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Ornamental Groundcover Characteristics of Rhizoma Peanut (Arachis Glabrata Benth.) in Sun and Shade

Permanent Link: http://ufdc.ufl.edu/UFE0045634/00001

Material Information

Title: Ornamental Groundcover Characteristics of Rhizoma Peanut (Arachis Glabrata Benth.) in Sun and Shade
Physical Description: 1 online resource (105 p.)
Language: english
Creator: Anderson, Benjamin D
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2013

Subjects

Subjects / Keywords: arachis
Environmental Horticulture -- Dissertations, Academic -- UF
Genre: Horticultural Sciences thesis, M.S.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: Since little is known about the ornamental performance ofrhizoma peanut (Arachis glabrata Benth.), a series of studies were conducted todetermine its suitability for ornamental use in the landscape. The objectivesof these studies were to quantify the following characteristics: canopy cover, height,flowering, and visual quality of 16 selections of rhizoma peanut, in full sunand under shade. These parameters were used to select low-growing germplasmwith maximum canopy height uniformity, abundant flower production, and a highaesthetic quality. Additionally, a container study was conducted to determinethe minimum rate of nitrogen which produced a salable plant as defined by highfoliage cover, a large canopy with even foliage distribution, high visual quality,and abundant flower production.   Full coverwas achieved in the year following planting. Shade neither affected the time to reach full cover nor the duration offull cover; rhizoma peanut selection had the greatest effect on thesevariables. Height increased throughout the study and further increased under shadeas did height variability. Ornamental types generally had the greatest flowerproduction, but shade tended to decrease flowering. Visual quality was mostaffected by selection, but these differences were less apparent during thesecond year of the study. EX1 and EX3 were most suitable for ornamental use;EX5, ‘Brooksville 67’, and ‘Brooksville 68’ also showed acceptable performance.To achieve salable plants under container production, a nitrogen rate of 4N isneeded. ‘Ecoturf’, EX7, and EX8 showed the greatest promise for successfulcontainer production.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Benjamin D Anderson.
Thesis: Thesis (M.S.)--University of Florida, 2013.
Local: Adviser: Knox, Gary W.
Local: Co-adviser: Gilman, Edward F.
Electronic Access: RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2015-05-31

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2013
System ID: UFE0045634:00001

Permanent Link: http://ufdc.ufl.edu/UFE0045634/00001

Material Information

Title: Ornamental Groundcover Characteristics of Rhizoma Peanut (Arachis Glabrata Benth.) in Sun and Shade
Physical Description: 1 online resource (105 p.)
Language: english
Creator: Anderson, Benjamin D
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2013

Subjects

Subjects / Keywords: arachis
Environmental Horticulture -- Dissertations, Academic -- UF
Genre: Horticultural Sciences thesis, M.S.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: Since little is known about the ornamental performance ofrhizoma peanut (Arachis glabrata Benth.), a series of studies were conducted todetermine its suitability for ornamental use in the landscape. The objectivesof these studies were to quantify the following characteristics: canopy cover, height,flowering, and visual quality of 16 selections of rhizoma peanut, in full sunand under shade. These parameters were used to select low-growing germplasmwith maximum canopy height uniformity, abundant flower production, and a highaesthetic quality. Additionally, a container study was conducted to determinethe minimum rate of nitrogen which produced a salable plant as defined by highfoliage cover, a large canopy with even foliage distribution, high visual quality,and abundant flower production.   Full coverwas achieved in the year following planting. Shade neither affected the time to reach full cover nor the duration offull cover; rhizoma peanut selection had the greatest effect on thesevariables. Height increased throughout the study and further increased under shadeas did height variability. Ornamental types generally had the greatest flowerproduction, but shade tended to decrease flowering. Visual quality was mostaffected by selection, but these differences were less apparent during thesecond year of the study. EX1 and EX3 were most suitable for ornamental use;EX5, ‘Brooksville 67’, and ‘Brooksville 68’ also showed acceptable performance.To achieve salable plants under container production, a nitrogen rate of 4N isneeded. ‘Ecoturf’, EX7, and EX8 showed the greatest promise for successfulcontainer production.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Benjamin D Anderson.
Thesis: Thesis (M.S.)--University of Florida, 2013.
Local: Adviser: Knox, Gary W.
Local: Co-adviser: Gilman, Edward F.
Electronic Access: RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2015-05-31

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2013
System ID: UFE0045634:00001


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1 ORNAMENTAL GROUNDCOVER CHARACTERISTICS OF RHIZOMA PEANUT ( Arachis Glabrata Benth .) IN SUN AND SHADE By BENJAMIN D. ANDERSON A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE UNIVERSITY OF FLORIDA 2013

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2 2013 Benjamin D. Anderson

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3 To my g randparents

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4 ACKNOWLEDGMENTS I would like to thank Dr. Gary Knox, Dr. Cheryl Mackowiak, Dr. Ann Blount, and Dr. Ed Gilman fo r their support during the completion of my research and thesis. I would also like to thank James C. Colee and James H. Aldrich for their technical assistance.

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5 TABLE OF CONTENTS page ACKNOWLEDGMENTS ................................ ................................ ................................ .. 4 LIST OF TABLES ................................ ................................ ................................ ............ 7 LIST OF FIGURES ................................ ................................ ................................ .......... 9 LIST OF ABBREVIATIONS ................................ ................................ ........................... 10 ABSTRACT ................................ ................................ ................................ ................... 11 CHAPTER 1 LITERATURE OVERVIEW OF RHIZOMA PEANUT ( A rachis glabrata Benth.) AND RESEARCH OBJECTIVES ................................ ................................ 13 Background and History of Rhizoma Peanut ................................ .......................... 13 Forage Uses of Rhizoma Peanut ................................ ................................ ............ 15 Ornamental Uses of Rhizoma Peanut ................................ ................................ ..... 16 2 ORNAMENTAL GROUNDCOVER CHARACTERISTICS OF RHIZOMA PEANUT ( Arachis glabrata Benth .): SHADE AFFECTS HEIGHT BUT NOT COVER ................................ ................................ ................................ .......... 26 Introduction ................................ ................................ ................................ ............. 26 Materials and Methods ................................ ................................ ............................ 28 Results ................................ ................................ ................................ .................... 30 Discussion ................................ ................................ ................................ .............. 33 3 ORNAMENTAL GROUNDCOVER CHARACTERISTICS OF RHIZOMA PEANUT ( Arachis glabrata Benth .): SHADE REDUCES FLOWERING BUT NOT VISUAL QUALITY ................................ ................................ .................. 44 Introduction ................................ ................................ ................................ ............. 44 Materials and Methods ................................ ................................ ............................ 46 Results ................................ ................................ ................................ .................... 48 Discussion ................................ ................................ ................................ .............. 51 4 CONTAINER PRODUCTION OF RHIZOMA PEANUT ( Arachis glabrata Benth .): NITROGEN FERTILIZATION AFFECTS PLANT SIZE, FLOWERING, VIS UAL QUALITY, AND SALABILITY ................................ ............ 59 Significance to the Nursery Industry ................................ ................................ ....... 59 Introduction ................................ ................................ ................................ ............. 59 Materials and Methods ................................ ................................ ............................ 61

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6 Results ................................ ................................ ................................ .................... 63 Discussion ................................ ................................ ................................ .............. 66 5 CONCLUSIONS ................................ ................................ ................................ ........ 82 Recommended S elections ................................ ................................ ...................... 82 Rate and Duration of Full Canopy C over ................................ ................................ 82 Height A ttributes ................................ ................................ ................................ ..... 83 Number of F lowers ................................ ................................ ................................ 85 Duration of Acceptable Visual Q uality ................................ ................................ ..... 87 Container P roduction ................................ ................................ .............................. 88 Other O bservations ................................ ................................ ................................ 91 Future W ork ................................ ................................ ................................ ............ 92 APPENDIX A ADDITIONAL TABLES ................................ ................................ ............................ 95 LIST OF REFERENCES ................................ ................................ ............................. 101 BIOGRAPHICAL SKETCH ................................ ................................ .......................... 105

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7 LIST OF TABLES Table p age 1 1 Description of current rhizoma peanut ( Arachis glabrata ) cultivars and selections. ................................ ................................ ................................ ........... 22 2 1 Field characteristic s at two experimental locations ................................ ............. 37 2 2 Released cultivars and experimental selections of rhizoma p eanut used in the study. ................................ ................................ ................................ ............ 38 2 3 Plant attributes of A. glabrata selections in Gainesville. ................................ ..... 39 2 4 Plant attributes of A. glabra ta selections in Quincy. ................................ ............ 41 3 1 Mean flower number and shade effects over two years of A. glabrata selections in Gainesville ................................ ................................ ..................... 55 3 2 Mean flower number and shade effects over two years of A. glabrata selections in Quincy. ................................ ................................ ........................... 57 4 1 Released cultivars and experimental selections of rhizoma peanut used in the study. ................................ ................................ ................................ ............ 71 4 2 Initial conta iner media soil testing results ................................ ........................... 72 4 3 Nitrogen effects on plant height of A. glabrata selections. ................................ .. 73 4 4 Nitrogen effects on plant diameter of A. glabrata selections. .............................. 74 4 5 Nitrogen effects on root dry mass of A. glabrata selections. ............................... 75 4 6 Nitrogen effects on shoot dry mass of A. glabrata selections. ............................ 76 4 7 Nitrogen effects on nodulation of A. glabrata selectio ns ................................ ..... 77 4 8 Nitrogen effects on visual quality of A. glabrata selections. ................................ 78 4 9 Nitrogen effects on flowering of A. glabrata sele ctions during the final 30 days of the study. ................................ ................................ ............................... 79 4 10 Nitrogen effects on plant form of A. glabrata selections. ................................ ... 80 A 1 Canopy u niformity of A. glabrata selections at two locations. ............................. 95 A 2 Nitrogen effects on plant height of A. glabrata selections. ................................ .. 97 A 3 Nitrogen effects on plant diameter of A. glabrata selections. .............................. 98

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8 A 4 Nitrogen effects on foliage cover of A. glabrata selections. Percent cover is stated relative to the surface area of the co ntainer. ................................ ............ 99 A 5 Nitrogen effects on number of flowers of A. glabrata selections. ...................... 100

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9 LIST OF FIGURES Figure page 2 1 Average monthly air temperature, soil temperature, and rainfall during the experimental peri od ................................ ................................ ............................ 43 4 1 Average daily maximum and minimum air temperatures and 10 day cumulative r ainfall totals during the study ................................ ........................... 8 1

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10 LIST OF ABBREVIATION S a.i. Active Ingredient N Nitrogen

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11 Abstract of Thesis Presented to the Graduate School of the University of Florida in Partial F ulfillment of the Requirements for the Degree of Master of Science ORNAMENTAL GROUNDCOVER CHARACTERISTICS OF RHIZOMA PEANUT ( Arachis Glabrata Benth .) IN SUN AND SHADE By Benjamin D. Anderson May 2013 Chair: Gary Knox Major: Horticultural Sc iences Sin ce little is known about the ornamental performance of rhizoma peanut ( Arachis glabrata Benth.), a series of studies were conducted to determine its suitability for ornamental use in the landscape. T he objectives of these studies were to quantify the follo wing characteristics: canopy cover, height flowering and visual quality of 16 selections of rhizoma peanut, in full sun and under shade. These parameters were used to select low growing germplasm with maximum canopy height uniformity abundant flower pro duction, and a high aesthetic quality Additionally, a container study was conducted to determine the minimum rate of nitrogen which produced a salable plant as defined by high foliage cover, a large canopy with even foliage distribution, high visual quali ty, and abundant flower production. Full cover was achieved in the year following planting. Shade neither affected the time to reach full cover nor the duration of full cover; rhizoma peanut selection had the great est effect on these variables. Height increased throughout the study and further increased under sh ade as did height variability. Ornamental types generally had the greatest flower production, but shade tended to decrease flowering. Visual quality was

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12 most affected by selection, but these diff erences were less apparent during the second year of the study. EX1 and EX3 were most suitable for ornamental use; EX5, howed acceptable performance. To achieve salable plants under container production, a nitro gen rate of 4N is needed. EX7, and EX8 showed the greatest promise for successful container production.

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13 CHAPTE R 1 LITERATURE OVERVIEW OF RHIZOMA PEANUT ( A RACHIS GLABRATA BENTH .) AND RESEARCH OBJECTI VES Background and History of Rhizoma Peanut Rhizoma peanut ( Arachis glabrata Benth.) is a leguminous, nitrogen fixing, tropical perennial native to South America specifically Brazil, Bolivia, Paraguay, Argentina, and Uruguay (Valls and Simpson, 1993 ). Its taxonomy places it in the Leguminosae Papi lionoideae (or Fabaceae) family, tribe Aeschynomeneae, subtribe Stylosanthinae, section Rhizomatosae. Wild populations of this genus are distinctly isolated, and have little gene flow among them. A. glabrata was described by Bentham in 1841, approximately a century after that of annual peanut by Linnaeus in 1753. The genus Arachis has likely existed for over 55 million years and has evolved in a diversity of habitats, from semi arid landscapes to lowland swamps. In areas where it has evolved, it has functio ned in ecosystems by providing forage material for direct animal consumption, pollen for bees and insects, a nitrogen source for grasses and associated plants, as well as acting as a groundcover to inhibit erosion (Simpson et al., 1994). Sexual recombinati on, selection, and isolation have contributed to high number of species and their associated diversity. The genus Arachis is characterized by aerial flowers that contain a tubular hypanthium (calyx tube), with separate types of anthers in the same flower. Flowers are located in the leaf axils of reproductive nodes along the aboveground stems. Flower corollas are papilionaceous and contain a large standard petal, two wing petals, and a keel petal which houses the pistil and stamens. A. glabrata has a small s tigmatic area, but is large enough to accommodate two pollen grains. Pollination occurs primarily by bees. Underground fruits are borne from the flowers and have a delicate seed

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14 tegument. However, species in section Rhizomatosae are known to produce few se eds, and propagation mainly occurs from vegetative rhizome divisions. Hybridization is possible once the barriers to compatibility are better understood and can thus be overcome. Seeds that are successfully formed yield a new genotype once they germinate ( Simpson et al., 1994 type that grew between two selections of A. gla brata (Prine et al., 1986 b ). Arachis germplasm is currently being extensively collected from wild populations, yielding new species and genotypes which are predominantly used as high quality forage crops. At the present time, little is known about the repr oduction and genetic variability of Arachis species, and future germplasm collection in unexplored areas needs to be accomplished (Valls and Simpson, 1993). A. glabrata is the predominant species in collections around the world and is the subject of molecu lar studies that seek Accessions are characterized by high heterozygosity and polyploidy (Simpson et al., 1993). Since rhizoma peanut was introduced into the U.S. in the 1930s, the p lant has gained popularity in the southeast as a nutritive perennial forage crop. Grown in USDA hardiness zones 8b and greater, rhizoma peanut is best adapted to coarse, sandy soils and the mild climate associated with peninsula Florida and the U.S. Southe rn Coastal Plain (Prine et al., 1990; Ocumpaugh, 1990; Terrill et al., 1996). Rhizoma peanut is able to persist on sandy soils under droughty conditions (Prine et al., 1990) and to fix atmospheric nitrogen, thus eliminating the need for nitrogen fertilizer inputs.

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15 Additionally, it is adaptable to a wide range of management systems (Williams et al., 1997). can account for up to 85% of the total plant biomass at the onset of dorma ncy (Williams, 1994) and extend as deep as 60 cm in the soil ( Terrill et al., 2000 ). As of the 2005 planting season, there were over 10,500 hectares of rhizoma peanut in cultivation in Florida (French et al., 2006) primarily for forage purposes Currently used cultivars and selections are displayed in Table 1 1 Rhizoma peanut is considered pest and disease resistant, however the species is susceptible to a few diseases; cotton root rot ( Phymatotrichum omnivorum ; Williams et al., 2002 ), leaf spot ( Cercospo ra arachidicola Cercospora personata Cercospora canescens ), anthracnose ( Colletotrichum gloeosporioides ), pepper spot ( Leptosphaerulina arachidicola ), rust ( Puccinia arachidis ), blight ( Rhizoctonia solani ), and scab ( Sphaceloma arachidis ) (Kelemu et al., 1993). Forage Uses of Rhizoma Peanut With few exceptions, past research with rhizoma peanut has focused almost (Table 1 1 ) with weeds and grasses, even under high nitrogen rat es (Valentim et al., 1986). greater height, more rapid growth in the spring, and increased drought tolerance. et al., 2006). s back occurs, which can result from fungal diseases such as Phymatotrichum omnivorum (Williams et al., 2002) In a study comparing the rate of In a study by Butler et al. (2006),

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16 new genotypes were also found to be superior t of cover. Rhizoma peanut also has the potential to be successfully grown in association with other plants, namely grasses (Dunavin, 1992). Ornamental Uses of Rhizoma Peanut I n the S outheastern U.S. rhizoma peanut h as been used almost exclusively as a forage crop, but has received little attention for its potential use as an ornamental groundcover Rhizoma peanut has the potential to be utilized in diverse situations, including roadside and right of way plantings, as an ornamental or utility turf, in cluding areas where mowing is difficult such as sloped or uneven terrain. Recently, evaluations of new rhizoma peanut genotypes have revealed some that establish and spread faster al., 2000) and tolerate high pH soils (Butler et al., 2006). Some were identified as possible ornamental turf or landscape selections (Freire et al., 2000 ), including cultivars (Prine These cultivars are low growing compared to groundcovers or turf alternatives (Pr ine et al., 2010). for ornamental use, based on its low height and shiny, waxy leaves which may increase its visual quality and provide some degree of pest resistance (Maura et al., 2006a). ribed as having dark green leaves (Maura et al., 2006b), promoting its suitability as an ornamental groundcover. Rhizoma peanut has been shown to outperform St. Augustinegrass ( Stenotaphrum secundatum Kuntze) during drought conditions, as measured by leaf color and visual appearance (Prine et al., 2010), as well as persisting during dry conditions that would normally kill St.

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17 Augustinegrass (French et al., 2001, revised 2006). Currently, little is known about Flowers are produced daily (Prine et al., 2010), typically open at sunrise and wilt by mid afternoon (Simpson et al., 1994). characterized by prolific flower production and has been shown to produce 150 to 250 flowers m 2 Flowering is increased by warm t emperatures, full sun, soils with low fertility, and under mowing (French et al., 2001, revised 2006). Flowers are yellow to yellow orange in color and are most abundant during the months of June August. Along with the potential for mixed plantings with tu rfgrasses, rhizoma peanut responded well to mowing practices in a preliminary study (Aldrich et al., 2012). Shade Effects on Rhizoma Peanut In past studies, the shading of legume seedlings has resulted in decreased nodulation, decreased relative growth rat e, smaller roots, and a decrease in the leaf to stem ratio (Kalmbacher and Martin, 1983). Few studies have focused on the performance of rhizoma peanut under shade. In one such study, rhizoma peanut, grown under 54% PPFD, a light environment similar to tha t of pine ( Pinus sp.) understories, persisted comparable to that grown under full sun (Johnson et al., 1994). Successful cultivation of rhizoma peanut in a shaded environment would allow a greater diversi ty of habitats to be utilized for ornamental purpose s. Rhizoma Peanut Production, Fertilization, and Soil Characteristics Rhizoma peanut e stablishment generally takes two or more years before full ground cover is achieved (Johnson et al., 1994; Adjei and Prine, 1976) and may be more a function of the genoty pe of the rhizome planting material than of the environmental conditions post planting (Williams, 1993; Venuto et al., 2000). However,

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18 irrigation for up to 90 days post planting has been shown to be an important factor of transplant survival (Williams et a l., 1997), but is not expected to influence forage yields of established rhizoma peanut, unless a severe reduction in soil water occurs (Dunavin, 1992). The optimal soil pH for rhizoma peanut is in the range of 5.0 to 7.5 (French et al., 2001); forage qual ity and yield have shown a negative response to high pH soils (Venuto et al., 2000; Niles et al., 1990). Venuto et al. (2000) demonstrated that rhizoma peanut established and grew better on a low pH site than one with a high pH, even though high levels of aluminum were present on the low pH site. In general, rhizoma peanut begins rapid growth at the beginning of the summer rainy season (Williams, 1994) and peaks during late summer or early fall (Terrill et al., 2006) before the onset of dormancy with the fi rst killing frosts. When rhizoma peanut is dormant, which generally lasts from about November to March in the coastal plain s of the Southeastern U.S., cool season crops can be successfully grown over the dormant rhizoma peanut, with no effect on subsequent yield of the peanut (Dunavin, 1990). Effects of nitrogen fixation by rhizoma peanut on soil characteristics have received some attention due to the possible enrichment of the soil environment by fixed N, once it has been returned to the soil. Under long term production, rhizoma peanut may supply C and N from plant and root residues, as well as from rhizodeposition; this may improve soil quality (Butler et al., 2006). In another study, soil under established rhizoma peanut was compared to soil under perenn ial forbs, with that under rhizoma peanut having improved soil quality and fertility (Sainju et al., 2003). Specifically, NH 4 N and particulate organic nitrogen from 0 to 15 cm were greater for rhizoma peanut associated soils than for forbs. Consequently labile N pools and microbial biomass in the soil have the

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19 potential to be increased as a result of the association with rhizoma peanut. In support of this, the N concentration in rhizoma peanut roots was found to be twice that of forbs and N accumulation was 2.5 times greater than observed in forbs. The N supplied by rhizoma peanut roots alone is expected to exceed that supplied by the combined roots and shoots of forbs. Additionally, microbial activities and microbial biomass in the soil may be increased as a result of rhizoma peanut root growth. Evidence of this includes elevated rates of potential carbon mineralization 30 to 90 cm in the soil profile and increased microbial biomass carbon from 0 to 30 cm deep, for the soil associated with rhizoma peanut Since rhizoma peanut fixes atmospheric nitrogen, it would be expected that its nitrogen requirement would be reduced. This has been demonstrated in past studies, where added nitrogen negatively affected establishment through reductions in coverage and y ield (Adjei and Prine, 1976) and decreased nodulation (Venuto et al., 1998). The nitrogen fixed by rhizoma peanut is generally thought to be adequate to support its growth, even in nutrient depleted soils (Venuto et al., 1998). In greenhouse container stud ies, applied N has hindered establishment by reducing nodulation of rhizoma peanut and increasing weed growth (Adjei and Prine, 1976). In contrast, it has also coverage under hig h N levels, however higher percentages of legume were found for lower rates of N and no N (Valentim et al., 1986). Only one study thus far has evaluated the effects of other nutrients on rhizoma peanut. In this experiment, phosphorus, potassium, magnesium,

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20 rhizoma peanut at 13 different locations with the conclusion that there was no significant benefit from their application (Niles at al., 1990). The use of rhizoma peanut has been limited by a slo w establishment rate and the requirement for vegetative propagation (Rice et al., 1996). The survival of emerging sprouts is one of the biggest problems associated with stand establishment (Dunavin, 1992) and the rate of coverage appears to be related to t he number of sprouts planted per unit of land area that survive emergence and initial establishment. Many succumb to late spring and early summer droughts that typically occur in the Southeast (Williams et al., 1997). Weed and grass competition for moistur e only adds to this problem (Dunavin, 1992). Additionally, a slow rate of spread occurs after sprouts emerge and it can take up to three years for complete establishment (Williams et al., 1997). The cost associated with vegetative establishment is one of t he greatest limitations to widespread use of rhizoma peanut (Dunavin, 1992). Many high pH soils around the world have the potential for rhizoma peanut production if plant material was available (Williams et al., 2002). Research Objectives The overall goal of this research was to evaluate the use of rhizoma peanut as an environmentally friendly groundcover or turf alternative in the Southeast U.S In order to facilitate this use, t he objectives of this study were to characterize the rate and seasonal duratio n of full canopy cover, height attributes the number of flowers produced, and the duration of acceptable visual quality of previously released cultivars and new selections of rhizoma peanut, in full sun and under shade in the field These characteristics were used to select low growing germplasm with m aximum canopy height uniformity

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21 abundant flower production, and a high aesthetic quality to propose selections for ornamental use. Additionally, a container study was conducted to determine the minimum rate of nitrogen which produces a salable plant as defined by high foliage cover, a large canopy with even foliage distribution, high visual quality, and abundant flower production. Data were used to recommend selections of rhizoma peanut that can be acceptabl y produced using conventional nursery production methods.

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22 Table 1 1 Description of current rhizoma peanut ( Arachis glabrata ) cultivars and selections. Name Year Introduced Comments 'Apalachee' Collected by Dr. Ann Blount of the University of Florida from a planting near a bridge in Blountstown, FL. 'Arb' 1964 Arb was the first RPP distributed to the general public and grown commercially in the USA. The plant was collected by W. Archer, a plant explorer, in 1936, near Campo Grande, Brazil (Prine, 19 64). The plant has large leaves, a coarse stem and bright yellow orange flowers. Conway and Ritchey (1949) observed that the plant had forage potential, but it was not until after the USDA SCS tested and promoted the accession, that it received recognition as a promising new forage (Blickensderfer et al., 1964). 'Arblick' (Reg. No. GP 128; PI 658528) 2008 Arblick (Reg. No. GP 128; PI 658528) was among the early lines of rhizoma peanut tested by the USDA SCS at the Arcadia and Brooksville Plant Materials C enters, but was not officially introduced by the USDA SCS and University of Florida. Arblick was collected near the town of Bela Vista, Brazil It has green group leaves (RHS 137B), with an orange group standard petal (RHS 24A and a yellow orange group win g petal (RHS 14B). Arblick is somewhat slower to establish than other forage type cultivars and has not been widely profusely during the growing season. This germplasm will benefit specia lty users of "ornamental" types of rhizoma peanut but also because of the dual use potential will diversify the rhizoma peanut plantings to avoid the near

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23 Table 1 1. Continued. Name Year Introduced Comments 'Arbrook' 1985 Arbrook (PI 262817) has erect growth, thicker stems and distinctive larger rhizomes that provide good spring growth. It is recommended for droughty, excessively drained sandy soils with warm winter temperatures, such as those that occur in peninsular Flor ida. Arbrook emerges and survives better following planting under dry soil conditions. From Itapa Department, Paraguay The University of Florida and the USDA 1985 (Prine et al., 1986a, 1990). It had been note d as a superior accession of rhizoma peanut at the Arcadia and Brooksville Plant Materials Centers, and at the University of Florida. Its major limitations are that it is less tolerant of poor soil drainage and has winter killed on heavy soils in northwest Florida and at Americus, GA (Prine et al., 1986a). Brooksville 67 Germplasm (Waxy) 2002 This selection is classified as A. glabrata var. hagenbeckii PI 262801 was selected for use as a low growing, low maintenance ground cover. Thick round leaves with a shiny, waxy coating make it easy to differentiate from other glabrata accessions. Canopy height of mature stands can range from less than 1 inch to over 6 inches. Few flowers (yellow to orange in color) seeds, and peanuts are produced. From Corrientes, A rgentina Brooksville 68 Germplasm (Pointed) 2002 NRCS # 9056068 (from Brazil) was selected for use as a low growing, low maintenance ground cover. Thick leaves are elliptic to lanceolate (pointy) in shape, typically small and dark green in color. The wax y coating on its leaves makes it less susceptible to insect and disease injury. Canopy height of mature stands can range from less than 1 inch to over 6 inches. A comparatively large number of flowers are produced (Maura et al., 2006b) which are yellow or ange Chico Selected in 2009 by Gary Knox and Ann Blount as an off type in a group of potted Chiquita plants (G. Knox, personal communication).

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24 Table 1 1. Continued. Name Year Introduced Comments Chiquita Selected in 2006 by Ann Blount and Chery l Mackowiak as an off type in a field of Arblick at the UF/IFAS Suwannee Valley Agricultural Extension Center, Live Oak, FL. It is prostrate with a low canopy and exhibits small, oval leaves (C. Mackowiak, personal communication). 'Ecoturf' (Reg. No. GP 129; PI 658529) 1992, 2008 Ecoturf (Reg. No. GP 129; PI 658529) was released by the University of Florida in 2008. This PI was identified by Drs. Prine and French in the early 1990s as a low growing (8 more floriferous tha n forage varieties. Ecoturf was collected along the Brazil Paraguay border near the town of Bela Vista, Mato Grosso do Sul, Brazil Flower color of Ecoturf is an orange group standard petal (RHS 24A and a yellow orange group wing petal (RHS 14B), but it ha s yellow green group leaves (RHS 144A). Ecoturf has gained acceptance by the commercial landscape industry for use as an ornamental ground cover. It will benefit specialty users of "ornamental" types of rhizoma peanut but also because of the dual use poten tial will diversify the rhizoma peanut plantings to avoid the near 'Florigraze' 1978 thought to be a natural outcrossing between two plant introductions or a vigorous seedling from Arb. Dr. Gordon Prine, selected this material and tested it in perennial peanut trials as Gainesville Selection No. 1 (GS 1). It was later formally released as The rhizome size of Florigraze is smaller than that of Arb or Arblick and has more bud sites and more shoots per unit area of rhizome than either Arb or Arblick (Prine et al., 1981). Flowers are a yellow orange color, similar to the flower color of Arb. The plant performed well in field trials and was released jointly by the University of Florida and the USDA SCS in 1978. To date, this cultivar dominates the acreage of rhizoma peanut planted in the Southern USA.

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25 Table 1 1. Continued. Name Year Introduced Comments 'UF Peace' (Reg. No. CV 108, PI 65 8214) 2008 UF Peace also originated as a plant introduction from Paraguay. Other material that has been maintained since the 1960s in Florida as PI 262839 was given the name Arblick by the USDA Soil Conservation Service and released in 2008 as germplasm ( Prine et al., 2010 ). Recent amplified fragment length polymorphism evaluation indicated that the plant material we received from Simpson and have evaluated is different from Arblic k and all other A. glabrata germplasm tested ( Maas et al., 2010 ). Like UF Tito, it resembles the plant type of Florigraze, and it also was one of 15 superior accessions identified for further evaluation from the work of Ruttinger Lamperti (1989) In the summary report by Freire et al (2000) competitiveness with weedy bermudagrass was inferior to that of UF Tito. This line is named in honor of the late Mr. Caroll Peace, of Valdosta, GA 'UF Tito' (Reg. No. CV 107, PI 262826) 2008 UF Tito originated as a plant introduction from Par aguay. It was collected in January 1959 by W.C. Gregory as Collection No. 9587 and assigned PI 262826 in May 1960. Two samples of PI 262826 were originally received from Dr. Simpson, and the material for this release traces to Sample (a). This plant introd uction resembles the plant type of Florigraze, and it was selected as 1 of 15 accessions from the research of Ruttinger Lamperti (1989) for further evaluation. It was identified b y Freire et al. (2000) as the top line out of a 10 yr evaluation experiment originally established by Kel ly (1994) at the AFRU near Gainesville, FL. In addition to having high dry matter yields in this 10 yr evaluation experiment, UF Tito had the highest percent pure peanut (lowest invasion by weedy common bermudagrass [ Cynodon dactylon (L.) Pers.] and the g reatest amount of spread at the AFRU ( Freire et al., 2000 ). This line is named in honor of the late Dr. Edwin C. "Tito" French, associate professor of agronomy, University of Flori da, and an avid researcher and proponent for rhizoma peanut.

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26 CHAPTE R 2 ORNAMENTAL GROUNDCOVER CHARACTE RISTICS OF RHIZOMA P EANUT ( Arachis glabrata Benth .): SHADE AFFECTS HEIGHT BUT NOT COVER Introduction Rhizoma peanut ( Arachis glabrata Benth.) is a leguminous, herbaceous, nitrogen fixing, warm season pe r ennial native to South America. It has been used almost exclusively as a forage crop in the United States since the 1930s. Grown in USDA hardiness zones 8b and greater, rhizoma peanut is best adapted to coarse, sandy soils and the mild climate associated with peninsular Florida and the U.S. Southern Coastal Plain (Prine et al., 1990 ; Ocumpaugh, 1990 ; Terrill et al., 1996). However, its utility as an ornamental groundcover has not been realized Extensive colonization of the soil by make it drought tolerant and persistent once established (Ortega S. et al., 1992; Prine et al., 1990). Addi tionally, it is pest and disease resistant (Baltensperger at al., 1986; Quesenberry et al., 2010), fixes nitrogen to support its growth (Venuto et al., 1998), produces abundant flowers and has a high aesthetic quality as an ornamental groundcover (Prine et al., 2010). Rhizoma peanut has the potential to be utilized in diverse situations, including roadside and right of way plantings, as an ornamental or utility turf, in cluding areas where mowing is difficult such as sloped or uneven terrain. Previous resea rch on rhizoma peanut has focused almost entirely on the forage i were subsequently released as superior forages, based on yield and drought tolerance (Quesenberry et al., 2010). In contrast lower growing forms of rhizoma peanut have received little attention for their potential use as an orn a mental groundcover Compared

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27 canopies and show promise as ornamental groundcovers or tur f alternatives. D uring Stenotaphrum secundatum Kuntze), as measured by leaf color and visual appearance (Prine et al., 2010). Generally, rhizoma peanut does not achieve full cover for at least two years (Adjei and Prine, 1976; Williams et al., 1997), necessitating the need for selections that provide faster cover, a characteristic of great importance ornamentally. Successful cultivation of rhizoma peanut in a shaded environment allow s for a greater diver sity of planting locations In one of only a few studies on rhizoma peanut shade tolerance, der 54% photosynthetic photon flux density (PPFD) pe r sisted comparable to that grown under full sun (Johnson et al., 1994). However, no selections have been evaluated for ornamental qualities in full sun vs. shaded environments. E n vironmental conditions may play less of a role in establishment of rhizoma peanut than genetics of the planti ng material (Williams, 1993). Furthermore, selections overlooked in forage evaluations may have desirable ornamental characteristics. W ater resource s carcity as a result of population needs and the overuse of chemical fertilizers, have di c tated the need for more environmentally friendly groundcovers. Rhizoma peanut has the potential to fill this need ; however, ornamentally impo r tant characteristics have not been studied among cultivars (Prine et al., 2010). Additionally, new ornamental cultivars will expa nd the commercially available germplasm diversity T he objectives of this study were to characterize the rate and duration of full canopy cover as well as height attributes, of previously released and new selections of

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28 rhizoma peanut, in full sun and und er shade. Height attributes were used for select ing low growing selections with minimal canopy height variability. These characteristics were used to propose selections for ornamental use. Materials and Methods Field locations. Plots were located at the No rth Florida Research and Education Center, Quincy, FL (Norfolk loamy fine sand: fine loamy, kaolinitic, thermic Typic Kandiudult ) and the Agronomy Forage Research Unit, Gainesville, FL (Chipley sand: thermic, coated Aquic Quartzipsamment ) (Table 2 1; Unite d States Department of Agriculture, 2012). The Quincy field was previously planted with Bahiagrass ( Paspalum notatum ) and the Gainesville field had fescue ( Festuca sp.) and clover ( Trifolium sp.) growing in it prior to the study. The Quincy field was sheet fumigated with methyl bromide (448 kg ha 1) prior to planting ; in Gainesville disking and leveling occurred prior to planting The field in Quincy was planted in July, 2009, approximately one year prior to the start of the study and was replicated in Gain esville one month before data collection began at both locations on June 28, 2010. Weeds in plots and aisles were controlled by hand weeding and herbicides; glyphosate (1.12 L a.i. ha 1 ), imazapic (70.6 g a.i. ha 1 ), and clethodim (0.15 L a.i. ha 1 ), with the additional use of 2,4 DB (0.55 L a.i. ha 1 ) in Gainesville. No soil amendments or fertilizers were applied at either location. Experimental design. Whole plots, each measuring 1.8 m x 3.0 m, were replicated four times in a split plot design, with pla nt selection as the main plot and shade treatment as the sub plot. Whole plots were arranged in a randomized complete block design. Rhizomes of sixteen selections (Table 2 2 ) vegetatively propagated from greenhouse grown plants in Quincy, were divided and potted into 0.55 and 0.43 L containers, 3 and 5 months prior to planting in Gainesville and Quincy, respectively.

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29 Whole p lots were oriented north south across the longest dimension and 1.2 m wide aisles separated all plots. Shade treatments were a full su n and a 30% shade treatment, imposed by erecting onto each plot, a 1.2 m x 1.5 m five sided shade structure 1.2 m tall using four plastic posts (Dare Products, Inc., Battle Creek, MI), covered on all sides with shade cloth (DeWitt Company, Sikeston, MO). A gap between the shade cloth and the ground of no greater than 0.25 m permitted air movement. P lants treated with Nitrogin EL cowpea inoculant (EMD Crop BioScience, Milwaukee, WI) at the time of planting were transplanted into each whole plot at a density of 1.1 plants m 2 Irrigation was used for approximately 60 days post planting, only during dry periods, to ensure survival. Average rainfall, soil temperature, and air temperature at both l ocations are displayed in Fig. 2 1 Data collection Height and c anopy cover were determined on a bi weekly basis using a 1.0 m 2 frame, subdivided into 25 squares of equal dimension Pegs were driven into the ground at the corners of the frame in both t he sun and shade treatments to ensure that the same area was evaluat ed each time. Each square of the grid represented 4% of the total frame area. To calculate percent cover each grid square was rated a 0, 1, 2, 3, or 4 based on the rhizoma peanut ground cover of that square. The ratings for all squares were summed to yiel d the total plot cover Two height measurements were taken within the inner nine squares of the grid, from the ground to the top of the canopy in the squares with the greatest and least height. Canopy uniformity was calculated as the difference between the two height measurements of each sub plot. Maximum average height was the greatest average height measurement during each growing season. Number of weeks to achieve full cover (defined as 95% or

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30 greater canopy cover of each sub plot ) was calculated from th e date of emergence. Duration of full cover was determined for each growing season. Statistical analysis. Data were analyzed with a 3 way factorial in a split plot with plant selection as the main plot and shade treatment as the sub plot using the PROC GL IMMIX procedure of SAS Version 9.2 (SAS Institute Inc., Cary, NC). Locations were analyzed separately due to different planting dates. Plant selection year after planting, and shade treatment were tre ated as fixed effects and block was treated as a random effect. Comparisons among selection and treatment means used the Tukey Kramer adjustment at P Results Maximum average height. At Gainesville there were significant shade year, shade selection, and year selection interactions; therefore dat a are presented by year and by shade treatment (Table 2 3). During year 1, shade resulted in greater height for sel ections EX1 and EX4 The following year, nearly half of all selections including most forage types, were taller in shade Regardless of shad e treatment, all released forage types in year 2 were significantly taller than selections EX3, EX4, EX7, EX9, and narrow leaf At the Qui ncy location (Table 2 4) there were significant interaction s among shade, year, and s election Very few differences occurred between sun and shade plots during both years of the study. Compared to released forage types, 'Brooksville 68', EX4 and EX9 were significantly shorter in full sun during both years. Shade did not result in selection s that were consistently shorter across both years. Selection EX3 maintained the lowest height during both years, likely due to it being planted in year 2 at Quincy.

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31 Generally, height of experimental selections was similar to released ornamental type s at both locations. A majority of selections at Gainesville were significantly taller in year 2 compared to year 1 ( comparisons not shown ) A similar trend occurred at Quincy where X5 all were significantly taller in year 3, regardless of shade treatment (year comparison data not shown). Canopy uniformity. At Gainesville there was a shade selection interaction (Table 2 3) ; only year 2 data was analyzed since plots did not reach full canopy cover during the first year of the study. At Quincy, there was a shade year interaction. A majority of selections at both sites exhibited less uniform canopies (i.e. greater height variability) under shade compared to full sun, with the excep tion of EX8 at Gainesville and EX1 in year 3 at Quincy. However, at Quincy the variability under both shade treatments tended to decrease from year 2 to year 3 ( Appendix A; Table A 1 ). Compared to forage types, ornamental types and EX1, EX3, EX5, and EX9 a t Gainesville generally remained more uniform under shade. Most experimental selections at Quincy were more unif orm than forages in full sun Released ornamentals at Quincy were generally more uniform than forages in year 2 EX1 and EX3 at Quincy performed similar to released ornamentals Time to achieve full cover. At Gainesville there was a significant shade selection interaction (Table 2 3) The year effect was not analyzed because full cover was not reached in year 1 cover for both shade treatment s and EX9 did not achieve full cover in shade. Light did

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32 not influence time to achieve full cover, except for EX4 which took longer to reach full cover under shade. At Quincy, selection and sh ade year were significant factors The shade year interaction occurred due to a shorter evaluation period in year 2 (24 weeks in 2010 and 44 weeks in 2011 ; data not shown ) full cover significantly faste 2 5). Full cover duration. N o selections achieved full cover during the first year of the study at Gainesville and only second year data are presented (Table 2 3). Selecti on was a significant factor and cover for a longer duration than most forage type s and nearly all experimental selections. ly short duration of f ull Shade year and year selection were significant interactions at Quincy (Table 2 5). The shade year effect was a result of a shorter evaluation period in the first yea r of the study (data not shown) duration of full cover during year 2 EX3 did not reach full cover in year 2 d ue to its later planting; however during the following year its full cover duration was similar to many of the ornamental selections In year 2 EX8 displayed the longest full cover duration. In year 3 the same selections significantly outperformed most forage types and both narrow leaf types.

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33 Discussion Winter dorman c y resulted in the complete dieback of plots and subsequent regrowth beginning in the spring. During year 1 at Gainesville, no selections ach ieved full cover, but nearly all selections did by year 2. Therefore, establishment of rhizoma peanut, as measured by full canopy cover, does not occur until at least the year following planting. This is also supported by data from the Quincy location, whe re nearly all selections achieved full cover during year 2. Additionally, in Quincy, full cover did not occur any faster in year 3 than in year 2, implying that establishment as measured by full cover likely occurred as early as year 2. At both locations, maximum average height increased during the second year of the study compared to the first year indicating that rhizoma peanut will likely continue to increase in height for at least two years following planting. At Gainesville, shade year was likely s ignificant due to lower heights during year 1 when canopies had not achieved full cover. At both locations, narrow leaf types performed poorly as indicated by their failure to reach full cover or a relatively short duration of full cover. Therefore, they a re not recommended for ornamental use based on the parameters of the study. cover at both locations. Selections recommended for ornamental use based on a lon g duration of full cover Based on height data alone, selections EX3, EX4, and EX9 show the greatest ornamental poten tial, as they generally achieved the shortest maximum height at both locations compared to forage types.

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34 type, confirming its previous recommendation as a dual use cultivar. Both released and proposed ornamental types generally had more uniform canopy heights than forage types; the use of these forage types for ornamental purposes is not supported by this study. and EX3 are best suited for ornamental use, due to their more uniform canopy heights In summary, the selections that have the greatest potential ornamental use based on all variables in Although preliminary observations proposed EX5 for ornamental use, it did not meet standards based on variables in this study. Shade did not effect the time to reach full cover or the duration of full cover, indicating that for these two variables, shaded plots will perform similarly to those in full sun. The duration of full cover was affected most by rhizoma peanut selection. Shaded plots emerged later in t he spring but full sun plots died back earlier in the fall (personal observation); this was not reflected in the duration of full cover data. As a result, successful ornamental performance may occur in both full sun and shaded conditions Both year and sha de affected height to varying degrees among selections. Therefore, selection is an important consideration for the ornamental use of rhizoma peanut. However, the response was not consistent between locations. For example, at Quincy, very few selections sho wed height differences based on shade treatment, indicating that most selections perform equally in sun or 30% shade conditions. At Gainesville nearly half of all selections grew taller under shade in year 2. This implies that once plots are established ( i.e. have reached full cover), greater maximum heights will be achieved

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35 under shade. At both locations, shaded plots had significantly less canopy uniformity than full sun plots for most of the selections, indicatin g that an ornamentally desirable uniform canopy is less likely to occur under shaded conditions. At Quincy, the interaction between shade treatment and year implies that regardless of selection, effects of shade are in consistent from year to year. Therefore, selections do not perform similarly ba sed on shade treatment for at least the first two years following planting. Narrow leaf types performed poorly at the Gainesville location, possibly due to a smaller root system noted for narrow leaf types growing in containers (p ersonal observation) or a low water holding capacity o f the coarse textured soil. At Quincy, forage types had a slower rate of c over than many ornamental types. F orage types at Gainesville reached full cover at the same rate as many of the ornamental types Long term studies are required to determine if the trends observed in this study continue over time. Further research is needed to determine management practices for rhizoma peanut grown for ornamental use. Since this plant is dormant during winter, man agement during this time needs to be explored further. There is the possibility that other plant species may be grown over dormant rhizoma peanut during this time, but little research has been devoted to the compatibility of cool season crops with rhizoma peanut. Mowing may be particularly important for aesthetics and may allow a wider range of rhizoma peanut germplasm to be used ornamentally. Maximum canopy height and non uniformity of canopies may be reduced through proper mowing methods; however naturall y low growing selections have the potential to greatly reduce or eliminate mowing when low maintenance landscape practices are desired. Additionally,

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36 since canopy cover parameters are not greatly affected by shade, achieving an ornamentally desirable low h eight and height variability through mowing would eliminate the negative effects of shade on these variables. Preliminary studies have indicated that rhizoma peanut responds well to mowing practices that are used to control height (Aldrich et al., 2012), b ut further work is needed in this area. Furthermore, flowering characteristics as well as ornamental aesthetic qualities of rhizoma peanut will play a critical role in recommending selections for ornamental use.

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37 Table 2 1. Field characteristics at two ex perimental locations. Mehlich 3 extractable macro and micro nutrients are expressed in mg kg 1 Parameter Quincy Gainesville Date of planting July 2009 May 2010 Lat./Long. 30.54, 84.59 29.80, 82.41 pH 5.7 5.7 P (ppm) 110.0 281.3 K (ppm) 56.0 34.7 S (ppm) 12.3 15.7 Mg (ppm) 108.6 28.6 Ca (ppm) 366.3 404.0 B (ppm) 0.2 0.3 Zn (ppm) 2.4 2.1 Mn (ppm) 18.0 3.4 Fe (ppm) 140.4 138.2 Cu (ppm) 0.8 2.8 Mo (ppm) 0.3 0.4 Total rainfall du ring study (mm) 1680.2 1637.5 30 year average rainfall (mm) 2536.4 1935.5

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38 Table 2 2 Released cultivars and experimental selections of rhizoma peanut used in the study. Selection /line no. Exp. name/PI z Proposed Use y Released PI 262817 Forage PI 658529 Dual Use PI 151982 Forage PI 658214 Forage PI 262826 Forage PI 262801 Ornamental NRCS #9056068 Ornamental Experime ntal EX1 Apalachee Ornamental EX2 Arlo Forage EX3 Chico Ornamental EX4 Chiquita Ornamental EX5 Cowboy Unknown EX6 QS 5W Forage EX7 QS 6WA Forage EX8 QS 6WB Dual Use EX9 Suwannee Ornamental z Exp. = experimental name of unreleased line s, as of this publication ; PI = Plant Introduction nomenclature given by USDA. y Proposed use was determined from observational data at the North Florida Research and Education Center preceding the study.

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39 Table 2 3. Plant attributes of A. glabrata selecti ons in Gainesville. Maximum average height Canopy uniformity v Time to achieve full cover v Full cover duration v Year 1 z Year 2 Year 2 Year 2 Year 2 Selection Sun Shade Sun Shade Sun Shade Sun Shade ----------------------------------------------cm --------------------------------------------------------------weeks -------------------Released 'Arbrook' 24.8 a y 22.1 a 34.8 a 36.4 ab 8.5 a B 12.2 a A 23.3 ab 24.0 bcd 5.8 e fg 'Brooksville 67' 8.1 d 8.1 de 17.5 bcde B 25.0 def A 4.2 defg 4.6 def 16.5 bc 17.0 d 25.0 a 'Brooksville 68' 9.2 d 7.8 de 8.8 ef 10.3 i 2.5 fg B 3.3 f A -x -0.0 g 'Ecoturf' 11.9 bcd 14.6 bc 25.1 abc B 32.1 abcd A 5.6 bcd B 7.9 b A 21.0 abc 22.0 bcd 20.5 abc 'Florigraze' 15.9 b 17.9 ab 26.3 ab B 30.8 abcd A 5.6 bcd B 6.8 bc A 20.0 abc 22.0 bcd 11.0 def 'UF Peace' 15.2 bc 17.8 ab 26.3 ab B 34.6 abc A 6.4 bc B 8.0 b A 20.0 abc 18.5 cd 19.8 abcd 'UF Tito' 14.8 bc 17.9 ab 26.8 ab B 34.1 abc A 6.7 abc 7.9 b 24.0 ab 25.5 b 4.8 efg Experimental EX1 9.9 cd B w 10.4 cde A 18.9 bcd 19.8 fgh 4.0 defg 4.2 ef 16.0 c 17.5 d 24.3 a EX2 11.8 bcd 13.3 bcd 29.6 a B 39. 3 a A 5.0 bcde B 7.1 bc A 18.5 abc 19.0 cd 14.0 bcde EX3 7.0 d 7.3 e 11.1 def 13.6 ghi 2.5 fg B 3.2 f A 18.5 abc 19.0 cd 23.3 ab EX4 8.6 d B 11.8 cde A 16.0 cdef 20.2 fg 4.2 defg B 8.6 b A 26.0 a B 40.0 a A 3.5 fg EX5 9.9 cd 12 .3 bcde 6.8 f 9.2 i 2.2 g B 3.2 ef A --0.0 g EX6 8.2 d 9.7 cde 18.1 bcde B 26.2 cdef A 4.4 def B 6.7 bcd A 21.0 abc 21.3 bcd 13.3 cde EX7 8.2 d 9.9 cde 15.8 cdef 21.5 efg 4.8 cde B 6.7 bcd A 24.5 a 24.0 bc 11.8 cdef EX8 9 .2 d 11.1 cde 26.8 ab 29.4 bcde 6.9 ab A 5.6 cde B 17.0 bc 17.5 d 24.8 a EX9 9.3 d 9.1 cde 12.7 def 11.3 hi 3.3 efg 3.9 ef 25.3 a -3.3 fg z Year after planting data for year 1 represents the number of weeks to attain 95% coverage after the study began on June 30, 2010 ; the field was planted in May, 2010. y Means within columns with the same lowercase letter are not statistically different by the Tukey Kramer test at P x Indicates that full cover was not achieved for a particula r selection.

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40 w Only means within rows for a given year and attribute with different uppercase letters are statistically different by the Tukey Kramer test at P v Only year 2 data are presented because plots did not achieve full cover in year 1.

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41 Ta ble 2 4. Plant attributes of A. glabrata selections in Quincy. Maximum average height Canopy uniformity Year 2 z Year 3 Year 2 z Year 3 Selection Sun Shade Sun Shade Sun Shade Sun Shade ------------------------------------------------------------------------cm ----------------------------------------------------------------------Released 'Arbrook' 26.6 abcd y 31.9 bcde 44.4 a 42.3 a 11.5 a 13.4 a 10.8 a B 13.7 a A 'Brooksville 67' 20.2 ghi 27.9 def 30.8 cdef 31.5 def 5.1 efg B 7.9 cd A 6.4 bcdefg 6.2 defg 'Brooksville 68' 13.8 ij 18.4 g 29.1 ef 32.3 cdef 5.0 f B 7.7 cd A 4.9 fg B 7.0 cdefg A 'Ecoturf' 31.8 bcde 33.7 abcde 35.2 bcde 36.7 bcd 6.5 def B 8.1 cd A 7.4 bcd 7.9 bcd 'Florigraze' 29.2 def 28.5 def 37.6 bcd 35.8 bcd 7.9 bcde B 10.4 abc A 6.3 cdefg B 8.0 bcd A 'UF Peace' 37.8 abc 37.4 ab 41.4 ab 38.7 ab 9.8 abc B 12.9 ab A 7.8 bc 8.5 bc 'UF Tito' 38.9 ab 36.3 abc 38.0 abc 39.9 ab 10.3 ab 10.8 abc 8.3 b B 9.9 b A Experimental EX1 22.3 fgh 26.9 ef 32.5 cdef 27.9 f 6.2 ef 5.9 d 6.5 cdef A 5.2 g B EX2 43.6 a 40.4 a 40.7 ab 37.4 abc 9.2 abcd 9.4 c 7.1 bcde 8.0 bcd EX3 x 9.5 j 8.9 h 16.8 g B 20.3 g A 2.1 g 2.3 e 4.8 g 5.4 fg EX4 19.3 hi B w 27.8 def A 27.3 f 30.1 ef 6.9 cdef 8.1 cd 5.5 efg 5.9 efg EX5 22.6 fgh 22.6 fg 31.1 def 31.8 def 7.3 cdef B 9.2 c A 5.8 defg B 7.4 cdef A EX6 3 3.4 bcde 34.5 abcd 35.2 bcde 34.6 bcde 7.5 bcdef B 9.4 c A 7.1 bcde 7.5 cde EX7 28.1 efg 29.9 cde 33.4 cdef 34.6 bcde 6.6 def 8.1 cd 6.0 defg B 7.2 cdefg A EX8 30.2 cdef 32.4 bcde 32.6 cdef 29.4 ef 7.9 bcde 8.1 cd 6.1 defg 6.7 cdefg EX9 18.8 hi B 27.8 def A 29.0 ef 32.3 cdef 6.8 def B 10.2 bc A 4.8 g B 6.7 cdefg A z Year after planting data for year 2 represents the maximum average height after the study began on June 30, 2010 ; the field was planted in July, 2009 y Means within columns with the same lowercase letter are not statistically different by the Tukey Kramer test at P x Selection EX3 was planted one year later than the other selections at the Quincy location. w Only means within rows for a given yea r and attribute with different uppercase letters are statistically different by the Tukey Kramer test at P

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42 Table 2 5. Canopy cover attributes of A. glabrata selections at the Quincy location. Time to achieve full cover Full cover duration Sel ection Year 2 z Year 3 ---------------------weeks -----------------------Released 'Arbrook' 18.5 a y 0.0 e B x 6.8 f A 'Brooksville 67' 4.8 c 22.8 a B 29.7 a A 'Brooksville 68' 11.0 abc 0.0 e B 14.8 e A 'Ecoturf' 6.4 b c 23.0 a 25.5 abc 'Florigraze' 12.5 ab 0.5 e B 5.8 f A 'UF Peace' 6.1 bc 15.0 b B 25.5 abc A 'UF Tito' 12.7 ab 0.3 e B 14.8 e A Experimental EX1 6.4 bc 21.5 a B 27.8 ab A EX2 4.0 c 6.5 cd B 15.5 e A EX3 w 16.3 a 0.0 e B 2 2.0 bcd A EX4 12.0 ab 9.3 c B 20.8 cde A EX5 7.5 bc 2.5 de B 15.8 e A EX6 5.3 c 21.3 a B 25.3 abc A EX7 4.6 c 22.5 a B 26.5 abc A EX8 4.0 c 22.5 a B 30.0 a A EX9 5.9 bc 10.8 bc B 18.0 de A z Year after planting data for year 2 rep resents the number of weeks to attain 95% coverage after the study began on June 30, 2010 ; the field was planted in July, 2009 y Means within columns with the same lowercase letter are not statistically different by the Tukey Kramer test at P x Only means within rows for a given attribute with different uppercase letters are statistically different by the Tukey Kramer test at P w Selection EX3 was planted one year later than the other selections at the Quincy location.

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43 Figur e 2 1. Average monthly air temperature, soil temperature, and rainfall during the experimental period; June, 2010 to January, 2012.

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44 CHAPTER 3 ORNAMENTAL GROUNDCOVER CHARACTE RISTICS OF RHIZOMA P EANUT ( Arachis glabrata Be nth .): SHADE REDUCES FLOWERING BU T NOT VISUAL QUALITY Introduction Rhizoma peanut ( Arachis glabrata Benth.) is a leguminous, herbaceous, nitrogen fixing, warm season pe r ennial native to South America It has been used almost exclusively as a forage crop i n the United States since the 1930s. Grown in USDA hardiness zones 8b and greater, rhizoma peanut is best adapted to coarse, sandy soils and the mild climate associated with peninsular Florida and the U.S. Southern Coastal Plain (Prine et al., 1990 ; Ocumpa ugh, 1990 ; Terrill et al., 1996). However, its utility as an ornamental groundcover has not been realized Ext ensive colonization of the soil by its rhizomes, make it drought tolerant and persistent once established (Ortega S. et a l., 1992; Prine et al., 1990). Additionally, it is pest and disease resistant (Baltensperger at al., 1986; Quesenberry et al., 2010), fixes nitrogen to support its growth ( Venuto et al., 1998), produces abund ant flowers and has a high aesthetic quality as an ornamental groundcover (Prine et al., 2010). Rhizoma peanut has the potential to be utilized in diverse situations, including roadside and right of way plantings, as an ornamental or utility turf, in cludin g areas where mowing is difficult such as sloped or uneven terrain. It has also been shown to successfully stabilize erosion prone areas (French et al., 2001, revised 2006). Rhizoma peanut has received little attention for its potential use as an orn a ment al groundcover Rhizoma peanut has been shown to outperform St. Augustinegrass ( Stenotaphrum secundatum Kuntze) during drought conditions, as measured by leaf

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45 color and visual appearance (Prine et al., 2010); it persists during dry conditions that would no rmally kill St. Augustinegrass (French et al., 2001, revised 2006). Currently, Flowers are produced daily (Prine et al., 2010), typically open at sunrise and wilt by mid afternoon (Simpson et al., 1 994). Flowering is increased by warm temperatures, full sun, soils with low fertility, and under mowing (French et al., 2001, revised 2006). Flowers are yellow to yellow orange in color and are most abundant during the months of June August. Previous resea rch on rhizoma peanut has focused almost entirely on the forage with the exception of al., 2006b). and glossy, waxy leaves which increase its visual quality and impart pest resistance (Maura et al., 2006a). (Maura et al., 2006b), promoting its suitability as an ornamental groundcover. characterized by prolific flower production and has been shown to produce 150 to 250 flowers m 2 over two years (Prine et al., 2010) Successful cultivation of rhi zoma peanut in a shaded environment allow s for a greater diversity of planting locations However, no selections have been evaluated for ornamental qualities in full sun vs. shaded environments as measured by flowering numbers and aesthetic quality. Furthe rmore, many selections overlooked in forage evaluations may have desirable ornamental characteristics. Water resource scarcity, as a result of population needs, and the overuse of chemical fertilizers have di c tated the need for environmentally friendly gro undcovers. Rhizoma peanut has the potential to fill

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46 this need; however, ornamentally impo r tant characteristics have not been studied among cultivars (Prine et al., 2010). Additionally, new ornamental cultivars will expand the commercially available germpla sm diversity. T he objectives of this study are to characterize the number of flowers produced and the duration of acceptable visual quality of previously released cultivars and new selections of rhizoma peanut, in full sun and under shade. These character istics were used to select germplasm with abundant flower production and a high aesthetic quality to propose selections for ornamental use. Materials and Methods Field locations. Plots were located at the North Florida Research and Education Center, Quincy FL (Norfolk loamy fine sand: fine loamy, kaolinitic, thermic Typic Kandiudult ) and the Agronomy Forage Research Unit, Gainesville, FL (Chipley sand: thermic, coated Aquic Quartzipsamment ) (Table 2 1; United States Department of Agriculture, 2012). The Qu incy field was previously planted with Bahiagrass ( Paspalum notatum ) and the Gainesville field had fescue ( Festuca sp.) and clover ( Trifolium sp.) growing in it prior to the study. The Quincy field was sheet fumigated with methyl bromide (448 kg ha 1) prio r to planting ; in Gainesville disking and leveling occurred prior to planting The field in Quincy was planted in July, 2009, approximately one year prior to the start of the study and was replicated in Gainesville one month before data collection began at both locations on June 28, 2010. Weeds in plots and aisles were controlled by hand weeding and herbicides; glyphosate (1.12 L a.i. ha 1 ), imazapic (70.6 g a.i. ha 1 ), and clethodim (0.15 L a.i. ha 1 ), with the additional use of 2,4 DB (0.55 L a.i. ha 1 ) i n Gainesville. No soil amendments or fertilizers were applied at either location.

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47 Experimental design. Whole plots, each measuring 1.8 m x 3.0 m, were replicated four times in a split plot design, with plant selection as the main plot and shade treatment as the sub plot. Whole plots were arranged in a randomized complete block design. Rhizomes of sixteen selections (Table 2 2 ) vegetatively propagated from greenhouse grown plants in Quincy, were divided and potted into 0.55 and 0.43 L containers, 3 and 5 months prior to planting in Gainesville and Quincy, respectively. Whole p lots were oriented north south across the longest dimension and 1.2 m wide aisles separated all plots. Shade treatments were a full sun and a 30% shade treatment, imposed by erecting onto each plot, a 1.2 m x 1.5 m five sided shade structure 1.2 m tall using four plastic posts (Dare Products, Inc., Battle Creek, MI), covered on all sides with shade cloth (DeWitt Company, Sikeston, MO). A gap between the shade cloth and the ground of no greater than 0.25 m permitted air movement. P lants treated with Nitrogin EL cowpea inoculant (EMD Crop BioScience, Milwaukee, WI) at the time of planting were transplanted into each whole plot at a density of 1.1 plants m 2 Irrigation was used for approx imately 60 days post planting, only during dry periods, to ensure survival. Average rainfall, soil temperature, and air temperature at both l ocations are displayed in Fig. 2 1 Data collection Number of flowers and visual quality were determined on a bi weekly basis using a 1.0 m 2 frame, subdivided into 25 squares of equal dimension Pegs were driven into the ground at the corners of the frame in both t he sun and shade treatments to ensure that the same area was evaluated each time. Flowers visible above the canopy were counted within the frame on the same day for all plots. Number of flowers was normalized based on the canopy coverage at the time when flower

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48 counts occurred. Bi weekly flower counts were averaged across each season. Visual quality was rate d on a scale from 1 5, where 1=no living foliage present, 2=poor quality (no green color present, greater than 50% chlorosis/necrosis), 3=fair quality (very little green color present, 25 50% chlorosis, some necrosis,), 4=good quality (overall light green color, less than 25% chlorosis, minor necrosis), 5=excellent quality (overall dark green color, minor chlorosis, no necrosis). Duration of acceptable visual quality was defined as the number of weeks that plots received a rating of at least 4 on the visual quality scale. Statistical analysis. Data were analyzed with a 3 way factorial in a split plot with plant selection as the main plot and shade treatment as the sub plot using the PROC GLIMMIX procedure of SAS Version 9.2 (SAS Institute Inc., Cary, NC). Locations were analyzed separately due to different planting dates. Plant selection and shade treatment were tre ated as fixed effects and block was treated as a random effect. Year was not analyzed for duration of acceptable visual quality due to a shorter evaluation period in year 1. When needed, data were transformed using the square root transformation to correct for non normal distribution and non homogeneity of variance. Comparisons among selection and treatment means used the Tukey Kramer adjustment a t P Results Mean number of flowers by season. At both locations there were significant year season shade treatment and year season selection interactions; therefore data are presented by cultivar by season, and by shade treatment by season ( Tables 3 3 and 3 4). Full sun resulted in significantly greater flower production during all seasons of the study at both locations. At Gainesville, flowering varied seasonally based on year; regardless of shade treatment, the greatest number of flowers o ccurred during

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49 the summer of year 2, followed by fall of year of 1, spring of year 2, summer of year 1, and then fall of year 2. At Quincy flowering by season across both shade treatments did not follow a clear pattern. Generally, the greatest flowering oc curred in summer of both years, followed by spring of year 3, with lowest flower production occurring in fall of both years. At Gainesville, few differences occurred among selections during spring of year 2. During summer of year 2 when flowering was grea test, EX1, EX3, EX5, and EX7 were similar to released ornamental type generally had greater flower production than released forage types EX9 had significantly more flowers than any other selection during this s eason. Fall of year 2 had very low flower production and therefore comparisons during this season were not made. Data are shown for informational purposes only. t was comparable to EX1, EX3, and EX9. In the summer of year 1, released ornamental type s had similar flower numbers and were the same as released forage types. Additionally during this season, similar to most remaining experimental selections. Selections with low flower production throughout the Experimental selections with high rates of flower production during the months of greatest flowering included EX1, EX3, EX5, and EX9. fall of year 3. forage types. During summer of year 2, when flow

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50 outperformed all other selections. majority of experimental selections during both summers. During spring of year 3, when compared to EX5 and EX9, which both outperformed most remaining experimental selections. In fall of year 2, EX3 had the greatest flower production. Overall, during and EX9 generally produced the most abundant flowers. The lowest flower production during the study occurred for EX4, EX6, EX7, EX8, as well as most forage types. Duration of acceptable visual quality. At Gainesville, selection year was a significant interaction (Table 3 5). Comparing selections, shade treatment had no significant effect on the period of acceptable visual quality. During year 1 only, Additionally, EX1, EX3, EX6, and EX8 to remaining experimental selections. The lowest duration of acceptable quality occurred for During year 2, fewer differences occurred among selections. Released ornamental types had equivalent weeks of acceptable quality compared to all experimental selections except EX2 and EX9, which both had relative ly poor performance. outperformed EX2, EX7, and EX9 during this year. At Quincy, selection year and selection shade were the only significant interactions; therefore data are presented by selection for both years and both shade treatments (Table 3 5). During year 2, EX1 and EX3 had a greater duration of

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51 acceptable visual quality than released ornamental types and experimental selections EX2, EX4, EX5, and EX9. However, EX3 was planted later than the remaining selec tions, possibly influencing this result. In year 3, few differences occurred among selections; released ornamental types were similar to nearly all experimental selections except EX4 and EX9. only selection that had a significant difference based on shade treatment; shaded plots had a greater duration of acceptable quality. Under both shade treatments, released Under Discussion At both locations, forage and dual use types generally produced fewer flowers than released ornamental types and some experimental selections. At Quincy, f ewer flowers produ ced by forages as well as most selections during year 3 can be explained by taller plant heights which obscured flowers in the canopy (personal observation). Height data showed that forage types generally grew taller than ornamental types and that plant he ight generally increased for at least two years after planting. The greatest flower production occurred during the summer months; the next greatest months of flower production differed by location. Generally, lower flower production occurred during the fal l, possibly due to lower temperatures and the onset of leaf senescence resulting in overall decline of the plants. Selection interactions at both locations for the duration of acceptable visual quality indicate that selection is an important factor for the ornamental use of rhizoma peanut. Selection year interactions occurred due to a different length of evaluation during each year of the study (24 weeks in 2010 and 44 weeks in 2011) and were not analyzed. In general, shade treatment did not affect the

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52 du ration of acceptable visual quality, indicating that rhizoma peanut performs equally in full sun and under shade. nths of overall moderate to high flower production. These selections are therefore best suited for ornamental use if abundant flower production is desired during warmer months. EX4 and EX8 had low flower production compared to remaining selections, making them less suitable for ornamental use. Height and cover data determined that low height and high canopy cover. The flower production data from thi s study indicates that these selections are validated for ornamental use. based on height and canopy cover, its ornamental use is not supported in this study due to low flower production at both locations. Across both years and locations, the duration of acceptable visual quality at the Gainesville location, i t achieved low can opy cover and it is not recommended for ornamental use in a coarse textured soil environment like that found at Gainesville. Based on duration of acceptable visual quality, it was not among the top performing selections at the Quincy loca tion. In summary, selections EX1 and EX3 achieved the greatest flower numbers as well as the greatest duration of acceptable visual quality and are therefore highly recommended for ornamental use. Their use is further validated by their low height and high canopy cover

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53 However, narrow leaf Leptosphaerulina crassias ca ) throughout the study which reduced their visual quality. Although EX9 achieved very high rates of flower production, its very low period of acceptable visual quality diminishes its acceptability for ornamental use. No forage types are recommended for o rnamental use based on this study due to l ow flower production and a low duration of acceptable visual quality. its low period of acceptable visual quality due to the presence of peanut stunt vir us, well documented in past studies ( Quesenberry et al., 2010 ) precludes its use as an ornamental. Compared to the 30 year rainfall average (Florida State University, 2011), rainfall during the experimental period at both locations was less than normal. De spite this, the rhizoma peanut germplasm evaluated in this study achieved high visual quality an d substantial flower numbers. When evaluating flowering as an ornamental attribute of rhizoma peanut, season of the year, shade treatment, and selection must b e considered. Overall, full sun resulted in greater flower production, regardless of year, implying that the ornamental value of rhizoma peanut, if measured by flower production, will be much greater in full sun compared to 30% shade. This agrees with flow ering characteristics described by French et al. (2001, revised 2006). Growing rhizoma peanut under shade had a negative impact on its ornamental quality based on flowering and height data from this study Taller canopies tended to obscure flowers produced lower in the canopy. Although it wa s not investigated, a short flower stalk (hypanthium) of some selections may be responsible for flowers not reaching the top of the canopy and becoming visible.

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54 Shade had relatively no effect on visual quality; therefore if this factor is of primary importance growing rhizoma peanut under shade may be acceptable from an ornamental standpoint. While locations are not directly comparable due to different planting dates, greater flower production at Gainesville compared t o Quincy may be a result of the coarse textured, low fertility soils at Gainesville, which increased flowering, as noted by French, et al. (2001, revised 2006). Low flowering during year 1 in Gainesville can be explained by lack of establishment of plants in this year. At both locations, fewer differences among selections occurred during the second year of the study, indicating that visual quality differences were not as apparent as plants became established. However, a long term study is needed to validate this over a period greater than two years. Further work is needed to determine management practices appropriate for ornamental rhizoma peanut. Mowing has been cited as a means to increase flower production (French et al., 2001, revised 2006); in a prelim inary study by Aldrich et al., (2012), mowing resulted in increased flower numbers and increased visual quality for some selections evaluated. Additionally, the presence of pepper spot was reduced as a result of mowing. However, selections that achieve hig h flower production and acceptable visual quality with little or no mowing have the potential to reduce maintenance needs and the associated costs. Future work is needed to determine the effects of mowing on ornamental characteristics of rhizoma peanut ove r the long term and to compare selections that display the greatest ornamental potential. Possible criteria for future selections of rhizoma peanut include a longer hypanthium length and flower p roduction earlier in the season, extending later into the fal l.

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55 Table 3 1 Mean flower number and shade effects over two years of A. glabrata selections in Gainesville. Flowering data are normalized based on canopy cover at the time of data collection. Year 1 z Year 2 Selection Summer Fall Spring Summe r Fall ---------------------------------flowers (m 2 ) -----------------------------------Released 'Arbrook' 9.1 abcd y A x 5.9 ef AB 2.5 abc BC 7.2 h AB 0.1 f D 'Brooksville 67' 16.8 ab B 46.5 a A 8.4 ab B 52.1 bc A 0.8 cde f C 'Brooksville 68' 3.9 bcd BC 11.3 cde B 5.6 abc BC 54.5 bc A 5.7 b BC 'Ecoturf' 8.6 abcd B 17.8 bcde A 2.3 abc C 18.1 fg A 0.2 ef C 'Florigraze' 15.7 ab A 21.1 bc A 5.0 abc B 28.5 def A 0.6 cdef C 'UF Peace' 10.0 abc C 25.8 abc B 8.0 abc C 46.4 bcd A 2.2 bcd D 'UF Tito' 3.3 bcd B 2.0 f B 1.3 bc BC 15.2 fgh A 0.2 def C Experimental EX1 24.4 a B 35.0 ab B 5.0 abc C 65.6 b A 2.7 bc C EX2 17.0 ab A 20.6 bcd A 3.6 abc B 28.5 def A 0.3 def C EX3 9. 7 abc C 34.5 ab B 5.8 abc C 61.6 bc A 2.9 bc CD EX4 0.2 d BC 1.8 f B 0.6 c BC 11.9 gh A 0.8 cdef BC EX5 5.7 abcd BC 13.3 cde B 4.7 abc BC 65.1 b A 6.1 ab BC EX6 2.3 bcd C 12.1 cde B 1.8 abc C 28.7 def A 1.1 cdef C EX7 5.4 abcd C 15.6 cde B 2.6 abc CD 41.0 cde A 1.9 bcde CD EX8 1.0 cd C 7.5 def B 1.5 bc C 26.7 ef A 0.8 cdef C EX9 9.7 abc CD 46.8 a B 11.9 a CD 111.7 a A 12.3 a C Radiation Sun 8.9 a y C x 21.4 a B 4.9 a D 48.6 a A 2.4 a E Shade 6.3 a C 13.3 b B 3.1 b D 27.0 b A 1.0 b E z Year after planting data for year 1 represents canopy unifo r mity after the study began on June 30, 2010 ; the field was planted in May, 2010

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56 y Means within columns with the same lowercase letter are not statistically differ ent by the Tukey Kramer test at P x Means within rows with the same uppercase letters are not statistically different by the Tukey Kramer test at P

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57 Table 3 2 Mean flower number and shade effects over two years of A. glabrata selections in Quincy. Flowering data are normalized based on canopy cover at the time of data collection. Year 2 z Year 3 Selection Summer Fall Spring Summer Fall ---------------------------------flowers (m 2 ) -----------------------------------Re leased 'Arbrook' 13.7 cde y A x 0.6 ef CDE 1.4 cd BC 2.3 fg B 0.0 cd DE 'Brooksville 67' 22.1 bcd A 0.8 def CD 2.0 cd C 6.1 efg B 0.1 bcd D 'Brooksville 68' 62.4 a A 8.4 b C 13.7 a BC 20.6 bc B 0.9 ab D 'Ecoturf' 9.6 defg A 0.3 f CD 1.2 cd C 4.1 fg B 0.2 bcd CD 'Florigraze' 24.0 bc A 4.0 bcd C 5.3 abc C 12.1 cde B 0.6 abc D 'UF Peace' 7.8 efg A 0.6 ef B 0.3 d B 6.6 ef A 0.5 abcd B 'UF Tito' 6.3 efg A 0.2 f D 1.4 cd C 3.0 fg B 0.1 cd D Ex perimental EX1 20.3 bcd A 1.2 cdef BC 3.6 bcd B 17.6 c A 0.4 abcd C EX2 9.6 def A 0.5 ef B 0.8 cd B 6.7 def A 0.5 abcd B EX3 w 36.0 b A 23.0 a A 2.9 cd B 28.8 ab A 0.5 abcd B EX4 3.2 fg A 0.3 f BC 0.6 cd B 2.7 fg A 0. 0 d C EX5 29.2 b A 2.6 cde C 11.6 ab B 14.0 cd B 0.5 abcd C EX6 2.6 g A 0.1 f B 0.2 d B 1.7 g A 0.0 cd B EX7 7.8 efg A 0.5 ef BC 1.4 cd B 4.9 fg A 0.2 bcd C EX8 4.4 fg A 0.2 f B 1.2 cd B 6.1 ef A 0.2 bcd B EX9 31.3 b A 4.8 bc BC 11.6 ab B 34.3 a A 1.1 a C Radiation Sun 18.9 a y A x 2.6 a D 5.0 a C 11.8 a B 0.4 a E Shade 12.2 b A 0.9 b C 1.1 b C 6.5 b B 0.2 b D z Year after planting data represents canopy unifo r mity after the study began on June 30, 2010 ; the field was planted in July, 2009 y Means within columns with the same lowercase letter are not statistically different by the Tukey Kramer test at P x Means within rows with the same uppercase letters are not statistically different by th e Tukey Kramer test at P w Selection EX3 was planted one year later than the other selections at this location.

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58 Table 3 3 Duration of acceptable visual quality of A. glabrata selections at two locations. Quincy Gainesville Selection Year 2 z Year 3 Sun Shade Year 1 z Year 2 --------------------------------------weeks --------------------------------------Released 'Arbrook' 13.3 cdef y 32.0 ab 19.0 abc 26.3 ab 7.5 def 33.5 ab 'Brooksville 67' 12.7 cde f 32.0 ab 21.3 abc 23.3 ab 20.3 a 36.8 a 'Brooksville 68' 11.0 def 30.0 ab 19.0 abc 22.0 ab 10.3 de 32.0 ab 'Ecoturf' 16.0 bcd 31.3 ab 21.3 ab 26.0 ab 12.5 bcd 33.8 ab 'Florigraze' 7.5 f 10.6 d 4.9 c B x 12.5 b A 2.0 f 16.5 c 'UF P eace' 15.3 cde 33.8 a 22.8 a 26.3 ab 13.5 bcd 30.5 ab 'UF Tito' 15.3 cde 33.8 a 22.5 a 26.5 ab 13.0 bcd 32.0 ab Experimental EX1 22.0 ab 33.3 a 27.3 a 28.0 a 21.0 a 34.8 ab EX2 7.5 f 26.8 bc 16.0 abc 18.3 ab 6.0 ef 19.5 c EX3 w 24.0 a 35.3 a 29.8 abc 29.5 a 20.3 a 36.3 a EX4 13.0 cdef 22.3 c 14.3 abc 21.0 ab 11.3 cde 33.8 ab EX5 11.3 def 29.8 ab 19.3 abc 21.8 ab 10.3 de 29.4 ab EX6 17.8 abc 31.3 ab 22.8 a 26.3 ab 18.0 ab 31.5 ab EX7 18.8 abc 30.3 ab 23.3 a 25.8 ab 9.5 de 28.8 b EX8 18.5 abc 30.8 ab 22.8 a 26.5 ab 16.5 abc 31.5 ab EX9 9.0 ef 23.8 c 15.0 ab 17.8 ab 6.0 ef 19.5 c z Year after planting data for year 2 in Quincy and year 1 in Gainesville represents can opy unifo r mity after the study began on June 30, 2010 ; the fields were planted in July, 2009 and May, 2010, respectively y Means within columns with the same lowercase letter are not statistically different by the Tukey Kramer test at P x Means within rows for shade treatments with different uppercase letters are statistically different by the Tukey Kramer test at P w Selection EX3 was planted one year later than the other selections at this location.

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59 CHAPTE R 4 CONTAINE R PRODUCTION OF RHIZ OMA PEANUT ( Arachis glabrata Benth .): NITROGEN FERTILIZATI ON AFFECTS PLANT SIZ E, FLOWERING, VISUAL QUALITY, AND SALABIL ITY Significance to the Nursery Industry Rhizoma peanut is an ecologically friendly groundcover and has the potentia l to greatly reduce inputs such as fertilizers, pesticides, and herbicides that have been associated with environmental degradation. However, little is known regarding its production under conventional nursery methods. In order to successfully produce and market this plant, growers need to know the best methods of production, namely fertilization as it affects growth rate and characteristics of salability. The goal of this study was to determine the optimal nitrogen rate for c ontainer production as it affec ts plant size, flowering, visual quality, and plant form. Salable plant material was produced within 90 days of planting rhizome divisions, with relatively low rates of nitrogen in comparison to standard nursery crops; however the overall percentage of sal able plants was low. Future work is needed to elucidate causes of variability across selections, determine potential micronutrient issues, establish the appropriate length of production in various container sizes, and examine seasonal effects on production Introduction Rhizoma peanut ( Arachis glabrata Benth.) is a leguminous, herbaceous, nitrogen fixing, warm season pe r ennial native to South America. It has been used almost exclusively as a forage crop in the United States since the 1930s. Grown in USDA hardiness zones 8b and greater, rhizoma peanut is best adapted to coarse, sandy soils and the mild climate associated with peninsular Florida and the U.S. Southern Coastal Plain (Prine et al., 1990 ; Ocumpaugh, 1990 ; Terrill et al., 1996). However, its uti lity as

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60 an ornamental groundcover has not been realized Extensive colonization of the soil by make it drought tolerant and persistent once established (Ortega S. et al. 1992; Prine et al., 1990). Additionally, it is pest and disease resistant (Baltensperger at al., 1986; Quesenberry et al., 2010), fixes nitrogen to support its growth (Venuto et al., 1998), produces abundant flowers and has a high aesthetic quality as an ornamental groundcover (Prine et al., 2010). Rhizoma peanut has the potential to be utilized in diverse situations, including roadside and right of way plantings, as an ornamental or utility turf, in cluding areas where mowing is difficult such as sloped or uneven terrain. Previous research on rhizoma peanut has focused almost entirely on field grown plantings. have been suggested for ornamental use, however production methods have not been explored. The successful landscape use of this plant requires growers to be able to quickly, economically, and reliably produce it using conventional nursery production method s. Traditional container production usually requires the application of nitrogen; because rhizoma peanut fixes nitrogen, little or no applied nitrogen may be needed. Given the financial and environmental costs of excess nitrogen fertilization, growers woul d benefit by knowing the optimal rate to produce this plant in containers. Adjei and Prine (1976) determined that nodulation was greatly reduced as a result of nitrogen applica tion for container grown plants. In past research, nitrogen was not typically re quired by container grown legumes (Kchenmeister et al., 2012), or was applied at a low rate (Trindle and Flessner, 2003). However, a preliminary study on rhizoma peanut container

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61 production concluded that foliage cover and plant width increased as a resul t of nitrogen application (Knox et al., 2010). In contrast, flowering and visual quality were unaffected by the addition of nitrogen. Our hypothesis is that only a minimal amount of applied nitrogen is needed to significantly increase the growth rate of rhizoma peanut above that which occurs when no nitrogen is applied. The objectives of this study were to determine the minimum rate of nitrogen which produce d a salable plant as defined by high foliage cover, a large canopy with even foliage distribution, high visual quality, and abundant flower production. Data were used to recommend selections of rhizoma peanut that can be acceptably produced using conventional nursery production methods. Materials and Methods Experimental design. The study was conducte d at the North Florida Research and Education Center, Quincy, FL, in a conventional nursery production area covered with black weed fabric and exposed to full sun. A 90 day experimental period was chosen since this warm season perennial might be successful ly produced outdoors in summer, when it has maximum growth and flowering. Two separate experiments were conduced, from July to September in 2010, and from June to August in 2011. Average rainfall and maximum and minimum temperatures are shown in Fig. 4 1. Overhead irrigation of 2.5 cm in the morning and 2.5 cm in the evening was applied daily. Total solar radiation during the study was 20,149 and 24,477 W m 2 during experiments 1 and 2, respectively. Nine selections of rhizoma peanut (Table 4 1) w ere propa gated from rhizome divisions 3 months prior to planting in 11.0 L containers (Classic 1200, Nursery Supplies, Inc., Chambersburg, PA) using a substrate composed of 80:10:10 by volume pine bark:peat:sand (Graco Fertilizer Company, Cairo, GA). Initial contai ner

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62 substrate testing results are shown in Table 4 2. Three slow release nitrogen fertilizer rates were used, with six replications of each selection fertilizer combination arranged in a completely randomized design. Containers were evenly spaced with 30 c m between containers Fertilizer treatments included: no N fertilizer, 2.06 g N, and 8.24 g N/container, hereafter referred to as 0N, 1N, and 4N, respectively. Fertilizers were incorporated into the substrate prior to planting. Nitrogen was applied as poly mer coated, sulfur coated urea (Growers Fertilizer Corp., Lake Alfred, FL), with 0.90 g and 3.57 g S/container, as free sulfur, for the 1N and 4N treatments, respectively. All plants received 2.16 g P and 5.48 g K/container, as triple superphosphate and po lymer coated potassium sulfate (Royster Clark, Tifton, GA; Growers Fertilizer Corp., Lake Alfred, FL). Plants were not inoculated with nitrogen fixing bacteria at any time during the study. To control fire ants ( Solenopsis sp.) and corn earworm ( Helicoverp a zea ), plants were treated with granular bifenthrin once during each experiment at a rate of 1.0 g a.i. per container. Data collection. Data were collected every 10 days and included the following measurements: widest width, width perpendicular to wide st width, number of flowers, visual quality, and plant form. Additionally, two height measurements were taken, one in each half of the container, alternating between North South and East West quadrants at each evaluation. Visual quality was rated on a scal e from 1 5, where 1=no living foliage present, 2=poor quality (no green color present, greater than 50% chlorosis/necrosis), 3=fair quality (some green color present, 25 50% chlorosis, some necrosis,), 4=good quality (overall light green color, less than 2 5% chlorosis, minor necrosis), 5=excellent quality (overall dark green color, minor chlorosis, no necrosis). Plant form, defined by

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63 overall plant size and uniformity of foliage distributed around the center of the container, was rated on a scale from 1 (ve ry poor) to 5 (excellent). After 90 days, plants were cut at the soil surface and the roots were washed free of soil. Nodulation of roots was visually ranked on a scale from 1 5, where 1=no nodulation, 2=minor nodulation, 3=moderate nodulation, 4=significa nt nodulation, and 5=extensive nodulation. Average number of flowers per container was determined during the final 30 days of the study, which corresponds to the period when plants were expected to be salable. Roots and shoots were separated, bagged, and p laced in a drying oven for a minimum of 5 days at approximately 46 C. Statistical analysis. Data were analyzed with a 3 way factorial in a completely randomized design using the PROC GLM procedure of SAS Version 9.2 (SAS Institute Inc., Cary, NC). Cultiva r, experiment and fertilizer treatment were treated as fixed effects and replication was treated as a random effect Comparisons among selection and treatment means used the Tukey Kramer adjustment at P Results Data are presented by selection by experiment by fertilizer treatment due to significant selection experiment treatment interactions. When experiment differences occurred fo r a given fertilizer treatment, experiment 1 had a significan tly greater widt h and height (Appendix A; Tables A 2 and A 3 ) as well as a greater root dry weight and shoot dry weight (data not shown) compared to experiment 2. However, for visual quality, experiment 2 generally had a greater visual quality than experi ment 1. Average height. For most selections the 1N and 4N treatments resulted in the greatest plant height at the conclusion of both experiments in the study compared to the 0N treatment (Table 4 3). Few differences between the 1N and 4N treatments occurr ed

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64 in either experiment use cultivar experiments Average width. For a majority of selections plant width increased from the 0N to the 1N treatment duri ng both experiments and further increased at the 4N treatment during experiment 2 (Table 4 4). In experiment 1, few differences occurred between the 1N and 4N treatments. Across both experiments and all fertilizer treatments, few selection differences occ urred. Root dry weight. Few differences in root dry weight occurred from the 0N to the 1N treatments; however dry weight increased at the 4N treatment for approximately half of the selections (Table 4 5). 0N to 1N during both experiments Shoot dry weight. During both experiments the 4N treatment generally resulted in a greater shoot dry weight compared to the 0N and 1N treatments (Table 4 6). During experiment 1, a majority of selections showed an incre ased shoot dry weight at the 1N compared to the 0N treatment; however during experiment and EX8 showed this difference. Dry weight differences for a given treatment were not consistent for particular selections during either ex periment During experiment 2 at the selections. Nodulation rating. Nodulation followed a significantly different pattern in experiment 1 compared to experiment 2 (Table 4 7). During experiment 1, nearly all selections had similar nodulation across all fertilizer treatments. During experiment 2, nodulation generally decreased from the 0N treatment to the 1N treatment, but was

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65 similar at the 1N and 4N treatments. A majority of experiment differences in nodulation for given selection fertilizer rate combinations had greater nodulation in experiment 2 (data not shown). Additionally, when nodulation was less during experiment 2, all instances of this occurrence were at the 4N fe rtilizer rate. greatest nodulation when nitrogen was applied. Visual quality. Visual quality differences due to fertilizer treatment were more pronounced during experiment 2 (Table 4 8). A majority of selections displayed an inc reased visual quality at the 1N compared to the 0N treatment. In experiment 1, nearly all selections had similar visual quality under the 4N and 1N treatments but in experiment 2, the greatest visual quality occurred at the 4N treatment. Most selections ha d similar visual quality at the 4N treatment during both experiments with the during experiment 1. exper iment Number of flowers. Flowering during the final 30 days of the study followed a similar trend in both experiments (Table 4 9). Flowers increased with N rate A majority of selections in each treatment followed this pattern, except for the 1N and 4N t reatments in experiment 1. Experiment differences in flowering for selections at a given fertilizer rate did not display a consistent trend ( Appendix A; Table A 5 ). significantly greater flowering than nearly all other selections during ex periment 1 under the 0N and 1N treatments. During experiment of flowers than all other selections at the 0N treatment and outperformed a majority of selections in the 1N treatment. Few differences among selections o ccurred during

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66 experiment 1 at the 0N and 1N nitrogen rates as well as during experiment 2 at the 0N rate. Plant form rating. During both experiments plant form rating was higher at the 4N treatment compared to the 0N treatment (Table 4 10). In experiment 1, ratings increased from the 0N to the 1N treatment and were similar to about half the selections at the 4N treatment. In experiment 2, ratings were generally similar at the 0N and 1N treatments, increasing at the 4N treatment. rating than most other selections during experiment 1 at the 0N and 1N rates. In experiment 2, Discussion The nitrogen rates used in this study were selected, based in part, on results from Knox et al. ( 2010), which indicated that a rate above the 4N rate did not result in a signifi cant increase in plant growth. Since rhizoma peanut fixes nitrogen, lower rates were hypothesized to yield satisfactory results. T he 4N rate used here corresponded to the low recommended rate for Osmocote Plus (15 9 12) for a 3 gallon container with a 5 6 month longevity at 70F. The application of nitrogen resulted in an increase of height, width, and visual quality above that which occurred under the 0N treatment. These results concur with those reported in a container production study of rhizoma peanut (Knox et al., 2010). There was generally no difference between the 1N and 4N treatments, indicating that there is no benefit of applying nitrogen beyond the 1N rate for these variables. Average plant width increased from the 0N to the 1N treatment; this factor was generally similar across all selections for a given treatmen t, indicating that a variety of germplasm may

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67 be produced without much variability in final plant width. Even though rhizoma peanut fixes nitrogen, some nitrogen is necessary under container production to significantly increase the visual quality (green co lor) of plants above that which occurs when no nitrogen is applied. Flowering was significantly affected by nitrogen rate during the final 30 days of both experiments in the study, with an overall increase in the number of flowers as the amount of nitroge n increased. For ornamental container production, where a high number of flowers is desirable for plant salability, a nitrogen rate of at least 4N is needed to produce the greatest number of flowers. Flowering trends were not significantly different betwee n experiments due to high variability Root and shoot dry weights were generally greatest at the 4N fertilizer rate indicating that growth was greatest under this treatment, despite similarities in average height and width under both rates of applied nitr ogen. Increased above ground growth as a result of greater root volume may have manifested itself under a longer production cycle than was evaluated here. Greater shoot dry weight under the highest rate of nitrogen did not translate into a greater plant he ight or width, but resulted in denser growth (more foliage per unit of area). This was confirmed by percent foliage cover measureme nts ( Appendix A; Table A 4 ), which indicated that a greater amount of foliage was present at the 4N treatment, despite simila rities in average plant width and height compared to the 1N treatment. These results imply that a nitrogen rate of at least 4N may be needed to produce a plant with a high foliage density. This type of plant is likely to be more salable since it will have a more compact form and thus appear healthier.

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68 The similarities in nodulation across all fertilizer treatments in experiment 1 indicate that nodulation was not greatly affected by increased availability of nitrogen to the plants. However, in experiment 2, the application of nitrogen resulted in decreased nodulation for nearly all selections evaluated, which agrees with results reported by Adjei and Prine (1976). Reduced nodulation was likely caused by the applied nitrogen which reduced the need for nitroge n fixation to sustain growth. The experiment differences in nodulation cannot be readily explained, except that greater rainfall in experiment 2 may have resulted in a greater release of nitrogen from the coated slow release fertilizer, depressing nodulati on to a greater extent than that which occurred during experiment 1. This cannot be proven, and it appears that the negative effects on plant growth previously described, as a result of greater nutrient leaching due to increased rainfall are more likely to have occurred than increased nutrient availability. Plant form rating was greatest during both experiments at the 4N fertilizer rate compared to the other treatments. This indicates that a nitrogen rate of at least 4N is needed to produce a plant with th e greatest potential salability. However, on average, actual plant form ratings were relatively low, indicating that a higher rate of nitrogen may be needed to produce plants with greater salability and reduce the length of production. The relatively short duration of production for container grown plants may not allow the full development of nitrogen fixing bacteria and associated nodules Additionally, due to increased leaching in containers compared to that in the field as a result of the need for higher volumes of irrigation, nitrogen in the container media may be lost in the leachate. Reductions in plant height, width, and root and shoot dry weights during experiment 2 may be explained by the greater amount of rainfall during this experiment

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69 (504 mm com pared to 304 mm during experiment 1), which likely caused increased leaching of applied nutrients, rendering them unavailable for plant growth. For container production of rhizoma peanut, flowering does not appear to be increased by rainfall, contradictory to observations in field grown plots (French et al., 2001, revised 2006). Lower fertilizer availability in the container media during experiment 2 due to possibly greater nutrient leaching may explain this, as flowering has been shown to increase under co nditions of low fertility. In conclusion, to achieve highly salable plants, a nitrogen rate of at least 4N is needed. The number of days to salability was not significantly different based on fertilizer treatment or selection (data not presented). However, the percentage of salable plants at the conclusion of the study (data not presented) indicates that, in general, the highest rate of nitrogen resulted in a greater percentage of salable plants than the lower rate. Overall, ornamental selections were short er than cultivars recommended for forage ornamental standpoint for at least 90 days. Selections that may have the greatest potential for container production based on variable s evaluated other selections and despite its success in this study, is not recommended for ornamental use. otential; however their overall salability decreased in experiment 2 compared to experiment 1 due to unknown reasons. One possibility is that initial transplants were not well established compared to those in experiment 1, necessitating the need for develo pment of protocols for propagation of rhizoma peanut for container production.

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70 Due to limited knowledge regarding the container production of rhizoma peanut, further work is also needed to determine production methods that will reduce the time needed to p roduce salable plants, such as greenhouse production during the dormant season. This study did not successfully produce a high percentage of salable plants; there is the possibility that a longer duration of production may be needed. Additionally, the effe cts of photoperiod and temperature on container production need to be investigated to increase the production window during the growing season and determine the most efficient timeframe in which to produce this plant. Based on the effects of nitrogen ferti lization investigated in this study, higher rates may decrease the time to salability and result in higher percentages of salable plants, and therefore need to be explored further. Micronutrient deficiencies observed in a preliminary study (Knox et al., 20 10) may have resulted in the poor growth and reduced visual quality of some selections, and their application may help to decrease the chlorosis that occurred and thereby increase overall visual quality. Time to salability has the potential to be decreased by using smaller containers, which may have a greater amount of foliage in comparison to the container size during the same production cycle. Smaller containers may also be more attractive to consumers looking to purchase large quantities of this plant. This study demonstrated that salable plants, defined by high visual quality, high foliage cover, and desirable plant form, can be produced in 90 days or less, but more work is needed in this area to reduce plant to plant variability which will lead to more uniformity of the crop and a higher percentage of salable plants at the conclusion of the production period.

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71 Table 4 1. Released cultivars and experimental selections of rhizoma peanut ( Arachis glabrata ) used in the study. Selection /Line No. Exp. Name/P I Proposed Use z Released PI 658529 Dual Use PI 151982 Forage PI 262801 Ornamental Experimental EX1 Apalachee Ornamental EX3 Chico Ornamental EX5 Cowboy Ornamental EX6 QS 5W Unknown EX7 QS 6WA Unknown EX8 QS 6WB Unknown z Proposed use was determined from observational data at the North Florida Research and Education Center preceding the study.

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72 Table 4 2. Initial container media soil testing results. Mehlich 3 extractable macro and micro nutrients are expressed in mg kg 1 Nutrient Concentration pH 4.7 Essential elements N 1.0 P 15.2 K 60.3 S 16.0 Ca 28.0 Mg 16.0 Fe 8.2 Mn 7.2 Zn 3.1 Cu 0.2 B Mo 0.1 0.23 Nonessential elements Na 11.0 Al 3.6

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73 Table 4 3. Nitrogen effects on plant height of A. glabrata selections. Experiment 1 Experiment 2 Selection 0N 1N 4N 0N 1N 4N ----------------------------------------------cm ------------------------------------------------Released 'Brooksville 67' 9.8 c z B y 15.1 abc A 12.2 bc AB 9.7 bc A 14.7 abc A 11.0 d A 'Ecoturf' 15.8 ab A 18.5 a A 20.5 a A 14.3 a B 19.1 a A 19.7 a A 'Florigraze' 16.8 a A 16.4 ab A 13.9 bc B 13.1 ab B 16.2 ab A 13.8 bc AB Experimental EX1 12.5 bc A 13.2 bc A 12.3 bc A 7.4 c B 10.8 cde A 12.0 bcd A EX3 8.9 c B 11.3 c AB 11.8 c A 7.2 c A 8.1 de A 8.9 e A EX5 10.5 c A 11.4 c A 11.2 c A 10.1 bc AB 7.4 e B 10.4 de A EX6 10.1 c B 12.5 bc AB 14.0 bc A 9.5 bc B 13.2 bcd A 11.4 cd AB EX7 10.8 c B 13.7 abc A 12.1 bc AB 14.3 a AB 16.8 ab A 12.5 bcd B EX8 10.2 c B 15.3 abc A 15.4 b A 9.3 bc B 12.7 bcd A 14.4 b A z Me ans within columns with the same lowercase letter are not statistically different by the Tukey Kramer test at P y Means within rows for a given experiment with the same uppercase letters are not statistically different by the Tukey Kramer test at P

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74 Table 4 4. Nitrogen effects on plant diameter of A. glabrata selections. Experiment 1 Experiment 2 Selection 0N 1N 4N 0N 1N 4N --------------------------------------------cm -----------------------------------------------Released 'Brooksville 67' 29.7 bc z B y 49.5 abc AB 64.7 ab A 31.2 a B 46.7 abc AB 50.3 abc A 'Ecoturf' 22.0 bc C 52.2 abc B 70.7 ab A 20.4 ab B 54.1 a A 61.1 ab A 'Florigraze' 46.1 a B 59.4 ab A 69.0 ab A 17.3 b C 43.3 a bc B 58.3 ab A Experimental EX1 33.3 b B 55.9 ab A 64.9 ab A 10.0 b C 36.3 abc B 57.2 ab A EX3 18.1 c C 38.8 bc B 58.3 ab A 18.1 ab B 31.2 c A 28.3 c AB EX5 24.5 bc B 27.8 c AB 44.7 b A 20.3 ab B 26.8 c B 45.4 bc A EX6 20.2 c B 55.3 ab A 48.6 ab A 13.5 b B 49.2 ab A 60.9 ab A EX7 22.3 bc B 69.8 a A 71.6 a A 16.4 b C 41.7 abc B 70.3 a A EX8 23.7 bc B 54.5 ab A 66.4 ab A 14.3 b C 34.0 bc B 68.8 ab A z Means within columns with the same lowercase letter are not statistically different by the Tukey Kramer test at P y Means within rows for a given experiment with the same uppercase letters are not statistically different by the Tukey Kramer test at P

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75 Table 4 5. Nitrogen effects on root dry mass of A. glabrata selections. Experiment 1 Experiment 2 Selection 0N 1N 4N 0N 1N 4N -----------------------------------------------g per pot -------------------------------------------------Released 'Brooksville 67' 4.8 bc z B y 6.2 bcd B 15.4 abcd A 5.8 a A 5.9 bcd A 12.3 abc A 'Ecoturf' 2.7 c C 15.1 ab B 27.8 a A 3.8 ab B 13.1 a A 13.6 abc A 'Florigraze' 10.3 a B 16.0 ab AB 19.2 ab A 1.1 bc B 6.9 bc A 9.9 bcd A Experimental EX1 9.4 ab B 19.6 a A 18.8 abc A 0.6 c B 2.5 bcd B 7.1 cd A EX3 2.6 c B 3.7 cd B 10.4 bcd A 1.3 bc A 2.0 cd A 2.2 d A EX5 1.7 c B 2.6 d B 5.3 d A 1.2 bc B 1.4 d B 7.8 cd A EX6 0.9 c B 10.1 abcd A 6.9 cd AB 0.7 c B 7.3 b A 5.9 cd AB EX7 1.3 c B 13.4 abc A 18.6 abc A 1.0 bc B 4.0 bcd B 17.6 ab A EX8 1.5 c B 9.2 bcd B 19.3 ab A 1.0 bc B 2.9 bcd B 18.9 a A z Means within columns with the same lowercase letter are not statistically different by the Tukey Kramer test at P y Means within rows for a given experiment with the same uppercase letters are not statistically different by the Tukey Kramer test at P

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76 Table 4 6. Nitrogen effects on shoot dry mass of A. glabrata selections. Experiment 1 Experiment 2 Selection 0N 1N 4N 0N 1N 4N ----------------------------------------g per pot ------------------------------------------Released 'Brooksville 67' 5.9 ab z B y 11.5 cd B 28.8 ab A 8.6 a B 13.6 abc AB 24.7 bc A 'Ecoturf' 3.0 a C 21.2 abc B 48.5 a A 3.2 b C 19.2 a B 36.8 ab A 'Florigraze' 15.1 a C 32.5 ab B 47.1 a A 1.5 b B 15.4 ab B 33.4 ab A Experimental EX1 10.3 a B 34.7 a A 40.4 a A 0.5 b B 8.7 bcd B 23.2 bc A EX3 2.1 a b B 9.6 cd B 30.5 ab A 2.4 b B 6.2 cd AB 6.4 c A EX5 3.4 b A 3.4 d A 9.0 b A 1.4 b B 2.4 d B 12.2 bc A EX6 1.7 b B 17.1 bcd A 12.0 b AB 0.8 b B 11.3 abcd AB 27.7 bc A EX7 1.9 ab B 20.8 abc A 27.9 ab A 1.1 b B 7.2 bcd B 31.3 abc A EX8 2.8 a B 21.4 abc B 52.6 a A 1.2 b C 9.6 bcd B 57.2 a A z Means within columns with the same lowercase letter are not statistically different by the Tukey Kramer test at P y Means within rows for a given experiment with the same uppercase letters are not statistically different by the Tukey Kramer test at P

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77 Table 4 7. Nitrogen effects on nodulation of A. glabrata selections. Nodulation of roots was visuall y ranked on a scale from 1 5, where 1=no nodulation, 2=minor nodulation, 3=moderate nodulation, 4=significant nodulation, and 5=extensive nodulation. Experiment 1 Experiment 2 Selection 0N 1N 4N 0N 1N 4N --------------------------nodu lation rating ------------------------------Released 'Brooksville 67' 1.8 abc z AB y 1.2 b B 2.0 ab A 4.2 abc A 3.0 ab A 1.3 b B 'Ecoturf' 1.2 bc A 1.5 b A 1.0 c A 3.0 bc A 1.0 b B 1.2 b B 'Florigraze' 2.3 ab B 3.0 a A 2.0 ab B 4.3 ab A 2.8 a B 2.5 a B Experimental EX1 2.5 a A 3.5 a A 2.8 a A 2.5 c A 1.0 b B 1.0 b B EX3 1.2 bc A 0.8 b A 0.8 c A 4.2 abc A 2.5 ab B 1.5 b B EX5 0.8 c A 1.2 b A 0.7 c A 4.0 abc A 1.5 ab B 1.0 b B E X6 0.8 c A 1.3 b A 0.7 c A 4.8 a A 3.0 a B 1.5 b C EX7 1.7 abc A 1.7 b A 2.2 ab A 3.5 abc A 2.0 ab B 1.5 b B EX8 1.2 bc A 1.7 b A 1.5 bc A 3.0 bc A 2.0 ab AB 1.0 b B z Means within columns with the same lowercase letter are not stati stically different by the Tukey Kramer test at P y Means within rows for a given experiment with the same uppercase letters are not statistically different by the Tukey Kramer test at P

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78 Table 4 8. Nitrogen effects on visual quality of A. glabrata selections. Visual quality was rated on a scale from 1 5, where 1=no living foliage present, 2=poor quality (no green color present, greater than 50% chlorosis/necrosis), 3=fair quality (very little green color present, 25 50% chlorosis, some nec rosis), 4=good quality (overall light green color, less than 25% chlorosis, minor necrosis), 5=excellent quality (overall dark green color, minor chlorosis, no necrosis). Experiment 1 Experiment 2 Selection 0N 1N 4N 0N 1N 4N ----------------------visual quality rating -------------------------Released 'Brooksville 67' 3.4 ab z C y 3.7 ab B 4.1 a A 3.5 ab B 3.7 bc B 4.6 a A 'Ecoturf' 3.0 bc B 3.5 bc A 3.6 b A 3.3 bcd C 4.0 ab B 4.4 ab A 'Florigraze' 3 .0 c B 3.0 d AB 3.2 c A 3.2 cd B 3.9 abc A 4.0 c A Experimental EX1 3.3 abc B 3.9 a A 4.0 a A 3.1 cd C 4.0 ab B 4.5 ab A EX3 3.1 abc C 3.6 ab B 4.0 a A 3.3 bcd C 4.2 a B 4.5 ab A EX5 3.2 abc B 3.4 bc AB 3.6 b A 3. 7 a B 4.0 ab B 4.6 a A EX6 3.0 bc A 3.3 cd A 3.0 c A 3.3 bcd C 3.9 abc B 4.5 ab A EX7 3.4 a A 3.6 ab A 3.6 b A 3.4 abc C 3.6 bc B 4.7 a A EX8 3.3 abc B 3.6 abc A 3.6 b A 3.0 d C 3.6 c B 4.2 bc A z Means within columns with the same lowercase letter are not statistically different by the Tukey Kramer test at P y Means within rows for a given experiment with the same uppercase letters are not statistically different by the Tukey Kramer test at P

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79 Table 4 9. Nitrogen effects on flowering of A. glabrata selections during the final 30 days of the s tudy. Experiment 1 Experiment 2 Selection 0N 1N 4N 0N 1N 4N ----------------------number of flowers ----------------------------Released 'Brooksville 67' 0.1 c z C y 1.6 b B 3.9 cd A 1.9 a B 3.5 a B 12.2 a A 'Ecoturf' 0.0 c C 1.2 b B 6.3 bc A 0.0 b C 1.2 bc B 5.0 bcd A 'Florigraze' 4.0 a B 8.8 a A 10.2 ab A 0.0 b C 2.0 ab B 8.4 abc A Experimental EX1 1.5 b B 9.4 a A 13.5 a A 0.0 b C 3.3 a B 10.2 ab A EX3 0.0 c C 0.5 b B 5.4 bc A 0.1 b B 1.2 bc A 0.9 e A EX5 0.9 b B 1.0 b B 3.3 cd A 0.1 b C 0.9 bc B 3.8 cde A EX6 0.0 c B 1.0 b A 1.1 d A 0.0 b C 0.4 cd B 2.3 de A EX7 0.1 c B 1.6 b A 4.0 cd A 0.0 b C 1.5 abc B 11.6 a A EX8 0.0 c B 1.8 b A 2.5 c d A 0.0 b B 0.0 d B 6.1 abcd A z Means within columns with the same lowercase letter are not statistically different by the Tukey Kramer test at P y Means within rows for a given experiment with the same uppercase letters are not statistically different by the Tukey Kramer test at P

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80 Table 4 10. Nitrogen effects on plant form of A. glabrata selections. Plant form, defined by overall plant size and uniformity of foliage distributed around the center of the container, was rated on a scale from 1 (very poor) to 5 (excellent). Experiment 1 Experiment 2 Selection 0N 1N 4N 0N 1N 4N --------------------------plant form ranking ----------------------------Released 'Brooksville 67' 1.1 bc z B y 1.3 cd B 2.0 ab A 1.1 a B 1.3 bc B 1.7 bc A 'Ecoturf' 1.0 c C 1.6 bc B 2.2 ab A 1.0 b C 1.6 a B 2.1 ab A 'Florigraze' 1.6 a B 2.2 a A 2.4 a A 1 .0 b C 1.6 ab B 2.1 ab A Experimental EX1 1.3 b B 2.5 a A 2.4 a A 1.0 b B 1.1 cd B 1.5 cd A EX3 1.0 c C 1.3 cd B 2.0 ab A 1.0 b A 1.1 d A 1.0 d A EX5 1.1 c A 1.1 d A 1.2 d A 1.0 b B 1.0 d B 1.4 cd A EX6 1.0 c C 1.6 bc A 1.3 cd B 1.0 b B 1.3 abc B 2.0 ab A EX7 1.0 c B 1.5 bc A 1.8 bc A 1.0 b B 1.1 cd B 2.0 b A EX8 1.0 c C 1.8 b B 2.2 ab A 1.0 b B 1.2 cd B 2.6 a A z Means within columns with the same lowercase letter are not statistically differ ent by the Tukey Kramer test at P y Means within rows for a given experiment with the same uppercase letters are not statistically different by the Tukey Kramer test at P

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81 F igure 4 1. Average daily maximum and minimum air temperatures and 10 day c umulative rainfall totals for experiment 1 (June 30, 2010 to September 30, 2010) and experiment 2 (June 8, 2011 to September 13, 2011).

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82 CHAPTER 5 CONCLUSIONS Recommended Selections Based on criteria of low height, minimal height variability, h igh flower production, and high visual quality, selections EX1 and EX3 are best suited for ornamental use in r production. Detailed conclusions pertaining to each factor are discussed below. Rate and Duration of Full Canopy C over At both locations, plots did not achieve full cover until the year following planting. Additionally, in Quincy, full cover did not occ ur any faster in year 3 than in year 2, implying that establishment as measured by rate of cover likely oc curred as early as year 2. Planting density will also greatly influence time to reach full cover; decreasing the planting density may delay establishm ent until the second year following planting. Initial transplant size will also play a role and the use of vegetative rhizome divisions compared to established container plants used in this study may further delay establishment. The use of irrigation follo wing planting is critical, especially in sandy soils such as those at Gainesville, and it was observed that poorly established transplants did not establish as fast as better established material, possibly due to lack of soil water during the early part of the study. At both locations, narrow leaf types performed poorly as indicated by their failure to reach full cover or a relatively short duration of full cover. Therefore, they are not recommended for ornamental use based on the parameters of the study. N arrow leaf types exhibited poor establishment at the Gainesville location during the year of planting possibly due to a smaller root system noted for narrow leaf

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83 types growing in containers (personal observation) as well as a low water holding capacity o f the coarse textured soil. Shade did not have a significant effect on both the time to reach full cover and the duration of full cover, indicating that for these two variables, shaded plots will perform similarly to those in full sun. The duration of full cover was affected most by rhizoma peanut selection. Plants in s haded plots emerged later in the spring but those in full sun plots died back earlier in the fall (personal observation); this is not reflected in the duration of full cover data. As a result successful ornamental performance may occur in both full sun and shaded conditions. their fast rate of cover at both locations. Selections recommended for ornamental use based EX8. Height A ttributes At both locations, maximum average height increased during the second year of the study, indicating that rhizoma peanut will likely continue to inc rease in height for at least two years following planting. Long term studies are needed to characterize plot heights over a longer period of time. Additionally, studies evaluating plots larger than those used here would be useful to better assess overall p lot heights, eliminating the influence of edge effects. Larger plots, when viewed as a whole, may eliminate the apparent non uniformity (i.e. greater height variability) of the small plots used in this study. The shading of rhizoma peanut plots has a sign ificant effect on both height and height variability, with shaded plots growing taller and having a less uniform canopy.

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84 Both year and shade affected height to varying degrees among selections. Therefore, selection is an important consideration for the orn amental use of rhizoma peanut. However, the response was not consistent between locations. For example, at Quincy, very few selections showed height differences based on shade treatment, indicating that most selections perform equally in sun or 30% shade c onditions. In comparison, at Gainesville, which is only about 51 miles further south in latitude, nearly half of all selections grew taller under shade in year 2. This implies that once plots are established (i.e. have reached full cover), greater maximum heights will be achieved under shade. At both locations, shaded plots had significantly more height variability than full sun plots for most of the selections, indicatin g that an ornamentally desirable uniform canopy is less likely to occur under shaded co nditions. At Quincy, the interaction between shade and year implies that regardless of selection, effects of shade are less consistent from year to year. Therefore, selections do not perform similarly based on shade treatment for at least the first two yea rs following planting. as well as experimental selections EX3, EX4, and EX9 show the greatest ornamental potential, as they generally achieved the lowest maximum height at b oth locations compared to forage types. ornamental and a forage type, confirming its recommendation as a dual use cultivar. Both released and proposed ornamental types generally had less height variabil ity than forage types; the use of these forage types for ornamental purposes is not supported by this study. are best suited for ornamental use, due to their low canopy height v ariability.

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85 In summary, the selections that have the greatest potential ornamental use based on height and cover variables al for ornamental use. Although preliminary observations suggested EX5 was best suited for ornamental use, it did not meet standards based on variables in this study. Unlike Quincy, where forage types had a slower rate of cover than many ornamental types, forage types at Gainesville reached full cover at the same rate as many of the ornamental types. When growing rhizoma peanut in a coarse textured soil environment similar to the one in Gainesville, an ornamentally desirable shorter height might be lost und er shade, evidenced from greater heights under shade compared to sun. Number of F lowers At both locations, forage and dual use types generally produced fewer flowers than released ornamental types and some experimental selections. At Quincy, f ewer flowers produced by forages as well as most selections during year 3 can be explained by taller plant heights which obscured flowers in the canopy (personal observation). Height data indicated that forage types generally grew taller than ornamental types and that plant height generally increased for at least two years after planting. The greatest flower production occurred during the summer months; the next greatest months of flower production differed by location. Generally, lower flower production occurred durin g the fall, possibly due to lower temperatures and the onset of leaf senescence resulting in overall decline of the plants. When evaluating flowering as an ornamental attribute of rhizoma peanut, season of the year, shade treatment, and selection must be considered. Overall, full sun resulted in greater flower production, regardless of year, implying that the ornamental

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86 value of rhizoma peanut, if measured by flower production, will be much greater in full sun compared to 30% shade. This agrees with flower ing characteristics described by French et al. (2001, revised 2006). Growing rhizoma peanut under shade had a negative impact on its ornamental quality based on flowering data from this study, as well as height results. Taller canopies tended to obscure fl owers produced lower in the canopy. Although it wa s not investigated, a short flower stalk (hypanthium) of some selections may be responsible for flowers not reaching the top of the canopy and becoming visible. While locations are not directly comparable due to different planting dates, greater flower production at Gainesville compared to Quincy may be a result of the coarse textured, low fertility soils at Gainesville, which increased flowering, as noted by French, et al. (2001, revised 2006). Low floweri ng during year 1 in Gainesville can be explained by lack of establishment of plants in this year. moderate to high flower production. These selections are therefore best suited for ornamental use if abundant flower production is desired during warmer months. EX4 and EX8 had low flower production compared to remaining selections, making them less suitab le for ornamental use. Se recommended for ornamental use based on low heig ht and high canopy cover. F lower production data indicates that these selections are validated for ornamental use. is not supported due to low flower production at both locations.

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87 Duration of Acceptable Visual Q uality Selection interactions at both locations for the duration of acceptabl e visual quality indicate that selection is an important factor for the ornamental use of rhizoma peanut. Selection year interactions occurred due to a different length of evaluation during each year of the study (24 weeks in 2010 and 44 weeks in 2011) a nd were not analyzed. In general, shade treatment did not affect the duration of acceptable visual quality, indicating that rhizoma peanut performs equally in full sun and under shade. I f this factor is of primary importance, growing rhizoma peanut under s hade may be acceptable from an ornamental standpoint At both locations, fewer differences among selections occurred during the second year of the study, indicating that visual quality differences were not as apparent as plants became established. However, a long term study is needed to validate this over a period greater than two years. Across both years and locations, the selections with the greatest duration of While released o the Gainesville location, it achieved low can opy cover and it is not recommended for ornamental use in a coarse textured soil environment l ike that found at Gainesville In summ ary, selections EX1 and EX3 achieved the greatest flower numbers as well as the greatest duration of acceptable visual quality and are therefore highly recommended for ornamental use. Their use is further validated by their low height and high canopy cover However, narrow leaf Leptosphaerulina crassiasca ) throughou t the study which reduced their visual quality. Although EX9 achieved very

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88 high rates of flower production, its very low period of acceptable visual quality diminishes its acceptability for ornamental use. No forage types are recommended for ornamental use based on this study due to l ow flower production and a low duration of acceptable visual quality. its low period of acceptable visual quality due to the pres ence of peanut stunt virus well docu mented in past studies ( Quesenberry et al., 2010 ) precludes its use as an ornamental. Compared to the 30 year rainfall average (Florida State University, 2011), rainfall during the experimental period at both locations was less than normal. Despite this, t he rhizoma peanut germplasm evaluated in this study achieved high visual quality and substantial flower numbers. Container P roduction The application of nitrogen resulted in an increase of height, width, and visual quality above that which occurred under the 0N treatment. These results concur with those reported in a preliminary container production study of rhizoma peanut (Knox et al., 2010). There was generally no difference between the 1N and 4N treatments, indicating that there is no benefit of applyin g nitrogen beyond the 1N rate for these variables. Average plant width increased from the 0N to the 1N treatment; this factor was generally similar across all selections for a given treatment, indicating that a variety of germplasm may be produced without much variability in final plant width. Even though rhizoma peanut fixes nitrogen, some nitrogen is necessary under container production to significantly increase the visual quality (green color) of plants above that which occurs when no nitrogen is applied Flowering was significantly affected by all three nitrogen treatments during the final 30 days of both experiments in the study, with an overall increase in the number of

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89 flowers as the amount of nitrogen increased. For ornamental container production, where a high number of flowers is desirable for plant salability, a nitrogen rate of at least 4N is needed to produce the greatest number of flowers. Flowering trends were not significantly different between experiments due to high variability Root and s hoot dry weights were generally greatest at the 4N fertilizer rate indicating that growth was greatest under this treatment, despite similarities in average height and width under both rates of applied nitrogen. Increased above ground growth as a result of greater root volume may have manifested itself under a longer production cycle than was evaluated here. Greater shoot dry weight under the highest rate of nitrogen did not translate into a greater plant height or width, but resulted in denser growth (more foliage per unit of area). This was confirmed by percent foliage cover measurements (data not shown), which indicated that a greater amount of foliage was present at the 4N treatment, despite similarities in average plant width and height compared to the 1N treatment. These results imply that a nitrogen rate of at least 4N may be needed to produce a plant with a high foliage density. This type of plant is likely to be more salable since it will have a more compact form and thus appear healthier. The simil arities in nodulation across all fertilizer treatments in experiment 1 indicate that nodulation was not greatly affected by increased availability of nitrogen to the plants. However, in experiment 2, the application of nitrogen resulted in decreased nodula tion for nearly all selections evaluated, which agrees with results reported by Adjei and Prine (1976). Reduced nodulation was likely caused by the applied nitrogen which reduced the need for nitrogen fixation to sustain growth. The experiment differences in nodulation cannot be readily explained, except that greater rainfall during

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90 experiment 2 may have resulted in a greater release of nitrogen from the coated slow release fertilizer, depressing nodulation to a greater extent than that which occurred durin g experiment 1. This cannot be proven, and it appears that the negative effects on plant growth previously described, as a result of greater nutrient leaching due to increased rainfall are more likely to have occurred than increased nutrient availability. Plant form was greatest during both experiments at the 4N fertilizer rate compared to the other treatments. This indicates that a nitrogen rate of at least 4N is needed to produce a plant with the greatest potential salability. However, on average, actual plant form ratings were relatively low, indicating that a higher rate of nitrogen may be needed to produce plants with greater salability and reduce the length of production. The relatively short duration of production for container grown plants may not a llow the full development of nitrogen fixing bacteria and associated nodules Additionally, due to increased leaching in containers compared to that in the field as a result of the need for higher volumes of irrigation, nitrogen in the container media may be lost in the leachate. Reductions in plant height, width, and root and shoot dry weights during experiment 2 may be explained by the greater amount of rainfall during this experiment (504 mm compared to 304 mm during experiment 1), which likely caused in creased leaching of applied nutrients, rendering them unavailable for plant growth. For container production of rhizoma peanut, flowering does not appear to be increased by rainfall, contradictory to observations in field grown plots (French et al., 2001, revised 2006). Lower fertilizer availability in the container media during experiment 2 due to possibly greater nutrient leaching may explain this, as flowering has been shown to increase under conditions of low fertility.

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91 In conclusion, to achieve highly salable plants, a nitrogen rate of at least 4N is needed. The number of days to salability was not significantly different based on fertilizer treatment or selection (data not presented). However, the percentage of salable plants at the conclusion of the s tudy (data not presented) indicates that, in general, the highest rate of nitrogen resulted in a greater percentage of salable plants than the lower rate. Overall, ornamental selections grew shorter than cultivars recommended for forage ornamental standpoint for at least 90 days. Selections that may have the greatest potential for container production based on variables evaluated H other selections and despite its success in this study, is not recommended for ornamental use. overall salability decreased in expe riment 2 compared to experiment 1 due to unknown reasons. One possibility is that initial transplants were not well established compared to those in experiment 1, necessitating the need for development of protocols for propagation of rhizoma peanut for con tainer production. Other O bservations Some deer feeding was observed during this study at Gainesville; this occurred The field at this location was surrounded by a fence and open fields may result in greater dee r feeding. Deer feeding resulted in reductions in plot height and uniformity; however this would not be as apparent on larger plots unless significant feeding occurred. The presence of off types (morphologically dissimilar growth) caused plot variability t o appear greater, as many of these off types had a much greater height than

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92 the remainder of the plot. The height measurements taken in this study did not include off types that were significantly different from the remainder of the plot. The presence of o ff types occurred mainly on EX1, EX3, and EX9. Released selections generally had few off types compared to unreleased selections. Future W ork Long term studies are required to determine if the trends observed in this study continue over time. Additional lo cation testing is also required to better estimate the factors that influence some of the location differences that were found in this study. Furthermore, flowering characteristics as well as ornamental aesthetic qualities of rhizoma peanut will play a cri tical role in recommending selections for ornamental use. Possible criteria for future selections of rhizoma peanut include a longer hypanthium length and flower p roduction earlier in the season, extending later into the fall. Further research is needed to determine management practices for rhizoma peanut grown for ornamental use. Mowing may be particularly important for aesthetics and may allow a wider range of rhizoma peanut germplasm to be used ornamentally. Mowing has been cited as a means to increase f lower production (French et al., 2001, revised 2006); in a preliminary study by Aldrich et al., (2012), mowing resulted in increased flower numbers and increased visual quality for some selections evaluated. Additionally, the presence of pepper spot was r educed as a result of mowing. However, selections that achieve high flower production and acceptable visual quality with little or no mowing have the potential to reduce maintenance needs and the associated costs. Maximum canopy height and height variabili ty may be reduced through proper mowing methods; however naturally low growing selections have the potential to greatly reduce or eliminate mowing when low maintenance landscape practices are desired.

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93 Additionally, since canopy cover parameters are not gre atly affected by shade, achieving an ornamentally desirable low height and height variability through mowing would eliminate the negative effects of shade on these variables. Due to limited knowledge regarding the container production of rhizoma peanut, f urther work is also needed to determine production methods that will reduce the time needed to produce salable plants, such as greenhouse production during the dormant season. This study did not successfully produce a high percentage of salable plants; the re is the possibility that a longer duration of production may be needed. Additionally, the effects of photoperiod and temperature on container production need to be investigated to increase the production window during the growing season and determine the most efficient timeframe in which to produce this plant. Based on the effects of nitrogen fertilization investigated in this study, higher rates may decrease the time to salability and result in higher percentages of salable plants, and therefore need to be explored further. Micronutrient deficiencies observed in a preliminary study (Knox et al., 2010) may have resulted in the poor growth and reduced visual quality of some selections, and their application may help to decrease the chlorosis that occurred a nd thereby increase overall visual quality. Time to salability has the potential to be decreased by using smaller containers, which may also be more attractive to consumers looking to purchase large quantities of this plant. This study demonstrated that sa lable plants, defined by high visual quality, high foliage cover, and desirable plant form, can be produced in 90 days or less, but more work is needed in this area to reduce plant to plant variability which will lead to more uniformity of the crop and a h igher percentage of salable plants at the conclusion of the production period. Future

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94 work is also needed to establish the appropriate length of production using various container sizes and to examine seasonal effects on production.

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95 APPENDIX A ADDITIONAL TABLES Table A 1. Canopy uniformity of A. glabrata selections at two locations. Quincy Gainesville Year 2 z Year 3 Year 2 Selection Sun Shade Sun Shade Sun Shade -----------------------------------height variability (cm) -------------------------------------Released 'Arbrook' 11.5 a y 13.4 a 10.8 a B 13.7 a A 8.5 a B 12.0 a A 'Brooksville 67' 5.1 efg B x 7.9 cd A 6.4 bcdefg 6.2 defg 4.2 defg 4.6 def 'Brooksville 68' 5.0 fg B 7.7 cd A 4.9 fg B 7.0 cdefg A 2.5 fg B 3.3 ef A 'Ecoturf' 6.5 def B 8.1 cd A 7.4 bcd 7.9 bcd 5.6 bcd B 7.9 b A 'Florigraze' 7.9 bcde B 10.4 abc A 6.3 cdefg B 8.0 bcd A 5.6 bcd B 6.8 bc A 'UF Peace' 9.8 abc B 12.9 ab A 7.8 bc 8.5 bc 6.4 bc B 8.0 b A 'UF Tito' 10.3 ab 10.8 abc 8.3 b B 9.9 b A 6.7 abc 7.9 b Experimental EX1 6.2 ef 5.9 d 6.5 cdef A 5.2 g B 4.0 defg 4.2 ef EX2 9.2 abcd 9.4 c 7.1 bcde 8.0 bcd 5.0 bcde B 7.1 bc A EX3 w 2 .1 g 2.3 e 4.8 g 5.4 fg 2.5 fg B 3.2 f A EX4 6.9 cdef 8.1 cd 5.5 efg 5.9 efg 4.2 defg B 8.6 b A EX5 7.3 cdef B 9.2 c A 5.8 defg B 7.4 cdef A 2.2 g B 3.2 ef A EX6 7.5 bcdef B 9.4 c A 7.1 bcde 7.5 cde 4.4 def B 6. 7 bcd A EX7 6.6 def 8.1 cd 6.0 defg B 7.2 cdefg A 4.8 cde B 6.7 bcd A EX8 7.9 bcde 8.1 cd 6.1 defg 6.7 cdefg 6.9 ab A 5.6 cde B EX9 6.8 def B 10.2 bc A 4.8 g B 6.7 cdefg A 3.3 efg 3.9 ef z Year after planting data represe nts canopy uniformity after the study began on June 30, 2010.

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96 y Means within columns with the same lowercase letter are not statistically different by the Tukey Kramer test at P x Only means within rows for a given year with different uppercase letters are statistically different by the Tukey Kramer test at P w Selection EX3 was planted one year later than the other selections at the Quincy location. Indicates year after planting is significantly different for a given shade treatmen t by the Tukey Kramer test at P

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97 Table A 2 Nitrogen effects on plant height of A. glabrata selections. Experiment 1 Experiment 2 Selection 0N 1N 4N 0N 1N 4N ----------------------------------------------cm ------------------------------------------------Released 'Brooksville 67' 9.8 c z B y 15.1 abc A 12.2 B c AB 9.7 bc A 14.7 abc A 11.0 d A 'Ecoturf' 15.8 ab A 18.5 a A 20.5 a A 14.3 a B 19.1 a A 19.7 a A 'Florigraze' 16.8 a A 16. 4 ab A 13.9 B c B 13.1 ab B 16.2 ab A 13.8 bc AB Experimental EX1 12.5 bc A 13.2 bc A 12.3 B c A 7.4 c B 10.8 cde A 12.0 bcd A EX3 8.9 c B 11.3 c AB 11.8 c A 7.2 c A 8.1 de A 8.9 e A EX5 10.5 c A 11. 4 c A 11.2 c A 10.1 bc AB 7.4 e B 10.4 de A EX6 10.1 c B 12.5 bc AB 14.0 B c A 9.5 bc B 13.2 bcd A 11.4 cd AB EX7 10.8 c B 13.7 abc A 12.1 B c AB 14.3 a AB 16.8 ab A 12.5 bcd B EX8 10.2 c B 15.3 abc A 15.4 b A 9.3 bc B 12.7 bcd A 14.4 b A z Means within columns with the same lowercase letter are not statistically different by the Tukey Kramer test at P y Means within rows for a given experiment with the same uppercase letters are not statistically different by the Tukey Kramer test at P Indicates experiment is significantly different for a given fertilizer treatment by the Tukey Kr amer test at P

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98 Table A 3 Nitrogen effects on plant diameter of A. glabrata selections. Experiment 1 Experiment 2 Selection 0N 1N 4N 0N 1N 4N --------------------------------------------cm ----------------------------------------------Released 'Brooksville 67' 29.7 bc z B y 49.5 abc AB 64.7 ab A 31.2 a B 46.7 abc AB 50.3 abc A 'Ecoturf' 22.0 bc C 52.2 abc B 70.7 ab A 20.4 ab B 54.1 a A 61.1 ab A 'Florigraze' 46.1 a B 59.4 ab A 69.0 ab A 17.3 b C 43.3 abc B 58.3 ab A Experimental EX1 33.3 b B 55.9 ab A 64.9 ab A 10.0 b C 36.3 abc B 57.2 ab A EX3 18.1 c C 38.8 bc B 58.3 ab A 18.1 ab B 31.2 c A 28.3 c AB EX5 24.5 bc B 27.8 c AB 44.7 b A 20.3 ab B 26.8 c B 45.4 bc A EX6 20.2 c B 55.3 ab A 48.6 ab A 13.5 b B 49.2 ab A 60.9 ab A EX7 22.3 bc B 69.8 a A 71.6 a A 16.4 b C 41.7 abc B 70.3 a A EX8 23.7 bc B 54.5 ab A 66.4 ab A 14.3 b C 34.0 b c B 68.8 ab A z Means within columns with the same lowercase letter are not statistically different by the Tukey Kramer test at P y Means within rows for a given experiment with the same uppercase letters are not statistically different by the Tukey Kramer test at P Indicates experiment is significantly different for a given fertilizer treatment by the Tukey Kr amer test at P

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99 Table A 4 Nitrogen effects on foliage cover of A. glabrata selections. Percent cover is stated relative to the surface area of the container. Experiment 1 Experiment 2 Selection 0N 1N 4N 0N 1N 4N ---------------------------------------------% cover -----------------------------------------------------Released 'Brooksville 67' 27.2 b z B y 37.7 c B 76.7 bc A 34.5 a B 47.5 ab B 71.3 bc A 'Ecoturf' 16.7 c C 55.8 bc B 97.1 abc A 20.0 b C 60.7 a B 95.3 b A 'Florigraze' 52.3 a B 97.5 a A 114.8 a A 15.2 bc C 57.8 a B 92.8 b A Experimental EX1 48.1 a B 104.5 a A 104.6 abc A 7.8 d C 29.2 cde B 59.1 bcd A EX3 15.3 c C 37.8 c B 79.0 abc A 14.3 bc B 22.2 de A 23.2 d A EX5 12.5 c B 13.7 d B 23.5 e A 12.6 cd B 15.8 e B 42.2 cd A EX6 11.3 c B 47.1 bc A 36.9 de A 11.6 cd C 44.7 abc B 95.9 b A EX7 11.8 c B 51.8 bc A 70.3 cd A 13.1 cd C 31.0 bcde B 87.5 b A EX8 15.7 c C 60.5 b B 107.6 ab A 11.0 cd B 34.3 bcd B 137.8 a A z Means within columns with the same lowercase letter are not statistically different by the Tukey Kramer test at P 0.05. y Means within rows for a given experiment with the same uppercase letters are not statistically different by the Tukey Kramer test at P Indicates experiment is significantly different for a given fertilizer treatment by the Tukey Kr amer test at P

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100 Table A 5 Nitrogen effects on number of flowers of A. glabrata selections. Experiment 1 Experiment 2 Selection 0N 1N 4N 0N 1N 4N -------------------------------------number of flowers ---------------------------------------Released 'Brooksville 67' 0.0 b z B y 0.5 b B 3.5 abc A 1.1 a B 6.7 a AB 14.4 a A 'Ecoturf' 0.0 b B 0.1 b B 4.3 abc A 0.0 b B 0.2 bcd B 3.2 b A 'Florigraze' 4.9 a A 4.7 a A 5.9 ab A 0.0 b B 0.7 bcd B 7.6 ab A Experimental EX1 1.2 ab B 5.0 a AB 8.8 a A 0.0 b B 4.7 a A 6.9 ab A EX3 0.0 b B 0.0 b B 3.4 abc A 0.1 ab A 1.6 abc A 1.6 b A EX5 0.8 b A 0.8 ab A 1.9 bc A 0.2 ab B 0.6 bcd B 4.2 b A EX6 0.0 b A 0.3 b A 0.5 c A 0.0 b B 0.1 cd B 2.0 b A EX7 0.1 b A 0.9 ab A 2.2 abc A 0.0 b C 2.4 ab B 7.1 ab A EX8 0.0 b A 0.5 b A 0.9 bc A 0.0 b B 0.0 d B 4.3 b A z Means within columns with the same lowercase letter are not statistically different by the Tukey Kramer test at P y Means within rows for a given experiment with the same uppercase letters are not statistically different by the Tukey Kramer test at P Indicates experiment is significantly different for a given fertilizer treatment by the Tukey Kr amer test at P

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101 LIST OF REFERENCES Adjei, M.B. and G.M. Prine. 1976. Establishment of perennial peanuts ( Arachis glabrata Benth.). Proc. Soil Crop Sci. Soc. Fla. 35:50 53. Aldrich, J.H., G.W. Knox, A.R. Blount, and C.L. Mackowiak. 2012. Landscape performance of mowed rhizoma perennial peanut. Proc. of the Southern Nursery Assoc. Res. Conf. 57:197 200. Baltensperger, D.D., G.M. Prine, R.A. Dunn. 1986. Root knot nematode resistance in Arachis glabrata Peanut Sci. 13:78 80. Blickensderfer, C.B., H. J. Haynsworth, and R.D. Roush. 1964. Wild peanut is promising forage legume for Florida. Crops Soils. 17:19 20. Butler, T.J., W.R. Ocumpaugh, M.A. Sanderson, R.L. Reed, and J.P. Muir. 2006. Evaluation of rhizoma peanut genotypes for adaptation in Texas. A gron. J. 98:1589 1593. Conway, T.H. and G.E. Ritchey. 1949. A report of plant species under test at Gainesville, 1914 1949. Final report to USDA Division of Forage Crops and Diseases, Bureau of Plant Industry, Soils and Agricultural Engineering. P. 274. Dunavin, L.S. 1990. Cool season forage crops seeded over dormant rhizoma peanut. J. Prod. Agric. 3:112 114. Dunavin, L.S. 1992. Florigraze rhizoma peanut in association with warm season perennial grasses. Agron. J. 32:148 151. Freire, M.J., C.A. Kelly Begazo, and K.H. Quesenberry. 2000. Establishment, yield, and competitiveness of rhizoma perennial peanut germplasm on a flatwoods soil. Soil Crop Sci. Soc. Fla. Proc. 59:6 72. French, E.C., G.M. Prine, and A.R. Blount. 2006. Perennial peanut: an alternative forage of growing importance S S AGR 39, Institute of Food and Agricultural Sciences, Univ. of Florida. French, E.C., J.A. Stricker, G.M. Prine, F.S. Zazueta, A.E. Dudek, and A.S. Blount. 2001 (Revised 2006). Establishment and management of ornamental perennial peanuts. UF/IFAS EDIS Pu blication SS AGR 19. Johnson, S.E., L.E. Sollenberger, and J.M Bennett. 1994. Yield and reserve status of rhizoma peanut growing under shade. Crop Sci. 34:757 761. Kalmbacher, R.S. and F.G. Martin. 1983. Light penetrating a bahia grass ( Paspalum notatum ) canopy and its influence on establishing jointvetch ( Aeschynomene americana ). Agron. J. 75:465 468.

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102 Kelemu, S., S. Lapointe, and F. Morales. 1993. Diseases and pests of wild Arachis species, p. 95 101. In: P.C. Kerridge and B. Hardy (eds.). Biology and a gronomy of forage Arachis Centro Internacional de Agricultura Tropical, Cali, Colombia. Kelly, C.A. 1994. Establishment and evaluation of perennial peanut (Arachis glabrata) in Florida. MS Thesis, Univ. of Fla., Gainesville. Knox, G.W., J.A. Aldrich, an d B.D. Anderson. 2010. Preliminary methods for container production of rhizoma perennial peanut ( Arachis glabrata ). Proc. of the Southern Nursery Assoc. Res. Conf. 55:406 409. Kchenmeister, K., F. Kchenmeister, N. Wrage, M. Kayser, and J. Isselstein. 20 12. Establishment and early development of five possible alternatives to Trifolium repens as a grassland legume. J. of Agric. Sci. 4:86 95. Maas, A.L., Anderson, W.F., Quesenberry, K.H. 2010. Genetic variability of cultivated rhizoma perennial peanut. Cro p Sci. 50:1908 1914. Maura, C., M.A. Gonter, and B.D. Gordon. 2006a. Brooksville 67 Germplasm. USDA NRCS Brooksville Plant Materials Center, Brooksville, FL. ID# 5054. 6 Aug. 2012. . Maura, C ., M.A. Gonter, and B.D. Gordon. 2006b. USDA NRCS Brooksville Plant Materials Center, Brooksville, FL. ID# 5055. 6 Aug. 2012 < http://www.plant materials.nrcs.usda.gov/pubs/flpmcrb5055.pdf>. Niles, W.L., E.C. French, P.E. Hildebrand, G. Kidder, and G.M. P rine. 1990. Establishment of florigraze rhizoma peanut (Arachis glabrata Benth.) as affected by lime, phosphorus, potassium, magnesium, and sulfur. Soil and Crop Sci. Soc. Fla. Proc. 49:207 210. Ocumpaugh, W.R. 1990. Production and nutritive value of Flor igraze rhizoma peanut in a semiarid climate. Agron. J. 82:179 182. Ortega S., J.A., L.E. Sollenberger, K.H. Quesenberry, J.A. Cornell, and C.S. Jones, Jr. 1992. Productivity and persistence of rhizoma peanut pastures under different grazing managements. A gron. J. 84:799 804. Prine, G.M. 1964. Forage possibilities in the genus Arachis. Soil and Crop Sci. Soc. Fla. Proc. 24:187 196. Prine, G.M. 1973. Perennial peanuts for forage. Soil Crop Sci. Soc. Fla. Proc. 32:33 35. Prine, G.M., L.S. Dunavin, J.E. Moo re, and R.D. Roush. 1981. Florigraze rhizoma peanut a perennial forage legume. Circ. S 275. Fla. Agric. Exp. Stn., Gainesville.

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103 Prine, G.M., L.S. Dunavin, R.J. Glennon, and R.D. Roush. 1986a. Arbrook rhizoma peanut a perennial forage legume. Circ. S 3 32. Fla. Agric. Exp. Stn., Gainesville. Prine, G.M., L.S. Dunavin, R.J. Glennon, and R.D. Roush. 1986b. Registration of 1085. Prine, G.M., L.S. Dunavin, R.J. Glennon, and R.D. Roush. 1990. Registration of 744. Prine, G.M., E.C. French, A.R. Blount, M.J. Williams, and K.H. Quesenberry. 2010. Registration of Arblick and Ecoturf rhizoma peanut germplasms for ornamental or forage use. J. Plant Reg. 4:145 148. Quesenber ry, K.H., A.R. Blount, P. Mislevy, E.C. French, M.J. Williams, and G.M. Prine. matter yields, persistence, and disease tolerance. J. Plant Reg. 4:17 21. Rice, R.W., L.E. Sollenberger, K.H. Quesenberry, G.M. Prine, and E.C. French. 1996. Establishment of rhizoma perennial peanut with varied rhizome nitrogen and carbohydrate concentrations. Agron. J. 88:61 66. Ruttinger Lamperti, A. 1989. Evaluation of perennial Arachis ge rmplasm for agronomic performance, response to peanut root knot nematode, and three peanut leaf spot diseases. MS Thesis, Univ. of Fla., Gainesville. Sainju, U.M., T.H. Terrill, S. Gelaye, and B.P. Singh. 2003. Soil aggregation and carbon and nitrogen poo ls under rhizoma peanut and perennial weeds. Soil Sci. Soc. Am. J. 67:146 155. SAS Institute. 2008. SAS for Windows, version 9.2. Cary, NC. Simpson, C.E., J.F.M. Valls, and J.W. Miles. 1994. Reproductive biology and the potential for genetic recombinatio n in Arachis, p. 43 52. In: P.C. Kerridge and B. Hardy (eds.). Biology and agronomy of forage Arachis. Centro Internacional de Agricultura Tropical, Cali, Colombia. Terrill, T.H., S. Gelaye, S. Mahotiere, E.A Amoah, S. Miller, R.N. Gates, and W.R. Windham 1996. Rhizoma peanut and alfalfa productivity and nutrient composition in central Georgia. Agron. J. 88:485 488. Terrill, T.H., U.M. Sainju, S. Gelaye, and B.P. Singh. 2000. Long term productivity of rhizoma peanut and alfalfa in central Georgia. p. 260 264. In M. Phillips (ed.) Proc. Forage and Grassland Conf., Madison, WI. 16 19 July 2000. Am. Forage and Grassl. Council, Georgetown, TX.

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104 The Florida State University. 2011. Florida Climate Center, Office of the State Climatologist: 1981 2010 normals. 2 0 Aug. 2012. . Trindle, J.D.C. and T.R. Flessner. 2003. Propagation protocol for production of container Lupinus latifolius SDA NRCS Corvallis Plant Materials Center, Corvallis, Oregon. In: Native Plant Network. Moscow, ID: University of Idaho, College of Natural Resources, Forest Research Nursery. 30 Aug. 2012. . United States Department of Agriculture. 2012. Natural Resources Conservation Service: Web Soil Survey. 8 Aug. 2012. http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx Valentim, J.F., O.C. Ruelke, and G.M. Prine. 1986. Yield and quality responses of tropical grasses, a legume and grass legume associations as affected by fertilizer nitrogen. Soil and Crop Sci. Soc. Fla. Proc. 45:138 143. Valls, J.F.M., B.L. Maass, and C.R. Lopes. 1993. Genetic resou rces of wild Arachis and genetic diversity, p.28 42. In: P.C. Kerridge and B. Hardy (eds.). Biology and agronomy of forage Arachis. Centro Internacional de Agricultura Tropical, Cali, Colombia. Valls, J.F.M. and C.E. Simpson. 1993. Taxonomy, natural distr ibution, and attributes of Arachis, p. 1 18. In: P.C. Kerridge and B. Hardy (eds.). Biology and agronomy of forage Arachis. Centro Internacional de Agricultura Tropical, Cali, Colombia. Venuto, B.C., D.D. Redfearn, and W.D. Pitman. 1998. Rhizoma peanut re sponses to harvest frequency and nitrogen fertilization on Louisiana coastal plain soils. Agron. J. 90:826 830. Venuto, B.C., W. Elkins, and D. Redfearn. 2000. Soil fertility effects on growth and nutrient uptake of rhizoma peanut. J. Plant Nutr. 23:231 2 41. Williams, M.J. 1993. Planting date and preplant tillage effects on emergence and survival of rhizoma perennial peanut. Crop Sci. 33:132 136. Williams, M.J. 1994. Growth characteristics of rhizoma peanut and nitrogen fertilized bahiagrass swards. Agro n. J. 86:819 823. Williams, M.J., C.A. Kelly Begazo, R.L. Stanley, Jr., K.H. Quesenberry, and G.M. Prine. 1997. Establishment of rhizoma peanut: interaction of cultivar, planting date, and location on emergence and rate of cover. Agron. J. 89:981 987. Wi lliams, M.J., E. Valencia, and L.E. Sollenberger. 2002. No till establishment of rhizoma peanut. Agron. J. 94:1350 135.

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105 BIOGRAPHICAL SKETCH Benjamin Anderson was born in Rochester, NY in 1984 and grew up in the rural part of upstate New York He attended the University of Florida in Gainesville where he ubl ic gardens m anagement in 2009 He received his M.S. degree in environmental horticulture in the spring of 2013. Af t er earning these degre es, Benjamin plans to continue his education to obtain a degree in environmental e ngineering.