t ools for introducing new plants to the public and private sectors, and for testing performance in a particular climate. Several Gaillardia cultivars and ecotypes were planted in a trial garden in north central Florida. There were no general trends among Gaillardia species, though uniformity was higher in vegetatively propagated types as compared to those grown from seed. Differences among separate populations with in a species (ecotypes) have been noted in several species, including Gaillardia pulchella . Several ecotypes were collected, germinated, and transplanted to three locations in Florida. Generally, plants performed better in north Florida than in north central or central south Fl orida. Survival rate varied widely by ecotype and planting location, thus emphasizing the value of ecotype selection and use.

PAGE 13

1 CHAPTER 1 INTRODUCTION AND LITERATURE REVIEW The floriculture industry is growi ng. Between 2003 and 2004, there was a two percent rise in flor iculture sales, brin ging the total wholesale greenhouse and nursery receipts to $15.7 billi on (floricultureÂ’s share of this is $6 billion) (Jerardo, 2005). The USDA Economic Research Service reported that most of the economic growth in floriculture in 2004 came from bedding and gard en plant sales (Jerardo, 2005). The costs of transporting and storage have gone up, re sulting in increasing prices on imported ornamental crops, while domestic prices have remained unchanged (Jerardo, 2005). These circumstances could provi de an opportunity for domestic growers to capture more market share with the introduction of new, affordable crops that can be produced within this country. Increasing native plant production may be pr ofitable for the flor iculture industry. As the value of using indigenous species is recognized, and native plant marketing is emphasized, consumer interest in native plants is rising (Hamill, 2005). Consumers often view native plants as easier to maintain since they are well-suited to the soils and climate of their native environment. Native plants are being used in land restoration projects, as well as in home gardens, along road sides, and in city landscaping. Though most nurseries sell some native plan ts, natives do not make up the majority of sales. As reported by respondents to a survey by Hodges and Haydu (2002), 58% of nurseries sell plants native to Florida. On e quarter of all responde nts said that natives represented over 20% of their sales.

PAGE 14

2 With a household annual consumption of floriculture crops up to $54 in 2004 (Jerardo, 2005), and a greater interest in usi ng natives, it is clear that the native plant industry has great potential for gaining a greater portion of th e market share. There are dozens of marketable native plants that have yet to move into br oad-scale production, not to mention the unending possibilities in cultivars of native species. It has been said that natives will be the “next big growth area for the industry” (Hamill, 2005). People may be surprised to know that ther e are several popular landscaping plants that are native, but are not always labeled as such. Many popular fl owers, grasses, and trees are native to the US. Marketing of these native plants is beginni ng to take off. One example of this is a native plant collecti on called ‘American Beau ties,’ which will soon be available in retail garden centers (Hamill, 2005). This could be a big step toward mainstreaming great numbers of native plants. Blanket flower ( Gaillardia spp. Foug.), also known as fi rewheel or Indian blanket, is a native plant that has found its way in to the realm of cultivation and extensive production. The Gaillardia genus is in the class Magnoliops ida, the order Asterales, and the family Asteraceae ( United States Depart ment of Agriculture [USDA], 2004). The genus was named after the 18th century patron of botany, M. Gaillard de Charentonneau (Armitage, 2001). G. aestivalis (Walt. H. Rock) and G. pulchella (Foug.) are the two Gaillardia species native to Florida (Figure 1-1A and B). G. pulchella is native to the continental US and Hawaii, with a wide gr owing range stretching from the northernmost to southernmost contiguous states (Figure 1-2). G. aestivalis has a narrower range, with Kansas as its northwestern reach, south to Te xas and Florida, and as far north as South Carolina on the east coast (USDA, 2004). An apparent physic al difference between these

PAGE 15

3 species is in the spac ing of ray florets; G. aestivalis has gaps between ray florets, while those of G. pulchella tend to grow abutting, or slightly overlapping. At least nine cultiv ars are in production unde r the parentage of G. aristata and G. pulchella (Michigan State University Extension [MSU], 1999), and can be found in most seed catalogs and in many nurseries. Several other cultivars of diverse parentage are also widely available. Many Gaillardia cultivars are grown from seed, and hybrids may be propagated by root cuttings (Floridata, 2003) or stem cuttings (Ball FloraPlant, 2005). Blanket flower is an annual or short-lived perennial (Floridata, 2003). Leaves may be basal and linear to lanceolate with a gray ish green appearance. The disk florets are generally red to brown. Ray florets may be solid yellow or red, but most are red with yellow tips. They will bloom from late spri ng to fall, longer if spent heads are removed (Floridata, 2003). Blanket flower plants and fl owers can be used to fit a variety of niches. Cut flowers can last up to a week in water (F loridata, 2003), but flow er heads may tend to droop due to thin pedicels. It is often used in wildflower plantings, along borders, roadsides, and in containers. Some of the more compact cultivars can accent walkways and embellish other formal environments. Im proved production practices, assessment of cultivar performance, and determination of ecotype use in distinct geographic areas will ultimately broaden the availability and use of blanket flower in various landscapes. These issues have been investigated in the following chapters. There are four studies featured in this thesis, covering production and evaluation aspects that address growth of blanket flower and its use in the landscape. The overall objectives of this thesis are to determine optimal production practices involving medium

PAGE 16

4 composition and plant growth regulator appli cations, to evaluate landscape performance of several blanket flower cultiv ars, and to evaluate performa nce of five different blanket flower seed sources when growing in north, nor th central, and central south Florida. Compost Usage in Blanket Flower Growing Medium There is an abundance of composting ma terial in the US. In 1998, Americans generated 6.9 million dry tons of biosolids ( United States Environmental Protection Agency [USEPA], 1999), which, along with yard waste, makes up the bulk of many composts. Twenty-one states have banned th e dumping of at least some forms of yard trimmings in their landfills (Kaufman et al ., 2004). Some waste management facilities have begun using these forms of waste to cr eate compost. As of 1997, Florida had 12 permitted composting facilities, including some of the largest in the country, yet production is far from meeting the potentia l demand for compost (Shiralipour and Smith, 1998). Studies demonstrating the benefits and lack of negati ve consequences of compost use in ornamental production media may serv e to encourage wider use of compost and help develop the market. It has been suggested that if producer s of compost were to control production methods and make a consistent and stable product, growers might be more willing to use compost in their growing medium (Raviv, 2005). The composition of composted material varies depending on the source of materials, the ratio of constituents used, and the length and type of maturing process. These factors vary by facility and age of compost. Some countries have adopted st andards for compost quality. Australia has listed standards of rates of compost to use ba sed on the electrical conductivity (EC) of the compost and salt tolerance of the plant (Woods End Res earch Laboratory, 2000). EC describes the concentration of soluble sa lts, which is important when growing

PAGE 17

5 containerized plants because an EC above 3.5 mS/cm (milliSiemens per centimeter) can be too high to support growth (Hicklent on, 1998). Having standards could increase consumersÂ’ willingness to use compost because they would be assured of its quality and consistency. Since few researchers have investigated the use of compost for native herbaceous plant production, Wilson et al. (2001a) conducte d a series of experiments addressing a multitude of factors influencing containeri zed perennial plant response to compost, including media composition, species specifi city (Wilson et al., 2002), plant nutrition (Wilson et al., 2003), and irrigation (Wilson et al., 2003). Commercial soilless mixes amended with up to 50% compost (biosolids an d yard trimmings) did not adversely affect size, appearance, or flowering. Plants gr own in media with hi gher percentages of compost (75% or 100%) were st ill considered marketable, but were reduced in size and appeared to have abnor mal root distribution. The wealth of literature documenting th e beneficial effects of compost on containerized plant growth emphasizes that results vary by sp ecies and source of compost. Previous research has largely fo cused on non-native ornamental plants without post-performance field assessments. There is rising interest and a pplications for native plant use in the landscape. Subsequently, containerized media compositions are being continually modified to optimize native plan t production. Canadian sphagnum peat is one of the primary components of many substrate blends used by the nursery industry, but up to 40% Florida peat (sedge peat) is used by some native nurseries in Florida. As a product consisting mainly of sedges and grasse s of wetland ecosystems, Florida peat is not considered by some as re newable at the level at which it is harvested (Barkham,

PAGE 18

6 1993; Buckland, 1993). Florida rank s in the top five states na tionally in the production of horticultural peat, with an annual mining industry value estimated at $8.18 million in 1999 (National Mining Associat ion, 2001). Although the lowe r cost may make Florida peat an attractive substitute fo r sphagnum peat, Florida peat is reportedly inconsistent in pH and quality (Alexander, 2001). To addre ss this, we conducted a study that evaluated blanket flower grown with or without compost-based media. Growth Regulator Use on Blanket Flower In many situations, growers want to contro l the growth of crops . While growth and development are desired, the amount of space a plant takes up affects shipping and holding capacity. A greater number of plants that can be placed on a truck and in a retail area translates into lower costs and greater potential for sales. More compact plants also have a greater aesthetic appeal (McMahon a nd Pasian, 2004). There are several methods that growers utilize to manage plant size during production. Alteri ng quality and quantity of light, lowering temperature and DIF (day temperature minus night temperature), mechanical stimulation (moving plants), and applying plant growth regulating chemicals are all methods growers use to control plant growth (McMahon and Pasian, 2004). Plant growth regulators (PGRs) are used for controlling many aspects of plant growth and development, includi ng height, flower initiation, a nd fruit set. Several PGRs interrupt physiological pathways of horm ones and enzymes, which disrupts normal growth. Many of these modes of action ar e far less obvious and unde rstood than are the results that they produce. There are three broad categories of gr owth retardants: ethylene releasers, gibberellin (GA) translocati on inhibitors, and GA biosynthesis inhibitors (Rademacher, 1991). One of the most important ethylene releasers is ethephon, which, among other

PAGE 19

7 effects, retards shoot growth in plants, especi ally graminaceous plants such as wheat, oat, and barley (Rademacher, 1991). Florel is a trade name for ethephon, and it is used on many horticultural crops. Other ethephon-containing produc ts are Pistill and Ethrel (Barrett, 2001). Ethephon is often used to eliminate undesired fruit on orname ntal trees. It ha s been used on apple trees to encourage flower bud formation and c ontrol growth (Jones et al., 1989). It is used on ornamental crops to abort and delay fl owers, abscise leaves, strengthen stems and reduce stem elongation. It does this by releasing ethylene wh en it is absorbed by cells and exposed to pH greater th an four (Rajala and PeltonenSainio, 2000). Auxin, which is a class of growth hormones, is involved in cell elongation and growth (Graham et al., 2003). It is made less ava ilable in the presence of ethyl ene (Rademacher, 1991). Cell elongation can be reduced when auxin is ma de less available, re sulting in shorter internodes and smaller plants. Another benefit of using Fl orel is to increase branch ing, which is good for stock plants and making plants appear more compact (Barrett, 1999 ). It has been recommended that growers spray Florel on liner s as a substitute for pinching to develop a uniform crop (Styer, 2004). Ethephon is commonly used to prevent flower ing in stock plants, and even prevent flowering in cuttings taken from that plant (Barrett, 1999). While this is beneficial for stem cutting health, the reduction in flowering could be detrimental to the marketability of flowering plants in a nurs ery. It can take up to 8 week s for plants to flower after treatment with ethephon, though the time can vary depending on rate (Barrett, 2001).

PAGE 20

8 The common rate at which Flor el is applied is 500 mg·L-1 (ppm), though a rate of up to 5,000 mg·L-1 is recommended for some crops (Latimer, 2004). However, the leaves of some plants can be damaged as a result of a high rate of Florel application (Barrett, 2001). The rate of application varies de pending on environmental conditions and crop (Barrett, 1999). Time of application can greatly alter the effects ethephon has on a crop. When applied to young pea plants, it reduced fina l height and caused a thickening of basal stems (Andersen, 1979). This could be an effect which growers would want to initiate in blanket flower plants to make pl ants stronger and easier to handle. The triazoles, which are GA biosynthesis inhibitors, inhibit the oxidation of ent kaurene to ent -kaurenoic acid, which is a part of the second step in GA biosynthesis (Gausman, 1991). This lowers the content of biologically active GAs (Gausman, 1991). Many of the intermediates produced during GA synthesis are used in other biotic functions, so inhibiting thei r production can further arre st growth by preventing the action of the processes for which the s ubstances are require d (Gausman, 1991). In the 1960’s, triazoles were developed for controlling fungal diseases in plants and animals (Fletcher et al., 2000). The method by which they work in fungi is to inhibit conversion of lanosterol to er gosterol (Fletcher et al., 2000). When being used for this purpose, it was found that treatments also reduce stem elongation. They reduce GA biosynthesis, ABA, ethylene, indole-3-acetic acid, inhibit sterol biosynthesis, and increase cytokinins content (Arteca, 1996). It is apparent that triazoles work by lowering levels of GA because the growth retarding effects are reversed when GAs are applied (Fletcher et al., 2000). Triazoles

PAGE 21

9 cause a decrease in plant height by induc ing a decrease in cell number and causing cortical cells to be shorter (Fletcher et al ., 2000). For packing a nd shipping, it is often better to have shorter stems to reduce the chance of them breaking, and increase the number of plants that can fit into the shipping containers a nd retail displays. Though plant growth regulator sales comprised a small fraction of the $20 billon industry of crop-protecting chemicals in 1988 (Gausman, 1991), they still are very important in agricultu re. Along with being the larg est group of systemic compounds, triazoles are also the most important growth inhibitors (Fletcher et al., 2000). Their importance can be partially attributed to the f act that they are eff ective at low doses and are not phytotoxic at low rates (Fletcher et al., 2000). Uniconazole, triapenthenol, BAS 11, LAB 150 978, and paclobutrazol are all triazo les. The most commercially used are uniconazole and paclobutrazo l, which differ by one carbon bond (Gausman, 1991). The concentration and method of applicati on of the chemical greatly influence PGR effects on plants. The plant itself has a gr eat deal to do with the outcome as well. Results will vary among species, and even among varieties and cultivars. Triazoles are primarily translocated via xylem . This has been shown using 14C-tracers in Malus (Fletcher et al., 2000). Since th ere is little movement out of the leaves via the xylem, a triazole will not have any effect when applie d to leaves, which is why foliar sprays are less effective than soil drenches or trunk in jections (Fletcher et al., 2000). Landscape Evaluations of Gaillardia Cultivars and Ecotypes Trial gardens are places where a variety of plants are grown alongside one another and evaluated based on a range of qualities. Th ere are several benefits to trialing plants. As the Pennsylvania State University trial garden mission statement puts it, their trial gardens “advance ornamental horticulture by pr oviding plant growers, plant breeders and

PAGE 22

10 selectors, and the gardening public with unbi ased evaluations of cultivar performance” (Shumac, 2004). For these same reasons, trial gardens are found in every corner of the US and in all seasons. There are several reasons for conducting trials. One reason is to test plants in a certain climate or time of year. Different cultivars of the same species may bloom at different times of year and have longer or shorter seasons of flowering (Kelly and Harbaugh, 2002). It is important to know thes e differences, especially in marketing and production. Plants must be made available to consumers at the best time of year for planting, and this date will vary across climat es. Performance of one cultivar can differ based on environmental elements such as so il, temperature, rain fall, day length and a number of other factors. Grow ers want to supply their custom ers with plants that will do well in their area, which is information they can obtain from local trial gardens (Schoellhorn, 2005). Another reason for having plant trials is to showcase new products. Growers can view new plant performance at local trials and base future crops on what they like in the trials. They are then able to provide the ne west and best of what is available to their customers (Schoellhorn, 2005). Trials also al low consumers to see plant performance in the landscape, giving a better idea of how they would look once planted at home. Trials can instigate further research on cult ivars. Investigations such as looking at why certain cultivars of the sa me species perform so different ly or deciding which traits should be bred into a new cultivar may begin af ter seeing cultivars together in a trial. The outstanding showing of blanke t flower in trials at the Un iversity of Florida prompted the studies presented in this thesis. It was a pparent that certain cultivars or native species

PAGE 23

11 of blanket flower could be great garden perf ormers, and further res earch of this plant could expand our knowledge base about it and increase it s marketability. Blanket Flower Ecotype Evaluations Turesson is credited with coining the term “ecotype” and describing the ecotype concept (1922). Ecotype is defined as “a ge netically induced variety within a single species, adapted for local ecological conditi ons” (Meyers et al., 2005), though there have been dissenters to the approval of such a definition. Quinn (1978) wrote that such units should be referred to as “populat ions,” or described by words such as “clinal variation.” Whatever the terminology, di versity exists within many plant species which can be characterized by genetic, morphological, phy siological, and life cycle differences (Daehler et al., 1999). Studies comparing ecotypes of a species have been conducted with spruce ( Picea glauca Voss.) (Chanway and Holl, 1993), blue grama grass [ Bouteloua gracilis (Willd. Ex Kunth) Lag. ex Griffiths] (Pitterman and Sage, 2000), ryegrass ( Lolium perenne L.) (Schmidt, 2003), vetiver grass ( Bouteloua gracilis Lag.) (Pitterman and Sage, 2000), black-eyed susan ( Rudbeckia hirta L.) (Norcini et al., 2001), as well as many other plant species. Most studies have found significant differences am ong traits of ecotypes. Included among these differences are floweri ng time, height, performance, and even disease resistance (C zembor et al., 2001). Phenotypic differences among ecotype s can be brought about by certain environmental factors (McCully, 2000). Enviro nmental factors such as substrate texture can affect survival rate of various ecotypes of one species (McCully, 2000). Differences among ecotypes in their ability to tolerate enviro nmental stresses have also been noted (Duncan, 2001).

PAGE 24

12 Today, region-specific plants, commonly refe rred to as ecotypes or regional seed sources, are often the preferred type of plant mate rial used in restoration projects. This is because ecotypes have genetically-evolved adap tations to certain environmental factors which help them to survive region-speci fic conditions (Heywood, 1986). Bringing in non-local plant material introdu ces novel genes which can alte r the adaptive traits of future generations (McKay et al., 2005). Lesi ca and Allendorf (1999) proposed that it is preferable to use local plants when the restoration site has experienced a low amount of disturbance, but if the degr ee of disturbance is high, us ing a mixture of local and nonlocal plants would be preferre d. Local plants would not be adapted to the much-altered environment, so introducing plants from out side populations woul d increase genetic variation, resulting in th e capacity for more rapid adaptation to the disturbed site (Lesica and Allendorf, 1999). Certain adaptations of ecotypes can make them more desirable in ornamental landscape applications and in production. For example, in turf production, an ecotype with lower seed production and a longer life cycle is preferred (Duncan, 2001). For a flowering annual plant such as blanket flower, an ecotype with a longer flowering season may be preferred. If seed production is of interest, it would be important to be familiar with seed differences among ecotypes. In a study of wiregrass ( Aristida beyrichiana Trin & Rupr.), seed weight and seedling emer gence differed among ecotypes (Gordon and Rice, 1998). The authors concluded that due to the significant differences among ecotypes, it is important to use local seed s ources which were growi ng in similar soil and hydrological conditions (Gordon and Rice, 1998).

PAGE 25

13 Figure 1-1. Counties in Florida with vouchered specimens (in green) of (A) Gaillardia aestivalis and (B) Gaillardia pulchella (in green) (Wunderlin and Hansen, 2002). A B

PAGE 26

14 Figure 1-2. States which ha ve vouchered specimens of Gaillardia pulchella (in green) (USDA, 2004).

PAGE 27

15 CHAPTER 2 CONTAINER AND FIELD-EVALUA TION OF BLANKET FLOWER ( Gaillardia pulchella FOUG.) PRODUCED IN COMPOST-BASED MEDIA Introduction Though the physical properties of peat make it an excellent component of container media for ornamental plant production, enviro nmental and economical implications of peat usage have led to the development of ne w substrate substitutes worldwide. Compost may be one of these peat alternatives. Compos t is described by Raviv (2005) as “organic matter that has undergone partial thermophilic , aerobic decomposition.” The source of this organic matter can come from a number of places, such as agricultural and municipal wastes. In the US, the amount of municipal so lid waste recovered for composting has greatly increased to nearly 17 million tons (about 7% of generated waste) from 1980 to 2003 (USEPA, 2005). As composting activitie s increase, the amount of processed compost available for use by businesses and homeowners will continue to increase. Compost is commonly used to amend soils fo r growing vegetable and fruit crops (Raviv, 2005), but a market for containe r use of compost is growing. Composts can provide a valuable source of nutrients within a nursery substrate (Hue and Sobieszczyk, 1999). In addition, co mposts have soil-borne disease suppression properties (Hoitink et al., 1991), and genera lly improve the physical, chemical, and biological properties of substrates (Inbar et al., 1993). Fitzpatric k (2001) has reviewed and cited numerous investigati ons illustrating the be neficial growth responses of compost

PAGE 28

16 utilization in ornamental and nursery cr op production systems including temperate woody ornamentals, bedding plants, foliage plants, and subtropical or tropical trees. There have not, however, been many studies of native plants produced in composted media. The objectives of this study were to co mpare peatand compost-based media for container production and landscap e performance of a popular US native, blanket flower ( Gaillardia pulchella Foug.). This plant has earned notoriety by providing copious blooms throughout the summer and into fall, while being able to withstand harsh conditions. It performs well in low moisture , sandy soils, and has some salt tolerance, as shown by the populations growing on salty sa nd dunes adjacent to the Atlantic Ocean. Abstract Seed propagated blanket flower ( Gaillardia pulchella Foug.) were container grown in a peator compost-based medium under greenhouse conditions for 10 weeks. The formulated compost-based medium had lower initial moisture, pH, total porosity, and container capacity ; and higher bulk and particle density than the other media. The compost-based medium and un-amended compost both had higher levels of N, P, K, Zn, Cu, Mn, and Fe th an the peat-based medium. At 10 weeks, plant height and shoot dry weight were greater for plants grown in the compostbased medium or compost alone than for pl ants grown in the peat-based medium. Incorporation of compost in the medium did not a ffect growth index, leaf greenness, flowering, or root mass. In a ddition, when transferred and planted out in the landscape for 16 weeks, initial contai ner medium did not affect subsequent plant height, growth inde x, or visual quality.

PAGE 29

17 Materials and Methods Plant Material and Media Composition Uniform blanket flower plugs grown from seed (D.R. Bates Nursery, Loxahatchee, FL) were transplanted into 1-gallon (3.8 L) plastic pots filled with a compost-based medium formulated on site (50% pine bar k, 40% compost, and 10% coarse sand) (by volume). Additional containers were filled with compost alone or a peat-based commercial soilless mix (50% pine bark, 40% Florida peat, and 10% coarse sand) (v:v:v) (Atlas 3000, Atlas Peat and Soil Inc., Boynton, FL). Compost was generated by the Palm Beach County Solid Waste Authority (West Pa lm Beach, FL) using a 1:1 ratio (w:w) of biosolids and yard trimmings (screened to 0.64 cm). All plants were topdressed at a manufacturer-recommended rate of 15 g per pot of 15N:9P:12K Osmocote Plus . Percent moisture, air-filled porosity (AFP) , total porosity (TP), container capacity (CC), bulk density (BD), and particle density (PD) were determined on five samples from each medium. Percent moisture was calcula ted by drying a known we ight of media at 105C for 24 h and weighing before and afte r drying. The AFP was determined in 500 mL containers using the Wolverhampton s ubmersion method of measuring the volume of drainage water in relation to the substrat e volume (Bragg and Chambers, 1998). Standard drying procedures were then used after vol ume displacement methods to determine TP, CC, BD, and PD [see (Niedziela and Nelson, 1992), for equations]. Electrical conductivity (EC), pH, and ch emical and nutrient composition were determined on three samples from each me dium prior to addi ng controlled-release fertilizer. Total C and N concentrations we re determined by a CNS analyzer (Carlo-Erba Na-1500; BICO, Burbank, California). The Environmental Protection Agency (EPA) method 3050 (USEPA, 1998) was used to determ ine total P, K, Ca, Mg, Fe, Zn, Cu, Mn,

PAGE 30

18 and B. An acid digestion procedure was us ed to prepare the samples for analysis by Inductively Coupled Argon Plasma Spectrosc opy (ICP) (Model 61E, Thermo Jarrell Ash Corp, Franklin, MA). Sample s were air-dried for 2 days and ground to a powder with a ball mill grinder. A 1-g portion of the sample wa s digested in nitric acid then treated with 30% hydrogen peroxide. The sample was then refluxed with nitric ac id, filtered through Whatman filter paper (no. 41), and diluted to 100 mL for analysis. Growth and Development Plant height and perpendicular widths were measured bi-weekly. After ten weeks, leaf greenness, dry shoot weight, and dry root weight of five plants from each treatment were measured. SPAD readings were measured on the fifth, sixth, and seventh leaves of the predominant stem using a SPAD-502 handheld chlorophyll meter (Minolta, Mahwah, NJ). Stems were separated from the roots at soil level and the r oots were rinsed to remove media prior to oven drying at 74C fo r 7 days. For subsequent field evaluations, the remaining plants were transplanted (13 April 2004) 0.91 m on center on raised beds covered with landscape fabric. Plants were watered by seep irrigati on as needed. Field conditions were as follows: 2.5% organic matter, pH 5.3, average monthly rainfall 3.31 cm, mean minimum and maximum temperatur es 14.9C and 34.9C, respectively. The soil was Ankona series, which is sandy, siliceous , and hyperthermic (National Resources Conservation Survey [NRCS], 1999). Floweri ng and visual quality were evaluated biweekly for 16 weeks after pl anting. Flowering was based on a scale of 1-5, where 1=no flowers or buds present, 2=flower buds pr esent, 3=several open flowers, 4=many open flowers, and 5=abundant open flowers. Visu al quality (color and form) ratings were based on a scale of 1 to 5 with 1 indicating very poor quality and 5 indicating excellent quality.

PAGE 31

19 Statistical Analysis In the greenhouse study, a randomized comp lete block experimental design was used with 5 single plant replications fo r each medium. The field study utilized a randomized complete block experimental desi gn with 3 replications (3 single plant samples per treatment per block). All data were subjected to an analysis of variance (ANOVA) and means separated at P 0.05 by DuncanÂ’s Multiple Range Test. Results and Discussion Physical, Chemical, and Nutrient Characteristics of the Media The formulated compost-based medium had lower initial moisture, pH, total porosity, and container capacity than the othe r media, with higher bulk and particle density (Table 2-1). Higher bulk density generally corresponds to a lower porosity (Poole et al., 1981). Passioura (2002) found th at high bulk density caused a decrease in shoot and root wei ght in young barley ( Hordeum vulgare L.) plants. Ai r filled porosity (6.7%) and container capacity (44.0%) were with in the optimal range reported as suitable for use as a substrate for container-grown pl ants (Rynk et al., 1992). Inbar et al. (1993) have reviewed physical, chemical, and biol ogical properties of compost used as a containerized media. More recently, Raviv (2005) reviewed the criteria necessary to produce high quality composts for horticultural purposes. While it is not unusual for composts to have pH values slightly above the desirable range (Nappi and Barberis, 1993), the compost used in this study had a pH value (6.53) similar to that of the peat-based commerci al mix (6.58). The EC of the compost-based medium was three times higher than that of the peat-based medium. High EC content, which has been reported for ot her composts made of bioso lids and yard waste (Vavrina, 1994), often limits the exclusive use of compos t without amendments, particularly for salt

PAGE 32

20 sensitive species. However, blanket flower th rives in coastal areas and did not appear to have been affected by the higher EC. Compost or compost-based media had hi gher N content than the peat-based medium (Table 2-2). Organic waste has been reported as a valuable source of N (Sims, 1995). Composts with C:N ratios less than 20 are considered stable and optimum for plant growth (Davidson et al., 1994), while thos e with ratios greater th an 30 may result in plant phytotoxicity and N im mobilization (Zucconi et al ., 1981). The compost-based medium had substantially more P and K than the peat-based medium (Table 2-2), which could lessen the need for additional P and K fertilizer. Phosphorus and K are often present at higher levels in compost media, which correlates with higher EC (McLachlan et al., 2004). Although this study only investigat ed nutrients within the media, a previous compost study analyzing nutrient content of leaf tissue show ed that plants grown in media amended with compost generally had high er leaf K, P, and Mn; similar N and Ca; and lower Mg, Fe, and Al content than plants grown in the peat-based medium (Wilson et al., 2003). Heavy metal contents did not exceed EPA acceptable levels for biosolids application (USEPA, 1994) for any substrate. Growth and Development Regardless of the medium, at 10 weeks a ll plants were considered marketable (Figure 2-1). The average heights of plan ts grown in the compost or compost-based medium were consistently greater than the av erage heights of plants grown in the peatbased medium (Figure 2-2). Compost had no e ffect on growth index, leaf color, flower number, root dry weight, or shoot:root ratio. Shoot dry weight was 45% greater in compost-based media than in peat-based medi a (Table 2-3). This was consistent with Wilson et al. (2004) who found that at 8 w eeks after transplanting in 100% compost,

PAGE 33

21 shoot dry weights of butterfly sage ( Cordia globosa (Jacq.) Kunth), firebush ( Hamelia patens Jacq.), scorpions tail ( Heliotropium angiospermum Murray), tropical sage ( Salvia coccinea BucÂ’hoz ex Etl.), climbing aster ( Symphyotrichum carolinianum (Walter) Wunderlin & B.F. Hansen), narrowleaf sunflower ( Helianthus angustifolius L.), pineland lantana ( Lantana depressa Small), spotted beebalm ( Monarda punctata L.), black-eyed susan ( Rudbeckia hirta L.), and Carolina wild petunia ( Ruellia caroliniensis (J.F. Gmel.) Steud.) were 1.5 to 8.0 times greater than that of plants grown in a peat-based medium. Interestingly, plant growth response of nativ e plants grown in compost-based media was generally greater than that of non-native species. In seve n out of the ten non-native perennial species evaluated, s hoot dry weight was reduced when grown in media with more than 50% compost (Wilson et al., 2001b). Subsequent to field transplanting, plants re ceived similar flower and visual quality ratings regardless of the initial container me dium used (Figure 2-3A and B). Visual quality ratings peaked for all treatments between weeks four and ten. After the week 10 evaluation, quality began to diminish, though fl ower ratings remained relatively high. Flower ratings for all treatments peaked around week 6, but c ontinued to receive relatively high ratings throughout the remainder of the evaluation period (Figure 2-3A). Verifying field establishment of Florida natives is particular ly warranted if they are not native to soils with high organic matter. In a study explori ng nursery and field establishment techniques to improve seedli ng growth of three Costa Rican hardwoods, Wightman et al. (2001) reported varying resu lts among ecologically distinct species. Pilon ( Hyeronima alchorneoides Fr. Allemao), grown initially in compost, retained its size advantage after a year in the field. Howe ver, for other species such as Spanish elm

PAGE 34

22 [ Cordia alliodora (R.P.) Cham] and santa maria ( Calophyllum brasiliense Cambess), container use of compost did not af fect subsequent field growth. Conclusions Blanket flower grown in compost or compostbased media grew as well as or better than those in peat-based media. More importantly, media composition did not affect subsequent field establishment or landscap e performance. However, container-grown blanket flower (particularly those with com post in the medium) could benefit from PGR application to control legginess. In the past, variation within and among commercial compost facilities reduced the quality and consistency of compost, whic h are necessary for use in horticultural enterprises. Horticultural grade composts of sufficient quantity and quality are now being produced by private enterprises and public municipalities and marketed at economical values. Therefore, composts may be an alternative to peat in containerized nursery media for blanket flower, while maintaining sufficient plant growth, development, and ultimately, plant quality.

PAGE 35

23Table 2-1. Chemical and physical propert ies of compost and peat-based mediaz. EC Air filled porosity Total porosity Container capacity Bulk densityParticle density Mediumy pH (mmho/cm) ---------------------------(% by vol)---------------------------------------(g cm-3)-------------Peat-based 6.58 ax 1.63 c 5.08 a 48.0 a 43.0 a 0.23 b 0.46 b Compost-based 5.97 b 5.73 b 4.06 a 41.6 b 38.0 b 0.33 a 0.57 a Compost 6.53 a 11.20 a 6.67 a 50.8 a 44.0 a 0.20 c 0.42 b z Data measured prio r to transplanting. y Peat-based commercial mix consists of 4:5:1 peat:pine bark:c oarse sand (v:v:v). Compost-based mix consists of 4:5: 1 compost:pine bark:coarse sand (v:v:v). Compost consists of yard waste : biosolids 1:1 (w:w). x Means separation by Duncan's Multiple Range Test, 5% level. Table 2-2. Elemental contents of compost and peat-based mediaz. N C C/N P K Ca Mg Mediumy --------(%)-----ratio -----------Con centration (mg·kg-1) ---------Peat-based 0.52 cx 31.8 a 60.7 a 103 c 267 c 13300 b 3660 a Compost-based 0.84 b 24.3 b 28.9 b 3540 b 1937 b 13940 b 1105 c Compost 2.43 a 30.7 a 12.7 c 10410 a 7150 a 47143 a 3096 b Zn Cu Mn Al Fe B Medium --------------------------Concentration (mg·kg-1)---------------------------Peat-based 5.4 c 3.6 c 20.1 c1326 c1174 c11.0 b Compost-based 40.9 b 58.0 b48.4 b1703 b4162 b15.6 b Compost 102.3 a 166.4 a115.6 a3749 a10557 a34.8 a z Data measured prio r to transplanting. y Peat-based commercial mix consists of 4:5:1 peat:pine bark:c oarse sand (v:v:v). Compost-based mix consists of 4:5: 1 compost:pine bark:coarse sand (v:v:v). Compost consists of yard waste : biosolids 1:1 (w:w). x Means separation by Duncan's Multiple Range Test, 5% level.

PAGE 36

24Table 2-3. Mean plant growth, leaf color, flowering, and dry weight of blanket flower ( Gaillardia pulchella ) grown in peat and compost-based media for 10 weeksz. Mediumz Growth indexy Leaf color (SPAD) Flower (no.) Shoot dry weight (g) Root dry weight (g) Shoot: root Peat-based 36.8 ax 36.4 a 10.6 a 14.1 b 2.7 a 6.2 a Compost-based 41.7 a 35.4 a 11.0 a 20.4 a 3.7 a 5.7 a Compost 39.6 a 36.8 a 12.6 a 19.4 a 3.0 a 6.6 a z Peat-based commercial mix consists of 4:5:1 peat:pine bark:c oarse sand (v:v:v). Compost-based mix consists of 4:5: 1 compost:pine bark:coarse sand (v:v:v). Compost consists of yard waste : biosolids 1:1 (w:w). y Measured as [(plant height + width 1 + width 2)÷3]. x Means separation by Duncan's Multiple Range Test, 5% level.

PAGE 37

25 Figure 2-1. Blanket flower ( Gaillardia pulchella ) grown in peat-based, compost-based and compost media for 10 weeks. Peat-based Compost-based Compost

PAGE 38

26 Figure 2-2. Bi-weekly plant he ight of blanket flower ( Gaillardia pulchella ) grown in peat-based, compost-based and compos t media during container production. Vertical bars represent standard error for each treatment at each time interval. 0 5 10 15 20 25 30 35 40 45 50 0246810 Time (weeks)Plant height (cm) Peat-based Compost-based Compost

PAGE 39

27 Figure 2-3. Flowering (A) and visual quality (B) of blanket flower ( Gaillardia pulchella ) that were transferred to the field fo llowing greenhouse cont ainer production in peator compost-based media. Flower ratings were based on a scale of 1-5, where 1=no flowers, 2=few flowers, 3= some flowers, 4=many flowers, and 5=peak flowering. Visual quality (color and form) was based on a scale of 1-5, where 1=very low quality, 2=low quali ty, 3=medium quality, 4=high quality, and 5=very high quality. Vertical bars repr esent standard error for each treatment at each time interval. 1 2 3 4 5 0246810121416 Time (weeks)Visual quality ratin g 0 1 2 3 4 5Flowering rating Peat-based Compost-based CompostB A

PAGE 40

28 CHAPTER 3 USE OF PLANT GROWTH REGULATO RS FOR PRODUCING MORE COMPACT BLANKET FLOWER ( Gaillardia pulchella FOUG.) Introduction Blanket flower ( Gaillardia pulchella Foug.) is an herbaceous annual in the Aster family. It is native throughout most of the US (Wunderlin and Hansen, 2002), and cultivated varieties are grown world-wide. In the right conditions, th ese plants are fastgrowing and can quickly reach a cumbersome size for handling and shipping. The use of plant growth regulators (PGRs) may help extend the amount of time these plants can be held before distribution and sale. There are many PGRs available for use on ornamental crops. They work through various biological systems in plants, and th eir effectiveness differs by plant. PGRs regulate growth by preventing lengthening of stems, resulting in a more compact plant with stronger stems (Whitman et al., 2005). Uniconazole is a growth retardant related to paclobutrazol (Bonzi), but with greater efficacy (Gent and McAvoy, 2000). Uniconazole-P is the active ingredient in Sumagic (0.055%), which is used on many ornamental cr ops. It has been reported that growth restrictions induced by uniconazole pers ist for 28 to 40 days in Mandevilla ( Mandevilla splendens Hook.) (Deneke et al., 1992), but persiste nce data for blanket flower have not been published. Ethephon [(2-chloroethyl) phosphonic acid] is the active ingredient in Florel at 3.9% by weight. It is applied as a spray, generally at 250 to 500 mg·L-1 (ppm) (Barrett,

PAGE 41

29 1999), but rates as high as 5,000 mg·L-1 can be applied to azalea ( Rhododendron L. sp.) (Latimer, 2004). Ethephon can be used to initi ate flower drop via the release of ethylene, however, some plants in Asteraceae have et hylene-insensitive flowers (Serek and Reid, 2000). When exposed to pH above 4.0, ethe phon decomposes to re lease ethylene (Goudy et al., 1987). Ethylene reduces availability of auxin (Rademacher, 1991). Auxin is a class of growth hormones which affects stem elongation. The lack of useable auxin can decrease overall stem length, and therefore pl ant size, because of a reduction in internode length. This results in plants that are more compact, easier to ship, and more attractive to consumers (McMahon and Pasian, 2004). A preliminary study was conducted by a pplying B-Nine (Uniroyal Chemical, Middlebury, Conn.) as a spray, Cycocel (Oly mpic Horticultural Products, Mainland, Pa.) as a spray, a tank mix of B-Nine/Cycocel as a spray, and Bonzi (Syngenta, Greensboro, N.C.) as a drench on a blanket flower cultiv ar (‘Torch’), and on an uncultivated blanket flower ecotype native to north Florida. The native blanket flower was chosen for these studies because of its large habit and leggy growth. While the ‘Torch’ cultivar has a more branching and less leggy habit than the native ecotype, it is not very compact. During the preliminary studies, it was noted that the two types of blanket flower have very different growth habits and could not be compared directly. Therefore, later studies were separated by plant type. Regard less of blanket flower type, none of the PGR treatments were effective in controlling stem elongation (Table 3-1). Subsequently, additional growth regulators were tested: Florel (Southern Agricultural Insecticides, Inc., Palmetto, FL), which is an ethylenereleasing compound (Rademacher, 1991); and Sumagic (Valent U.S.A. Corporation, Walnut Creek, CA), which is a triazole like B-

PAGE 42

30 Nine, but is more active (Barre tt, 1999). The objective of th is study was to determine if the PGRs uniconazole and ethephon, used at varying rates, could reduce stem elongation in Gaillardia pulchella ‘Torch’ and a blanket flower ecot ype, resulting in more compact, marketable plants. Abstract Growth regulators are used on ornament al crops often to reduce stem elongation, resulting in more compact plants. Blanket flower ( Gaillardia pulchella ) is generally characterized by having lo ng internodes, giving plants a leggy appearance. Two plant growth regulator s were applied to ‘Torch’ and native blanket flower plants to tr y to reduce final production size. Florel (ethephon) was applied as a spray at a rate of 500 and 1,000 mg·L-1 (ppm) one and two times per plant. Sumagic (uniconazole) was applied as a soil drench at rates of 6, 12, and 24 mg·L-1 one and two times per plant. Regardle ss of application ra te, ‘Torch’ plants that were sprayed twice w ith ethephon were the most compact. Regardless of whether plants were drenched once or twice, Uniconazole treatments of 24 mg·L-1 resulted in the smallest ‘Torch’ plants. No treatments effectively reduced the size of the blanket flower ecotype. Materials and Methods Unrooted ‘Torch’ stem cuttings (Ball Flor aPlant, West Chicago, IL) were stuck in Fafard #2 medium (Fafard Inc., Apopka, FL) in 72-cell trays. Seeds of blanket flower from a source in Crestview, Florida were so wn in Fafard #2 medium in 128-cell trays. Seed trays and cuttings were kept under in termittent mist (10 seconds per 20 minutes) for 10 days, then moved to a greenhouse wh ere they were watered with 150 mg·L-1 20-10-20

PAGE 43

31 (N-P-K) liquid fertilizer (The Scotts Company, Marysville , OH). Rooted cuttings were transplanted into 3.8 L containe rs with Fafard #2 medium. Dr ip tubes delivered fertilized irrigation as needed throughout the study. Growth Regulators All solutions were prepared using dei onized water (pH 7.0). Uniconazole was applied with a CO2 sprayer at 2 quarts per 100 square feet, or as a drench using 180 milliliters per container at rates of 6, 12, and 24 mg·L-1 (Table 3-2). Ethephon was applied using a CO2 sprayer at 3 quarts per 100 squa re feet at rates of 500 and 1,000 mg·L-1. The spray adjuvant Capsil (Aquatrols, Cherry Hill, NC) was added to ethephon solutions at a rate of 0.5 ml per liter. The second application for treatments which received 2 applications was applied 1 w eek following the initial treatment for both uniconazole and ethephon treatments. Measurements On the day of the first treatment, the height and widths of all plan ts were measured. Height was measured from the soil level to the highest vegetative point. Width was measured first at the widest vegetative point passing through th e center of the plant, and a second measurement was taken perpendicular to the first. These same measurements were taken at the end of each study, before plants were harvested to determine dry weight. At harvest, all plant material above soil level was put into separate paper bags and dried in an oven at 70C for 1 week, after which dry weights were recorded. Statistical Design and Analysis The treatments were arranged in a comple tely randomized block design with three blocks and three replications per treatment. Means were separated using the Waller-

PAGE 44

32 Duncan K-ratio t Test. This is a non-c onservative test and allowed for missing data points. Results and Discussion Visual ratings of each plant were recorded for how compact the plant looked at the end of the study. Compactness ra tings were based on a scale from one to three, where 1=not compact, 2=somewhat compact, and 3=hi ghly compact. These ratings were made by looking through the center of each plant fr om the side and estimating the amount of open space visible compared to total area ta ken up by the plant. A highly compact plant had less than 10% of open space when looki ng through the plant. In a somewhat compact plant, more than 10% but less than 30% of the area was open space. If greater than 30% of the area was open, the plant wa s not compact. An example of compactness ratings of 1, 2, and 3 are can be seen in Fi gure 3-1A, where the cont rol plant (left) was rated a 1, the center plant was rated a 2, a nd the plant on the right was rated a 3 for compactness. Ethephon Regardless of spray number or spray rate, ethephon applications did not affect the native blanket flower, so data has not been pr esented. A reason for the lack of affect could be that ethephon breaks down quickly, and not enough chemical may have been present to affect stem elongation when bolting began (J.E. Barrett, personal communication, 2005). To be effective, ethe phon should be applied at the point when plants are beginning to bolt out of the rosette stage. Growth is not uniform in a seedproduced crop, so bolting times vary, making pr oper application for each plant extremely difficult. Other options for reducing stem elongation include restri cting fertilizer and water, increasing light intensity, an d mechanically stimulating plants.

PAGE 45

33 Ethephon did have a significant effect on gr owth of ‘Torch.’ All treated plants were more compact than control, and were of saleable quality at the end of the study (Figure 3-1). Plants treated with 500 mg·L-1 ethephon twice and with 1,000 mg·L-1 ethephon once or twice received the highest ra ting (3.0) for compactness (Table 3-3). This compactness was due to reduction of in ternode lengths. This is consistent with results of Hansen and Grossman (2000) in which shoot growth of catchweed bedstraw ( Galium aparine L.) and tomato ( Lycopersicon esculentum Mill.) were reduced after exposure to ethephon. Plants with the smallest growth index (G I) and least change in size were those which received two applications of ethephon (Table 3-3). The number of applications was significant, while the rate of ethephon was not significant (Table 3-4). Therefore, two applications of 500 mg·L-1 ethephon was just as effectiv e in controlling GI as two applications of 1,000 mg·L-1 ethephon. Ethephon did not aff ect dry weights. This is noteworthy because though the GI of plants treat ed twice were smaller than plants treated once, the weight of vegetation was not less. This meant that the same amount of growth occurred among treatments, but the growth was more dense wh en two applications were administered. There were significant differences am ong treatments in compactness ratings, though only average ratings above 2.0 would be considered marketable. Thus, the treatment of 500 mg·L-1 applied twice and both 1,000 mg·L-1 Ethephon treatments resulted in very compact, marketable plants (Figure 3-1). Flowering was affected by ethephon. At th e time of final measurements, (3 weeks after initial app lication and 2 weeks after second app lication), only the untreated plants had flowers (Table 3-3). One week later, no open flowers were present on plants treated

PAGE 46

34 with two ethephon applications. With one application, the 500 ppm treatment showed about 7 flowers, and the 1,000 ppm treatment showed less than one flower. Untreated plants exhibited about 12 fl owers per plant. Rate, numbe r of applications, and their interaction had an effect on flowering at four weeks after initial trea tment (Table 3-5). All ethephon-treated plants had many fl ower buds at both 3 and 4 weeks after initial application. Plants treated with one application had many large buds; plants treated with two applications had many small buds (data not shown). The plants that had only one ethephon application flowered first, wh ich is better for marketing since plants with flowers or flower buds sell more readily than those without (Keever and McGuire, 1991). Since the 1,000 mg·L-1 single application resulted in plants of marketable size similar to the double applicati on treatment plants, it would be better to use the high rate single application for plants of marketable size and earlier floweri ng. This would also reduce on labor needed for a second applica tion. However, flowering will still be delayed until about 5 weeks after ethephon appl ication. By this time, plants will have begun to grow out of the effects of the grow th regulator and inte rnode lengthening will occur. If plants must be in flower before this, uniconazole may be a more desirable option for growth regulation, as it did not im pact flowering in this study. Additionally, growth-controlling effects of ethephon do not last very long compared to effects of uniconazole, which may be important to gr owers wanting to hold plants longer. Uniconazole Regardless of application number or rate, uniconazole applied as a spray or as a drench had no effect on the blanket flower ecoty pe so final harvest data is not presented (Table 3-2). It is possible that plant size was not affected because during bolting, growth is mostly due to auxin (J.E. Barrett, personal communication, 2005). Bolting, or the

PAGE 47

35 elongation of flowering stems ma y be mediated by a shift in the control of elongation to auxins as well as gibberlic acid. Since th e elongation process at this time may be controlled by both auxin and gibberellin pathways uniconazole would offer less control over the process. No research has been done to evaluate the family Asteraceae in this regard. Additionally, there are several GA pathways which could be utilized by the plant, essentially working around those th at are blocked by uniconazole. Uniconazole applied as a foliar spray had no significant effect on ‘Torch’ plants. In unpublished studies, high rates of uniconazole foliar spray were required for control in some Asteraceae plants (J.E. Barre tt, personal communication, 2005). Soil drenches of uniconazole were effec tive in controlling growth of ‘Torch’ Gaillardia . The rate of uniconazole drench had a significant effect on the GI and change in size (Table 3-6), though the number of times treatment was applied (once or twice) and the interaction of rate and nu mber of treatments was not si gnificant (Table 3-7). All treated plants were of saleable quality at the end of the study (Fi gure 3-2). Compactness was greatest when two applications of the 12 mg·L-1 drench was applied, and with either one or two applications of 24 mg·L-1 drench. Since there were no differences between GI, change in size, dry weight or compactne ss for single and double applications of the 24 mg·L-1 rate, one 24 mg·L-1 application on ‘Torch’ is sufficient for optimum size control. A notable risk of using PGRs is a delay in flowering. However, this effect varies by species. For example, uniconazole has i nduced an increase in flower number of Camellia ( Camellia sasanqua Thunb.) (Keever and McGu ire, 1991) and delayed flowering in Mandevilla (Deneke et al., 1992). Changes in flowering may depend on

PAGE 48

36 time of application. In a study by Keever a nd Oliver (1994), time to flower decreased when azalea plants were treated at an early stage of development and increased when application occurred at a later stage. In our study, uniconazole treatments had no significant affect on flow ering (Table 3-6). Conclusions Plant growth regulators (B-Nine, Cyco cel, Bonzi, Uniconazole, and Ethephon) were not effective in controlling growth of a north Florida blanket flower ecotype, regardless of delivery method, application numbe r or application rate. However, either ethephon spray or uniconazole drench can be used to effectively control growth of cultivated Gaillardia pulchella ‘Torch.’ It should be noted that these experiments were conducted during late summer in Florida. In more northern states, growth regulators are often needed in lower amounts than in the south (Latimer et al., 2003), so the recommended rates in this study may need to be adjusted for growers outside of Florida.

PAGE 49

37 Table 3-1. Summary of prelim inary plant growth regulator studies and resulting size comparisons of a cultivar and north Florida ecotype of Gaillardia pulchella . PGR Rate (mg·L-1) No. of applications Application method Gaillardia type % of growth index of control B-Nine 5000 1 Spray ‘Torch’ NDz B-Nine/Cycocel 5000/12001 Spray ‘Torch’ ND Cycocel 1200 1 Spray ‘Torch’ ND Bonzi 30 1 Spray ‘Torch’ ND Bonzi 60 1 Spray ‘Torch’ ND Bonzi 120 1 Spray ‘Torch’ ND Bonzi 3 1 Drench ‘Torch’ ND Bonzi 6 1 Drench ‘Torch’ ND Bonzi 12 1 Drench ‘Torch’ ND B-Nine 5000 1 Spray ecotype ND B-Nine/Cycocel 5000/12001 Spray ecotype ND Cycocel 1200 1 Spray ecotype ND Bonzi 30 1 Spray ecotype ND Bonzi 60 1 Spray ecotype ND Bonzi 120 1 Spray ecotype ND Bonzi 3 1 Drench ecotype ND Bonzi 6 1 Drench ecotype ND Bonzi 12 1 Drench ecotype ND z ND=Not visually different in size compared to untreated controls, thus measurements were not recorded.

PAGE 50

38 Table 3-2. Summary of PG R applications and resulti ng size comparisons for Gaillardia pulchella ‘Torch’ and a north Florida ecotype. PGR Rate No. of applications Application method Gaillardia type % reduction of growthz Florel 500 1 Spray ‘Torch’ 14.1 Florel 500 2 Spray ‘Torch’ 20.9 Florel 1000 1 Spray ‘Torch’ 15.6 Florel 1000 2 Spray ‘Torch’ 26.3 Sumagic 6 1 Drench ‘Torch’ 8.2 Sumagic 6 2 Drench ‘Torch’ 16.0 Sumagic 12 1 Drench ‘Torch’ 18.9 Sumagic 12 2 Drench ‘Torch’ 18.5 Sumagic 24 1 Drench ‘Torch’ 31.1 Sumagic 24 2 Drench ‘Torch’ 29.2 Sumagic 60 1 Spray ‘Torch’ NSy Sumagic 60 2 Spray ‘Torch’ NS Sumagic 120 1 Spray ‘Torch’ NS Sumagic 120 2 Spray ‘Torch’ NS Sumagic 180 1 Spray ‘Torch’ NS Sumagic 180 2 Spray ‘Torch’ NS Florel 500 1 Spray ecotype NS Florel 500 2 Spray ecotype NS Florel 1000 1 Spray ecotype NS Florel 1000 2 Spray ecotype NS Sumagic 6 1 Drench ecotype NS Sumagic 6 2 Drench ecotype NS Sumagic 12 1 Drench ecotype NS Sumagic 12 2 Drench ecotype NS Sumagic 24 1 Drench ecotype NS Sumagic 24 2 Drench ecotype NS Sumagic 60 1 Spray ecotype NS Sumagic 60 2 Spray ecotype NS Sumagic 120 1 Spray ecotype NS Sumagic 120 2 Spray ecotype NS Sumagic 180 1 Spray ecotype NS Sumagic 180 2 Spray ecotype NS z Growth calculated as one minus the growth index of treated plants divided by the growth of untreated control plants. y There were not significant differences in size among ‘Torch’ plants treated with uniconazole spray and control (untreated) plants, nor among a ny treatments of the blanket flower ecotype and control.

PAGE 51

39 Table 3-3. Growth index, size change, dry weight, compactne ss rating, flower number at week 3, and flower number at week 4 of Gaillardia pulchella ‘Torch’ treated with ethephon. Rate (mg·L-1) # of sprays Growth indexz Size changeyDry weight (g) Compactness ratingx Flower no. at 3 weeks Flower no. at 4 weeks Control 26.3 aw 16.6 a 8.9 a 1.2 c 2.3 a 12.3 a 500 1 22.6 b 14.1 b 6.1 bc 2.0 b 0.0 b 7.3 b 1000 1 22.2 bc 12.9 bc 7.5 b 3.0 a 0.0 b 0.7 c 500 2 20.8 cd 12.1 c 6.5 bc 3.0 a 0.0 b 0.0 c 1000 2 19.4 d 10.2 d 5.9 c 3.0 a 0.0 b 0.0 c z Growth index (GI) was calculated by the equation: (height+(wi dth 1+width 2)/2)/2. y Size change=final GI – initial GI. x Compactness rating was a visual assessmen t based on a scale of 1-3, where 1=not compact, 2=somewhat compact, and 3=highly compact. w Mean separation by Waller-Duncan with p=0.05. Table 3-4. Anova table data fo r growth index at three week s after initial treatment for Gaillardia pulchella ‘Torch’ treated with ethe phon. Size was calculated by the equation: (height+( width 1+width 2)/2)/2. Rate (mg·L-1) One ethephon application Two ethephon applications Mean rate 500 22.6 bz 20.8 cd 21.7 a 1,000 22.2 bc 19.4 d 20.8 a Untreated 26.3 a Mean no. application 22.4 a 20.1 b z Mean separation by Waller-Duncan with p=0.05. ANOVA Pr>F No. application 0.0006 Rate NS No. application x rate NS

PAGE 52

40 Table 3-5. Anova table for flower number four weeks after initial treatment for Gaillardia pulchella ‘Torch’ treated with ethephon. Rate (mg·L-1) One ethephon application Two ethephon applications 500 7.3 az 0.00 b 1,000 0.7 b 0.00 b Untreated 12.3y z Mean separation by Waller-Duncan with p=0.05. y Mean significant difference for all treat ments including control (untreated)=1.50 ANOVA Pr>F No. application 0.0001 Rate 0.0004 No. application x rate 0.0004

PAGE 53

41 Table 3-6. Growth index, size change, dry weight, co mpactness rating, and flower number data of Gaillardia pulchella ‘Torch’ treated with uniconazole drench. Rate (mg·L-1) # of sprays Growth indexz Size changey Dry weight (g) Compactness ratingx Flower no. at 3 weeks Flower no. at 4 weeks Control 31.8 aw15.0 a 15.4 a 1.0 b 4.7 a 9.5 a 6 1 29.2 b 13.3 a 14.9 abc 1.3 b 3.0 a 11.0 a 6 2 26.7 c 11.1 b 12.9 bcd 1.4 b 3.2 a 5.0 a 12 1 25.8 c 9.8 c 12.4 cd 1.4 b 4.3 a 9.5 a 12 2 25.9 c 8.6 c 15.1 ab 2.2 a 2.7 a 3.5 a 24 1 21.9 d 6.6 d 10.7 d 2.7 a 3.2 a 5.5 a 24 2 22.5 d 4.9 d 12.4 d 2.4 a 2.3 a 5.0 a z Growth index (GI) was calculated by the equation: (height+(wi dth 1+width 2)/2)/2. y Size change=final GI – initial GI. x Compactness rating was a visual assessmen t based on a scale of 1-3, where 1=not compact, 2=somewhat compact, and 3=highly compact. w Mean separation by Waller-Duncan with p=0.05. Table 3-7. Anova table data fo r growth index at three week s after initial treatment for Gaillardia pulchella ‘Torch’ treated with unicon azole. Size was calculated by the equation: (height+( width 1+width 2)/2)/2. Rate (mg·L-1) One uniconazole application Two uniconazole applications Mean rate 6 29.8 az 26.7 c 27.9 a 12 25.7 c 25.9 c 25.8 b 24 21.9 d 22.5 d 22.2 c Untreated 31.8 a Mean no. application 25.8 a 25.0 a z Mean separation by Waller-Duncan with p=0.05. ANOVA Pr>F No. application NS Rate <0.0001 No. application x rate NS

PAGE 54

42 Figure 3-1. Gaillardia pulchella ‘Torch’ after treatment w ith ethephon. (A) Control, 500 mg·L-1 (ppm) ethephon sprayed once, 500 mg·L-1 ethephon sprayed twice, 1 week apart. (B) Control, 1,000 mg·L-1 ethephon sprayed once, 1,000 mg·L-1 ethephon sprayed twice, 1 week apart. Control 500 mg·L-1 spray x 1 500 mg·L-1 spray x 2 B A Control 1,000 mg·L-1 spray x 1 1,000 mg·L-1 spray x 2

PAGE 55

43 Figure 3-2. Gaillardia pulchella ‘Torch’ after uniconazole so il drench. (A) Control, 6 mg·L-1 (ppm) uniconazole drench once, 12 mg·L-1 uniconazole drench once, and 24 mg·L-1 uniconazole drench once. (B) Control, 16 mg·L-1 (ppm) uniconazole drench twice, 12 mg·L-1 uniconazole drench twice, and 24 mg·L-1 uniconazole drench twice, 1 week apart. Control 6 mg·L-1 drench x 1 24 mg·L-1 drench x 2 B A Control 12 mg·L-1 drench x 2 24 mg·L-1 drench x 2 12 mg·L-1 drench x 1 6 mg·L-1 drench x 2

PAGE 56

44 CHAPTER 4 EVALUATION OF Gaillardia CULTIVARS AND ECOTYPES FOR LANDSCAPE PERFORMANCE IN NORTH CENTRAL FLORIDA Introduction While many consumers may chose a plan t based on catalog pictures, price, and availability, these factors tell little about the plantÂ’s ability to perform in a given climate. Facts about performance often come from plant trials. Ma ny universities have bedding plant trials to compare how various cultivars perform in a landscape environment. Trial entries are generally rated on qualities such as flowering and dis ease susceptibility. Plant trials can be important for introducing new crops. For example, Allan ArmitageÂ’s trials at the University of Ge orgia (University of Georgia [UGA], 2005) and the trials at the University of Florida (Unive rsity of Florida, 2005) allow both private and public sectors to view new and interesting crops and monitor their performance in a specific growing region. Growers may base thei r future crops on results of the trials, and consumers may modify their preferences and buying habits depending on what they see at these trials. Many of the entries in these trials are newly discovered cultivars that have promise in the bedding plant market. Few native pl ants get this same kind of publicity, though there are some that do capture the publicÂ’s attenti on. Species of Gaillardia (Foug.), many of which native to the US, have been cr ossed and cultivated, producing an array of cultivars. Several of these cu ltivars and species have been included in the trials at the University of Georgia for at least the last 3 years. The Gaillardia trialed there have

PAGE 57

45 received high ratings, most averaging above 4 on a scale of 1-5 (UGA, 2005). In the 2003 trial, two cultivars, ‘Torch Flame’ and ‘T orch Yellow’ were chosen to be among the “UGA Best of the Best” (UGA, 2005). Gaillardia cultivars have also been in trials at Colorado State University, North Carolina St ate University, Auburn University, Penn State University, and even in Canada at th e University of Guelph, where ‘Arizona Sun’ was one of the 2004 Public’s Picks (Univers ity of Guelph, 2005). ‘Arizona Sun’ was also a winner of the 2005 All-America Selectio ns, which conducts pl ant trials throughout North America (All-America, 2005). At the 2003 University of Florida trials, Gaillardia plants, of both native and cultivated origins were triale d, and the native plants were among the best entries in the trial (Schoellhorn, 2004). Their impressive pe rformance prompted interest in further evaluations of both native a nd cultivated varieties of Gaillardia . In the following study, several native and cultivated Gaillardia varieties were trialed in the 2004 Spring Trials at the University of Florida in Gainesville (USDA Hardiness Zone 8b). There are several reasons for conducting trials. One reason is to test plants in a certa in climate or time of year. Different cultivars of the same species may bloom at different times of year and have longer or shorter seasons of flowering (Kelly and Harbaugh, 2002). It is important to know these differences, especially in mark eting and production. Plants must be made available to consumers at the best time of y ear for planting, and this date will vary across climates. Performance of one cultivar can differ based on environmental elements such as soil, temperature, rainfall, day length and a number of other factors. Growers want to supply their customers with plants that will do well in their area, which is information they can obtain from local tria l gardens (Schoellhorn, 2005).

PAGE 58

46 Another reason for having plant trials is to showcase new products. Growers can view new plant performance at local trials and base future crops on what they like in the trials. They are then able to provide the ne west and best of what is available to their customers (Schoellhorn, 2005). Trials also al low consumers to see plant performance in the landscape, giving a better idea of how they would look once planted at home. Trials can instigate further research on cult ivars. Investigations such as looking at why certain cultivars of the sa me species perform so different ly or deciding which traits should be bred into a new cultivar may begin af ter seeing cultivars together in a trial. The outstanding showing of blanke t flower in trials at the Un iversity of Florida prompted the studies presented in this thesis. It was a pparent that certain cultivars or native species of blanket flower could be great garden perf ormers, and further res earch of this plant could expand our knowledge base about it and increase it s marketability. Many Gaillardia cultivars have been bred from the parentage of G. pulchella and G. aristata . The resulting cross is named G . x grandiflora (Floridata, 2003). This hybrid has some cold-hardiness inherited from G. aristata and some heat and humidity tolerance inherited from G. pulchella (Schoellhorn, 2004). Other cultivars have been selected from various Gaillardia species, generally from G. aristata or G. pulchella . As a result, at least 32 cultivars of Gaillardia can now be attained from a number of seed companies, propagators and growers. The cultivars differ in floral attributes, flowering time, and vegetative characterist ics. They also differ in landscape performance. Most of the cultivars availa ble today are propagated from seed. There are benefits to both seedand vegetativ e-propagated varieties of Gaillardia . As vegetative cuttings

PAGE 59

47 come from essentially one plant, gene s are homologous, resulting in a uniform crop (Thomas, 2002). Plants grown from seed, on the other hand, generally lack uniform morphological characteristics due to genetic variation. Abstract Twenty-three Gaillardia spp. cultivars and ecotypes were evaluated for 12 weeks in a trial garden in north central Florida. Plants were evaluated bi-weekly based on vigor, uniformity, flowering and landscap e impact. ‘Torch Red Ember’ received the highest ratings for uniformity. ‘A rizona Sun,’ ‘Double Lorenziana,’ and ‘Lollipop Gold’ received the highest ratings for flowering, and ‘Torch Red Ember’ and the St. Lucie County ecotype received the highest ratings for landscape impact. Materials and Methods Plant Material and Site Conditions Four vegetatively propagated Gaillardia cultivars, 13 seed-produced Gaillardia cultivars, and 6 naturally-occurring Gaillardia accessions were obtained from various sources (Table 4-1). The seeds were sown atop 72-cell trays containing Fafard #2 media (Fafard Inc., Apopka, FL) and lightly covered (1 -2 mm) with Fafard #2. Trays were kept under intermittent mist until germination occurr ed, at which time trays were transferred to a greenhouse where they were grown until time of transplant. After about 14 days, plugs were transplanted into prepared tria l beds, along with the vegetatively propagated plants. The beds were prepared by tilling the native soil, incorporating mushroom compost, and covering with 6.6 cm of organic mulch. Within a single row, nine of each

PAGE 60

48 Gaillardia selection were evenly spaced in a pl ot 96 cm wide by 112 cm long. Drip tape delivered water and liquid fertilizer as need ed throughout the durati on of the trial. Average daily temperature throughout the study was 25.9 C, with a minimum temperature of 18 C and a maximum of 36 C. Average weekly rainfall was 4.07 cm (1.6 inches) during the study. Average daily solar radiation was 222 watts/m2. Evaluations Six evaluations were conducted bi-weekly from 9 June to 12 August, 2004. Vigor, uniformity, flowering and landscape impact ratin gs were based on the visual average of all nine plants in each plot. Vigor ratings were based on a scale of 0 to 3, where 0=dead plants, 1=low vigor, 2=medium vigor, and 3=high vigor. Vigor is an indication of how well plants are growing. High vigor plants had new leaf emergence, branching, and were producing flowers. A plant with medium vigor was not producing a flush of new leaves, but was maintaining the current amount of vegetation. A plant with low vigor was not producing new leaves or increasing stem length. These plan ts ultimately died because of the lack of growth maintenance. Uniformity was rated on a scale of 1 to 3, where 1=low uniformity, 2=medium uniformity, and 3=high uniformity. Uniformity ratings encompassed size, vigor, health, and flowering of plants. A one rating indica ted greater than 40% deviation of one or more of these parameters, a two rating i ndicated 20-40% deviati on, and a three rating indicated less than 40% deviation within a plot. Flowering ratings were based on a scale of 0 to 2, where 0=no flowers, 1=less than 20% of the plant was covered by fully open flow ers, and 2=20% or more of the plant was covered in flowers.

PAGE 61

49 Landscape impact ratings were based on a scale of 1 to 3, where 1=not pleasing, 2=somewhat pleasing, and 3=very pleasing. A rating of one was assigned if plants were very small, not in flower, diseased, or dying. This rating indicated that plants lacked a positive impact on the aesthetics of the landscape. A rating of two was assigned to plants with a pleasing, but not outstanding appear ance. These plants may have had some flowers, been of small or medium size, or ha d slight, if any, insect or disease problems. This rating indicated that plants had a sligh tly positive impact on the landscape. A rating of three was assigned to plants that were in full flower and had abundant healthy vegetation. Results and Discussion Uniformity ‘Torch Red Ember’ had the highest averag e uniformity rating (3.0) for all biweekly evaluations and ‘Burgundy’ had the lowe st average uniformity rating (1.7) (Table 4-2). On average, uniformity ratings of seed-propagated Gaillardia were much lower than that of vegetatively propagated Gaillardia . Flowering ‘Arizona Sun,’ ‘Double Lorenziana,’ and Lollipop Gold’ had the highest average flowering (2.0). ‘Torchlight,’ ‘Burgundy,’ and ‘Monarch’ all received average flowering ratings less than one. Landscape Impact In the landscape impact category, ‘Torch Red Ember’ and plants from the St. Lucie County source both had a 2.8 average, wh ich was the highest average for all Gaillardia types.

PAGE 62

50 Weekly landscape impact ratings are s hown in Figure 4-1, which allowed us to categorize trial entries by when peak occurred. Plants were separated into three groups based on the time of their peak performance (T able 4-3). Peak performance was the time when plants rated an average of above 2 in the landscape impact category over a period of time. Averages of landscape performa nce were calculated for weeks 5-9 and weeks 11-15 for each Gaillardia selection. Selections which received average ratings above 2.0 for weeks 5-9 were considered early perfor mers (Table 4-3). Those which received average ratings above 2.0 for weeks 11-15 were considered late performers. If both averages were greater than 2.0, the selection was considered a long season performer. ‘Torchlight’ and ‘Burgundy’ did not receive av erage ratings above 2.0 for either period, so could not be designated as long, early or late season performers. These cultivars may not have had time to reach their peak within the time of the study, so a longer study may be required to determine their peak seasons. Conclusions Although vegetatively propagated Gaillardia were more uniform than seed propagated Gaillardia , there were no general trends among species with regards to overall performance. A longer study in va rying climates would have revealed more conclusive data on plant performance. Cultivars of G. aristata and G. x grandiflora , for example, have greater cold tolerance than those of G. pulchella (Schoellhorn, 2004), and subsequently may have had higher ratings fo r a longer period if grown during cooler conditions. The best choice of Gaillardia for a landscape ultimately depends on the desired outcome. If small, neat plants are needed, the best choice based on this study may be one of compact varieties such as ‘Goblin,’ ‘Fanfare’ or Bijou.’ These may be more

PAGE 63

51 appropriate for formal gardens and front bor ders. The Florida native ecotypes and most of the cultivated varieties of G. pulchella have a spreading habit, becoming large and filling in space, which may be appropriate for wildflower meadow plantings. However, uniformity, flowering, and la ndscape impact ratings among G. pulchella cultivars and ecotypes varied widely. Due to the di fferences among the native blanket flower ecotypes, additional research is warranted to observe regional variation among ecotypes.

PAGE 64

52Table 4-1. List of cultivar or ecotype name, source, species name, propagati on method, flower descrip tion and plant descriptio n of Gaillardia trialed in north central Florida. Name Source Species Propagatio n Flower description Habit ‘Arizona Sun’ Benary Seed (Sycamore, IL) G. aristata Seed Single, red with yellow tipsCompact ‘Bijou’ Proven Winners (Sycamore, IL) G. aristata Vegetative Single, red with yellow tipsCompact ‘Goblin’ Thompson & Morgan (T&M) Seed (Jackson, NJ) G. aristata Seed Single, red with yellow tipsSemi-compact ‘Indian Yellow’ T&M Seed (Jackson, NJ) G. aristata Seed Single, large yellow Upright Leon County, FL Jeff Norcini (Quincy, FL) G. aristata Seed Single, red with yellow tipsSpreading ‘Sundance’ T&M Seed (Jackson, NJ) G. aristata Seed Double, red with yellow tip s Spreading ‘Torchlight’ Benary Seed (Sycamore, IL) G. aristata Seed Single, red with yellow tipsCompact Okaloosa Co., FL Jeff Norcini (Quincy, FL) G. pulchella Seed Single, red with yellow tipsSpreading ‘Double Lorenziana ’ Stokes Seed (Buffalo, NY) G. pulchella Seed Double, many colors Spreading St. Lucie Co., FL Sandy Wilson (Ft. Pierce, FL) G. pulchella Seed Single, red with yellow tipsSpreading ‘Lollipop Gold’ Sahin Seed (The Netherlands) G. pulchella Seed Double, yellow Spreading ‘Red Plume’ T&M Seed (Jackson, NJ) G. pulchella Seed Double, dark red Spreading TX (Farm-raised) DR Bates (Loxahatchee, FL) G. pulchella Seed Single, red with yellow tipsSpreading TX (Wild-grown) DR Bates (Loxahatchee, FL) G. pulchella Seed Single, red with yellow tipsSpreading ‘Torch Red Ember’ Ball FloraPlant (W Chicago, IL) G. pulchella Vegetative Double, bright red Spreading Volusia Co., FL The Natives, Inc. (Davenport, FL) G. pulchella Seed Single, red with yellow, orange or white tips Spreading ‘Yellow Flame’ R.H. Shumway (Randolph, WI) G. pulchella Seed Single, large yellow Upright ‘Burgundy’ T&M Seed (Jackson, NJ) G. x grandiflora Seed Single, dark red Semi-compact ‘Dazzler’ Proven Winners (Sycamore, IL) G. x grandiflora Vegetative Single, red with yellow tipsSemi-compact ‘Fanfare’ PlantHaven, Inc. (Santa Barbara, CA) G. x grandiflora Vegetative Single, red tubular ray florets with yellow tips Compact ‘Gold Goblin’ T&M Seed (Jackson, NJ) G. x grandiflora Seed Single, large yellow Upright ‘Grandiflora Mix’ T&M Seed (Jackson, NJ) G. x grandiflora Seed Single, all red or red with yellow tips Spreading ‘Monarch’ Stokes Seed (Buffalo, NY) G. x grandiflora Seed Single, red with yellow tipsSemi-compact

PAGE 65

53 Table 4-2. Frequency table of Gaillardia trial entries with th e number of times each received a specific rating in the unif ormity, flowering, and landscape impact categories for six bi-weekly evaluations. For uniformity, 1=low, 2=medium, and 3=high uniformity. For flowering, 0= no flowers present, 1=1-20% of the plants were covered in flowers, and 2=greater than 20% of plants were covered in flowers. For landscape impact, 1=negative aesthetic impact, 2=slightly positive aesthetic impact, and 3=highly positive aesthetic impact on the landscape. One rating for each category was given to each plot which contained nine replicate plants. Uniformity Flowering Landscape Impact Name Overallz 1 2 3 Overall0 1 2 Overall 1 2 3 ‘Arizona Sun’ 2.7 0 2 4 2.0 0 0 6 2.5 0 3 3 ‘Bijou’ 2.7 0 2 4 1.2 2 1 3 2.3 1 2 3 ‘Goblin’ 1.8 0 1 5 1.5 1 1 4 2.5 0 3 3 ‘Indian Yellow’ 2.5 0 3 3 1.5 1 1 4 2.5 0 3 3 Leon County, FL 2.2 1 3 2 1.5 0 3 3 2.7 0 2 4 ‘Sundance’ 2.8 0 1 5 1.8 0 1 5 2.2 2 1 3 ‘Torchlight’ 1.8 1 5 0 0.0 6 0 0 1.3 4 2 0 Okaloosa Co., FL 2.7 0 2 4 1.5 0 3 3 2.5 0 3 3 ‘Double Lorenziana’ 2.0 0 6 0 2.0 0 0 6 2.5 1 1 4 St. Lucie Co., FL 2.8 0 1 5 1.7 0 2 4 2.8 0 1 5 ‘Lollipop Gold’ 2.7 0 2 4 2.0 0 0 6 1.8 3 1 2 ‘Red Plume’ 2.3 0 4 2 1.8 0 1 5 2.2 2 1 3 TX (Farm-Raised) 2.5 0 3 3 1.0 2 2 2 2.3 1 2 3 Texas Wild-Grown 2.0 0 6 0 1.3 1 2 3 1.7 1 3 1 ‘Torch Red Ember’ 3.0 0 0 3 1.8 0 1 5 2.8 0 1 5 Volusia Co., FL 1.8 2 3 1 1.5 0 3 3 2.0 1 4 1 ‘Yellow Flame’ 2.2 1 3 2 1.5 1 1 4 2.0 0 2 4 ‘Burgundy’ 1.7 2 4 0 0.2 5 1 0 1.3 4 2 0 ‘Dazzler’ 2.5 1 1 4 1.7 0 2 4 2.7 0 2 4 ‘Fanfare’ 2.7 0 2 4 1.8 0 1 5 2.7 0 2 4 ‘Gold Goblin’ 2.3 1 2 3 1.5 1 1 4 2.5 1 1 4 ‘Grandiflora Mix’ 2.5 0 3 3 1.0 2 2 2 2.2 1 3 2 ‘Monarch’ 2.5 0 3 3 0.5 4 1 1 2.2 1 3 2 z Overall figure is an average of all 6 bi-weekly evaluations in that category.

PAGE 66

54 Table 4-3. Gaillardia cultivars and ecotypes based on landscape impact during periods of the landscape trial. “Early perfor mers” received an average rating above 2.0 for the period from week 5 to week 9, “late performers” received an average rating above 2.0 for the period from week 11 to week 15, and “long season performers received an average rating above 2.0 both periods, where 2=slightly positive impact and 3=highly positive impact on landscape aesthetics. ‘Burgundy’ and ‘Torchlight’ received average landscape impact ratings of 2 or 1, so they could not be assigned to any of the aforementioned categories. Early Performers Late Performers Long Season Performers ‘Arizona Sun’ ‘Bijou’ ‘Goblin’ ‘Sundance’ TX (Farm-Raised) ‘Indian Yellow’ ‘Double Lorenziana Mix’ ‘Gold Goblin’ Leon County, FL ‘Lollipop Gold’ ‘Grandiflora Mix’ Okaloosa County, FL ‘Red Plume’ ‘Monarch’ St. Lucie County, FL Texas Wild-Grown ‘Torch Red Ember’ Volusia County, FL ‘Yellow Flame’ ‘Dazzler’ ‘Fanfare’

PAGE 67

55 Figure 4-1. Landscape impact ratings of Gaillardia cultivars and ecotypes evaluated in the study. Ratings were based on a scale of 13, where 1=plants had a negative impact, 2=a slightly pos itive impact and 3=a highly positive impact on landscape aesthetics. Evaluations began 6 June 2004, 5 weeks after planting, and ended 18 Aug 2004. 0 1 2 3 'Ari zon a Su n' 'Bij o u' ' G o bl i n ' ' I n di an Yellow' L eon Co un t y, FL 'Sundance' ' T or c hl ight' O ka l oo s a County, F L 'D o ubl e Lore z ian a Mix ' St. L uci e C ou nt y , F L ' L ol li po p G o l d' 'R e d Plu m e' T exa s F ar m-r a ise d Texas Wild 'T orch R ed E mber' Vol u s ia C ou nt y , F L ' Y ellow Flame' 'Burgundy' 'Dazzl er' 'FanFare' 'Golden Goblin' ' Gr and i fl o r a Mix' 'M on ar ch S t rain' 0 1 2 3Landscape impact rating . 0 1 2 3Evaluation 1 (week 5) Evaluation 2 (week 7) Evaluation 3 (week 9)

PAGE 68

56 Figure 4-1 continued. 0 1 2 3 'Ariz o na Sun' 'B ij ou ' 'Goblin' ' In di a n Y e ll o w ' Le on County , F L 'Sundan c e' ' To rchlight' Okaloo s a County, F L ' D o ub l e Lo re z ia n a Mi x ' St. Lu c ie Co u nt y , F L 'Lollipo p Gold' 'R e d P lu m e ' Texas Fa rm -rai s e d Te x a s Wil d 'Torch Red Embe r ' Volusia County, F L 'Yellow Flam e ' ' B u rg u nd y ' 'Daz z ler' 'Fa n Fare' ' G o ld e n G o b lin ' ' G ra n d iflo ra Mi x ' ' Mo n a rc h Strai n ' 0 1 2 3Landscape impact rating 0 1 2 3Evaluation 4 (week 11) Evaluation 5 (week 13) Evaluation 6 (week 15)

PAGE 69

57 CHAPTER 5 GROWTH, FLOWERING, AND SURVIVAL OF BLANKET FLOWER ( Gaillardia pulchella FOUG.) BASED ON SEED SOURCE AND GROWING LOCATION Introduction Over the past few years, there has been an emphasis towards using more native plants in landscapes. For some native speci es, the use of plants that are regionally adapted to the planting location can be of par ticular importance. The ecotype concept of environmentally-based genotypic differences wi thin species was firs t introduced in 1922 by Turesson (Turesson, 1922). Since then, several terms and varied definitions have been used to describe distinct groups that have adapted to local co nditions (Quinn, 1978). What makes one ecotype distinct from othe rs is a genetic difference resulting in a morphology and physiology adapted to a certai n region (Daehler et al., 1999). Clary (1975) showed that adaptations resulted in varied timing of phonological development and growth rate among ecotypes. The envir onmental factors to which an ecotype has adapted may include the soil type, elevation, and climate within an area of about 321 km (200 ft) (McCully, 2000). Norcini et al. (2001) studied the effects of ecotype on blackeyed susan ( Rudbeckia hirta L.), a wildflower native to the US, and found evidence of regional adaptation to conditions such as low fertility. Heywood (1986) reported that there are two ecotypes of blanket flower ( Gaillardia pulchella Foug. [Asteraceae]), referred to as “races,” among populations in central Texas which were differentiated by the carbonate content of the soil in which they grew. If similar divisions exist among

PAGE 70

58 populations of blanket flower in Florida, physiological differences could result when plants are grown in soils unlike th at to which they have adapted. There were two objectives of this study: (1) to assess possible genetic variation characteristic of blanket fl ower seed sources through visu al observation of phenotypic differences, and (2) to determine how blanke t flower from various sources perform in varying growing locations in Florida. Abstract Blanket flower ( Gaillardia pulchella ) seeds were collected from wild populations in east Texas (ET) and northeast Florid a (NEF), central west Florida (CWF), central east Florida (CEF), and southeast Florida (SEF). Seeds were germinated in plug trays, and finished in 3.8 L pots prior to planting in three locations in Florida (north, north central, and central south). Plant size, vigor, flowering, quality, and survival were evaluated bi-weekly for 22 w eeks. In north Florida, total vigor and flowering were similar among ecotypes, but the quality of the NEF ecotype was significantly higher than the ot her ecotypes. In north centr al Florida, flowering was similar among ecotypes, but the vigor and quality of the CEF ecotype was generally lower than that of the other ecotypes. In cen tral south Florida, vigor, flowering, and quality of NEF, SEF, and ET ecotypes were generally higher than that of the CEF ecotype. Plant survival varied widely by ecotype and planting location, thus emphasizing the value of ecotype selection and use.

PAGE 71

59 Materials and Methods Plant Material Seeds of blanket flower were collected fr om five sites: northeast Florida (NEF) (29.8oN 81.2oW; AHS Heat Zone 9, USDA Hardine ss Zones 9a), central west Florida (CWF) (28.6oN 82.3oW; AHS Heat Zone 10, USDA Hardin ess Zones 9a), central east Florida (CEF) (28.8oN 80.9oW; AHS Heat Zone 9, USDA Ha rdiness Zones 9b), southeast Florida (SEF) (26.9oN 80.1oW; AHS Heat Zone 10, USDA Hardiness Zones 10a), and east Texas (ET) (29.8oN 95.6oW; AHS Heat Zone 9, USDA Hardiness Zones 9a) (Figure 5-1). The collection sites were natural ar eas where seeds had not been intentionally planted. Seeds were sown on the surface of plug tr ays containing Fafard #2 medium (Fafard Inc., Apopka, FL), lightly covered (1-2mm) w ith Fafard #2, and placed under intermittent mist. Once a root system was established, plugs were potted up into 3.8 L (one-gallon) pots using Fafard #2 media. Plants we re produced under greenhouse conditions and watered as needed via drip ir rigation tubes delivering 150 mg·L-1 (ppm) 20-10-20 N-P-K liquid fertilizer (The Scotts Company, Marysville, OH) until they were transplanted the first week of April 2005. Site Conditions The three sites chosen for this study were north, north central, and central south Florida (Figure 5-1). The nor thern site was Quincy (30.5oN, 84.6oW; AHS Heat Zone 9, USDA Hardiness Zone 8b) in Gadsden Count y. The soil was Ruston series, having fineloamy, siliceous, and semiactive properties (NRCS, 1999). The north central site was Gainesville (29.6oN, 82.4oW; AHS Heat Zone 10, USDA Ha rdiness Zone 8b) in Alachua County. The soil was Millhopper series, wh ich is loamy, siliceous, and semiactive

PAGE 72

60 (NRCS, 1999). The central sout h site was Fort Pierce (27.4oN, 80.4oW; AHS Heat Zone 10, USDA Hardiness Zones 9b) in St. Lucie County. The soil was Ankona series, which is sandy, siliceous, and hyperthermic (NRCS, 1999). Soil samples were taken from a composite of soil from several planting holes at each of the three planting sites, and were sent to A&L Southern Agricultural Laboratories Inc. (Pompano Beach, FL) for elemental analys is. Sites were prep ared by tilling the native soil and covering rows with black landscape fabric (Synt hetic Industries Inc., Alto, GA). Daily rainfall, minimum and maximum temperatures, and solar radiation were recorded at each site by Florida Automa ted Weather Network (FAWN) monitoring stations. Nine replicate plants of each ecotype were chosen at random from the median 80% of the produced population, and planted at each site and watered by dr ip (north and north central Florida) or canal irri gation (central south Florida) until established (about two weeks). No irrigation was administered after establishment, and no fertilizers or pesticides were applied at anytime after transplant. Growth index for each plant was recorded at four interval s throughout the study. Height was measured from the soil level to the highest vegetativ e point. One width measurement was taken at the widest vege tative point of the pl ant passing through the center; the second width was measured perpen dicular to the first. The growth index value was made using the equation (( W1+W2)/2+H)/2, where W1=width one, W2=perpendicular width, and H=plant height. Initial measurements were taken when plants were transplanted at each site dur ing the first week in April (week 0). Measurements were also taken 10 and 17 week s after transplanting, when most plants

PAGE 73

61 were at a first and second peak in quality and flowering. Final m easurements were taken on the last evaluation day (during week 22). At the time when most plants at all sites were at or near thei r first peak (week 10), one plant was harvested from each treatment in every block. The stem was severed at the soil level and the aboveground plant materi al was dried at 70C for one week. Visual evaluations based on the vigor, fl owering, and quality of each plant were recorded bi-weekly for the duration of the st udy (22 weeks). Vigor ratings for this study referred to the growth rate in plants and we re based on a scale from one to three, where 1= low vigor, 2= medium vigor, and 3= high vigor. Plants with high vigor (3) were characterized by active growth of new leaves and branches. Plants with medium vigor (2) were characterized by maintenance growth where new leaves are produced, but only at the rate that olde r leaves are dying. Plants with low vigor were not growing, with leaves dying faster than new ones were be ing produced. The flower rating was based on the amount of live flowers on each plant. To be counted as a flower, the flowering body had to have fully extended ray florets. Ra tings ranged from zero to three, where 0= no flowers present, 1= one to th ree fully open flowers, 2= more than three flowers, but no more than one-third of the plant was covered in flowers, and 3= grea ter than one-third of the plant was covered in open flowers. Th e quality rating described the overall look, attractiveness, and health of the plant. This included the fullness of vegetation and flower coverage, and was based on a scale of 1 to 3, where 1=low quality, 2=medium quality, and 3=high quality. Once a plant died, it was no longer included in evaluations. A high rating (3) described a plant that had flowers, a healthy amount of vegetation, and was at or near its peak. If the plant had fewer flow ers, did not look full, or had disease or pest

PAGE 74

62 problems, the plant received a medium rating (2 ). A low rating (1) was assigned to plants that may have been small or unattractive, a nd had few or no flowers. These plants would be unacceptable when in a cultivated landscape. Experimental Design The experimental design was a split plot. The three planting sites were the blocks, and each of these contained three main plots. Subplots of the five treatments (ecotypes) were randomized within each main plot. A proc GLM SAS (version 8.02 Cary, NC) program using Waller-Duncan Mean Separator was applied to data for individual sites. This allowed for missing data when plants were absent due to s ub-sampling harvest or death. For identifying interactions among sites, a repeated measures analysis mixe d procedure was run in SAS. For all other mean separation, Tukey-Kramer was applied. For identifying interactions among sites, a repeated measures analysis mixed procedure wa s run in SAS. Survival data was arc-sine transformed to identify differences within sites and among ecotypes. Results and Discussion Site Conditions Initial soil analysis of each location indi cated that north Florida had higher K, Mg, Ca, and pH than north central or central south locations (Table 5-1). Heywood (1986) found ecotypic differences due to soil conten ts among Texas ecotypes of blanket flower. The ecotypes used in this study could also have experienced varying reactions to the soil, which may have contributed to the varied pe rformance of ecotypes among planting sites. Gordon and Rice (1998) also conc luded that local soil condi tions were a major factor when choosing an ecotype for plantings. No rth Florida had high Mg, Ca, and pH relative to the other planting sites, which may indicate the presence of dolomitic lime

PAGE 75

63 (CaMg(CO3)2) (J.G. Norcini, personal communica tion). Ecotypes in north Florida generally had greater survival rates and growth indexes than in the other sites, which could correlate with the difference in soil if the ecotypes had a proclivity for better growth under such conditions. North, north central, and central sout h Florida received 230, 214, and 219 w/m2 (watts per square meter) average daily solar radiation during the experiment, respectively (Figure 5-2A). While the mean monthly maximum temperatures were similar among sites, the mean monthly minimum temperatures were substantially greater in central south Florida than in the other locations (Figure 5-2B). Average rainfall was substantially greater in central south Flor ida throughout the first twelve weeks of the study (AprilJune) compared to the other sites (Figur e 5-2C). Rainfall in north Florida was significantly greater th an the other sites from week 13 through the end of the study. Growth In north Florida, ecotype CEF was the smalle st and had the lowest dry weight at the first peak (week 10) (Table 5-2), but at the second peak (week 17) a nd at the end of the study (week 22), ecotypes were similar in size (Tab le 5-3). In north central Florida, there were no differences among ecotype s in size or dry weight at first peak. At the second peak, the NEF ecotype was larger than the othe r ecotypes, but similar in size to ET. By the end of the study, the grow th index was similar among NEF, SEF, and ET ecotypes. In central south Florida at fi rst peak, the ET ecotype was larger in size than the CWF, CEF, and SEF ecotypes, though dry weight were not significantly different among ecotypes. At the second measurement, eco types from CEF and ET were significantly larger than the CWF ecotype; by the end of the study, growth index was similar among

PAGE 76

64 surviving ecotypes. The NEF, CWF, a nd SEF ecotypes had significantly lower dry weight at first peak in central south Florid a as compared to north Florida (Table 5-2). Vigor In north Florida, there were no signifi cant differences among the ecotypes for vigor in any single week, nor when data from each evaluation were compiled (Figure 5-3, Table 5-4). For north central Florida, the CEF ecotype had signifi cantly less vigor than the other ecotypes when data were compile d. During weeks 18-22, a noticeable decline in vigor was observed for ecotypes ET, CEF, and SEF in the north and north central Florida. In central south Fl orida, all ecotypes experiences a decline in vigor between weeks 12 and 14, with the exception of the WC F ecotype, all of which died by week 18. When all data were compiled among weeks, the CWF ecotype had the highest average vigor, though all CWF plants died before th e end of the study, t hus the average vigor included only evaluations for which plants were alive. This could have caused artificially high average vigor for CWF. There was a si gnificant interaction among site, treatment, and time (Pr>F=0.0003) for vigor. Flowering The ET ecotype had the highest floweri ng ratings during the first and second evaluations for central south Florida, as well as for the second and third evaluations in north and north central Florida (Figure 5-4). This indicates that plants from the ET seed source are earlier flowerers than the others . Flower ratings among ecotypes in north Florida were similar for the remainder of th e study. Subsequently, total flowering was not significantly different among ecotypes (Table 5-4). In central south Florida, the CWF and CEF ecotypes had the lowest overall fl owering compared to all ecotypes over the

PAGE 77

65 course of the study. There was a significant interaction among site, treatment, and time (Pr>F=0.0002) for flowering. Quality The NEF ecotype had the highest and th e CEF ecotype had the lowest overall quality rating in north Florida (Figure 5-5). In north central and cen tral south Florida, CEF had the lowest overall quality while th e other ecotypes were not significantly different in quality ratings (Table 5-4). There was not a signif icant interaction among site, treatment, and time for quality. Survival In north Florida, all plants survived th e study except for those of the CEF ecotype, having 83% survival (Table 5-5). The CEF ecot ype also had the lowest survival rate in north central Florida (66.7%), though there was no significant difference among survival for ecotypes in north central Florida (Table 5-5). The CEF ecotype had the second lowest in central south Florida (33.3%), with CWF ha ving the lowest surviv al (0%). Only the SEF ecotype had 100% survival in central sout h Florida. It is possible that the high survival rate of this ecotype when grown in central south Florida is due to its genetic adaptation to the climate and soils of the area. This is consistent with results of Marois and Norcini (2003), who found that north Florid a black-eyed susan ecotypes had a greater survival rate when planted in north Florida than ecotypes from central Florida and Texas. It is interesting to note that the CEF ecot ype had the lowest (north and north central Florida) or second lowest (centr al south Florida) survival rate for all three planting sites. This could suggest that there is a genetic difference in the life cycle of plants from this seed source as compared to those from othe r areas. A varied life cycle could mean that more energy went into production of seed ra ther than maintenance of growth. This

PAGE 78

66 occurs in ecotypes of annual bluegrass ( Poa annua L.), in which the annual ecotype produced more seed than the other ecotypes evaluated and was less vigorous vegetatively (Frank, 2000). Further investiga tion into seed number and quality could help to confirm or deny that this occurs in blanket flower ecotypes. The only significant difference in surviv al within an ecotype was for the CWF ecotype (Table 5-5). The other ecotypes perf ormed similarly regardle ss of planting site. These results indicate that planting site does not affect survival for most ecotypes. Conclusions As there were minimal differences in te mperature and solar radiation among the sites during the time of this study, and less than a 70m difference in altitude, soil and rainfall may have been what determined ecotype performance among sites. In central south Florida, the ground was flooded several days from mid-June through July. This coincides with the sudden decrease in vigor , flower, and quality ratings. Most ecotypes (the exception being the CWF ecotype) recovere d well after this time and were back to previous flowering and quality performa nce by the end of the study, although, these ratings were mostly in the unacceptable range of below two. Ecotypes of paspalum grass ( Paspalum L. sp.) have shown variance in ability to tolerate stress from such occurrences as drought and flood (Duncan, 2001). Similar ab ilities to tolerate e nvironmental stresses may occur in blanket flower ecot ypes other than the CWF ecotype. North Florida received more rain in A ugust than the other sites, but unlike the plants in central south Florid a, after experienci ng high rainfall, plants continued to do well with consistent ratings. This could be due to a lower water ta ble in north Florida and/or soil with better draina ge. As indicated by these fi ndings, blanket flower plants grow best in well-drained soils regardless of ecotype.

PAGE 79

67 Since there were significant interactions among site a nd treatment for vigor and flowering, it is important to choose the be st ecotype for the planting location. For restoration plantings, however, it may be appr opriate to use local sources or a mix of local and non-local, depending on the desire fo r genetic variability. Lesica and Allendorf (1999) recommend using local ecotypes for sligh tly disturbed sights, and a mix of local and non-local sources for very disturbed site s to introduce more ge netic variability for speedier establishment and adaptability. This study used transplants of blanket flow er, thus results apply only to the use of plants produces outside of th e final planting site. Results may vary due to possible differences in germination and establishment if ecotypes were to have been directly seeded at the planting sites.

PAGE 80

68 Table 5-1. Analysis of soil from the three plan ting locations in Florid a used in this study. Planting site Organic matter (%) Est. N release (kg/ha) P (mg·L-1) K (mg·L-1) Mg(mg·L-1) Ca (mg·L-1) pH North 3.9 137 81 102 131 1040 6.1 North central 4.0 139 119 60 98 610 5.5 Central south 3.7 132 9 18 42 330 5.4 Table 5-2. Dry weight (in gram s) of five blanket flower ( Gaillardia pulchella ) ecotypes planted in north, north central, and central south Florida. Ecotype North North central Central south NEFz 346.8y Axawv 190.3 Aab 121.2 Ab CWF 343.5 Aa 237.3 Aab 122.5 Ab CEF 122.3 Ba 238.4 Aa 98.4 Aa SEF 339.4 Aa 273.2 Aab 97.8 Ab ET 306.1 Aa 233.6 Aa 134.3 Aa p values Ecotype Site Ecotype * site 0.0022 0.0188 0.0006 z NEF=northeast Florida, CWF=central west Florida, CEF=central east Florida, SEF=southeast Florida, and ET=east Texas. y Values taken from averages of replications within each block. x Uppercase letters signify difference w ithin columns (main effect of site). w Lowercase letters signify difference w ithin rows (sub effect of ecotype). v Mean separation by Tukey-Kramer (p=0.05).

PAGE 81

69 Table 5-3. Growth index of five blanket flower ( Gaillardia pulchella ) ecotypes planted in north, north central, a nd central south Florida. GI Tiz GI T1 GI T2 GI T3 Ecotype NEFy CWF CEF SEF ET 24.9 abcx 25.5 ab 21.7 c 23.2 bc 27.1 a 62.7 a 60.3 a 53.2 b 58.3 ab 62.8 a 79.3 a 63.0 b 66.9 ab 64.6 b 79.3 a 80.4 a dead 68.3 b 68.3 b 79.7 a Site North North central Central south 22.4 b 23.8 b 27.3 a 67.5 a 65.0 a 45.9 b 91.7 a 73.4 b 70.2 b 84.3 a 81.0 a non-estimable p values Ecotype Site Ecotype * site 0.0021 0.0122 NS <0.0001 0.0008 NS 0.0008 <0.0001 NS 0.0044 <0.0001 NS z GI=Growth index, calculated as: (height+(width 1+width 2)/2 )/2; Ti=date of planting at site, T1=date of average first peak flower ing for all plants, T2=GI on date of second average peak flowering, and T3=GI at date of final evaluation. y NEF=northeast Florida, CWF=central west Florida, CEF=central east Florida, SEF=southeast Florida, and ET=east Texas. x Mean separation by Tukey-Kramer (p=0.05).

PAGE 82

70 Table 5-4. Total vigor, fl owering, and quality ratings compiled from bi-weekly evaluations of five blanket flower ( Gaillardia pulchella ) ecotypes grown in the north, north central, a nd central south Florida. Planting site Ecotypez Vigory Floweringx Qualityw North NEF CWF CEF SEF ET 2.75 av 2.72 a 2.59 a 2.83 a 2.70 a 1.90 a 1.83 a 1.76 a 2.10 a 2.06 a 2.22 a 2.00 bc 1.92 c 2.06 b 2.09 b p values Ecotype 0.1211 0.3634 0.0003 North central NEF CWF CEF SEF ET 2.80 a 2.68 a 2.45 b 2.64 a 2.66 a 1.86 a 1.89 a 1.60 a 1.92 a 1.85 a 2.38 a 2.21 ab 2.06 b 2.27 a 2.24 ab p values Ecotype 0.0032 0.3142 0.0140 Central south NEF CWF CEF SEF ET 1.90 b 2.17 a 1.85 b 1.91 b 1.81 b 1.69 ab 1.32 c 1.48 bc 1.80 ab 1.92 a 2.04 ab 2.09 a 1.94 b 2.08 a 1.96 ab p values Ecotype 0.0007 <0.0001 <0.0001 z NEF=northeast Florida, CWF=central west Florida, CEF=central east Florida, SEF=southeast Florida, and ET=east Texas. y Vigor was based on a scale from 1 to 3 where 1=low vigor, 2=medium vigor, and 3=high vigor. x Flowering was based on a scale from 0 to 3 where 0=no fully open flowers present, 1=one to three fully open flowers present, 2= more than three flowers but less than onethird of the plant was covered in fully open fl owers, and 3=one-third or more of the plant was covered in fully open flowers. w Quality was based on a scale from 1 to 3 where 1=low quality, 2=medium quality, and 3=high quality. v Means within each site with different lette rs are significantly different according to Waller-Duncan mean separation (p=0.05).

PAGE 83

71 Table 5-5. Percent survival of su rvival of five blanket flower ( Gaillardia pulchella ) ecotypes grown in the north, north ce ntral, and central south Florida. Ecotype North North central Central south NEFz 100% Ayaxw 100% Aa 83% ABa CWF 100% Aa 100% Aa 0% Cb CEF 83% Ba 67% Aa 33% BCa SEF 100% Aa 83% Aa 100% Aa ET 100% Aa 83% Aa 83% ABa p values Ecotype Site Ecotype * site 0.0044 NS 0.0043 z NEF=northeast Florida, CWF=central west Florida, CEF=central east Florida, SEF=southeast Florida, and ET=east Texas. y Uppercase letters signify difference w ithin columns (main effect of site). x Lowercase letters signify difference w ithin rows (sub effect of ecotype). w Means within each site with different lette rs are significantly different according to Tukey-Kramer mean separation (p=0.05). Mean separation was done on arc-sine transformed data. Values shown are original percent survival. Figure 5-1. Map of blanket flower ( Gaillardia pulchella ) ecotype planting locations and seed sources in Florida and Texas (Col, 2005). Planting location Ecotype source NEF CEF SEF WCF ET

PAGE 84

72 0 50 100 150 200 250 300Solar Radiation (w/m^2) North North central Central sout h 0 5 10 15 20 25 30 35Temperature (C) 0 5 10 15 20 25 30 35 AprilMayJuneJulyAugust MonthRainfall (cm) Figure 5-2. Monthly average total daily so lar radiation (A), average maximum and minimum daily temperatures (B), and to tal of rainfall (C) from first planting date (5 Apr. 2005) to last evaluation da te (9 Sept. 2005) at three planting sites (north, north central, and central so uth Florida) used in this study. B A C Max Min Rainfall (cm) Solar radiation (w/m2) Temperature (C)

PAGE 85

73 0 1 2 3 NEF CWF CEF SEF ET 0 1 2 3Vigor ratin g 0 1 2 3 246810121416182022 Figure 5-3. Weekly vigor ratings of five blanket flower ( Gaillardia pulchella ) ecotypes (NEF=northeast Florida, CWF=central west Florida, CEF=central east Florida, SEF=southeast Florida, ET=east Texas) planted in three locations in Florida [north, north central, and central south]. Ratings were ba sed on a scale of 1 to 3 where 1=low vigor, 2=medium vigor, and 3=high vigor. Ver tical bars represent standard error. Time (weeks after planting) North North central Central south

PAGE 86

74 -1 0 1 2 3 NEF CWF CEF SEF E T -1 0 1 2 3Flowering rating -1 0 1 2 3 246810121416182022 Figure 5-4. Weekly flower rati ngs of five blanket flower ( Gaillardia pulchella ) ecotypes (NEF=northeast Florida, CWF=central west Florida, CEF=central east Florida, SEF=southeast Florida, ET=east Texas) planted in three locations in Florida [north, north central, and centr al south]. Ratings were based on a scale of 1 to 3 where 0=no flowers present, 1=one to three flowers present, 2=more than three flowers but less th an one-third of the plant covered in flowers, and 3=one-third or more of th e plant covered in flowers. Vertical bars represent standard error. North central North Time (weeks after planting) Central south

PAGE 87

75 0 1 2 3 NEF CWF CEF SEF ET 0 1 2 3Quality rating 0 1 2 3 246810121416182022 Figure 5-5. Weekly quality ratin gs of five blanket flower ( Gaillardia pulchella ) ecotypes (NEF=northeast Florida, CWF=central west Florida, CEF=central east Florida, SEF=southeast Florida, ET=east Texas) planted in three locations in Florida [north, north central, and centr al south]. Ratings were based on a scale of 1 to 3 where 1=low quality, 2= medium quality, and 3=high quality. Vertical bars represent standard error. Time (weeks after planting) North North central Central south

PAGE 88

76 CHAPTER 6 CONCLUSIONS Environmental and economical implicatio ns of peat usage have led to the development of new substrate substitutes worldwide, many of which contain waste byproducts. Horticultural grade composts of sufficient quantity and quality are now being produced by private enterprises and public municipalities and marketed at economical values. Our study evaluated blanket flower ( Gaillardia pulchella Foug.) grown in peat or compost-based media, and found compost to be a viable alternative to peat use in containerized nursery media, while maintaining sufficient plant growth, development, and ultimately, plant quality. Rapid growth of blanket flower in contai ners can result in a leggy appearance and become problematic for handling and shippi ng. Our study evaluated the effect of two plant growth regulators (Flo rel and Sumagic) on the growth and development of Gaillardia pulchella ‘Torch’ and a native north Florida ecotype. While neither growth regulator affected plant size of the north Florida ecotype, application of Florel or Sumagic (drench only) significantly reduced plant size of ‘Torch ’. Thus, use of Florel or Sumagic may help extend the production time s of ‘Torch’ and facilitate shipping. Plant trials are an important part of nurse ry trade, as they allow both private and public sectors to view new and interesting crops and monitor their performance in a specific growing region. Ou r study evaluated twenty-three Gaillardia spp. cultivars and ecotypes for 12 weeks in a trial garden in north central Florida. Uniformity, flowering, and landscape impact ratings varied widely among G. pulchella cultivars and ecotypes.

PAGE 89

77 ‘Torch Red Ember’ received the highest ratin gs for uniformity. ‘Arizona Sun,’ ‘Double Lorenziana,’ and ‘Lollipop Gold’ received th e highest ratings for flowering, and ‘Torch Red Ember’ and the St. Lucie County ecotype received the highest ratings for landscape impact. For some native species, the use of plants that are regionally adapted to their planting location can be of particular importance. Our study evaluated five geographically distinct ecotype s planted in north, north centr al, and central south Florida for 22 weeks. In north Florida, total vigor and flowering were similar among ecotypes, but the quality of the northeast ecotype was significantly higher than the other ecotypes. In north central Florida, flowering was sim ilar among ecotypes, but the vigor and quality of the east central ecotype was ge nerally lower than that of th e other ecotypes. In central south Florida, vigor, flower ing, and quality of northeast, southeast and east Texas ecotypes were generally higher th an that of central west and central east ecotypes. Plant survival varied widely by ecotype and pl anting location, thus em phasizing the value of ecotype selection and use.

PAGE 90

78 LIST OF REFERENCES Alexander, R. 2001. Compost utilization in la ndscapes. In: P.J. Stoffella and B.A. Kahn (eds.). Compost utilization in horticultu ral cropping systems. CRC Press LLC, Boca Raton, FL. All-America. 2005. AAS Winners. All-Ameri ca Selections. 4 October 2005. . Andersen, A.S. 1979. Plant growth retardants: Present and future use in food production. In: T.K. Scott (ed.). Plant regulation a nd world agriculture. Plenum Press, New York. Armitage, A.M. 2001. Armitage's manual of annuals, biennials, and half-hardy perennials. Timber Press, Portland, OR. Arteca, R.N. 1996. Plant growth substances: Principles and applications. Chapman and Hall, New York. Ball FloraPlant. 2005. Ball FloraPlant 2005 Pr opagation Guide. Ball Horticultural Company. 2 October 2005. . Barkham, J.P. 1993. For peat's sake: Conserva tion or exploitation? Biodiversity and Conservation. 2:556-566. Barrett, J. 2001. Mechanisms of action, p. 32-47. In: M.L. Gaston (ed.). Tips on regulating growth of floriculture cr ops. O.F.A. Services, Columbus, OH. Barrett, J. 1999. Chemical growth regulator s, p. 94-104. In: C.A. Buck, S.A. Carver, M.L. Gaston, P.S. Konjoian, L.A. Kunkle, and M.F. Wilt (eds.). Tips on growing bedding plants. O.F.A. Services, Columbus, OH. Bragg, N.C. and B.J. Chambers. 1998. Interp retation and advisory applications of compost air-filled porosity (AFP) measurements. ISHS Acta Horticulturae 221: Symposium on Horticultural Substrates and their Anal ysis, GI. Avernaes, Funen, Denmark. p. 35-44. Buckland, P.C. 1993. Peatland archaeology: A conservation resource on the edge of extinction. Biodiversity a nd Conservation. 2:513-527. Chanway, C.P. and F.B. Holl. 1993. Field perf ormance of spruce seedlings inoculated with plant growth prom oting rhizobacteria. Can. J. Microbiology. 39:1084-1088.

PAGE 91

79 Clary, W.P. 1975. Ecotypic adaptation in Sitanion hystrix. Ecology. 56:1407-1415. Col, J. 2005. USA latitude and longitude act ivity. Enchanted Learning. 4 October 2005. . Czembor, E., U. Feuerstein, and G. Zurek. 2001. Preliminary observations on resistance to rust diseases of Kentucky bluegras s ecotypes from Poland. J. of Phytopathol. 149:83-89. Daehler, C.C., C.K. Anttila, D.R. Ayers, D.R. Strong, and J.P. Bailey. 1999. Evolution of a new ecotype of Spartina alterniflora (Poaceae) in San Francisco Bay, California, USA. Amer. J. Bot. 86:543-546. Davidson, H., R. Mecklenburg, and P. C. 1994. Nursery management: Administration and culture. Prentice Hall, Englewood Cliffs, N.J. Deneke, C.F., G.J. Keever, and J.A. McGuir e. 1992. Growth and fl owering of 'Alice du Pont' Mandevilla in response to Sumagic. J. Envion. Hort. 10:36-39. Duncan, R.R. 2001. All seashore paspalums are not created equal. Golf Course Management. Fitzpatrick, G.E. 2001. Compost utilization in ornamental and nursery crop production systems, p. 135-150. In: P.J.S.a.B.A. Kahn (ed.). Compost utilization in horticultural cropping systems. CRC Press LLC, Boca Raton, FL. Fletcher, R.A., C.R. Sopher, and N. N. Vettakkorumakankav. 2000. Regulation of gibberellins is crucia l for plant stress protection. In: A.S. Basra (ed.). Plant growth regulators in agriculture and horticulture: their role and commercial use. Food Products Press, New York. Floridata. 2003. Gaillardia pulchella. Floridata. 28 July 2005. . Frank, M.J. 2000. Pointers for perfect poa. Golf Course Management. 20 September 2005. Gausman, H.W. 1991. Plant biochemical regulat ors. Marcel Dekker, Inc., New York. Gent, M.P.N. and R.J. McAvoy. 2000. Plant growth retardants in orna mental horticulture: A critical appraisal. In: A.S. Basra (ed.). Plant growth regulators in agriculture and horticulture: Their role and commercial use. Food Products Press, New York. Gordon, D.R. and K.J. Rice. 1998. Patterns of differentiation in wiregrass (Aristida beyrichiana): Implications for restora tion efforts. Restor ation Ecol. 6:166-174. Goudy, J.S., H.S. Saini, and M.S. Spencer . 1987. Uptake and fate of ethephon [(2chloroethyl)phosphonic acid] in dormant weed seeds. Plant Physiol. 85:155-157.

PAGE 92

80 Graham, L.E., J.M. Graham, and L.W. Wilcox. 2003. Plant biology. Pearson Education, Upper Saddle River, N.J. Hamill, N. 2005. Natives go mainstream. Today's Garden Center. 2(7): 20-22. Hansen, H. and K. Grossman. 2000. Auxin-i nduced ethylene triggers abscisic acid biosynthesis and growth inhibi tion. Plant Physiol. 124:1437-1448. Heywood, J.S. 1986. Clinal variation associ ated with edaphic ecotones in hybrid populations of Gaillardia pulchella . Evolution. 40:1132-1140. Hicklenton, P.R. 1998. Effectiveness and cons istency of MSW compost as a component in container growing media. Natl. Com posting Conf. of The Composting Council of Can., Ottawa, Ontario, November 4-6, 1998. Hodges, A.W. and J.J. Haydu. 2002. Economic impacts of the Florida environmental horticulture industry, 2000 EI 02-3. Uni v. of Fla., IFAS, Gainesville, Fla. Hoitink, H.A.J., Y. Inbar, and M.J. Boehm. 1991. Status of compost-amended potting mixes naturally suppressive to soil-borne di seases of floricultu ral crops. Plant Dis. 75:869-873. Hue, N.V. and B.A. Sobieszczyk. 1999. Nutrit ional values of some biowastes as soil amendments. Compost Sci. and Utilization. 7:34-41. Inbar, Y., Y. Chen, and H.A.J. Hoitink. 1993. Properties for establishing standards for utilization of compost in container media. In: H.A.J. Hoitink and H.M. Keener (eds.). Science and engineering of composting: Design, environmental, microbiological and utilization aspe cts. Renaissance, Worthington, OH. Jerardo, A. 2005. Floriculture and nurser y crops situation and outlook yearbook FLO2005. U.S. Dept. of Agr., Washington, D.C. Jones, K.M., T.B. Koen, M.J. Oakford, and S.J. Longley. 1989. Using ethephon and daminozide to regulate growth and initi ate flower buds on bearing red delicious trees. Austral. Temperate Fru its Conf., Australia. p. 185-188. Kaufman, S.M., N. Goldstein, K. Millrath, a nd N.J. Themelis. 2004. The state of garbage in America. BioCycle. 45:31. Keever, G.J. and J.W. Olive. 1994. Response of 'Prize' azalea to Sumagic applied at several stages of shoot apex deve lopment. J. Envion. Hort. 12:12-15. Keever, G.J. and J.A. McGuire. 1991. Suma gic (uniconazole) enhances flowering of 'Shishi-Gashira' camellia. J. Envion. Hort. 9:185-187. Kelly, R.O. and B.K. Harbaugh. 2002. Evaluation of marigold cultivars as bedding plants in central Florida. HortTechnol. 12:447-484.

PAGE 93

81 Latimer, J. 2004. Plant growth regulator chart, p. 48-66. In: C.A. Cut hbert (ed.). Tips on managing floriculture crop problems: Pests, diseases and growth control. O.F.A. Services, Columbus, OH. Latimer, J., H. Scoggins, and V. Groover. 2003. Asteraceae response to PGRs. Greenhouse Product News. 13(3): 26-34. Lesica, P. and F.W. Allendorf. 1999. Ecologica l genetics and the restoration of plant communities: Mix or match? Restoration Ecol. 7:42-50. Marois, J.J. and J.G. Norcini. 2003. Survival of black-eyed susan from different regional seed sources under low and high inpu t systems. HortTechnol. 13:161-165. McCully, W.G. 2000. Utilizing the ecotype concept. In: B.L. Harper-Lore (ed.). Roadside use of native plants. Island Press, Washington, D.C. McKay, J.K., C.E. Christian, S. Harrison, and K.J. Rice. 2005. How local is local? A review of practical and concep tual issues in the genetics of restoration. Restoration Ecol. 13:432-440. McLachlan, K.L., C. Chong, R.P. Voroney, H.W. Liu, and B.E. Holbein. 2004. Variability of soluble salts using diffe rent extraction methods on composts and other substrates. Compost Sc i. and Utilization. 12:180-184. McMahon, P. and C. Pasian. 2004. Cultural alternat ives to chemical growth regulators, p. 120-124. In: C.A. Cuthbert (ed.). Tips on managing floriculture crop problems. O.F.A Services, Columbia, OH. Meyers, P., R. Espinosa, C.S. Parr, T. Jones, G.S. Hammond, and T.A. Dewey. 2005. The animal diversity web. University of Mi chigan Museum of Zoology. 27 September 2005. . Michigan State University Extension (MSU). Gaillardia x grandifl ora blanketflower. 1999. Michigan State Univers ity Extension. 2 October 2005. . Nappi, P. and R. Barberis. 1993. Compost as a growing medium: Chemical, physical, and biological aspects. ISHS Acta Hortic ulturae 342: International Symposium on Horticultural Substrates other than Soil in situ, Florence, Italy, 1 June 1993. p. 249256. National Mining Association. 2001. Mining in Florida. Nation al Mining Association. 10 July 2003. . National Resources Conservation Services (NRCS). 1999. National Cooperative Soil Survey. USDA. 16 August 2005. .

PAGE 94

82 Niedziela, C.E. and P.V. Nelson. 1992. A rapid method for determining physical properties of undisturbed subs trate. HortSci. 27:1279-1280. Norcini, J.G., M. Thetford, K.A. Klock-M oore, M.L. Bell, B.K. Harbaugh, and J.H. Aldrich. 2001. Growth, flowering, and surviv al of black-eyed susan from different regional seed sources. HortTechnol. 11:26-30. Passioura, J.B. 2002. Soil conditions and plan t growth. Plant, Cell Environ. 25:311-318. Pitterman, J. and R.F. Sage. 2000. Photosynthe tic performance at low temperature of Bouteloua gracilis Lag., a highaltitude C4 grass from the Rocky Mountains, USA. Plant, Cell Environ. 23:811-823. Poole, R.T., C.A. Conover, and J.N. Join er. 1981. Soils and potting mixtures, p. 179-202. In: J.N. Joiner (ed.). Fo liage plant production. Prentice Hall, Englewood Cliffs, NJ. Quinn, J.A. 1978. Plant ecotypes: Ecological or e volutionary units? Bulletin of the Torrey Botanical Club. 105(1): 58-64. Rademacher, W. 1991. Biochemical effects of plant growth reta rdants. In: H.W. Gausman (ed.). Plant biochemical regul ators. Marcel Dekker, New York. Rajala, A. and P. Peltonen-Sainio. 2000. Mani pulating yield potential in cereals using plant growth regulators. In: A.S. Basra (ed.) . Plant growth regula tors in agriculture and horticulture: Their role and commercia l uses. Food Products Press, New York. Raviv, M. 2005. Production of high-quality com posts for horticultural purposes: A minireview. HortTechnol. 15:52-57. Rynk, R., M. van de Kamp, G.B. Willson, M.E. Singley, T.L. Richard, J.J. Kolega, F.R. Gouin, L.J. Laliberty, D. Kay, D.W. Mu rphy, H.A.J. Hoitink, and W.F. Brinton. 1992. On-farm composting handbook. Schmidt, J. 2003. The European Lolium perenne core collection in the Botanical Garden of the Plant Breeding and Acclimatizati on Institute, Bydgoszcz, Poland. Report of a Working Group on Forages: Eighth Meet ing, Linz, Austria, April 10-12 2003. p. 132-140. Schoellhorn, R. 2005. Boost profits with trial gardens. Lawn and Garden Retailer. 4(4): 24-31. Schoellhorn, R. 2004. Gaillardia. Gr eenhouse Product News. Feb: 14-16. Serek, M. and M.S. Reid. 2000. Role of grow th regulators in the postharvest life of ornamentals. In: A.S. Basra (ed.). Plan t growth regulators in agriculture and horticulture: Their role and commercial uses. Food Products Press, New York.

PAGE 95

83 Shiralipour, A. and W.H. Smith. 1998. Strate gy for compost market development in Florida. Composting in the Southe ast, Athens, GA, September 9-11. Shumac, K. 2004. Department of horticultu re trial gardens. Pennsylvania State University. 27 September 2005. . Sims, J.T. 1995. Organic wastes as altern ative nitrogen sources , p. 487-535. In: P.E. Bacon (ed.). Nitrogen fertiliz ation in the environment. Marcel Dekker, New York. Styer, R.C. 2004. Taming the beasts! Greenhouse Product News. 14(7): 84-89. Thomas, B.D. 2002. Tissue culture: The science of perfection. Greenhouse Product News. 12(10): 30-35. Turesson, G. 1922. The species and the variety as ecological units. Hereditas. 3:100-113. University of Florida. 2005. Florida st atewide plant trials. RedRockWin.com. 9 September 2005. . University of Georgia (UGA). 2005. The Ga rdens at UGA. Clarity Connect, Inc. 20 September 2005. . University of Guelph. 2005. University of Guelph's trial garden. 20 September 2005. . United States Department of Agricu lture (USDA). 2004. The PLANTS Database, Version 3.5. National Plant Data Center. 28 July 2005. . United States Environmental Protection Agen cy (USEPA). 2005. Municipal solid waste generation, recycling, and dis posal in the United States : Facts and figures for 2003 EPA530-F-05-003:1-11. U.S. Environmenta l Protection Agency, Washington, D.C. United States Environmental Protection Agen cy (USEPA). 1999. Biosolids generation, use, and disposal in the United States EPA530-R-99-009:25. U.S. Environmental Protection Agency, Washington, D.C. United States Environmental Protection Ag ency (USEPA). 1998. Test methods for evaluating solid waste SW-846 (Methods 3050) SW-846. U.S. Environmental Protection Agency, Washington, D.C. United States Environmental Protection Agen cy (USEPA). 1994. A plain English guide to the EPA part 503 biosolids rule EPA/832/R-93/003. U.S. Environmental Protection Agency, Washington, D.C. Vavrina, C.S. 1994. Municipal solid waste materials as soilless media for tomato transplant production. Fla. State Hort. Soc. p. 118-120.

PAGE 96

84 Whitman, C., M. Olrich, and E. Runkle. 2005. Sumagic on bedding plants. Greenhouse Product News. 15(4): 66. Wightman, K.E., T. Shear, B. Goldfarb, and J. Haggar. 2001. Nursery and field techniques to improve seedling growth of three Costa Rican hardwoods. New Forests. 22:75-96. Wilson, S.B., L.K. Mecca, P.J. Stoffella, and D.A. Graetz. 2004. Using compost for container production of orna mental hammock species native to Florida. Native Plants J. 5.2:186-194. Wilson, S.B., P.J. Stoffella, and D.A. Graetz. 2003. Compost amended media and irrigation system influence containerized pe rennial salvia. J. Amer. Soc. Hort. Sci. 128:260-268. Wilson, S.B., P.J. Stoffella, and D.A. Gr aetz. 2002. Development of compost-based media for containerized perenni als. Scientia Hort. 93:311-320. Wilson, S.B., P.J. Stoffella, and D.A. Graet z. 2001a. Evaluation of compost as an amendment to commercial mixes used for container-grown golden shrimp plant production. HortTechnol. 11:31-35. Wilson, S.B., P.J. Stoffella, and L.A. Krum folz. 2001b. Containerized perennials make good use of compost. BioCycle. 42:59-61. Woods End Research Laboratory. 2000. Compost quality standards a nd guidelines. N.Y. State Assn. of Recyclers, Albany, N.Y. Wunderlin, R.P. and B.F. Hansen. 2002. Atlas of Florida Vascular Plants. The Florida Center for Community Design and Research. 2 October 2005. . Zucconi, F., A. Pera, M. Forte, and M. DeBe rtoldi. 1981. Evaluating toxicity of immature compost. BioCycle. 22:54-57.

PAGE 97

85 BIOGRAPHICAL SKETCH Helen Danielson received her Bachelor of Science degree in Natural Resource Conservation from the University of Flor ida in December 2003. Remaining at UF, she earned her MasterÂ’s of Science degree in Envi ronmental Horticulture two years later, in December of 2005.