Effect of Low Water and Nutrient Environments on Growth Characteristics of Eight Native Ornamental Perennial Species

Jeremy Boychyn

An M.Sc. Thesis Presented to The University of Guelph

In partial fulfillment of requirements for the degree of Master of Science in Plant Agriculture

Guelph, Ontario, Canada

ABSTRACT

Effect of Low Water and Nutrient Environments on Growth Characteristics of Eight Native Ornamental Perennial Species

Jeremy Boychyn Advisor: University of Guelph 2016 Dr. J. Alan Sullivan

Native plants are often recommended to reduce inputs in urban landscapes.

Morphological and physiological responses of Liatris spicata, Liatris pycnostachya, Liatris aspera, Liatris scariosa, Liatris cylindracea, Amsonia tabernaemontana, Thermopsis caroliniana, and Baptisia australis to varying fertility and moisture conditions were studied to determine their ability to reduced input. A field study showed wet adapted species L. pycnostachya and L. spicata had greater increased dry mass in response to irrigation compared to dry adapted species while there was no response to fertilizer in all species. A greenhouse trial showed T. caroliniana and B. australis had greater decreased dry weight compared to other species. A. tabernaemontana, L. scariosa, and L. cylindracea displayed decreased growth and photosynthesis with high water treatment. For all other species, higher water availability increased photosynthetic rate and growth. A third study showed no significant response in root morphology to deficit irrigation. This research shows the ability of native plants to reduce inputs in species dependent.

ACKNOWLEDGEMENTS

First off, I would like to take the time to thank my Advisor, Al Sullivan, for giving me this opportunity. The path that has led to the completion of this MSc. Thesis has been nothing short of eventful. Through all the difficulties, Al was there to give perspective and provide support. This thesis would not have been completed if it were not for his guidance.

I would also like to thank my friends for their support throughout my programs duration.

Life around the office would not have been the same without Emily Moeller and Abhishek

Chattopadhyay. Thank you for all of your assistance around the lab and you unwavering friendship. In addition, a big thanks to my friends who were there for me during the times away from studies, Brian Collins and Brad Seward, for always having input toward the conversation of graduate study struggles. For all of my friends who were a part of my life during this program, thank you. Each of you played a role in shaping my graduate experience. Finally, a big thank you to my second family at 402 College.

Thank you to Rodger J Tschanz, who was always there to help keep all of the research flowing smoothly as well as always being available for a laugh. Also, a big thanks to the Bovey

Greenhouse, Guelph Turfgrass Institute, and Elora Research Station crew, who with their help, supported the success of this research.

Lastly, I would like to thank my family for being there throughout this entire experience.

I am a product of your guiding lessons so this work is as much mine as yours.

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TABLE OF CONTENTS ABSTRACT ______ii ACKNOWLEDGEMENTS ______iii TABLE OF CONTENTS ______iv List of Tables ______vi List of Figures ______xii List of Abbreviations ______xiv Chapter 1: Native Plants in Gardens ______1 History ______1 Current Uses and Benefits ______1 Drought and Water Stress Resistance ______2 Photosynthesis in Optimal and Dry Conditions ______8 Growth and Development ______9 Short term and long term effects of drought ______13 Fertilizer ______13 Water by fertilizer interaction ______15 Liatris spp. ______15 Amsonia tabernaemontana ______17 Baptisia australis & Thermopsis caroliniana ______18 Study Objectives ______18 Literature Cited ______19 Chapter 2: Growth and photosynthetic response of eight native ornamental perennials under three watering regimes ______24 Abstract ______24 Introduction ______25 Materials and Methods ______28 Results ______34 Discussion ______47 Summary ______60 Literature Cited ______62 Tables and Figures ______67 Chapter 3: Effects of fertilizer and irrigation on eight native perennial ornamentals in field conditions over two years. ______78 Abstract ______78

Introduction ______79 Materials and Methods ______83 Results ______87 Discussion ______98 Conclusion ______107 Literature Cited ______109 Tables and Figures ______113 Chapter 4 Effect of deficit irrigation on root and shoot growth of eight native ornamental perennial species ______136 Abstract ______136 Introduction ______137 Materials and Methods ______141 Results ______144 Discussion ______146 Conclusion ______150 Literature Cited ______152 Tables and Figures ______156 Chapter 5: General discussion ______170 Literature Cited ______177 List of ANOVA Tables ______179 Appendix A: ANOVA Tables ______179 Appendix B: Supplementary Tables and Figures ______220

List of Tables Table Title Page 2.1 Effects on all growth, flowering and carbon exchange rates of three 67 separate and distinct watering regimes including Cyclic Drought, Low Water, and High Water regimes imposed under greenhouse conditions on eight native perennial ornamental species. Cyclic Drought imposed multiple drought cycles in which soil was saturated and then allowed to dry until 50% of plants displayed wilt. Low Water maintained soil moisture between 23% and 40%. High Water maintained soil moisture between 55% and 70%. 2.2 Species response to Low Water and Cyclic Drought watering regimes 68 based on total dry weight decrease within each regime. 2.3 Percent change of growth characteristics under three separate and 69 distinct watering regimes including Cyclic Drought, Low Water, and High Water regimes imposed under greenhouse conditions on a eight native perennial ornamental species. Cyclic Drought imposed multiple drought cycles in which soil was saturated and then allowed to dry until 50% of plants displayed wilt. Low Water maintained soil moisture between 23% and 40%. High Water maintained soil moisture between 55% and 70%. 2.4a Results of growth characteristics under three separate and distinct 70 watering regimes including drought, Low Water, and High Water regimes imposed under greenhouse conditions on eight native perennial ornamental species. Cyclic Drought imposed multiple drought cycles in which soil was saturated and then allowed to dry until 50% of plants displayed wilt. Low Water maintained soil moisture between 23% and 40%. High Water maintained soil moisture between 55% and 70%.

2.4b Results of growth characteristics under three separate and distinct 71 watering regimes including drought, Low Water, and High Water regimes imposed under greenhouse conditions on eight native perennial ornamental species. Cyclic Drought imposed multiple drought cycles in which soil was saturated and then allowed to dry until 50% of plants displayed wilt. Low Water maintained soil moisture between 23% and 40%. High Water maintained soil moisture between 55% and 70%. 2.5 Flowering characteristics in the Low Water and High Water regimes 72 expressed as percent change from the High Water regime under three separate and distinct watering regimes including drought, Low Water, and High Water regimes imposed under greenhouse conditions on eight native perennial ornamental species. Cyclic Drought imposed multiple drought cycles in which soil was saturated and then allowed to dry until 50% of plants displayed wilt. Low Water maintained soil moisture between 23% and 40%. High Water maintained soil moisture between 55% and 70%.

2.6 Flowering characteristics under three separate and distinct watering 73 regimes including Cyclic Drought, Low Water, and High Water regimes imposed under greenhouse conditions on a eight native perennial ornamental species. Cyclic Drought imposed multiple drought cycles in which soil was saturated and then allowed to dry until 50% of plants displayed wilt. Low Water maintained soil moisture between 23% and 40%. High Water maintained soil moisture between 55% and 70%. 2.7 Effects on flowering dates under three separate and distinct watering 74 regimes including Cyclic Drought, Low Water, and High Water regimes imposed under greenhouse conditions on eight native perennial ornamental species. Cyclic Drought imposed multiple drought cycles in which soil was saturated and then allowed to dry until 50% of plants displayed wilt. Low Water maintained soil moisture between 23% and 40%. High Water maintained soil moisture between 55% and 70%. 2.8 Photosynthetic measurements under Low Water, High Water, and 75 Cyclic Drought watering regime imposed under greenhouse conditions on eight native perennial ornamental species. Cyclic Drought imposed multiple drought cycles in which soil was saturated and then allowed to dry until 50% of plants displayed wilt. Low Water maintained soil moisture between 23% and 40%. High Water maintained soil moisture between 55% and 70%. 2.9 Percent change of photosynthetic measurements from High Water 76 treatment under Low Water and Cyclic Drought watering regime imposed under greenhouse conditions on eight native perennial ornamental species. Cyclic Drought imposed multiple drought cycles in which soil was saturated and then allowed to dry until 50% of plants displayed wilt. Low Water maintained soil 3.1 Seed sources for species used in GTI & Elora trials in 2011 and 2012. 117 3.2 Effects of supplemental water (rainfall plus irrigation up to 25 118 mm/week) on growth characteristics of eight native perennial ornamental species in 2012 in reproductive growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario, represented as percent change. Values indicate percent change from the rainfall control. 3.3a Effects of supplemental water (rainfall plus irrigation up to 25 119 mm/week) on growth characteristics of eight native perennial ornamental species in 2012 in reproductive growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario.

3.3b Effects of supplemental water (rainfall plus irrigation up to 25 120 mm/week) on growth characteristics of eight native perennial ornamental species in 2012 in reproductive growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario.

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3.4 Effects of supplemental fertilizer (20-10-10 at 135g N/6 m row) on 121 growth characteristics of eight native perennial ornamental species in 2011 in vegetative growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario, represented as percent change. Values indicate percent change relative to the unfertilized control. 3.5 Effects of supplemental fertilizer (20-10-10 at 135g N/6 m row) on 122 growth characteristics of eight native perennial ornamental species in 2011 in vegetative growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario. 3.6 Effects of supplemental fertilizer (20-10-10 at 135g N/6 m row) on 123 growth characteristics of a eight native perennial ornamental species in 2012 in reproductive growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario, represented as percent change. Values indicate percent change from the unfertilized control. 3.7 Effects of supplemental fertilizer (20-10-10 at 135g N/6 m row) on 124 growth characteristics of eight native perennial ornamental species in 2012 in reproductive growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario. 3.8 Effects of three separate fertilizer treatments (0, 81, 122.4, and 163.2 125 g of N/ 3.5 m row) on growth characteristics of eight native perennial ornamentals located in a field trial at the Elora Research Station in Elora, Ontario in 2011 in vegetative growth year. 3.9a Effects of three separate fertilizer treatments (0, 81, 122.4, and 163.2 126 g of N/ 3.5 m row) on growth and flowering characteristics of eight native perennial ornamentals located in a field trial at the Elora Research Station in Elora, Ontario in 2012 in reproductive growth year.

3.9b Effects of three separate fertilizer treatments (0, 81, 122.4, and 163.2 127 g of N/ 3.5 m row) on growth and flowering characteristics of eight native perennial ornamentals located in a field trial at the Elora Research Station in Elora, Ontario in 2012 in reproductive growth year.

3.10 Effects of supplemental water (rainfall plus irrigation up to 25 128 mm/week) on growth characteristics of eight native perennial ornamental species in 2011 in vegetative growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario, represented as percent change. Values indicate percent change from the rainfall control. 3.11 11 Effects of supplemental water (rainfall plus irrigation up to 25 129 mm/week) on growth characteristics of a eight native perennial ornamental species in 2011 in vegetative growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario. 3.12 Effects of supplemental fertilizer (20-10-10 at 135g N/6 m row) on 130 growth characteristics of eight native perennial ornamental species in viii

2011 in vegetative growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario. 3.13 Effects of supplemental water (rainfall plus irrigation up to 25 131 mm/week) on flowering time of eight native perennial ornamental species in 2012 in reproductive growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario. 3.14 Effects of supplemental fertilizer (20-10-10 at 135g N/ 6 m row) on 132 flower timing of eight native perennial ornamental species in 2012 in reproductive growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario. 3.15 Effects of three separate fertilizer treatments (0, 81, 122.4, and 163.2 133 g of N/ 3.5 m row) on flowering time of eight native perennial ornamentals located in a field trial at the Elora Research Station in Elora, Ontario in 2012 in reproductive growth year. 3.16a Effects of supplemental fertilizer (+F) (20-10-10 at 135g of N/6 m 134 row) with no supplemental water (-W), supplemental water (+W) (rainfall plus irrigation up to 25 mm/week) with no supplemental fertilizer (-F), and supplemental water with supplemental fertilizer on plant growth characteristics of eight native perennial ornamental species in 2011 in vegetative growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario.

3.16b Effects of supplemental fertilizer (+F) (20-10-10 at 135g N/6 m row) 135 with no supplemental water (-W), supplemental water (+W) (rainfall plus irrigation up to 25 mm/week) with no supplemental fertilizer (- F), and supplemental water with supplemental fertilizer on plant growth characteristics of eight native perennial ornamental species in 2011 in vegetative growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario.

3.17 Effects of supplemental fertilizer (+F) (20-10-10 at 135g N/6 m row) 136 with no supplemental water (-W), supplemental water (+W)(rainfall plus irrigation up to 25 mm/week) with no supplemental fertilizer (- F), and supplemental water with supplemental fertilizer on plant growth characteristics of eight native perennial ornamental species in 2012 in reproductive growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario.

3.18 Effects of supplemental fertilizer (+F) (20-10-10 at 135g N/6 m row) 137 with no supplemental water (-W), supplemental water (+W)(rainfall plus irrigation up to 25 mm/week) with no supplemental fertilizer (- F), and supplemental water with supplemental fertilizer on flowering time of eight native perennial ornamental species in 2012 in reproductive growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario. 4.1 Effects of deficit (1/2 of water loss through transpiration) and 160

supplemental (100% of water loss from transpiration) irrigation on several growth characteristics of eight native ornamental perennial species at the University of Guelph (Guelph, Ontario, Canada) in 2011. Data presented are the mean of eight species. 4.2 Differences between deficit (1/2 of water loss through transpiration) 160 and supplemental (100% of water loss from transpiration) irrigation on percent change of several growth characteristics of eight native ornamental perennial species at the University of Guelph (Guelph, Ontario, Canada) in 2011. 4.3 Effects of deficit (1/2 of water loss through transpiration) and 165 supplemental (100% of water loss from transpiration) irrigation on several growth characteristics of eight native ornamental perennial species at the University of Guelph (Guelph, Ontario, Canada) in 2011. 4.4 Effects of deficit (1/2 of water loss through transpiration) and 166 supplemental (100% of water loss from transpiration) irrigation on the dry weight of primary and tertiary roots at three different depths of eight container grown native ornamental perennial species at the University of Guelph (Guelph, Ontario, Canada) in 2011.

4.5 Effects of deficit (1/2 of water loss through transpiration) and 167 supplemental (100% of water loss from transpiration) irrigation on percent change in the dry weight of primary and tertiary roots at three different depths of eight container grown native ornamental perennial species at the University of Guelph (Guelph, Ontario, Canada) in 2011 4.6 Effects of deficit (1/2 of water loss through transpiration) and 168 supplemental (100% of water loss from transpiration) irrigation on the number of primary roots at different depths of eight container grown native ornamental perennial species at the University of Guelph (Guelph, Ontario, Canada) in 2011. 4.7 Effects of deficit (1/2 of water loss through transpiration) and 169 supplemental (100% of water loss from transpiration) irrigation on percent change in the number of primary roots at different depths of eight container grown native ornamental perennial species at the University of Guelph (Guelph, Ontario, Canada) in 2011. 4.8 Effects of deficit (1/2 of water loss through transpiration) and 170 supplemental (100% of water loss from transpiration) irrigation on several root growth characteristics of eight container grown native ornamental perennial species at the University of Guelph (Guelph, Ontario, Canada) in 2011. 4.9 Effects of deficit (1/2 of water loss through transpiration) and 171 supplemental (100% of water loss from transpiration) irrigation on percent change of several root growth characteristics of eight container grown native ornamental perennial species at the University of Guelph (Guelph, Ontario, Canada) in 2011.

4.10 Effects of deficit (1/2 of water loss through transpiration) and 172 supplemental (100% of water loss from transpiration) irrigation on root architecture in a container trial at the University of Guelph (Guelph, Ontario, Canada) on eight native ornamental perennial species in the reproductive year in 2011. Data represented as the mean of eight species. 4.11 Seed sources for species used in University of Guelph (Guelph, 172 Ontario Canada) deficit irrigation container trials in 2012.

List of Figures Figure Title Page 2.1 Expected photosynthetic response of native plant species to High 77 Water, Low Water, and Cyclic Drought watering regimes over one cycle of drought. 3.1 Cumulative rainfall, irrigation, and rainfall plus irrigation received 115 (mm) at the GTI trial during the 2011 growing season. 3.2 Cumulative rainfall, irrigation, and rainfall plus irrigation received 115 (mm) at the GTI trial during the 2012 growing season. 3.3 Cumulative rainfall (mm) received at the Elora trail site during the 116 2011 growing season. 3.4 Cumulative rainfall (mm) received at the Elora trail site during the 116 2012 growing season. 4.1 One primary root image of Amsonia tabernaemontana scanned for 159 analysis using WinRHIZO. 4.2 One primary root image of Baptisia australis scanned for analysis 159 using WinRHIZO. 4.3 Diagram of crosses (a), forks (b), and tips (c) of root system as 159 measured by WinRHIZO 4.4 Full root system of Liatris aspera at conclusion of container trial in 161 which the species was exposed to 100% replacement of water lost based on weight (SI) and 50% replacement of water lost based on container weight (DI). 4.5 Full root system of Liatris spicata at conclusion of container trial 161 in which the species was exposed to 100% replacement of water lost based on weight (SI) and 50% replacement of water lost based on container weight (DI). 4.6 Full root system of Thermopsis caroliniana at conclusion of 162 container trial in which the species was exposed to 100% replacement of water lost based on weight (SI) and 50% replacement of water lost based on container weight (DI). 4.7 Full root system of Amsonia tabernaemontana at conclusion of 162 container trial in which the species was exposed to 100% replacement of water lost based on weight (SI) and 50% replacement of water lost based on container weight (DI). 4.8 Full root system of Liatris pycnostachya at conclusion of container 163 trial in which the species was exposed to 100% replacement of water lost based on weight (SI) and 50% replacement of water lost based on container weight (DI). 4.9 Full root system of Liatris scariosa at conclusion of container trial 163 in which the species was exposed to 100% replacement of water lost based on weight (SI) and 50% replacement of water lost based on container weight (DI). 4.10 Full root system of Liatris cylindracea at conclusion of container 164 trial in which the species was exposed to 100% replacement of

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water lost based on weight (SI) and 50% replacement of water lost based on container weight (DI). 4.11 Full root system of Baptisia australis at conclusion of container 164 trial in which the species was exposed to 100% replacement of water lost based on weight (SI) and 50% replacement of water lost based on container weight (DI).

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List of Abbreviations

AMAX Maximum Carbon Exchange Rate CDW Cyclic Drought CER Carbon Exchange Rate Ci Internal CO2 DAT Days After Treatment DI Deficient Irrigation DMSO Dimethyl sulfoxide gs Stomatal Conductance GTI Guelph Turfgrass Institute HW High Water LF Low Fertilizer LW Low Water MF Medium Fertilizer MLF Medium-Low Fertilizer NF No Supplemental Fertilizer NW No Supplemental Water P:F Plant to Flower Ratio PAR Photosynthetic Active Radiation R:S Root to Shoot Ratio SF Supplemental Fertilizer SI Supplemental Irrigation

Chltot Total Chlorophyll Content SW Supplemental Water TR Transpiration VWC Volumetric water content WUE Water Use Efficiency

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Chapter 1: Native Plants in Gardens

History

Gardens that include floral plants have, and continue to be an important part of the urban culture. There has been a large diversity of plant material used in gardens across the world and throughout history (Thacker, 1979). Over the past 150 to 200 years, an interest in native plant use has expanded across North America. Even more recently (within the past decade), a significant increase of public interest in native plant use has occurred (McMahan, 2006).

Increased use of native ornamentals is driven by strong public desire (Jones, 2009). The utilization of native species in gardens has been used as an attempt to reduce negative impact on native flora and fauna that has been seen when invasive species are introduced (Helfand et al.,

2006). Native plants are also important in ecological research and restoration. Heleno et al.

(2010) replaced all alien and invasive species with native species in a landscape considered to be ecologically damaged resulting in a substantial increase of natural flora and fauna.

Current Uses and Benefits

People are willing to incorporate native flora into their landscape as long as the perceived environmental benefit outweighs the cost of installation without compromising aesthetics

(Helfand et al., 2006). Use of native plants increases shelter for wildlife, restoration of native plant communities, and in some cases can be more cost effective (McMahan, 2006). As well, native flowering plants in urban landscapes can decrease water use, contrasting non-native species, which are typically less water efficient. As a result of the use of non-native flora, water consumption by landscape irrigation can amount to 40-70% of the total municipal water use (St.

Hilaire et al., 2008). If the proper drought tolerant native species are selected for use, water usage can be significantly decreased (Lockett et al., 2002). Lockett (2002) demonstrated through surveys that reduced water requirements of native species can increase the desire for native plant use in 79% of gardeners.

A direct positive effect of local wildlife has been seen when the use of native plant species increases. This is due to natural relations between the natural fauna and flora. For example, Heleno et al. (2010) removed all non-native species from a particular landscape and allowed growth of native species resulting an increase in native seeds, herbivorous insects, insect parasitoids, and birds by 110%, 85%, 5%, and 7%, respectively.

Drought and Water Stress Resistance

Water stress is caused by reduced availability of water to a point in which functions of the organism are impaired (Opik and Rolfe, 2005). Plants react to water stress in one of three ways: desiccation postponement, desiccation tolerance, and drought avoidance. Postponement is a plant’s ability to maintain tissue hydration during water deficit. Tolerance is a plant’s ability to function during dehydration. Avoidance is a plant’s ability complete it’s life cycle outside of periods of high water stress (Taiz and Zeiger, 2006). Used together, or separately, these responses generate water stress resistance in the plant (Chaves et al., 2003; Opik and Rolfe,

2005).

Internal and external water potential (Ψw) fluctuations will influence the level of water stress that a plant encounters. The surrounding environment is the main factor affecting water potential changes. The external Ψw decreases (becomes more negative) during times of low water availability. This is likely to happen in environments of low humidity or decreased available water in the soil. Low Ψw within the soil is affected by gravitational potential (Ψg),

matric potential (Ψπ), and osmotic potential (Ψo) (Öpik and Rolfe, 2005). In relation to plant accessibility, the soil water potential can vary from -0.01 MPa (field capacity) to -1.5 MPa

(permanent wilting point of most herbaceous plants). Below the permanent wilting point, water becomes unavailable to most plants (Lambers et al., 2006).

Mechanisms of resistance

Herbaceous plants are made up of 80-90% water. The continuation of a plants physiological processes rely heavily of the presence of water (Karamanos, 1981). Drought can affect nearly all aspects of plant growth and development (Blum, 1996; Opik and Rolfe, 2005).

In response, plants have developed a variety of physiological, morphological, anatomical, and biochemical defense mechanisms (Chapman and Augé, 1994; Begg et al., 1980). These responses directly relate to the plants ability to survive under drought.

Morphological and Anatomical Resistance Traits

Some of the general morphological features of plants tolerant to water stress are extensive root systems, higher root:shoot ratio, and specialized leaf characteristics (Begg et al.,

1980; Chapman and Augé, 1994; Opik and Rolfe, 2005). These adaptations can be found together or separately, depending on species.

An extensive root system helps to increase water uptake in dry areas. A plant that has a higher surface area of roots will increase root contact with soil water which can increase water uptake (Kummerow, 1980; Zollinger et al., 2006). Due to the large carbon investment needed to maintain a root system, extensive root systems are typically most suited for perennial plants

(Kummerow, 1980). Typically, plants adapted to areas of increased drought occurrences are more likely to have a larger root system. Root systems develop in one of three ways as: specialized tap root, both taproot and lateral roots (generalized), and specialized lateral root

(Chaves et al., 2003; Kummerow, 1980; Opik and Rolfe, 2005; Zollinger et al., 2006). Typically, plants adapted to environments with decreased water availability will have longer and deeper root systems as compared to plants adapted to environments with abundant water (Clarke and

Durley, 1981a).

As plants encounter lower water availability, an increase in root:shoot ratio typically occurs (Blum, 1996; Opik and Rolfe, 2005; Prevete et al., 2000). An increased root:shoot ratio is a result of increased root growth or decreased leaf expansion and leaf abscission during water deficit (Clarke and Durley, 1981b). Leaf abscission in response to increased synthesis of the plant hormone ethylene will occur after extended periods of water deficit. This defense mechanism helps to maintain plant water during drought by reducing transpirational loss (Taiz and Zeiger, 2006). However, reduced leaf area can result in decreased assimilate production, decreasing or arresting root growth (Clarke and Durley, 1981b). As well, mild water deficits can also increase root growth in some plant species. Increased assimilate movement to the root system allows for continued root expansion. Clark (2009) demonstrated Aquilegia water stress adaptation in which certain species displayed increased root:shoot ratio under induced water deficit. During flowering, assimilate distribution becomes more complicated due to increased partitioning to the reproductive organs (Taiz and Zeiger, 2006).

Leaf morphology plays a large role in water loss reduction. Waxy leaf coatings, reductions in leaf area via abscission, (Begg et al., 1980; Chaves, 2002; Opik and Rolfe, 2005), and specialized stomatal characteristics (Mehri et al., 2009) can play a role in above ground water loss. Transpiration loss through the leaf cuticle can account for 5-10% of total water loss.

To restrict cuticle water loss, particular species produce epicuticular waxes that cover the cuticle and decrease transpirational loss (Taiz and Zeiger, 2006).

Stomata maintain photosynthesis through adjustment of leaf internal atmosphere (i.e. CO2 levels). However, the collection of CO2 comes at the cost of water loss through transpiration of the open stomata. To reduce water loss during periods of moisture stress, plants close their stomata. Stomatal closure can lead to increased leaf temperature and subsequently damage the leaves internal mechanisms. Specialized stomata features including reduced stomatal density, sunken stomata and stomata shape/size can help balance water loss and internal heating (Clarke and Durley, 1981b). Buttery et al. (1993) investigated stomatal density of drought tolerant soybean cultivars. Results demonstrated that cultivars with decreased stomatal density had increased drought tolerance through decreased water loss. However, reduced stomatal density also reduced photosynthetic rates and decreased yields. Sunken stomata create a thicker boundary layer between the stomata and the atmosphere, decreasing transpiration. Lastly, smaller stomata will allow less water loss. Mehri et al., (2009) demonstrated that drought tolerant wheat cultivars had stomata significantly smaller in size than those of non-tolerant cultivars.

Physiological Responses

Water deficit can significantly affect physiological processes in a plant. In response, plants have developed physiological defense mechanisms (Samarah, 2005). The main objective of these physiological responses is to reduce transpirational water loss through maintenance of turgor pressure, stomatal control through osmotic adjustment, abscisic acid (ABA) synthesis

(Taiz and Zeiger, 2006; Begg et al., 1980), and cell membrane stability (Farooq et al., 2009).

One of the first signs of water stress is reduction of cell expansion. As the soil dries and the leaf water potential (ΨL) decreases and a decrease in osmotic potential (Ψπ) occurs. The osmotic potential decrease is then naturally controlled by the solute concentration increase that results from water loss. This increased concentration of solutes increases ΨL and causes

increased water extraction from the soil. However, the increase in ΨL seen is typically short lived and not significantly beneficial for plant growth to continue (Taiz and Zeiger, 2006). Cellular osmotic potential is essential to control turgor pressure and cell expansion. Although cell turgidity can be seen as a defense mechanism against water stress, it is important to note that this ability does not particularly relate to reductions in plant wilt and desiccation (Zollinger et al.,

2006). Osmotic adjustment also takes place within the roots but is less understood. Turgor pressure maintenance in the root apical meristem is important to allow continued root growth and water absorption (Taiz and Zeiger, 2006).

Stomata play a significant role in photosynthetic rate. Stomatal opening controls the internal balance of CO2, allowing photosynthesis to continue efficiently. Transpirational leaf water loss can cause a reduction in stomatal opening (Öpik and Rolfe, 2005). In addition, rapidly induced water stress can lead to stomatal closure. Conversely, slow, long-term drought can provoke multiple responses affecting stomata including hydropassive and hydroactive closure.

Hydropassive stomatal closure occurs when guard cells loss water to the atmosphere.

Hydroactive closure occurs when the entire plant structure loses water to the atmosphere causing a reduction in the solute content of the guard cells, in turn reducing the osmotic potential (Taiz and Zeiger, 2006). These processes are controlled by ABA, which is produced within the roots and transported to the guard cells via the xylem (Taiz and Zeiger, 2006). ABA acts as an osmotic regulator for guard cells, and causes stomatal closure (Damour et al., 2010).

Maintenance of cell membrane structure plays a vital role in a plant’s drought tolerance.

As water content within plant cells decreases, the plant cell becomes more compact and an increase in solute concentration occurs. As the cell becomes more compact, the solutes within the cell may interact leading to possible protein denaturation and membrane fusion. The exact causes

of cell membrane instability are unknown. However, it is possible that this interaction of solutes potentially causes damage (Farooq et al., 2009). Through hardening, osmotic adjustment with compatible solutes, and increased turgor pressure a plant can increase its cell membrane stability

(Taiz and Zeiger, 2006).

ABA plays an important role in drought tolerance through control of root and shoot growth/cessation. As well, ABA controls physiological and biochemical features including regulating seed maturation, promoting seed storage reserve accumulation (Taiz and Zeiger,

2006). There are still many competing ideas on the role of ABA during drought stress. However, research conducted over the past 25 years has yielded many advancements in the role of ABA

(Sharp and LeNoble, 2002). The biosynthesis of ABA takes place within the chloroplast and other plasmids via the terpenoid pathway. A vital step in the terpenoid pathway is the cleavage of violaxanthin into neoxanthin by the enzyme 9-cis-epoxycarotenoid diocygenase (NCED). A family of genes, which are expressed during water stress, are responsible for the increased synthesis of NCED. Plant ABA concentration varies greatly depending on the life stage of the plant as well as the environmental conditions. ABA can increase 50 times the normal concentration within four to eight hours under water stress. Decrease to normal ABA concentrations takes the same amount of time when plants are re-watered (Taiz and Zeiger,

2006). As well, redistribution of free ABA, degradation, compartmentalization, conjugation, and transport will cause changes in ABA concentrations (Taiz and Zeiger, 2006).

Interestingly, recent research investigating the effects of ABA on root:shoot ratio has revealed that ABA may not have a direct effect on root and shoot growth. Instead, ABA synthesis may indirectly controls root and shoot growth by limiting ethylene production, a growth inhibitor. During periods of water stress, accumulation of ABA within the roots is higher

compared to the shoots, resulting in increased ethylene levels in above ground plant material, leading to reduced shoot growth (Chaves et al., 2003).

Photosynthesis in Optimal and Dry Conditions

Plants utilize the energy of light to drive the synthesis of carbohydrates through the following formula:

6 CO2 + 12 H2O + light → C6H12O6 + 6 O2 + 6 H2O

Photosynthesis takes place primarily within chlorophyll which is housed in chloroplasts within the mesophyll cells.

Photosynthesis, even though somewhat impaired, can continue during the earlier stages of drought as it is much more resilient to water stress than cell turgor. This slight impairment of photosynthesis is due to reduced CO2 within the leaf caused by stomatal closure. The photosynthetic process can be severely impaired during times of extended drought as mesophyll cells become dehydrated, and the metabolism of these specialized cells becomes compromised

(Taiz and Zeiger, 2006). Typically, the greatest impact of drought on photonsynthesis is observed when mesophyll dehydration persists after re-watering.

During extended drought, energy supplies to the plant are cut off due to significant photosynthetic impact, reducing a plant’s ability to maintain growth and produce yield (Clark and Durley, 1981). Due to impact of drought on photosynthetic response, water stress in plants has been extensively researched over the past decade (Colom, 2003; Peeva and Cornic, 2009;

Prevete et al., 2000; Starman and Lombardini, 2006; Zollinger et al., 2006). Results from these studies indicate that effects of drought on photosynthesis are species dependent. Prevete et al.,

(2000) demonstrated variation between species via drought regimes imposed on herbaceous

flowering species Boltonia asteroids, Eupatorium rugosum, and Rudbeckia triloba. Eupatorium rugosum was unable to maintain photosynthesis, displaying long-term decreases in photosynthetic capacity. In contrast, Boltonia asteroids and Rudbeckia triloba were able to maintain photosynthetic activity. Starman and Lombardini (2006) investigated the effects of drought on PSII functionality on Lantana camara, Lobelia cardinalis, Salvia farinacea and

Scaevola aemula. All species mantained PSII functionality during simulated drought events.

Zollinger et al., (2006) examined the effects of imposed drought on Echinacea purpurea,

G.aristata, Lavandula angustifolia, Leucanthemum x superbum, Penstemon barbatus, and

Penstemon x Mexicali. Impact on photosynthesis within the trial varied greatly between species.

These results indicate that photosynthetic response to drought is species dependent and there are other mechanisms at work that allow continued photosynthesis during varied levels of water stress.

Growth and Development

Dry matter production/accumulation

Accumulation of dry matter is done through mineral uptake by the roots and photosynthetic fixation of carbon (Canny, 1973). During optimal growing conditions, dry matter production and accumulation can progress efficiently. As the plant grows, accumulated dry matter is distributed throughout the plant to different sinks depending on phenological stage.

Sinks can be defined as any organ that does not produce enough photosynthetic material to sustain its own growth. These sinks can be immature leaves, roots, and reproductive organs.

During water stress, the plant’s ability to allocate dry matter will be limited photosynthesis and consequently reduces cell growth in sinks (Taiz and Zeiger, 2006). The common example of dry matter partitioning adjustment during drought stress is increased root:shoot dry matter ratio.

Numerous studies have investigated the effects of water stress on dry matter accumulation and distribution (Bilbro, 1992; Clark, 2009; Hassen et al., 2007; Nautiyal et al.,

1994; Zollinger et al., 2006). Investigation of drought regimes on growth characteristics of native ornamental species by Clark (2009) demonstrated significant changes in dry matter distribution.

Dry matter distribution during drought varied depending on species as A. alpina and A. caerulea

‘McKana’ T displayed significant decreases of 10.6g to 4.8g and 12.3g to 4.4g, respectively, when comparing drought to high water regimes. In contrast, the species A. rockii J and A. skinneri T displayed lower decreases of dry matter production with no decrease of dry matter (A. rockii J) and a reduction from 6.7g to 5.3g (A. skinneri), when comparing drought to high water regimes.

CHO partitioning

As a result of photosynthesis an accumulation of sugars occurs. These sugars, otherwise known as carbohydrates (CHO), accumulate in the ‘source’ leaf. A source can be defined as any exporting organ that produces more photosynthetic products than it requires. In most cases, sources are mature leaves (Taiz and Zeiger, 2006). These sources send photosynthetic material, about 80% CHO, to sinks via mass flow. Sinks can include roots, fruits, immature leaves, etc.

The pathways for CHO movement are determined by proximity from source to sink, stage in plant development, and the vascular connections (Taiz and Zeiger, 2006; Slewinski and Braun,

2010).

The driving force in CHO partitioning is dependent on sugar consumption/utilization by the sink. CHO consumption increases solute potential within the phloem, which reduces turgor pressure in the sink (Dinant and Lemoine, 2010; Slewinski and Braun, 2010) and generates a gradient, known as the pressure-flow model, allowing CHO to move from source to sink (Taiz

and Zeiger, 2006). The activity of CHO partitioning during drought conditions can be significantly reduced due to leaf senescence of mature source leaves. Reduction of source leaves reduces CHO resulting in reduced growth or senescence of sinks such as reproductive organs

(Chaves et al., 2003).

Impact on growth due to impaired CHO partitioning becomes increasing evident during the reproductive stage of ornamental plants. During flower bud initiation, CHO partitioning favours translocation to the inflorescence. Decreases in turgor pressure due to water deficit reduces cell expansion and growth of the inflorescence significantly, in turn, reducing CHO translocation (Begg et al., 1980). Studies quantifying water deficit’s reduction of inflorescence quality due to changes to CHO partitioning in ornamentals are uncommon. However, Clark

(2009) observed significant inflorescence reductions within low water and drought regimes when compared to high water conditions. Aquilegia alpina drastically reduced floral numbers from

16.7 to 2.7 from high water to drought, respectively. Inclusion of all 28 Aquilegia species demonstrated a floral number decrease of 74% during drought as compared to high water. As well, drought decreased flower duration and size during the trail.

Yield

Yield of plants is the generation of a sink and the subsequent filling of the sink by a source (Blum, 1996). The ability to fill a sink to produce yield, depends largely on the availability of water during different plant growth stages. Research conducted on the effects of water stress on crop yield within the past two decades has revealed that water stress timing, duration, and severity will affect yield differently (Samarah, 2005). Yield reductions in maize vary in severity depending on timing of water stress. During the grain filling growth stage, drought stress reduced yield by 79-81% (Monneveux et al., 2006), while stress during the

reproductive (flowering) growth stage reduced yields by 63-87% (Kamara et al., 2003) and 47-

70% (Chapman and Edmeades, 1999). Maize subjected to water stress during the vegetative stage reduced yield by 25-60% (Atteya, 2003). Water stress, mild and severe, imposed during the grain filling stage of rice decreased yields by 30-55% and 60%, respectively (Basnayake et al.,

2006). A second study imposed mild and severe water stress during the reproductive stage of rice growth resulted in similar reductions of 53-92% and 48-94%, respectively (Lafitte et al., 2007).

Soybean, sunflower, and canola yields responded to water deficit with yield reductions of 46-

71% (Samarah et al., 2006), 60% (Mazaheri Laghab et al., 2003), and 30% (Sinaki et al., 2007), respectively.

Stomatal conductance

Stomata play an important role in maintaining CO2 balance and controlling transpirational water loss and combating water stress (Damour et al., 2010; Nautiyal et al., 1994; Taiz and

Zeiger, 2006). Although much is understood about stomatal aperture, conductance, and function in response to environmental conditions, many factors not fully understood. An example of this is how the guard cells organize cascading signals (Brodribb and Jordan, 2008; Damour et al.,

2010).

Hydropassive and hydroactive stomatal closures are controlled through the production of

ABA in response to water stress. Zollinger et al,. (2006) demonstrated that this process results in a 72-81% reduction in stomatal conductance for E. purpurea and P. barbatus. This response to water stress can vary widely between plant species. Drought tolerant plants that react rapidly to drought stress can reduce stomatal conductance quickly to maintain relatively constant water potential during drought (Taiz and Zeiger, 2006).

Short term and long term effects of drought

Plant responses to water stress can be broken into two categories, short-term responses and long-term responses. The first response to water deficit is the plant’s recognition of water stress. Sensing water stress involves the expression of the osmosensor AtHTK1. It is believed that this is the first sensing mechanism triggering dehydration gene expression and subsequently

ABA production leading to further physiological and biochemical responses (Chaves et al.,

2003).

During long periods of drought, synthesis of osmolytes such as proline and glycine betaine occurs to help maintain turgor pressure (Hare et al., 1999). The increased maintenance of turgor pressure within the roots allows for continued root growth leading to increased root:shoot ratio and absorption area.

Fertilizer

Nitrogen

Nitrogen is essential for plant growth and development because it is a fundamental part of many plant cell components including proteins, amino acids, nucleic acids, hormones, and chlorophyll. Plants obtain the majority of nitrogen necessary for growth from the soil as either nitrate (NO3-) or ammonium (NH4+) (Hopkins and Hüner, 2008).

Limiting nitrogen can produce negative effects including restricting growth of plant organs, roots, stems, leaves, flowers, and fruit. These restrictions in growth as well as a reduction in the production of chlorophyll causes the plant to appear stunted, pale or chlorotic, and in the case of extreme deficiency can cause necrosis (Barker and Pilbeam, 2007). Nitrogen deficiency will lower dry matter production resulting in lower plant yields. In contrast, excessive application of nitrogen causing increased salinity in the soil can result in negative effects on the

soil as well as the plant (Barker and Pilbeam, 2007). When nitrogen is limiting, the plant’s growth in restricted by reduced amino acid production. However, when nitrogen is in excess, the genetic capacity of the plant limits the plant’s ability to utilize amino acids and other metabolites

(Hopkins and Hüner, 2008; Lawlor, 2002).

Numerous studies have investigated plant response to different nitrogen levels. Response of corn to increased nitrogen rates produce a higher grain yields (Eck, 1984; Shapiro and

Wortmann, 2006). Similar studies investigating the effects of nitrogen rates on growth of wheat demonstrated similar increases to dry weight (Camberato and Bock, 1990) and yield. (Ortiz-

Monasterio et al., 1997). Research investigating the effects of nitrogen rate on the growth of ornamentals has displayed similar results. Cabrera (2003) imposed increasing nitrogen rates

(complete nitrogen solutions of 15, 30, 60, 120, 210, and 300 mg l-1) on two ornamental woody species. Results indicated that shoot dry weight increased up to an N rate of 60 mg l-1. Nitrogen rates above this produced a decrease in shoot dry weight. Conversely, not all species respond as expected to increased nitrogen rates. A study by Proctor (2005) investigated the effects of fertilization rates on six herbaceous ornamental perennials including Canna L., Coreopsis verticillata L., Echinacea purpurea L., Iris siberica L., Panicum virgatum L., and Sedum L with varying response between species. In these herbaceous perennials response to nitrogen was species specific.

Fertilization of herbaceous ornamental perennials in urban landscapes

Fertilization of ornamental gardens is common practice within many areas of North

America. A survey conducted within Florida demonstrated that 80% of residents fertilized their ornamental landscapes (Shober et al., 2010). That same study indicated landscape professionals in Florida conducted fertilizer application on 46% of their client’s ornamental landscapes.

Similarly, a study conducted in Atlanta indicated 68% of professionals supplied fertilizer supplements to client’s ornamental beds. A separate Atlanta survey revealed 76% and 68% of landscapes composed of turf or ornamental beds, respectively, were fertilized yearly (Beverly et al., 1997). A similar study conducted in Georgia determined that 76% of residents applied fertilizer yearly (Varlamoff et al., 2001). If these trends continue, exacerbated by increasing population, increased occurrences of environmental damages such as algal blooms is likely

(Erickson et al., 1999).

Water by fertilizer interaction

Soil moisture plays an important role in nutrient availability of plants. The available soil water can affect the passive and active mechanisms involved with nutrient uptake. In instances of limited water availability, plants react with decreased transpiration due to stomatal closure. In turn, this reduces the mass flow of nutrients being pulled towards the root surface from the soil matrix (Gupta, 2005, Poorter and Nagel, 2000). However, plant utilization of applied fertilizer plays a stronger role in plant growth within well-watered conditions as compared to water stress conditions (Eck, 1988). Gajri (1993) investigated the interaction of water and nutrient availability on yield of winter wheat and demonstrated greater nutrient availability under higher levels of water. Consequently, the benefit of applying additional fertilizer will increase with increased water availability.

Liatris spp.

The genus Liatris contains 42 known species and hybrids that are native to eastern North

America. Distribution ranges from northern Canada to Colorado and New Mexico (King and

Robinson, 1987). Species can usually be found within prairie or open wood areas and prefer dry or stony ground (Brickell and Zuk, 1997). As one of the most widely distributed genus within the

subtribe, Liatris has received much attention from botanists over the years (King and Robinson,

1987). However, as this may be true, available knowledge surrounding the genus was generated rior to 1990. The majority of information available after this time is limited to encyclopedias and books directed toward home gardening.

Liatris is a member of the Europatorieae tribe within the Asteraceae family. The genus, an erect corm-containing herb, has some 40 species with varying characteristics. Stems are usually terete and striated with alternating leaves. Although most often the leaves are opposite, linear, and frequent, leaf characteristics can differ greatly between species (Dole and Wilkins,

1999). The head of the plant contains anywhere from 3-80 florets which can display a variety of colours from white to lavender (King and Robinson, 1987). Florets are commonly 1.5cm across in dense clusters which bloom anywhere from midsummer to late fall (Brickell and Zuk, 1997).

Flowers can be closely attached to the head or they can have a peduncle. Blooming always begins from the most apical bud and matures downward. Plant height can be anywhere from 25-

150cm where leaves can be found on the bottom two thirds of the stem and the flowers on the upper third (Dole and Wilkins, 1999).

Knowledge and research pertaining to physiological characteristics of Liatris are limited at best. The majority of studies, conducted during the 1980s, investigate effect of treatments such as photoperiod, temperature (Zieslin and Geller, 1983b, 1983a), and cold (Waithaka and

Wanjao, 1982) on the growth and flowering capacity of Liatris spicata. Flower bud opening of this species was also investigated for post-harvest use (Borochov and Keren-Paz, 1984). Zieslin and Geller (1983b) demonstrated that cold storage of corms for up to 75 days increased number of flowering stems in the following growing season by 2.5 times. Zieslin and Geller’s (1983a) following study revealed that photoperiod did not affect flowering formation in Liatris spicata.

However, increased photoperiod of 16-hour days increased stem elongation and as well as endogenous gibberellins within the shoot tips. Borochov and Keren-Paz (1984) established that

Liatris spicata flowers harvested at the “tight bud” stage and placed in solution of 0.1% TOG III

(thiabendazole, hydroxyquinoline and glycolic acid) and 5% sucrose resulted in the longest vase life of 7.8 days compared to three days in distilled water.

Liatris production involves both field and greenhouse production for fresh cut and garden ornamentals. The primary species used in production is L. spicata although the species L. aspera,

L. microcephala, L. pycnostachya, and L. scariosa are used but are less common. Water use for the genus during production is dependent on the species. The species L. spicata is naturally found in moist habitats and subsequently requires more water. In contrast, L. pycnostachya is naturally found in dry areas and requires comparatively less irrigation in conjunction with well- drained soils (Dole and Wilkins, 2005). Similar to information on Aster production, knowledge on Liatris production concentrates on temperature and photoperiod control to influence proper flowering and maximizing yields.

Amsonia tabernaemontana

Amsonia is a member of the Plumerioideae tribe under the sub-family Rauvolfodeae within the family Apocynaceae, otherwise known as the dogbane family (McLaughlin, 1982;

Scocco et al., 1997). The family Apocynaceae consists of 424 genera which are found within five different subfamilies: Rauvolfiodeae, Apocynoideae, Periplocoideae, Secamonoideae, and

Asclepiadoideae (Endress and Bruyns, 2000). The species Amsonia tabernaemontana is of special interest within the pharmaceutical sector. A. tabernaemontana produces tabersonine and rutine, an alkaloid for cerebrovascular pathologies and bio-flavanoid for capillary protection, respectively, at high percentages in its leaves (Scocco et al., 1997). Unfortunately, very little

scientific literature is available on its production. The majority of information on its growth can be found in gardening literature.

A. tabernaemontana, also known as Blue-Dogbane, can be found growing in moist woodlands and at the edges of stream banks, reaching 2-3 feet tall. It prefers dry to moist soils with partial shade and is widespread throughout southern United States and coastal New Jersey.

Flowering occurs between May and June, when it produces 2 cm steel blue flowers in terminal clusters (Armitage, 2008; Leopold, 2005; Miles, 1996).

Baptisia australis & Thermopsis caroliniana

Baptisia australis and Thermopsis caroliniana originate from the family fabaceae.

Fabaceae, the pea family of flowering plants, is distributed worldwide and is the third largest angiosperm family. The family contains 700 genera and 20,000 species including trees, shrubs, vines, and herbs. Fabaceae is an extremely economic important family, containing species such as Glycine max, Pisum sativa, and Arachis hypogeae (Britannica, 2013).

Study Objectives

The objectives of the current study are:

1. Determine the growth and reproductive characteristics of the eight species under varying

water and fertility conditions.

2. Determine the photosynthetic response of the eight species under varying water

conditions.

3. Determine if natural habitat is linked to drought tolerance characteristics

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Chapter 2: Growth and photosynthetic response of eight native ornamental perennials under three watering regimes

Abstract

Given recent concerns regarding the amount of water use in urban landscapes and greenhouse production of plants necessitate new techniques to reduce water usage minimize environmental impact. The use of perennial ornamentals native to the locale may be useful in reducing water use. The current study included eight ornamental perennials native to North

America (Liatris aspera, Liatris cylindracea, Liatris pycnostachya, Liatris scariosa, Liatris spicata, Baptisia australis, Thermopsis caroliniana, and Amsonia tabernaemontana) from varying habitats subjected to three greenhouse watering regimes: High Water (HW) (maintained at 55%-70% volumetric water content (VWC)), Low Water (LW) (maintained at 23%-40%

VWC), and Cyclic Drought (CDW) (soil saturation followed by a period of water cessation until wilt). Species native to habitats that were more water abundant (B. australis and T. caroliniana), displayed the greatest loss in overall growth under LW and CDW. Variability was observed amongst the Liatris spp. response to water deficit. Prairie species (L. aspera and L. scariosa) displayed comparatively less decrease in overall growth under LW and CDW while species adapted to wetter environments (L. spicata and L. pycnostachya) displayed greater water deficit sensitivity. The ability of species to maintain photosynthetic capacity as measured by carbon exchange rate (CER) also followed the trend of the natural environment of the species, correlating to their tolerance of water deficit. A. tabernaemontana was unique in that it had the least CER sensitivity to LW and CDW as compared to other species. However, this may have been due to its lack of adaptation to saturated soil conditions. The exception was L. aspera, a dry adapted species that displayed a 60% reduction in CER under CDW.

Introduction

Water availability is one of the most important factors affecting plant growth. Lack of available water can lead to severe limitations in growth and development (Chaves and Oliveira,

2004). Herbaceous plants, which consist of 80-90% water, rely heavily on the presence of water for physiological, morphological, and biochemical processes (Karamanos, 1981). The changing climate produces reductions in rainfall, increasing the likelihood of drought conditions

(Houghton et al., 2001) which in turn may lead to reductions in plant growth. Plants respond to moisture stress in a variety of ways (Chaves and Oliveira, 2004; Chaves et al., 2003). These can include production of extensive root systems, increased root:shoot ratio, and specialized leaf characteristics (Chapman and Auge, 1994; Opik and Rolfe, 2005); stomatal features including stomatal shape/size (Clarke and Durley, 1981); and elevated stomatal response to water stress

(Chapman and Auge, 1994). Using morphological and physiological water-conserving adaptations some plants are able to maintain growth and reproduction during drought conditions.

Drought avoidance methods include features such as shortened life cycles and deep root systems

(Taiz and Zeiger, 2006)

The response of plant growth and reproductive characteristics to drought has been examined in numerous species. Response to drought can differ between species as well as between phenological stages within a species (Lilley and Fukai, 1994). Moisture stress prior to and during silking of corn can lead to grain yield reductions of 25% and 50%, respectively (Denmead and

Shaw, 1960). Similarly, drought stress on soybean plants in later stages of growth (i.e. seed development) results in significant yield reduction compared to drought stress during earlier phenological stages of growth (Foroud et al., 1993). These results demonstrate that particular

stages of development are more sensitive to drought stress with regard to seed production and yield.

It is important to note that different species have different responses to drought. Plant species have evolved physiological, morphological, and biochemical characteristics in response to their natural habitats (Zhang et al., 2004). Research by Zollinger et al., 2006 has supported the theory that species differ in their response to moisture stress. In their study, Penstemon barbatus was capable of quickly reducing stomatal aperture, thus reducing excess water loss. Other species

(i.e. L. x superbum and G. aristata) that were unable to respond to moisture stress with rapid stomatal closure experienced leaf abscission and wilting, both of which are undesirable characteristics for ornamentals. In a similar study investigating the response of four Indigofera species (I. amorphoides, I arrecta, I. coerulea, and I. vicioides) to high, moderate, and low moisture stress, only I. amorphoides displayed a significant drop in growth while under water stress. The authors determined that even within a genus, response to water stress could be species-specific. (Hassen et al., 2007). Therefore, it is important to recognize species-specific drought responses when selecting for drought tolerant species.

Plants experience water stress in a variety of ways. Flexas et al. (2012) explained water stress

- in three phases in relation to stomatal conductance (gs). Mild water stress (gs > 0.15 mol H2O m

2 s-1) usually causes a restriction of growth through decreased stomatal conductance, resulting in less CO2 available for carbon fixation. The second phase, moderate water stress (0.15 > gs > 0.05

-2 -1 mol H2O m s ), involves additional factors that reduce CER such as reduced mesophyll conductance. As plant cells dehydrate, there is a reduction in conductance of aquaporins within the mesophyll boundary layer. The reduction in aquaporin conductance causes a direct reduction in available CO2 in the mesophyll (Flexas and Medrano, 2002; Miyazawa et al., 2008). During

-2 -1 the third phase, severe water stress (gs < 0.05 mol H2O m s ), causes damage to photosystem I and II. Dehydration of leaf cells causes cell shrinkage (Taiz and Zeiger, 2006), leading to denaturation of cell proteins. Interaction of these denatured proteins causes toxicity to key photosynthetic enzymes responsible for basic metabolic activity (Farooq et al., 2009).

One of the key factors causing CER reduction is decreased activity of Rubisco (Bota et al.,

2004), the first enzyme, in C3 plants, responsible for converting CO2 into carbohydrates. To prevent damage to Rubisco and other enzymes, plants maintain turgid cells by increasing solutes within the cell, otherwise known as osmotic adjustment. The net increase in cell solutes results in decreased cell water potential, allowing increased water extraction from the drying soil and the maintenance of turgid cells (Chimenti et al., 2002). Many studies have demonstrated strong differences of osmotic adjustment capacity both within and between species. Plants adapted to environments with lower available water are capable of maintaining physiological activity at lower (more negative) water potential (Morgan, 1984). Significant differences in osmotic potential in sorghum lines (Basnayake et al., 1993), rice lines (Lilley and Ludlow, 1996), pea cultivars (Sánchez et al., 1998), sunflower lines (Chimenti et al., 2002) and species of bentgrass

(DaCosta and Huang, 2006) have been documented. Results of these studies demonstrate that plants with increased osmotic adjustment were able to maintain proper metabolic function in periods of extreme water stress showing a high correlation between osmotic adjustment and drought tolerance. However, it is important to note that much of the research regarding decreased photosynthesis through non-stomatal restrictions is still under debate. There are often contradictory results between studies in water stress (Chaves et al., 2003). Nonetheless, it seems likely that plants that can resist these metabolic restrictions in CER contain key characteristics,

physiological or biochemical, that allow for continued productivity while experiencing low water availability.

The purpose of this study was to investigate native ornamental perennials under varying water stress conditions to determine tolerance to low water availability and drought conditions. The species studied (Liatris spicata, L. cylindracea, L. aspera, L. pycnostachya, L. scariosa,

Thermopsis caroliniana, Amsonia tabernaemontana and Baptisia australis) were selected based on ornamental potential and native habitat. With such a large variation in habitat, it is likely that low input morphological and physiological adaptations allow for increased survivability, maintenance of growth, and sustained floral characteristics will be present in certain species.

Observation of response to drought in a variety of growth characteristics including plant height, flower number, flower size, plant survival, dry weight, and photosynthetic response may lead to an understanding of morphological and physiological traits associated with drought tolerance.

The objectives of the study were:

1. Determine the growth and reproductive characteristics of the eight species

under three water regimes including HW, LW, and CDW.

2. Determine the CER and gs of the eight species under three water regimes

including HW, LW, and CDW.

3. Determine if habitat plays a role in determining characteristics of species that

would encourage growth under low input conditions

Materials and Methods Seed sources, germination and establishment

Seeds for the trial were collected from various sources (Refer to GTI (Guelph Turfgrass

Institute) and Elora Seed sources, germination and establishment Section 3.3). Plants selected for

the greenhouse trial were transplanted into 13 cm pots, remained in the greenhouse throughout the 2011 season, and watered daily as needed. Once a week, plants were watered with water- soluble fertilizer (20N-8P-20K) (Plant Products, Brampton ON). At the end of the growing season above ground plant material was harvested and the pots were placed in a cold frame

(December 1, 2011 to February 10, 2012). Care was taken to ensure pots were moist but not saturated. After 10 weeks, with temperatures below 0°C, the plants were removed and transferred to the greenhouse.

Experimental design

The trial was set up as a split plot with four replications with water regimes randomized to the main plots and species randomized to the sub-plots. Each sub-plot consisted of 10 plants of one species. Watering regimes were imposed over a sixteen-week period (March 20, 2012 to July

9, 2012). At the end of the trial period, all surviving plants from each subplot were harvested.

Flowers were separated from the stalk at the base of the petiole and dried separately from the remaining above ground plant material and then dried separately at 80°C for 48 hours and weighed. Water regimes imposed were HW, LW, and CDW and are described in detail below.

Water Regimes

High water The HW treatment maintained soil at a consistently high level of moisture (55% to 70% VWC) throughout the experiment. Soil moisture was measured daily using a HH2 soil moisture meter and a WET-2/d WET sensor (Delta-T Devices Ltd. Burwell, Cambridge, United

Kingdom.). On evaluation days, a soil moisture level measurement on a random sample of three plants of each species was collected using the HH2 moisture meter. If the average of the three samples taken read below 55%, the entire row was watered to container capacity. The HH2 soil moisture meter was calibrated using methods suggested by the manufacturer.

Low water Total water volume of the container and soil was determined by filling the containers to soil saturation (added water to the soil and weighed container with soil when the container stopped dripping), weighing them, and then drying the containers in an oven at 60°C until the weight stabilized. The pots were then weighed again. The weight difference between saturated and fully dried was the determined total VWC (657 g). Percent volumetric water content could then be calculated. The LW regime treatment maintained the soil at 23-40% VWC.

On evaluation days, a randomly selected sample of three plants from each species was weighed.

If the sample selected had a combined weight that indicated the soil moisture was below the 23% treatment threshold, plants were supplied with 113g of water to raise soil moisture back to a maximum of 40%. As the growth cycle progressed and water needs increased, the water requirements of some plants exceeded the daily amount (113 g) supplied. In the case where

VWC dropped below 15% as indicated by weight, 193 g of water was added to bring the VWC back to a max of 40%.

To account for error caused by change in plant weight, sample plants of each species from an adjacent area were measured at weekly intervals for fresh weights. These values were used to adjust the amount of water applied (i.e. this eliminated plant weight from the average weight used to establish watering requirements).

Drought cycle The CDW imposed a repeated cyclic drought on the plants. At the beginning of the trial, plants within the drought cycle regime were saturated overnight using sub- irrigation. The following day irrigation was stopped and the plants were allowed to dry until the plants displayed signs of wilting including reduced leaf turgor and reduced leaf/petiole angle.

When 50% of the plants within a species subplot were considered wilted, the cycle was completed with re-watering to saturation. Prior to re-saturation, each plant within the row was

weighed and it was noted whether wilting was observed. This cycle was repeated throughout the trial period.

Data collection

Data collected for the greenhouse trial were photosynthetic measurements including CER

-2 -1 -2 -1 -1 (mol CO2 m s ), gs (mol H2O m s ), internal CO2 (Ci) (µmol mol ), transpiration rates (TR)

-2 -1 (mol H2O m s ), and instantaneous water use efficiency (WUE). In addition, chlorophyll content (Chltot) (mg chlorophyll/g of dry leaf) and growth parameters were measured including plant height, number of flowering stalks, total stalks, flower number, flower width (cm), flowering area length (cm), number of aborted stalks, percentage of plants that produced flowers, date of first flowering, date of last flowering, percent plant survival, above ground non-flowering dry weight, flower dry weight, root dry weight, corm dry weight, and root:shoot ratio(R:S).

Leaf gas exchange measurements

Leaf gas exchange measurements were made using a Li-Cor 6400 under synthetic light using the RBG light source. Measurements for each species were taken to correspond to the drought cycle for that species. Measurements were taken every day on the most recently matured leaves on five plants of that species for each of the three watering regimes. Duration of measurement was determined by length of the CDW treatment. Prior to treatment measurements, light curve measurements were taken from two sample plants of each species to determine species-specific maximum rate of CER (Amax). This was measured by incrementally increasing photosynthetic active radiation (PAR) until photosynthetic rate no longer increased. During measurements, the following settings were maintained: CO2 at 400 ppm, humidity at 50-60%, and airflow at 300-500 µmol s-1. All measurements were taken using the RBG light source under species-specific PAR required to produce Amax. These species specific PAR levels were as

follows; A. tabernaemontana (1500 µmol photons m−2s−1), T. caroliniana (1600 µmol photons m−2s−1), B. australis (1800 µmol photons m−2s−1), L. pycnostachya (2100 µmol photons m−2s−1),

L. scariosa (2400 µmol photons m−2s−1), L. aspera (2000 µmol photons m−2s−1), and L. cylindracea (2200 µmol photons m−2s−1). In order to properly collect Li-Cor measurements, the area of leaf within the Li-Cor leaf clip was measured and used as a factor of measurement each time measurements were made on each plant. Leaves were acclimated in the chamber for five minutes prior to data logging. When maintaining 50%+ humidity levels was problematic (e.g. in the case of wilted leaves), a 50L container filled 1/2 full with water and covered with a plastic sheet was used to supply the Li-Cor with the required chamber humidity via surgical tubing to the instrument inlet. Measurements were taken between 1000 and 1400 hours.

Chlorophyll measurements

Leaf disk samples were taken from randomly selected plants of each species, frozen in liquid nitrogen and stored in a freezer at -80°C. For analysis, disks were removed from the freezer, thawed and weighed using an analytical balance (Sartorius CP124S). Seven ml of

DMSO was pipetted into a graduated vial, and the vials were placed in a 65 °C water bath. When the DSMO reached 60 °C, three weighed leaf disks were transferred into the heated DMSO for a

30-minute extraction. Once the heated extraction was complete, an additional 3ml of DMSO was added to the vial (bringing the total volume to 10ml) and vials were placed into a black out cabinet for 24 hours. The sample was then removed from the cabinet and 3ml of the sample was added to a disposable cuvette. Chlorophyll was measured using a spectrophotometer that had been calibrated using a blank sample of DMSO. Data collected from the spectrophotometer were then used to measure Chltot using the calculations (Richardson et al., 2002);

(1) Chla (g/L) = 0.0127(A663) 3/L) = 0.01645)

(2) Chlb (g/L) = 0.0229(A645) - 0.00468(A663)

(3) Chltot (g/L) = 0.0202(A645) + 0.00802(A663)

Chltot was calculated per unit leaf area as well as per unit leaf fresh weight.

Dry weights

Upon completion of the trial, top growth of surviving plants for all species was separated from the roots at the junction of the root and the shoot. Flowers were separated from the stalk at the base of the petiole and dried separately from the remaining above ground plant material.

Above ground plant material was then dried for 48 hours at 80°C or until weights were stable.

Below ground plant material was washed of growing media and then dried for 48 hours at 80°C.

For the Liatris spp., roots and corm were separated, dried, and weighed separately. Percent difference in total dry weight between HW to LW and HW to CDW regimes were used to indicate drought tolerance of species.

Morphological growth and flowering characteristics

Traits related to morphological growth and flowering were measured at the end of the trial. Plant height was defined as the distance from the soil surface to the tip of the tallest point of the plant. The number of flowering stalks was characterized as the number of stalks on each plant that displayed at least one open bloom throughout the trial. Total stalks was defined as the total number of flowering and non-flowering stalks on each plant. Flower number was measured as the total number of blooms on all stalks for each plant. The number of aborted stalks was defined as the number of stalks that reached full necrosis and did not display petals on their flower buds. Percent flowering was calculated as the number of plants withing a sub-plot to

display flowers. Flower width was measured during full bloom and was defined as the average diameter of 10 randomly selected blooms on each plant. Length of flowering stalk was measured as the distance between proximal and distal flowers on an individual stalk. The date of first flowering and final bloom date were defined as the date on which the first plant within each treatment displayed petals and the date that the final bloom lost its petals respectively. For L. aspera and L. scariosa, the trial ended prior to final bloom. In this situation, trial end was used as final bloom date. Finally, survival was calculated as the percent of plants within a species in each treatment that still contained at least one living stalk at the end of the trial.

Data analysis

All data was analyzed in SAS v9.2 (SAS Institute Inc., Cary, NC, USA, 2009) using general linear model procedures for ANOVA tables. Means comparisons were done using a

Tukey’s Studentized range test at P<0.05 level. Analysis of variance results are presented in appendix A.

Results Dry Weight Measurements

Total dry weights

When comparing mean dry weights between watering regimes, significant differences were observed. On average, HW (44.8 g) produced the highest dry weight followed by LW (36.7 g) and CDW (21.8 g) (Table 2.1). To assist in evaluating the responses of the species to each watering regime, species were placed in response groups based on their percent change between regimes (Table 2.2). This allowed trends between species across all characteristics to be more easily determined.

All species, with the exception of A. tabernaemontana, produced the greatest mean dry matter under the HW regime. Significant decreases in total dry weight LW compared to HW were seen in B. australis (-45%) and T. caroliniana (-38%). All Liatris species displayed only minor reductions of total dry weights ranging from 1% to 17% none of which were significant. A. tabernaemontana increased total dry weight by 19% under the LW regime compared to the HW regime (Table 2.3). Based on the response to LW regime the species were divided into three groups: Group 1: species (B. australis and T. caroliniana) demonstrating large reduction (38%-

45%) in total dry weight; Group 2: species (all five Liatris species) demonstrating minor reduction (1%-16%) in total dry weight; and Group 3: species (A. tabernaemontana) demonstrating increased (19%) total dry weight (Table 2.2).

The CDW resulted in the lowest total dry matter for all species. However, the dry weight reduction in CDW was more prominent in certain species. Significant reductions in total dry weight were seen in B. australis (72%), T. caroliniana (56%), L. spicata (49%), L. pycnostachya

(49%), and L. scariosa (46%) (Table 2.3). Comparatively, L. cylindracea, L. aspera, and A. tabernaemontana also responded with similar but non-significant reductions in total dry weight between 32%-47% under CDW.

Although all species demonstrated a large decrease in total dry weight between HW and

CDW regimes (32%-72%), species can be grouped by severity of dry weight decrease within the

CDW regime. Group 1, the most severely affected, consisted of B. australis and T. caroliniana, and displayed a decrease of 72% and 56%, respectively; group 2 consisted of the less severely

(39-49% decrease) affected (all Liatris spp.); and group 3 consisted of the least (32% decrease) affected (A. tabernaemontana) (Table 2.2).

Above and Below Ground Dry Weight and Root:shoot Ratio

There were significant differences among the treatments for above ground dry weight and

R:S. HW regime produced the greatest above ground dry weight of 25.3g followed by LW

(19.9g) and CDW (11.1g) (Table 2.1). There was a similar pattern for below ground dry weights with the HW producing the highest below ground dry matter of 19.5g followed by LW (16.8g) and CDW (10.7g) regimes.

Three of the eight species displayed substantial differences between change in the above ground dry weight and the below ground dry weight when water stress regimes were imposed. A. tabernaemontana, L. cylindracea, and L. scariosa displayed changes of -53%, -72% and -58% under CDW in above ground dry weight while the below ground dry weight displayed changes of -12%, 63%, and -14%, respectively (Table 2.3).

When comparing R:S between treatments, HW (0.76) and LW (0.86) were statistically similar. However, HW and LW were both statistically lower than the CDW regime (1.09) (Table

2.1). In general, the LW and CDW regimes generated increases in R:S for all species measured.

When the LW regime was imposed, no significant differences between treatments within species were observed. For five of the eight species measured, the LW regime generated percent changes of -15% to +12% while CDW exhibited changes of -4% to +20% (Table 2.3). The remaining three species, L. scariosa, L. cylindracea, and A. tabernaemontana, displayed the greatest increases in root:shoot dry weight while under CDW regimes. The species displaying the greatest increase was L. cylindracea, which increased its ratio by 78% and 506% in the LW and CDW regime, respectively.

Corm Dry Weight

Only the Liatris spp. produced corms. The HW (14.7g) and LW regimes (14.3g) displayed no significant change for corm dry weights across all Liatris spp.. However, the CDW regime (9.5g) was significantly different from both HW and LW regimes (Table 2.1).

When subjected to the LW and CDW regimes, L. aspera, L. pycnostachya, and L. spicata displayed decreased corm dry weights in the LW regime and the CDW regime (Table 2.3). L. scariosa displayed an increase in corm dry weight within the LW regime and CDW regime of

23% and 14%, respectively. While L. cylindracea, increased 51% and 68%, for the respective regimes (Table 2.3).

Reproductive characteristics

Flower Dry Weight

A. tabernaemontana and B. australis did not flower during the trial period and, T. caroliniana flowered between weeks three and six .Therefore, no flower dry weights were available for these species at harvest. When flower dry weights were compared for all species that flowered between watering treatments, the HW regime (4.9g) was different from the CDW (2.0g) while the LW (3.7g) was intermediate and not statistically different from either HW or CDW. (Table

2.1).

Although total flower dry weight was greatest under the HW regime, only L. scariosa and L. pycnostachya followed this trend. Interestingly, L. cylindracea had the greatest flower dry weight within the CDW regime as compared to the other regimes. In the LW regime, L. cylindracea and L. scariosa exhibited flower dry weight decreases of 44% and 58%, respectively

(Table 2.3). Interestingly, these were the only two species to also exhibit a large increase in root dry weight under LW regime. L. pycnostachya was able to maintain flower dry weight under the

LW regime. However, under CDW, its flower weight dropped substantially. Two Liatris species,

L. spicata (with 32%) and L. aspera (with 40%), exhibited the largest increase in flower dry weight under the LW regime (Table 2.3).

In the CDW regime, four of the five Liatris species (L. spicata, L. pycnostachya, L. aspera, and L. scariosa) exhibited lower flower dry weight with L. scariosa displaying the largest (and only significant) percent decrease of 78%. The other species with the exception of L. cylindracea had dry weight decreases between 30% and 42% (Table 2.3). L. cylindracea, the exception to this trend, displayed a 25% increase in flower dry weight under the CDW regime.

Under the LW and CDW regimes, a general decrease in total dry weight was seen across all species. Interestingly, some species, even though displaying reductions in total dry weight, exhibited a greater resistance to flower dry weight loss under water deficit conditions. For example, L. aspera displayed a 40% increase from 4.1g to 5.7g of flower dry weight while exhibiting a non-significant decrease in total dry weight under LW. L. spicata also exhibited a similar response. In contrast, L. cylindracea and L. scariosa exhibited greater percent loss of flower dry weight than total dry weight.

Flowering characteristics A variety of flowering characteristics were measured throughout the trial to determine the effects of water stress on ornamental quality. For all species measured, water stress led to a general decrease in length of flowering area. When comparing length of flowering area between watering regimes, significant differences were seen between all treatments. The HW regime produced the longest flowering area (42.7cm) followed by the LW (27.0cm) and CDW (19.8cm) regimes (Table 2.1). Compared to the HW regime, the LW regime led to reductions in length of flowering area between 20.6% and 56.2%, with the species ranging from in T. caroliniana

(56.2%) and L. scariosa (40.9%), to L. cylindracea (20.6%) (Table 2.5). However, the decreases

were not significant. The decrease in the CDW regime was greater and significant for four (L. aspera, L. pycnostachya, L. scariosa, and L. spicata) of the six species measured with decreases between 41.2% and 71.9%. Interestingly, T. caroliniana and L. cylindracea were able to maintain greater length of flowering area under the CDW regime compared to the LW regime.

When comparing flower number between treatments, the HW (26.8) and LW (26.4) watering regimes displayed no significant difference. However, a significant difference was seen between HW and CDW (17.3) regimes (Table 2.1). L. aspera (5.3%) and L. scariosa (8.1%) exhibited responses similar to the observed general trend of decreased in flower number (Table

2.5). Conversely, L. cylindracea flower number decreased 31.7% under the LW regime. When subjected to the CDW treatment, no significant differences were seen. However, L. scariosa exhibited the largest, reduction followed by L. aspera with percent decreases of 57.1% and

24.3%, respectively. As well, a minor decrease of 5.0% was seen in L. cylindracea.

With regard to flower stalk number between watering regimes, the LW and HW regimes exhibited the highest number of flowering stalks (2.4 and 2.0, respectively) while the drought regime (1.8) had the lowest stalk number (Table 2.1). Significant differences were seen only between the LW and CDW regimes. L. pycnostachya, L. scariosa, and L. spicata displayed the highest number of flower stalks within the LW regime. T. caroliniana and L. aspera displayed flower stalk number reduction in both LW and CDW regimes. Interestingly, L. cylindracea produced more flower stalks when subjected to the LW and the CDW regimes than HW (Table

2.5).

Differences in flower width caused by the treatments were species specific. In L. cylindracea, flower width actually increased by 20% from HW. The remaining species from both group 1 and 2 exhibited width decreases ranging from 1% to 12% (Table 2.5).

The percent of plants that flowered in the CDW regime was 66.0%, which was significantly lower than both HW and LW regimes. No significant difference was observed between the HW (82.5%) and LW (91.0%) water regimes (Table 2.1). Among species, the largest decreases in percentage flowering were seen under the CDW regime by L. cylindracea (-

42%) and L. spicata (-38%). The only species to exhibit a substantial increase in flowering percentage was L. scariosa under the LW regime (29%).

Flowering dates

Total time in bloom

Within the LW regime, T. caroliniana displayed a 6-day reduction in flowering time from 18 DAT to 12 DAT, the largest decrease of all species within both flowering groups.

Generally, a trend of minor fluctuation of ±2 days in total bloom time was seen within the LW regime for group 2 species (Table 2.7).

The influence of CDW treatment on bloom dates was more pronounced than the LW regime for five of the six species that displayed floral characteristics. T. caroliniana, the only species to display a delayed flowering time under CDW regime compared to LW, decreased its flowering time by only 2 days. Of the Liatris species, L. scariosa and L. spicata displayed the largest reduction in flowing time with decreases of 13 and 9 days, respectively. The remaining

Liatris species within this group exhibited changes ranging from -4 to +3 days.

Vegetative Characteristics

Vegetative measurements were collected throughout the study as well as at its conclusion. Differences in plant growth were observed in response to the three watering regimes.

Plant Height

Plant height measurements represent an important architectural trait for ornamental species. Final plant height was measured for all species in all watering regimes at trial’s end.

Significant differences in plant height were seen between treatments. The HW regime exhibited the tallest plants (94.8cm) followed by the LW (73.9cm) and CDW regime (69.0cm) (Table 2.1).

All of the species plant height decreased with decreasing water availability, with the exception of L. cylindracea. In the case of L. cylindracea, the LW regime exhibited the shortest plants (Table 2.3 & 2.4b). Similar to the response to plant dry weight, species within group 1, B. australis and T. caroliniana, exhibited the greatest decrease in plant height. Significant decreases of 25.1% and 22.1% were seen in the LW regime as compared to the HW regime for B. australis and T. caroliniana, respectively. However, B. australis and T. caroliniana still had acceptable plant heights of 58.6cm and 68.9 cm, respectively. Group 2 species exhibited a range of responses to the LW regime. L. spicata and L. pycnostachya displayed the largest, as well as the only significant decreases of 19.5% and 18.5%, respectively. The remaining group 2 species, L. aspera, L. cylindracea, and L. scariosa, displayed only minor decreases ranging from 3.8% to

13.8%. A. tabernaemontana (group 3) displayed a minor decrease (5.9%) in plant height under the LW regime, and continued to be least affected by reduced water availability.

The CDW regime exacerbated the reduction of plant height for all species with the exception of L. cylindracea. Significant decreases were seen for all species except L. cylindracea

(group 2) and A. tabernaemontana (group 3). Similar to LW, CDW exhibited the greatest loss in plant height within species of group 1. B. australis and T. caroliniana displayed decreases of

29% and 23%, respectively (Table 2.3). Likewise, four of the five species within group 2 displayed decreases in plant height between 17.6% and 22.9%. A. tabernaemontana displayed

the second smallest decrease in plant height (16.6%) under the CDW regime, second only to L. cylindracea.

Survival rate

Survivability of the plant is an important factor when investigating species’ response to water stress and low input conditions. A plant that is capable of sustaining aesthetic appeal as well as a high survival rate is more likely to gain acceptance within the ornamental and landscape industries. In general, species’ survivals rates did not change between watering regimes. LW regime produced the highest percent survival of 91% followed by HW and CDW regimes at 89% and 84%, respectively (Table 2.3). The only species to display a substantial decrease in survival under the HW regime was L. scariosa, which is naturally adapted to well- drained habitats.

Photosynthetic measurements

The variability within species for the characteristics described above in response to the three water regimes may be due to the genetic variability within certain species. The variability was especially prominente for the Liatris species. The variability within species was likely compounded by the extreme nature of all three imposed regimes. Inevitably, the variability within species also had an impact on the photosynthetic response measurements.

To enhance the understanding of species response to the three imposed regimes, photosynthetic measurements including CER, gs, Ci, and TR were collected throughout the trial period. Measurement periods were coupled with the CDW regime for each species. As a drought cycle began, measurements of all three regimes were collected once per day on plants of that species during the entire drought cycle period. However, it is important to note that data for each species were taken at different periods during the trial. Therefore, plant phenological stage as

well as the increasing regime stress over time may have influenced results. These compounding issues restrict species-to-species comparison as well as constraining inferences of photosynthetic trends in relation to overall growth. As a result, the photosynthetic data was intended to portray a snapshot of species’ performance during a specific time-period for each watering regime, rather than to conclusively depict overall response throughout the trial period. Predicted CER response to the watering regimes are depicted in Figure 2.1.

Gas exchange Analysis of CER for the eight species was used to generate two separate data sets. The first data set (Appendices 2.1, 2.2, and 2.3) contains the values for every measurement day of each watering regime within each species. Using these data, we are able to extract visible trends for each species within each watering treatment. However, not every watering treatment could be measured for each day within a species. Therefore, to view differences between watering treatments on each day, the data points on each day where all three watering treatments were measured, were used to build a second data set (Table 2.8). Table 2.8 was used to discuss comparable data points while appendices 2.1-2.3 were used for supportive discussion.

Baptisia australis and Thermopsis caroliniana, the species that displayed the largest decrease in total dry weights in LW (45% and 38% decrease, respectively) and CDW (72% and

56% decrease, respectively) watering regimes as compared to HW, displayed dissimilar CER response to LW regime. B. australis maintained a general trend of similar CER values under LW

(-2%) as compared to HW regime (Table 2.9). However, gs for this species under LW were generally sustained at a decreased level (-24%) as compared to the HW regime. Conversely, T. caroliniana displayed consistently lower CER ratios within the LW regime, exhibiting a significant decrease of -22% as compared to the HW regime. However, both B. australis and T. caroliniana displayed significantly decreased CDW CER ratios as compared to the HW regime

(-45% and -33%, respectively) throughout their individual drought cycles. Both species also displayed significant decreases in CDW gs measurements as compared to the HW regime (-67% and -63%, respectively).

Of the five Liatris species within the trial, photosynthetic measurements were taken on L. aspera, L. cylindracea, L. pycnostachya, and L. scariosa. Although these species displayed similar total dry weight changes to the LW and CDW regime, clear differences in CER responses were seen. L. aspera and L. pycnostachya both displayed a decrease in CER when exposed to the

LW regime (-11% and -22%, respectively) (Table 2.9). L. pycnostachya’s decrease in CER was significantly different compared to the HW regime. As well, L. pycnostachya gs displayed a similar and significant decrease in the LW regime (-19%), contrasting L. aspera, which exhibited a much larger gs decrease (-51%) during the measurement period (Table 2.9). Although CER of

L. pycnostachya and L. scariosa responded similarly to the LW regime, the CDW regime provoked dissimilar responses. L. aspera generally had a large decrease in CER under CDW (-

60%) as compared to the HW regime, while L. pycnostachya displayed only a -28% significant decrease. The gs measurements of these species within the CDW regime support the CER results with L. aspera displaying a greater decrease (-80%) than L. pycnostachya (-41%) (Table 2.9).

The two remaining Liatris species, L. cylindracea and L. scariosa exhibited contrasting photosynthetic results as compared to L. aspera and L. pycnostachya. Both L. cylindracea and L. scariosa exhibited increased CER measurements in both the low (46% and 37%, respectively) and CDW regimes (16% and 25%, respectively) as compared to the HW regime. Only on the first and last measurement days of the LW and CDW regimes for L. scariosa were CER values similar to that of the HW regime (Appendix 2.1). Interestingly, CDW regime CER measurement of L. scariosa on the final measurement day was the only day in which CER was lower than that

of the HW regime. Although both species displayed trends of increased CER under the water stress regimes, gs of L. cylindracea was lower on 1 of 3 and 2 of 3 measurements day for LW and

CDW, respectively, exhibiting changes of -28% and -43%, respectively. Comparatively, gs of L. scariosa was consistently lower (-51% and -39% for LW and CDW, respectively) under the stress regimes throughout the measurement period with the exception of drought on day 4, in which gs was similar to that of the HW regime.

Amsonia tabernaemontana, the species that exhibited an increase in total dry weight and the smallest decrease in dry weight for the LW and CDW regimes, respectively, displayed trends of increased CER under the two stress regimes. Under the LW regime, A. tabernaemontana maintained consistently higher CER (91%). While under the CDW regime, CER was similar to or higher than that of HW depending on the day of measurement (Appendix 2.1). Interestingly, gs of A. tabernaemontana in the LW regime was similar to or higher than that of the HW regime

(9%) for three of the four measurement days (Table 2.9). As well, gs under CDW, began lower than the HW treatment, then rose above the HW treatment before once again falling lower than the HW treatment at the end of the drought cycle.

Water Use Efficiency For all species, the LW regime provoked an increase in WUE ranging from minor to large during the measurement period. Comparatively, group 1 species, B. australis and T. caroliniana, generally exhibited the smallest mean increase in WUE with increases of 21% and

30%, respectively (Table 2.9). Under the LW regime, group 2 species displayed trends of WUE increasing twice that of HW, with the exception of L. pycnostachya. L. scariosa had the largest increase of WUE (144%), followed by L. cylindracea (89%) and L. aspera (87%). L. pycnostachya exhibited the smallest increase across all species of 9%. Interestingly, A.

tabernaemontana, the species that was able to maintain dry weight production under the LW regime, exhibited a smaller increase of WUE (72%) compared to some of the group 2 species.

Within the CDW treatment, all species displayed a trend of increased WUE. B. australis(39%) and T. caroliniana (59%) exhibited larger increases in WUE under CDW than those observed within the LW regime (Table 2.9). This trend continued within group 2 species with the exception of L. scariosa, which displayed a smaller increase (126%) than was seen under LW. The remaining Liatris species, L. aspera, L. cylindracea and L. pycnostachya, increased WUE by 65%, 133%, 39%, respectively. A. tabernaemontana increased WUE by 91%.

Chlorophyll content At the end of the trial period, leaf samples from all species under all watering regimes were collected for Chltot analysis. Investigation of Chltot changes in relation to water stress help in understanding species’ growth response. No significant differences in total chlorophyll content were seen between watering treatments with HW, LW, and CDW regimes showing Chltot of 0.18 mg chl/g of leaf, 0.21 mg chl/g of leaf, and 0.20 mg chl/g of leaf, respectively (Table 2.1).

However, there was a species-specific response of chlorophyll to the watering regimes, which was not related to the groupings based on the total dry weight results. Even though no significant differences were seen, some trends were observed. For instance, decreased water caused an increase in Chltot for five (A. tabernaemontana, L. aspera, B. australis, L. cylindracea, and L. scariosa) of the eight species measured. Chltot values for all species displayed only minor, non- significant changes, when exposed to LW and CDW water regimes. The largest increase in Chltot was seen by A. tabernaemontana under the LW (133%) and CDW (108%) regimes (Table 2.9).

The greatest decreases in Chltot were seen by L. pycnostachya and L. spicata with decreases of -

27% and -25%, respectively, under the CDW regime.

Discussion

Three distinct watering regimes were used to characterize the response of eight native ornamental perennials to varying water stresses. The watering regimes were designed to provide for a comprehensive investigation of species response to two different water stress treatments compared to well-watered conditions. Previous research on the effects of moisture stress has utilized various methods to investigate water stress. These include irrigation frequencies or irrigation cessation (Chapman and Auge, 1994; Galmés et al., 2007; Houle and Belleau, 2000;

Kjelgren et al., 2009; Lenzi et al., 2009; Mills et al., 2009; Prevete et al., 2000; Starman and

Lombardini, 2006; Zhang et al., 2011; Zollinger et al., 2006), deficit irrigation (Álvarez et al.,

2009), maintenance of specific soil moisture contents (Hassen et al., 2007; Jaleel et al., 2008), and long term low input landscape settings (Thetford et al., 2011; Thetford et al., 2009).

However, many of these studies only investigated one type of moisture stress at a time, either specific intervals with water cessation or extended periods within maintained soil moisture levels. Although these studies provide insight into plant response to reduced soil moisture availability, individually they fail to acknowledge the range of water stress conditions that can occur. For example, a study by Kjelgren et al. (2009) investigated how environmental conditions may produce growing conditions with extended periods of reduced water availability without the plant ever reaching the wilting stage. In contrast, extended periods of minimal water availability leading to plant wilt and possibly death (Hassen et al. (2007), pose a different type of water stress that is expected to produce distinct responses within species. The current study, encompassing both types of moisture stress, can compare plant response to both types of stresses, while a well-watered treatment serves as a control treatment for comparison. As well, this

research investigated the relationships between native plant habitat and plant response to water stress.

The selection of species for the current research was based on their ornamental potential

(aesthetics), as well as their distinctive North American native habitats. The ornamental potential of a species can be based on many factors (Younis et al., 2009), and the effect of habitat was measured by selecting from habitats ranging from prairie to woodlands and stream banks.

Species may have developed specialized and unique characteristics that allow them to flourish in the environments that vary in water availability. Species from different habitats may be expected to respond differently to the imposed water stress regimes.

The ability of a plant to sustain growth and maintain ornamental quality under water stressed conditions depends heavily on adaptive mechanisms that assist in water conservation and increased water uptake. These mechanisms can include increases in root:shoot ratio, stomatal closure, and increased WUE (Begg et al., 1980; Starman and Lombardini, 2006) and can be defined as drought tolerance strategies (Chaves et al., 2003). By avoiding tissue dehydration through these methods, a plant can maintain photosynthetic capabilities and therefore maintain growth while avoiding desiccation.

A general trend of decreased total plant dry weight was seen within the LW regime as well as within the CDW regime (Table 2.1 & 2.3). Although a general decrease was seen, species displayed variable total dry weight response ranging from an increase of 19.5% to a decrease of

45.3%. Exposure to the CDW regime resulted in comparably larger reductions in total plant dry weight for all species. This increased sensitivity of dry weight in the CDW regime is likely due to the physiological effects of the drought stress. The LW regime subjected plants to consistently low soil moisture that likely lead to stomatal closure, decreased turgor pressure, and a potential

decrease in leaf photosynthesis (Taiz and Zeiger, 2006), causing decreased assimilation and cell expansion, resulting in decreased plant size. The CDW regime exposed plants to periods of extended wilting causing a severe decline or cessation of photosynthetic rate, stomatal conductance, and translocation(Taiz and Zeiger, 2006). As well, severe drought may have resulted in cell dehydration and damage to the photosynthetic apparatus(Taiz and Zeiger, 2006), leading to cell death, cessation of growth, and eventually plant death. It should be noted that the species groupings for both CDW and LW were the same, indicating that a species response to

LW could be indicative of its response to CDW, or vice versa, when compared to the remaining species. B. australis and T. caroliniana (group 1 species), exhibited the greatest decreases in total dry weight under the LW and CDW watering regimes. Interestingly, both species have been described as drought tolerant species (Steiner, 2012; Thomas and Schrock, 2004). As well as being drought tolerant, both species are native to moist habitats (Hitchmough et al., 2004;

McIntire, 2004). In contrast, A. tabernaemontana exhibited an increase in total dry weight under the LW regime and had the lowest reduction in dry weight within the CDW regime.

Unfortunately, very little research regarding A. tabernaemontana is available. Limited information describes A. tabernaemontana as preferring low moisture riverbanks, floodplains, woodlands, and clearings with the ability to grow in drier poor soils with drought tolerant characteristics (Gardner, 2011a; Godfrey, 1981; Mohlenbrock, 2002; Odenwald, 2006). The native habitats A. tabernaemontana are likely prone to periods of low water availability due to increased drainage, possibly explaining its better performance in the LW regime. The ability to thrive in drier soils is consistent with the species’ ability to maintain dry matter production during the imposed water stresses in this study. Liatris species (response group 2) displayed varying response to the LW regime with modest reductions in total dry weight ranging from 1%

to 17%. L. pycnostachya, the species in group 2 most affected by the LW regime (17%), is found naturally within wet-mesic soils as well as prairie lands (Gardner, 2011a; Gardner, 2011b;

Keller, 1950) and therefore may not have the same water conserving characteristics observed within species found in drier habitats. The remaining species in this group displayed reductions between 1% and 10%, and are generally found in drier habitats (Chapman, 2008; Hadley and

Levin, 1967; Vickery, 2002), with the exception of L. spicata, which is native to marshes and moist prairies. However, when group 2 species were subjected to the CDW regime, the reduction of total dry weight was much more pronounced, displaying decreases between 39% and 49%.

The substantial difference in dry weight reduction within all groups between the LW and CDW regime, especially within groups 2 and 3, provides insight into the species ability to acclimatize and continue to grow with consistently low soil moisture content. It also provides insight into their inability to maintain that growth when subjected to extended periods of water stress severe enough to cause wilt.

When a plant is subjected to water stress conditions over extended periods of time, one adaptive mechanism to assist in water uptake while reducing water loss through above ground organs is to shift assimilate resources to below ground growth (Taiz and Zeiger, 2006).

Therefore, plants able to maintain or increase resource allocation to the roots have increased drought tolerance (Chaves et al., 2002). Root :shoot was significantly increased within the CDW

(1.09) regime. However, no difference was seen between the HW (0.76) and LW (0.86) watering regimes. The species B. australis, T. caroliniana, L. pycnostachya, and L. spicata exhibited only minor increases in R:S under the LW regime, ranging from 1% to 12%. The inability of these species to substantially increase resource allocation to below ground growth likely explains why these species represent three of the four species in which growth was most negatively affected by

this regime. In other words, the plants were unable to increase root:shoot ratio to uptake more unavailable water and continue optimum growth. Interestingly, L. aspera, native to drier habitats, exhibited a decreased R:S of 15% within the LW regime. This is in contrast to the suggestion that it would be drought tolerant based on its native habitat. The remaining species L. cylindracea, L. scariosa, and A. tabernaemontana increased R:S between 26% and 78%, displaying higher root water stress tolerance by maintaining root cell turgidity and growth.

Similarly, these three species also displayed substantially increased R:S within the CDW regime while all other species displayed comparatively minor changes in R:S (-4% to 20%). Therefore, it is likely that L. cylindracea, L. scariosa, and A. tabernaemontana maintained higher R:S and drought tolerance in both water stress regimes imposed. Similar results were seen by Huang and

Fry (1998) in which tall fescue demonstrated increases in R:S when subjected to moisture stress.

The resulting increase in root:shoot ratio within the current study may have been due to species sensitivity to ABA and/or the plant’s ability to maintain turgor within the root system (Chaves et al., 2002).

The majority of the species with a corm displayed decreases in corm size under moisture stress with the exception of L. cylindracea under LW and CDW regimes and L. scariosa under

LW regimes. L. cylindracea displayed decreased above ground dry weight; therefore, this species shifted its assimilated carbohydrates to the below ground corm sink. This was seen in L. scariosa in the LW regime as the dry weight increase in its corm was concomitant with its decrease in above ground dry weight. This can be seen as a stress response in which the species shifts resources to its corm, increasing its chance of long-term survival.

The three regimes of HW, LW, and CDW, were designed to impose three distinct environmental conditions that mimicked potential landscape environments or production

methods. Extreme plant responses were seen in all three regimes. An explanation of the three watering regimes may provide a better understanding of the plant responses. The HW regime, designed to impose high soil moisture levels, maintained VWC between 55% and 70%. This range generated a soil environment with ample water availability. To maintain these conditions, plants were regularly watered to container capacity when average soil moisture was close to or below 55%. However, this watering method caused periods of potentially anaerobic and over- saturated soil conditions. Soils become anaerobic when the majority of pore space within the soil is taken up by water, with very little oxygen to support cellular respiration. Restricted cellular respiration can have detrimental effects on plant growth and potentially lead to root and eventually plant death. Interestingly, species as well as plants within a species demonstrated extreme variability in growth response to the watering regime. For example, some plants expressed signs of chlorosis and stunted growth, while other plants of the same species exhibited vigorous and seemingly unrestricted growth. As well, L. spicata seemed to thrive in the HW regimes, while L. cylindracea displayed many negative responses to the HW regime.

The LW regime, in contrast to the HW regime, was designed to impose an uninterrupted period of low water availability between 23% (slightly above wilting point) and 40% VWC. This might mimic a chronically under-watered situation. Plants and container samples were weighed at regular intervals and data collected were used to calculate VWC. If the average weight of three containers (accounting for increasing plant weight) indicated VWC of 23% or below, a predetermined amount of water was added to increase soil moisture to the upper regime threshold. However, a flaw of this design arose when VWC was slightly above 23% at time of measurement. In this scenario, no watering occurred, leading to periods of VWC below the regime threshold the following days until re-watering occurred. To account for this, plants found

to be below 20% VWC were supplied with supplemental water in addition to the predetermined amount of water applied. The plant-to-plant variability measured in the HW regime was paralleled in the LW regime. As soil moisture reached, or went below, the lower limit of the regime threshold, there were outward indications of stress (i.e. wilting) in some plants of some species. Consequently, some plants within a species may have experienced conditions that were similar to the CDW regime.

Lastly, the CDW regime was designed to impose declining soil moisture ranging from saturated to minimal water availability leading to wilt. This might mimic a situation of plants growing in soils with low water holding capacity and low external water from any source. There was a high level of variability within species, which lead to some plants displaying signs of wilt up to two days before other plants within that sub-plot. Consequently, certain plants within a plot were subjected to longer periods of extreme moisture stress than others. In other words, the extreme stress of the CDW was able to excentuate the variability between plants in the same species and subsequently, variability in collected data.

Investigation of species photosynthetic response to the water stress regimes provided further insight into species’ tolerance to water stress. However, as mentioned previously, it is important to note that the measurements were taken during different time periods for each species; therefore, results may also have been affected by phenological stage of development and compounded by the responses from the watering regimes. Each species displayed seemingly distinct CER and gs responses to the watering regimes. L. aspera, L. pycnostachya, B. australis and T. caroliniana exhibited only minor fluctuations in CER when exposed to the LW regime.

However, of these species, only L. aspera consistently displayed increased gs sensitivity; this trait may be related to its natural habitat of dry sandy prairies (Hadley and Levin, 1967). B.

australis and T. caroliniana (Hitchmough et al., 2004; McIntire, 2004) are generally native to areas with more moisture and would be expected to have less stomatal sensitivity to low water availability. However, T. caroliniana displayed a large stomatal response to low water availability, compared to that of L. aspera, indicating that this species may contain some level of drought resistance. B. australis and L. pycnostachya displayed relatively minor changes in gs, possibly indicating a decreased stomatal sensitivity under minor water deficits. These results are in contrast to work done on Australian native ornamental wildflowers by Chaves et al. (2003) who noted that species (Dianella revoluta and Ptilotus notbilis) from drier habitats had adapted to low water environments with rapid stomatal closure under water stress conditions, while species from habitats with abundant water did not close stomates as rapidly when subjected to decreased water. In the Chaves et al. study, habitat was a predictor of stomatal response. In the current study, three species, A. tabernaemontana, L. cylindracea, and L. scariosa had increased

CER under the LW regime. These results are reflective of species adapted to the drier prairie native habitat, which is home for both L. cylindracea and L. scariosa. A. tabernaemontana, normally found within moist riverbanks and floodplains, displayed increased CER measurements while under the LW regime, which is not consistent with species native to moist habitats.

However, this may be due, in part, to the experimental media, which may have had a greater water holding capacity compared to a sandy riverbank, possibly causing an anaerobic soil environment within the HW treatment which in turn reduced gs, Chltot and subsequently CER

(Chen et al., 2010; Yordanova and Popova, 2007). Interestingly, even though CER of L. scariosa was generally higher within the LW regime, it maintained consistently lower gs than the HW regime. This is likely due to L. scariosa, which is native to drier prairies, balancing gs to minimize water loss and still maintain Ci to drive photosynthetic functions. As well, higher

moisture seen in the HW treatment may have caused adverse effects on the CER of L. scariosa.

Previous research has shown soil flooding can reduce photosynthetic rates in species such as maize (Yordanova and Popova, 2007), mungbean (Islam et al., 2010), and field bean (Pociecha et al., 2008). The potential negative response seen within L. scariosa and A. tabernaemontana in the HW regime may have caused an artifically higher CER under the LW regimes.

When examining the photosynthetic response of species to CDW regime, A. tabernaemontana, L. cylindracea, and L. scariosa all had increased CER. These results were similar to those observed in the LW regime for these species, indicating that these species can tolerate large fluctuations in soil moisture better than the consistent abundant water conditions seen in the HW treatment. These species also displayed significant decreases is gs under the

CDW regime, further reinforcing their preference and physiological adaptation to water deficit conditions. The remaining species, L. aspera, B. australis, L pycnostachya, and T. caroliniana, all displayed significant decreases in CER and gs under the CDW regime. Interestingly, the gs of these species generally had a larger percent decrease than the species that displayed increased

CER (A. tabernaemontana, L. cylindracea, and L. scariosa) under CDW. This larger decrease may be an indicator of increased stomatal sensitivity under water deficit and therefore increased drought resistance. However, this may also indicate an overall decrease in stomatal opening causing a lack of available CO2 for CER under severe drought.

As each cycle of the drought regime progressed, CER was expected to enter a period of recovery (given the measurements were taken following a previous CDW cycle), a subsequent period of maximum CER, followed by a period of CER decline (Appendix 2.1). Both A. tabernaemontana and L. scariosa exhibited recovery periods with maximum CER greater than the HW regime, while in B. australis and T. caroliniana CER was consistently lower than the

HW regime. These results are likely due to B. australis and T. caroliniana’s increased adaptability to high moisture conditions while A. tabernaemontana and L. scariosa are less tolerant of waterlogged conditions, causing a reduction of CER due to stomatal closure as well as physiological damage. As expected, gs of these species mirrored the trends seen in CER.

However, although CER of A. tabernaemontana and L. scariosa was generally higher within the

CDW regime (with exceptions of the first and last measurement days), gs for these species was generally lower than or equal to (in the case of maximum CER period) the HW regime. This increased CER with decreased gs potentially indicates that the HW regime had a negative impact on the CER of A. tabernaemontana and L. scariosa (Islam et al., 2010; Pociecha et al., 2008;

Yordanova and Popova, 2007). Interestingly, L. aspera and L. pycnostachya, dry and wet adapted species, respectively, displayed CER responses to the CDW regime that differ from the expected based on their natural habitats. L. aspera displayed increased sensitivity to the drought regime while CER of L. pycnostachya was less affected. Measurements of these two species were taken during similar periods within the trial so it is unlikely the results were affected by the time of measurement or stage of growth. As well, gs of L. pycnostachya under the CDW regime were equal to the values observed in the HW regime while L. aspera exhibited a substantial decrease in gs. It is likely that L. pycnostachya was able to maintain CER with increased gs and the substantial gs decrease in L. aspera lead to a larger CER decrease as compared to L. pycnostachya. L. aspera, native to prairie landscapes, may be displaying resource conservation by decreasing gs. Although this may reduce overall growth and CER, it may be assuring its future survival. In contrast, L. pycnostachya is less conservative with water use. L. cylindracea followed a similar trend as was seen in L. pycnostachya. However, L. cylindracea maintained a slighter higher CER in the CDW regime. Interestingly, gs of L. cylindracea was considerably

lower on the first and last measurement days while maintaining a consistent CER. Therefore, it is likely that the photosynthetic apparatus of L. cylindracea is more resilient to low moisture levels than L. aspera. Natural habitat seems to be somewhat of an indicator of how species will respond to low input environments. Plants adapted to habitats with more available water are less likely to display water conservation characteristics. If these wetter adapted species do display drought tolerance mechanisms, they will be displayed at a lower level than in dry adapted species.

A plant’s ability to conserve water during times of stress can mean the difference between survival or desiccation leading to death. When a plant is exposed to moisture stress, one of the first response mechanisms is stomatal closure. The purpose of this response is to reduce the amount of water lost through transpiration. This balance between CER and water loss is used to calculate (WUE). A plant that is capable of maintaining a high CER while reducing the amount of water loss has a high WUE and vice versa. For the current study, WUE was calculated as a ratio of CER to gs.

An increase in WUE is commonly seen as plants respond to water stress and can be a characteristic of a drought tolerant plant (Davies and Lakso, 1979). All species measured displayed an increase in WUE when subjected to both LW and CDW regimes with the exception of L. pycnostachya’s response to LW regime. As L. pycnostachya exhibited no change in CER or gs within the LW regime, it is likely that, except under extreme water stress (i.e. CDW regime),

L. pycnostachya exhibits minimal stomatal water stress response, consequently having a higher gs leading to a depletion of water resources. As well, B. australis and T. caroliniana displayed only minor increases in WUE as compared to A. tabernaemontana, L. aspera, L. cylindracea, and L. scariosa, indicating that increased WUE may relate to native habitat. Generally, the CDW regime resulted in WUE increases similar to the LW regime. Occasionally, WUE increased in

the CDW regime above those seen within the LW regime on the first (B. australis, T. caroliniana) and final (A. tabernaemontana, L. cylindracea, L. scariosa, and T. caroliniana) measurement days. This is likely due to the extreme nature of the CDW regime during the wilting period, which caused substantial reductions in gs, and consequently increased WUE.

Similar results were observed by Starman and Lombardini (2006) where withholding water for extended periods led to continual increases in WUE as well as decreases in gs.

The HW regime had the highest Chltot followed by LW and CDW regimes. However, B. australis, L. aspera, and A. tabernaemontana, displayed increased Chltot under water stress.

Although both B. australis and A. tabernaemontana are native to moist habitats, continuously saturated soil may have negative effects on Chltot. Leaf chlorophyll content has been shown to decrease in times of water stress (Sanchez et al., 1983) as well as in waterlogged conditions(Ashraf and Mehmood, 1990). For the remaining species, Chltot was generally unchanged under the LW and CDW regimes. Within these species, CDW generated a larger reduction in Chltot as compared to the LW regime, with the exception of L. cylindracea. It is likely that successive decreases in Chltot during the periods of wilt within the regime caused continual decreases in Chltot. This parallels research done by Sanchez et al. (1983) in which extreme moisture stress led to substantial decreases in chlorophyll content in maize. Although recovery of chlorophyll content was seen after re-watering, chlorophyll levels did not return to the levels seen in the control treatment. Interestingly, L. spicata and L. pycnostachya, two species adapted to moist habitats, demonstrated the greatest loss of Chltot in the CDW and LW regimes (for group 2), further demonstrating their preference for increased moisture environments.

Increased water stress had negative effects on total flower dry weight. Increased deficit irrigation (increased water stress) is known to cause decreased flower dry weight (Snnchez-

BSánchez-Blanco et al. (2009)). As well, water stress greatly influenced flowering percentage, length of flowering area, number of flower stalks, and number of flowers per plant for LW and

CDW regimes compared to HW. Within the LW regime, three of the five species that could be measured for flower dry weight demonstrated a 5% to 58% decrease in flower dry weight. Past studies have demonstrated that water stress has negative effects on flower dry weights of chrysanthemums (Gray et al., 2004) and geraniums (Sánchez-Blanco et al., 2009). However, L. aspera and L. spicata exhibited increases of 40% and 32%, respectively. For L. aspera, it is likely that its adaptation to drier habitats and poor performance under nearly saturated soil conditions caused the negative effects seen in the plants floral production by the HW regime. For

L. spicata, the increase in flower dry weight under the LW regime was related to an increase of number of flower stalks (58%). These results are consistent with the study by Starman and

Lombardini (2006) in which the herbaceous perennial, Scaevola aemula demonstrated increased inflorescence number under water stressed conditions. Interestingly, for L. scariosa, the LW regime caused a minor decrease of 8% compared to HW. This result is beneficial as it provides proof that some of these species may not only be suitable for low input urban environments but will also display increased aesthetic appeal. As expected, the CDW regime caused comparatively greater reductions of flower dry weight than the LW regime. The exception to this trend was L. cylindracea. Although L. cylindracea decreased its flower dry weight under the LW regime, an increase was seen within CDW. The difference between HW and CDW regime flower dry weights is likely due to inflorescence abortion during periods of severe wilt. When the plant is

subjected to severe wilt, it is likely that the newly formed bud is aborted and thus does not produce a flower.

Summary

The objectives of this study were to determine the growth and reproductive characteristics, CER, and relate species performance to native habitat for each of the eight species. L. scariosa, A. tabernaemontana, and L. cylindracea all displayed positive CER response when subjected to water stress while L. aspera, B. australis, L. pycnostachya, and T. caroliniana all displayed decreases. The growth and photosynthetic characteristics under each water regime has allowed us to relate each species’ performance to their native habitat. The wet adapted species, L. pycnostachya, B. australis, and T. caroliniana all displayed the greatest decreases in CER and total dry weight under water stress. The drier adapted species, L. scariosa and L. cylindracea, displayed increased CER and comparatively lower dry weight losses than the wetter adapted species. A. tabernaemontana, L. cylindracea, and L. scariosa, species adapted to drier and well-drained soils, displayed decreased dry weight, chlorophyll, and CER effects within the HW regime compared to LW. These results have indicated that species’ habitat provides some indication of its ability to thrive under water stressed conditions.

Interestingly, all of the species that were the least drought tolerant are from more mesic habitats. The remaining species, with the exception of A. tabernaemontana, are native to prairie environments. Therefore, when looking for species capable of flourishing under low input environments, plants native to prairie habitats appear to have the greatest potential. The example of A. tabernaemontana indicates that habitats with well-drained soiled conditions may also harbour drought tolerant plant species.

When considering all of the measurements taken in this trial, A. tabernaemontana, L. cylindracea, and L. scariosa displayed the most drought tolerance. L. aspera displayed moderate drought tolerance and B. australis, T. caroliniana, L. spicata, and L. pycnostachya were the least drought tolerant.

The current trial provided some insight into the unexpectedly high plant-to-plant variability found in the population of these native plant species. This variability made taking measurements such as photosynthetic capacity difficult on a relatively small number of plants within a species.

However, variability between plants within a species can be beneficial when looking to exploit specific traits for a breeding program. For example, T. caroliniana had a generally low resistance to water stress based on response of dry weight; however, certain plants within that species were able to maintain higher than average CER under water stress. Such individuals could be used in future breeding programs.

If these species were used within a breeding program, then simple traits such as plant height, length of flowering area, flower dry weight, and plant survival would be the easiest characters to measure, if the capacity to maintain floral characteristics and survive under low input urban landscapes was the objective of the program. Measuring traits such as CER, gs, and

WUE response may give some understanding of the physiological response to low input conditions.

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Tables and Figures

Table 2.1 Effects on all growth, flowering and carbon exchange rates of three separate and distinct watering regimes including Cyclic Drought (CDW), Low Water (LW), and High Water (HW) regimes imposed under greenhouse conditions on eight native perennial ornamental species. Cyclic Drought imposed multiple drought cycles in which soil was saturated and then allowed to dry until 50% of plants displayed wilt. Low Water maintained soil moisture between 23% and 40%. High Water maintained soil moisture between 55% and 70%. Statistical analysis appended in Tables A.1 to A.25.

Watering Regime Cyclic Drought High Water Low Water Total Dry Weight (g) 21.8 c 44.8 a 36.7 b

Total Above Ground Dry Weight (g) 11.1 c 25.3 a 19.9 b

Foliage Dry Weight (g) 9.8 c 22.2 a 17.6 b

Flower Dry Weight (g) 2.0 b 4.9 a 3.7 ab

Total Below Ground Dry Weight (g) 10.7 c 19.5 a 16.8 b

Root Dry Weight (g) 4.8 c 10.3 a 7.8 b

Corm Dry Weight (g) 9.5 b 14.7 a 14.3 a

Root:shoot Ratio 1.09 a 0.76 b 0.86 b

Root:shoot Ratio Without corm 0.55 a 0.41 b 0.48 ab

Survival Percentage (%) 84.1 a 88.8 a 90.9 a

Plant Height (cm) 69.0 b 94.8 a 73.9 b

Number of Flower stalks 1.8 b 2.0 ab 2.4 a

Flower Height (cm) 19.8 b 44.5 a 27.0 b

Average Flower Height (cm) 11.8 c 19.8 a 15.6 b

Flower Number 17.3 b 26.9 a 26.4 a

Flower Width (cm) 2.7 a 2.8 a 2.7 a

Total Stalks 2.3 a 2.7 a 2.7 a

Aborted Stalks 0.4 a 0.3 a 0.1 b

Flowering Percentage (%) 66.0 b 82.5 a 91.0 a

Final Bloom Date (DAT) 88.0 a 85.7 a 87.9 a

First Bloom Date (DAT) 70.0 a 64.2 b 68.5 a

Time in Bloom (Days) 17.6 b 22.6 a 21.6 a

Carbon Exchange Rate (mol CO2 m-2 s-1) 7.7 b 10.1 a 9.6 a

Gs (mol H2O m-2 s-1) 0.1 b 0.2 ab 0.2 b

WUE 5.5 a 3.3 c 4.9 b Chlorophyll (mg Chl/g leaf) 0.20 a 0.18 a 0.21 a

Identical letters within a measured characteristics indicate that results are not significantly different at p=0.05.

Table 2.2: Species response to Low Water and Cyclic Drought watering regimes based on total dry weight decrease within each regime.

Dry Weight Group Species Response

Baptisia australis Most severely Thermopsis caroliniana Group 1 affected

Liatris aspera Liatris cylindracea Group 2 Moderately effected Liatris pycnostachya Liatris scariosa Liatris spicata

Amsonia Group 3 Least effected tabernaemontana

Table 2.3 Percent change of growth characteristics under three separate watering regimes including Cyclic Drought (CDW), Low Water(LW), and High Water(HW) regimes imposed under greenhouse conditions on eight native perennial ornamental species. Cyclic Drought imposed multiple drought cycles in which soil was saturated and then allowed to dry until 50% of plants displayed wilt. Low Water maintained soil moisture between 23% and 40%. High Water maintained soil moisture between 55% and 70%.

Total Total Total Above Foliage Flower Below Root Root:Shoot Corm Dry Root:Shoot Survival Plant Chlorophyll (mg Species Treatment Dry Ground Dry Dry Ground Dry Ratio w/o Weight Ratio (%) Height Chl/g Leaf) Weight Dry Weight Weight Dry Weight corm Weight Weight Amsonia LW 19% 5% 5% N/A 33% 33% N/A 26% 26% -8% -17% 133% tabernaemontana CDW -32% -53% -53% N/A -12% -12% N/A 87% 87% 0% -6% 108%

Liatris aspera LW -3% 5% -3% 40% -12% 18% -13% -15% 17% 6% -38% 42% CDW -39% -42% -45% -30% -36% -36% -36% 10% 11% 9% -32% 14%

Baptisia australis LW -45% -48% -48% N/A -43% -43% N/A 11% 11% -3% -29% 29% CDW -72% -71% -71% N/A -73% -73% N/A -4% -4% -8% -25% 42%

Liatris cylindracea LW -1% -12% -11% -44% 47% 67% 51% 78% 88% 0% -10% 2% CDW -47% -72% -76% 25% 63% 100% 68% 506% 522% 9% -17% 19%

Liatris pycnostachya LW -17% -17% -18% -5% -17% 0% -17% 1% 20% 0% -21% 9% CDW -49% -52% -53% -42% -45% -58% -45% 11% -15% -24% -19% -27%

Liatris scariosa LW -10% -25% -6% -58% 25% 68% 23% 42% 83% 29% -20% 21% CDW -46% -58% -48% -78% -14% -23% -14% 79% 60% 21% -4% 2%

Liatris spicata LW -6% -8% -11% 32% -4% -16% -3% 7% -10% 9% -39% -2% CDW -49% -46% -47% -33% -55% -56% -55% -2% 1% -35% -36% -25%

Thermopsis LW -38% -41% -41% N/A -34% -34% N/A 12% 12% -5% -23% -10% caroliniana CDW -56% -59% -59% N/A -52% -52% N/A 20% 20% -8% -22% 15% LW: The percent change of the Low Water treatment as compared to the High Water treatment CDW: The percent change of the Cyclic Drought treatment as compared to the High Water treatment

Table 2.4a Results of growth characteristics under three separate watering regimes including Cyclic Drought (CDW) Low Water(LW), and High Water(HW) regimes imposed under greenhouse conditions on eight native perennial ornamental species. Cyclic Drought imposed multiple drought cycles in which soil was saturated and then allowed to dry until 50% of plants displayed wilt. Low Water maintained soil moisture between 23% and 40%. High Water maintained soil moisture between 55% and 70%. Statistical analysis appended in Tables A.2, A.3, A.5, A.6, A.9, and A.10.

Total Above Foliage Total Below Total Dry Flower Dry Root Dry Species Treatment Ground Dry Dry Ground Dry Weight (g) Weight (g) Weight (g) Weight (g) Weight (g) Weight (g) Amsonia CDW 19.7 ijk 6.7 hi 6.7 ij N/A 13.1 cdefg 13.1 de tabernaemontana LW 34.4 efghi 14.7 efghi 14.7 fgh N/A 19.7 bcd 19.7 cd HW 28.8 fghij 14.1 efghi 14.1 fgh N/A 14.8 cde 14.8 cde

Liatris aspera CDW 24.3 hij 12.6 fghi 9.8 hi 2.8 b 11.8 cdefg 0.4 f LW 39.1 cdefgh 23 bcdef 17.3 defg 5.7 ab 16.2 cde 0.7 f HW 40.2 cdefgh 21.9 bcdefg 17.8 defg 4.1 b 18.4 bcde 0.6 f

Baptisia australis CDW 18.4 ijk 8.5 hi 8.5 hij N/A 9.9 defg 9.9 e LW 35.9 defghi 15.3 defgh 15.3 efgh N/A 20.7 bcd 20.7 c HW 65.7 a 29.4 abc 29.4 ab N/A 36.3 a 36.3 a

Liatris CDW 6.3 k 2.7 i 2.3 j 0.5 b 3.6 fg 0.2 f cylindracea LW 11.8 jk 8.6 hi 8.4 hij 0.2 b 3.2 fg 0.1 f HW 11.9 jk 9.8 ghi 9.4 hij 0.4 b 2.2 g 0.1 f

Liatris CDW 26.7 ghij 14.6 efghi 12.1 ghi 2.4 b 12.2 cdefg 0.4 f pycnostachya LW 43.6 bcdefg 25.1 bcde 21.2 cdef 4 b 18.5 bcde 0.9 f HW 52.3 abcd 30.1 abc 25.9 abc 4.2 b 22.2 bc 0.9 f

Liatris scariosa CDW 29.3 fghij 16 defgh 12.8 ghi 3.2 b 13.4 cdef 0.4 f LW 48.5 abcde 29 abc 23.1 bcd 5.9 ab 19.5 bcd 0.9 f HW 54.1 abc 38.5 a 24.5 bcd 14.1 a 15.6 cde 0.6 f

Liatris spicata CDW 23.1 hijk 14.8 efghi 13.5 ghi 1.3 b 8.3 efg 0.5 f LW 42.7 bcdefg 25.1 bcde 22.4 bcde 2.6 b 17.7 bcde 0.9 f HW 45.5 bcdef 27.2 abcd 25.2 abc 2 b 18.4 bcde 1.1 f

Thermopsis CDW 26.6 ghij 13.1 efghi 13.1 ghi N/A 13.6 cdef 13.6 cde caroliniana LW 37.6 cdefgh 18.8 cdefgh 18.8 cdefg N/A 18.9 bcde 18.9 cd HW 60.4 ab 31.8 ab 31.8 a N/A 28.5 ab 28.5 b Identical letters within a measured characteristics indicate that results are not significantly different at p=0.05.

Table 2.4b Results of growth characteristics under three separate watering regimes including Cyclic Drought (CDW) Low Water (LW), and High Water (HW) regimes imposed under greenhouse conditions on eight native perennial ornamental species. Cyclic Drought imposed multiple drought cycles in which soil was saturated and then allowed to dry until 50% of plants displayed wilt. Low Water maintained soil moisture between 23% and 40%. High Water maintained soil moisture between 55% and 70%. Statistical analysis appended in Tables A.11, A.7, A.8, A.4, and A.13.

Species Treatment Corm Dry Weight (g) Root:Shoot Ratio Root:Shoot Ratio w/o corm Survival (%) Plant Height (cm) CDW N/A 1.96 a 1.96 a 100 a 44.7 gh Amsonia tabernaemontana LW N/A 1.33 bc 1.33 b 92.5 a 50.5 fgh HW N/A 1.05 bcdef 1.05 bc 100 a 53.6 efgh

Liatris aspera CDW 11.4 bc 0.93 bcdefg 0.03 d 90 a 75.5 bcdefgh LW 15.5 abc 0.72 defghi 0.03 d 87.5 a 82.7 bcdefgh HW 17.8 ab 0.85 bcdefgh 0.03 d 82.5 a 121.7 ab

Baptisia australis CDW N/A 1.18 bcde 1.18 bc 92.5 a 55.3 defgh LW N/A 1.36 b 1.36 b 97.5 a 58.6 defgh HW N/A 1.23 bcd 1.23 bc 100 a 78.3 bcdefgh

Liatris cylindracea CDW 3.4 d 1.27 bc 0.05 d 90 a 43.5 gh LW 3.1 d 0.37 hi 0.02 d 82.5 a 40.2 h HW 2 d 0.21 i 0.01 d 82.5 a 48.3 efgh

CDW 11.8 bc 0.82 cdefgh 0.03 d 70 a 93.5 abcdefg Liatris pycnostachya LW 17.6 ab 0.74 defgh 0.04 d 92.5 a 97 abcdef HW 21.3 a 0.74 defgh 0.03 d 92.5 a 119.1 abc

Liatris scariosa CDW 12.9 bc 0.86 bcdefgh 0.03 d 85 a 85.6 bcdefgh LW 18.6 ab 0.68 efghi 0.03 d 90 a 103.1 abcde HW 15.1 abc 0.48 ghi 0.02 d 70 a 107.1 abcd

Liatris spicata CDW 7.8 cd 0.64 fghi 0.04 d 55 a 86.2 bcdefgh LW 16.8 ab 0.71 efghi 0.04 d 92.5 a 90.1 bcdefgh HW 17.3 ab 0.66 fghi 0.04 d 85 a 141.8 a

CDW N/A 1.08 bcdef 1.08 bc 90 a 67.9 defgh Thermopsis caroliniana LW N/A 1 bcdef 1 bc 92.5 a 68.9 cdefgh HW N/A 0.9 bcdefg 0.9 c 97.5 a 88.4 bcdefgh Identical letters within a measured characteristics indicate that results are not significantly different at p=0.05.

Table 2.5 Flowering characteristics in the Low Water(LW) and Cyclic Drought (CDW) regimes expressed as percent change from the High Water regime under three separate and distinct watering regimes including drought, Low Water, and High Water regimes imposed under greenhouse conditions on eight native perennial ornamental species. Cyclic Drought imposed multiple drought cycles in which soil was saturated and then allowed to dry until 50% of plants displayed wilt. Low Water maintained soil moisture between 23% and 40%. High Water maintained soil moisture between 55% and 70%.

Number of Length of Average Water Flower Flower Total Stalk Aborted Flowering Species Flower Flower stalk Flower Treatment Number Width Number Stalks (%) stalks Area Height

Amsonia CDW N/A N/A N/A N/A N/A N/A N/A N/A tabernaemontana LW N/A N/A N/A N/A N/A N/A N/A N/A

Liatris aspera CDW -22% -51% -23% -24% -2% -22% 0% 6% LW -8% -29% 9% 5% 4% -8% 0% -9%

Baptisia australis CDW N/A N/A N/A N/A N/A N/A N/A N/A LW N/A N/A N/A N/A N/A N/A N/A N/A

Liatris CDW 28% 9% N/A -5% 20% N/A N/A 12% cylindracea LW 11% -11% N/A -32% 9% N/A N/A -42%

Liatris CDW -5% -41% -38% N/A -6% -27% -22% 0% pycnostachya LW 41% -35% -42% N/A -5% 2% -100% -3%

Liatris scariosa CDW -13% -70% -51% -57% -10% -24% -100% 29% LW 18% -41% -16% -8% -10% 3% -100% -7%

Liatris spicata CDW -12% -72% -48% N/A -8% 17% 64% 9% LW 58% -39% -33% N/A 6% 12% -50% -38%

Thermopsis CDW -28% -65% -44% N/A -2% -22% 0% N/A caroliniana LW -15% -70% -58% N/A -5% -8% 0% N/A LW: The percent change of the Low Water treatment as compared to the High Water treatment CDW: The percent change of the Cyclic Drought treatment as compared to the High Water treatment

Table 2.6 Flowering characteristics under three separate and distinct watering regimes including Cyclic Drought (CDW), Low Water (LW), and High Water (HW) regimes imposed under greenhouse conditions on eight native perennial ornamental species. Cyclic Drought imposed multiple drought cycles in which soil was saturated and then allowed to dry until 50% of plants displayed wilt. Low Water maintained soil moisture between 23% and 40%. High Water maintained soil moisture between 55% and 70%. Statistical analysis appended in Tables A.14 to A.19, A.12,

Length of Average Number of Flower Number Flower Total Flower Aborted Flowering Species Treatment Flower stalk of Width Stalk Height Stalks (%) stalks/Plant region Flowers (cm) Number (cm) (cm) Amsonia tabernaemontana CDW N/A N/A N/A N/A N/A N/A N/A N/A LW N/A N/A N/A N/A N/A N/A N/A N/A HW N/A N/A N/A N/A N/A N/A N/A N/A

Liatris aspera CDW 2.4 bcdef 38.3 bcd 19.9 abcd 35.0 abc 1.04 ef 2.4 bcde 0.0 c 75 abc LW 2.8 abcd 54.8 ab 28.1 a 48.7 a 1.11 ef 2.8 abcd 0.0 c 87.5 ab HW 3.0 ab 77.5 a 25.8 ab 46.3 ab 1.07 ef 3.0 abcd 0.0 c 82.5 abc

Baptisia australis CDW N/A N/A N/A N/A N/A N/A N/A N/A LW N/A N/A N/A N/A N/A N/A N/A N/A HW N/A N/A N/A N/A N/A N/A N/A N/A

Liatris cylindracea CDW 1.2 ef 11.2 de N/A 4.0 e 1.03 ef N/A N/A 47.5 c LW 1.1 f 9.2 e N/A 2.9 e 0.93 f N/A N/A 92.5 a HW 0.9 f 10.3 de N/A 4.2 e 0.86 f N/A N/A 82.5 abc

Liatris pycnostachya CDW 2.8 abc 28.7 bcde 10.2 de N/A 2.48 bc 3.0 abcd 0.3 c 90 ab LW 4.2 a 31.8 bcde 9.6 de N/A 2.51 bc 4.2 a 0.0 c 92.5 a HW 3.0 abc 48.9 bc 16.5 bcde N/A 2.65 b 4.1 a 0.3 c 92.5 a

Liatris scariosa CDW 1.1 f 15.1 de 14.4 cde 12.9 de 1.36 ef 1.1 e 0.0 c 65 abc LW 1.5 cdef 30.2 bcde 24.8 abc 27.6 cd 1.35 ef 1.5 de 0.0 c 90 ab HW 1.3 def 51.1 abc 29.4 a 30.0 bcd 1.51 de 1.5 de 0.2 c 70 abc

Liatris spicata CDW 1.5 cdef 11.3 de 8.3 de N/A 2.06 cd 3.5 ab 1.9 a 52.5 bc LW 2.6 bcde 24.3 cde 10.8 de N/A 2.38 bc 3.4 abc 0.6 bc 92.5 a HW 1.7 bcdef 39.8 bcde 16.0 abcde N/A 2.23 bc 3.0 abcd 1.2 b 85 abc

Thermopsis caroliniana CDW 1.8 bcdef 14.1 de 6.2 e N/A 8.20 a 1.6 de 0.0 c N/A LW 2.1 bcdef 11.9 de 4.7 e N/A 7.98 a 1.9 cde 0.0 c N/A HW 2.4 bcdef 39.7 bcd 11.1 de N/A 8.36 a 2.0 bcde 0.0 c N/A Identical letters within a measured characteristics indicate that results are not significantly different at p=0.05.

Table 2.7 Effects on flowering dates under three separate and distinct watering regimes including Cyclic Drought (CDW), Low Water(LW), and High Water(HW) regimes imposed under greenhouse conditions on eight native perennial ornamental species. Cyclic Drought imposed multiple drought cycles in which soil was saturated and then allowed to dry until 50% of plants displayed wilt. Low Water maintained soil moisture between 23% and 40%. High Water maintained soil moisture between 55% and 70%. Statistical analysis appended in Tables A.20-A.22

First Final Time in Species Treatment Flowering Flowering Flower Date (DAT) Date (DAT)

Liatris aspera CDW 84 cd 109 bc 26 abce

LW 82 cde 111 ab 30 a HW 73 ef 103 c 30 ad

Liatris CDW 74 def 92 de 16 f cylandracea

LW 75 def 87 def 15 f HW 70 fgh 81 ef 14 f

Liatris CDW 65 fgh 83 def 16 f pycnostachya

LW 63 gh 83 def 21 bcef HW 61 h 79 f 19 ef

Liatris CDW 102 a 118 ab 18 bcdef scariosa LW 95 ab 118 ab 31 abc HW 90 bc 120 a 31 ab

Liatris CDW 74 def 87 def 14 f spicata LW 72 fg 91 d 21 cef HW 68 fgh 91 de 23 abcef

Thermopsis CDW 23 i 40 g 16 cef caroliniana LW 25 i 38 g 12 f HW 23 i 41 g 18 abcef

Identical letters within a measured characteristics indicate that results are not significantly different at p=0.05.

Table 2.8 Photosynthetic measurements under Low Water (LW), High Water (HW), and Cyclic Drought (CDW) watering regime imposed under greenhouse conditions on eight native perennial ornamental species. Cyclic Drought imposed multiple drought cycles in which soil was saturated and then allowed to dry until 50% of plants displayed wilt. Low Water maintained soil moisture between 23% and 40%. High Water maintained soil moisture between 55% and 70%. Statistical analysis appended in Tables A.23 to A.25 and A.1. CER g (mol Chlorophyll (mol s Species Treatment H2O m-2 WUE (mg Chl/g CO2 m-2 s-1) Leaf) s-1)

Amsonia CDW 5.45 g 0.07 j 5 def 0.126 ef tabernaemontana LW 7.67 f 0.11 gh 4.51 efg 0.141 ef

HW 4.02 h 0.1 h 2.62 j 0.06 f

Liatris aspera CDW 5.04 gh 0.06 jk 3.73 hi 0.163 def

LW 11.19 bc 0.15 de 4.22 fghi 0.204 bcde HW 12.53 ab 0.31 a 2.26 jk 0.144 ef Baptisia CDW 5.11 gh 0.04 k 7.2 a 0.347 a australis LW 9.18 e 0.09 hij 6.24 bc 0.315 abc

HW 9.34 de 0.12 fgh 5.16 de 0.245 abcde Liatris CDW 10.96 c 0.19 c 4.4 fgh 0.146 ef cylindracea LW 13.74 a 0.24 b 3.57 i 0.125 ef

HW 9.42 de 0.34 a 1.89 k 0.123 ef

Liatris CDW 8.43 ef 0.1 hi 6.22 bc 0.139 ef pycnostachya LW 9.1 e 0.14 efg 4.87 defg 0.207 abcde

HW 11.68 bc 0.17 cd 4.47 efgh 0.19 cdef

Liatris scariosa CDW 10.81 cd 0.15 def 5.07 def 0.174 def

LW 11.85 bc 0.12 efgh 5.47 cd 0.206 bcde

HW 8.68 ef 0.24 b 2.24 jk 0.17 def

Liatris spicata CDW N/A N/A N/A 0.166 def

LW N/A N/A N/A 0.219 abcde

HW N/A N/A N/A 0.223 abcde

Thermopsis CDW 7.6 f 0.07 ij 6.69 ab 0.333 ab caroliniana LW 8.77 ef 0.1 h 5.44 d 0.259 abcde

HW 11.28 bc 0.19 c 4.19 ghi 0.289 abcd

Identical letters within a measured characteristics indicate that results are not significantly different at p=0.05.

Table 2.9 Percent change of photosynthetic measurements from High Water treatment under Low Water (LW) and Cyclic Drought (CDW) watering regime imposed under greenhouse conditions on eight native perennial ornamental species. Cyclic Drought imposed multiple drought cycles in which soil was saturated and then allowed to dry until 50% of plants displayed wilt. Low Water maintained soil moisture between 23% and 40%. High Water maintained soil moisture between 55% and 70%. CER (mol gs (mol Chlorophyll (mg Species Treatment CO2 m-2 s- H2O m-2 s- WUE Chl/g Leaf) 1) 1)

CDW 36% -30% 91% 108% Amsonia tabernaemontana LW 91% 9% 72% 133%

Liatris aspera CDW -60% -80% 65% 14% LW -11% -51% 87% 42%

Baptisia australis CDW -45% -67% 39% 42% LW -2% -24% 21% 29%

Liatris cylindracea CDW 16% -43% 133% 19% LW 46% -28% 89% 2%

CDW -28% -41% 39% -27% Liatris pycnostachya LW -22% -19% 9% 9%

Liatris scariosa CDW 25% -39% 126% 2% LW 37% -51% 144% 21%

Liatris spicata CDW N/A N/A N/A -25% LW N/A N/A N/A -2%

CDW -33% -63% 59% 15% Thermopsis caroliniana LW -22% -46% 30% -10%

LW: The percent change of the Low Water treatment as compared to the High Water treatment

CDW: The percent change of the Cyclic Drought treatment as compared to the High Water treatment

Figure 2.1 Predicted photosynthetic response (CER) of native plant species to High Water (High), Low Water (Low), and Cyclic Drought (Drought) watering regimes over one cycle of drought.

High CER 6 Low

4 Drought

0 4 5 6 7 8 6 10 11 12 13 Day

Chapter 3: Effects of fertilizer and irrigation on eight native perennial ornamentals in field conditions over two years. Abstract

Recent concerns regarding water usage and fertilizer requirement in urban landscapes have created a need for low input ornamentals capable of thriving with minimal water and fertilizer inputs. The use of native perennial ornamentals may be helpful in reducing water use.

The current study, involving two field trials, included eight native ornamental perennials (Liatris aspera, Liatris cylindracea, Liatris pycnostachya, Liatris scariosa, Liatris spicata, Baptisia australis, Thermopsis caroliniana, and Amsonia tabernaemontana) from varying habitats. One field trial (GTI) included these watering treatments: 1. no supplemental water (NW) 2. supplemental water up to 25 mm per week (SW) as well as no supplemental fertilizer (NF) and supplemental fertilizer 6.75 g N/plant (SF). The second field trial (Elora) included these fertilizer levels: 1. 4 g N/plant (LF) 2. 6.1 g N/plant (MLF) 3. 8.2 g N/plant (MF) 4. a check

(NF). All species were generally non-responsive to fertilizer treatments in both field trials. A. tabernaemontana, L. cylindracea, and T. caroliniana all displayed similar growth in supplemental (SW) and check water (NW) treatments. L. spicata, L. pycnostachya, and, B. australis displayed the largest growth increases when subjected to supplemental fertilizer. Visual plant quality was maintained for A. tabernaemontana, L. aspera, L. scariosa, and T. caroliniana when each was subjected to NF. In contrast, L. spicata and L. pycnostachya’s floral quality suffered the most under NW. In general, species’ habitats were indicative of their response to low input environments.

Introduction

The phrase “urban landscapes” can evoke a plethora of images ranging from perfectly mowed turf lawn to expansive floral displays. However, the majority of individuals would think of the former. These commonplace sculpted turf landscapes can cause significant environmental damage and require an abundance of inputs (i.e. water and fertilizer)(Nassauer, 1993). For instance, a study in the United States recently reported that landscape water use accounted for

40% to 70% of total residential water demand (Hilaire et al., 2008). With an increasing number of studies predicting declines in water availability around the world (Gober and Kirkwood, 2010;

Hoekstra et al., 2012; Rockstrom et al., 2009), restrictions on landscape water usage are likely to increase.

A second concern regarding urban landscape is fertilizer usage. An Atlanta survey revealed 76% and 68% of landscapes composed of turf or ornamental beds, respectively, were fertilized yearly (Beverly et al., 1997). A similar study also conducted in Georgia determined that 76% of residents applied fertilizer yearly (Varlamoff et al., 2001). With increased social pressure to reduce environmental impact (Fox, 2008) and increasing fertilizer costs (Huang and

Beckman, 2012; Huang, 2009), an alternative to high input landscapes is necessary.

A potential method of reducing water and fertilizer usage in urban landscapes is the use of low input gardens, otherwise known as xeriscaping (Damasceno et al., 2011; Younis et al.,

2009). Xeriscaping utilizes plant species and landscape design techniques to reduce or eliminate high input maintenance (McKenney and Terry, 1995). A dominant characteristic of low input landscapes is the use of native species. Research concerning water use of native species and their adaptability to low-input landscape environments has demonstrated native species originating from low input natural habitats (e.g. prairie land) exploit specialized drought tolerance

characteristics. Some of these characteristics include stomatal sensitivity, osmotic adjustment

(Chapman and Augé, 1994), greater cuticle wax (Bolger et al., 2005), increased root: shoot ratio, and deeper rooting depth (Kjelgren et al., 2009; Zollinger et al., 2006). These characteristics prevent plant desiccation in reduced soil moisture conditions through increased water uptake and/or decreased plant water loss. However, due to the sustained popularity of water-loving non- native (i.e. introduced) ornamentals, the use of xeriscaping in urban areas remains low (Kaufman and Barnes, 2009).

Although the demand for introduced species remains strong, a gradual increase in the use of native ornamentals in urban landscapes has been observed over the past few years. (Brzuszek and Harkess, 2009). The ‘green’ movement is likely contributing to the shift in consumer plant preferences (Fox, 2008). However, the push toward native plant use must derive not only derive from niche consumer demands but also from producer supply. If the consumer demand for native species is low, reduced monetary return can be expected at the producer level, resulting in minimal production. Consequently, a significant shift in consumer demand toward native species is necessary to drive increased production.

Numerous surveys investigating the use of native plants in the home landscape reveal consumer preferences. In 2007, Brzuszek (2010) surveyed 979 Master Gardeners. It was determined that this consumer group is very enthusiastic about native plant use. The study found consumers believed marketing of native species could grow if the number of species and availability were increased. In 2007, a study conducted by Brzuszek (2007), found landscape architects were using a larger portion of native plants within their designs. Furthermore, Yue

(2011) investigated the effects of plant labeling as either ‘native’ or ‘invasive’ and found consumers’ willingness to purchase increased if plants were labeled as ‘native’. These studies

demonstrate that consumer knowledge can be a driving force for increased native plant sales.

Similar trends were seen when consumers were asked to rank landscapes while considering maintenance costs. Consumers often chose to pay more when landscapes involved attractive native species (Helfand et al., 2006). Subsequently, producers have recognized increased consumer interest in native species (Brzuszek and Harkess, 2009; Kauth and Perez, 2011).

Brzuszek and Harkess (2009) and Kauth and Perez (2011) concluded that enhanced public education would benefit market sales. Consumer knowledge associated with market sales becomes evident when reviewing earlier literature regarding the native plant market. One third of the industry producers surveyed in 1996 recognized no increase in native plant demand between

1991 and 1996 (Waterstrat et al., 1998). Collectively, these studies demonstrate the desire for low-input native landscapes is present and has been growing in the past two decades. However, areas such as marketing, variety of species, and plant availability still require further research and growth. To increase plant variety and availability, extensive research must be conducted on potentially beneficial species and their response to low input conditions.

Plants are capable of responding to water stress through a variety of mechanisms.

Responses such as rapid stomatal closure, leaf shedding, reduced plant size (Begg et al., 1980) and deep extensive root systems (Taiz and Zeiger, 2006) are categorized as drought avoidance characteristics. These mechanisms reduce the amount of water lost through plant organs and allow increased water uptake. In contrast, drought tolerant plants are capable of sustaining survival through osmotic adjustment. Osmotic adjustment aids the plant by maintaining cell turgor, and allowing continued metabolic activity (Ludlow et al., 1985). Favorable species maintain esthetic appeal (i.e. large flowers and plentiful foliage) while tolerating water stress through internal mechanisms (e.g. osmotic adjustment). However, it is important to recognize

certain drought stress mechanisms may not be desirable in ornamental plants. Species that respond to moisture stress by shedding leaves may not be desirable in landscape settings.

Therefore, it becomes crucial when selecting new low-input species to ensure a continued esthetic appeal while water stress is present.

Understanding how native plants respond to fertilizer treatments is an important factor when selecting for low input landscapes. However, minimal research has been conducted in this area. Thetford (2011) investigated the effects of supplemental fertilizer and supplemental water on the growth response of a selection of native perennial grasses. Plants were treated with three fertilizer levels including no fertilizer, synthetic fertilizer, and organic fertilizer. Five (T. dactyloides, E. elliottii, M. capillaris, S. scoparium, and M. sinensis) of the nine species studies displayed response to supplemental water or fertilizer. However, the study concluded that the minimal response seen across native species was due to high native adaptability to low input landscapes.

To generate knowledge used to understand the native ornamental landscape market, as well as increase available species for this market, further research into native ornamentals and their species-specific response to low input environments is necessary. Kjelgren (2009) investigated the response of native Australian species originating from contrasting natural habitats (i.e. dry versus wet habitats) under water stress conditions. The study found the response of species originating from drier habitats was physiologically different to species originating from wet habitats. The dry-adapted species responded rapidly to water stress through stomatal closure. The wet-adapted species displayed decreased stomatal closure response, resulting in wilting and desiccation of leaves. Consequently, species that have evolved for specific natural

habitats may have characteristics that contribute to successful growth under low-input conditions.

The objectives of this study are to characterize the effects of low input conditions on eight native ornamental perennials. Species selected for the study were Liatris spicata, L. cylindracea, L. aspera, L. pycnostachya, L. scariosa, Thermopsis caroliniana, Amsonia tabernaemontana and Baptisia australis. Species were selected to represent a variety of natural habitats. With extensive variability of natural habitat, selected species may hold certain growth characteristics that allow for sustained growth under low input conditions. Specific objectives of the study were:

1. Characterize the vegetative and reproductive growth parameters of eight native

perennial ornamentals under low and moderate input conditions.

2. Determine if habitat plays a role in developing characteristics of species that

would encourage growth under low input conditions

Materials and Methods Seed sources, germination and establishment

Seeds of Liatris aspera, Liatris scariosa, Liatris spicata, Liatris pycnostachya, Liatris cylindracea, Amsonia Tabernaemontana, Baptisia australis, and Thermopsis caroliniana, collected from commercial sources (Table 3.1), were stratified in a sealed plastic bag containing

1:1 vermiculite:water by volume and placed in cold storage at 3.5°C ±1°C for the recommended stratification period as indicated by the supplier. After stratification, seeds from seven species, excluding B. australis, were sown in Sunshine LP5 (Sun Gro Horticulture, Vancouver BC, ON)

and sparingly covered with fine vermiculite. B. australis contains a large taproot that if damaged, can lead to an inadequate plant. To reduce damage to the taproot during transplanting, B. australis was seeded and germinated in Jiffy7 flats with sown seeds placed in misting beds to promote germination. Flats remained in misting beds until the first true leaf stage. At first true leaf stage, seedlings were transplanted into black 50 cell flats filled with Sunshine 4 media.

Seedlings were then moved into a larger greenhouse area and watered as needed. Seedlings were fertilized using water soluble 20N-8P-20K (Plant Products, Brampton ON) 1.25 g/L pH adjusted

6.0 and E.C. 2.5.

When Liatris spp., Baptisia spp., Thermopsis spp. and Amsonia spp. species reached the five, six, eight and seven leaf stage (June 1, 2011), respectively, plants were moved outdoors for a seven-day acclimation period prior to transplanting into the field trials. After seven days, all plant species were hand transplanted into the trial at the GTI (Guelph Turfgrass Institute). After four weeks of establishment, the experimental treatments were applied. To assist establishment,

0.67L of water-soluble 20-20-20 (Plant Products, Brampton ON) (400ppm) fertilizer was applied to each plant. An overhead sprinkler system was used to maintain moist soil during the plant establishment period. Weeds were controlled by hand as needed.

For winter protection, field plots were covered (December 16th, 2011) with a permeable cloth, which was removed on March 1st, 2012.

Response to Water and Fertilizer Trial

The response to fertilizer trial was conducted at the GTI (Fox sandy Loam) in Guelph,

Ontario, Canada. Experimental design was a split-split plot with levels of water randomized to the main plot, and two levels of fertilizer randomized as the sub plot over four replications. Each row (i.e. sub-sub plot) consisted of 20 plants per species with 0.3 meter spacing between plants

and 0.6 meter spacing between rows. There were two fertilizer treatments: a control treatment

(NF), which had no supplemental fertilizer, and a supplemental fertilizer treatment (SF), which was a one-time hand application of granule 20-10-10 (Plant Products, Brampton ON), applied at

135g/row (6.75g/plant) based on recommendations from University of Maryland Cooperative

Extension (2009). Application was made along the row within 6” of the plant stem. Care was taken to minimize fertilizer contact with plant material. Control treatments received no fertilizer application.

Plants receiving supplemental irrigation (SW) received 12.5 mm water per treatment day while non-irrigated plants (NW) received only rainfall. SW was applied using a drip-irrigation system (Vanden Busshe Irrigation, Milton, Ontario). Plants under SW received an individual drip emitter, supplying 3.8 L of water per hour. SW treatments were applied Monday and Thursday throughout the two growing seasons. Rainfall measurements were collected on Monday and

Thursday of each week. If rainfall was greater than zero but less than ½ acre-inch, supplemental water treatment plots were supplied with irrigation water to maintain treatment requirements for that treatment day. If more than ½ acre-inch of rain was received between the treatment days, supplemental irrigation was withheld.

Response to Fertilizer Trial

The response to fertilizer only trial was conducted at Elora, Ontario, Canada as a split plot that was replicated four times. The soil type at Elora is Conestoga silt loam soil. Two levels of water were randomized as the main plot, two levels of fertilizer were randomized as the sub- plot, and eight species were randomized as the sub-sub-plot. Plants were spaced one foot apart and each row contained 12 plants. Fertilizer treatments applied included no fertilizer (NF), low fertilizer (LF) (81g/row of 20N-10P-10K), medium-low fertilizer (MLF) (122.4g/row of 20N-

10P-10K) and medium fertilizer (MF) (163.2g/row of 20N-10P-10K) based on recommendations from University of Maryland Cooperative Extension (2009). Fertilizer was evenly distributed by hand along the length of the row in a band within 15cm of the plant. Care was taken to minimize fertilizer contact with plant material.

Data collection during vegetative year

Data collections were conducted during the establishment (2011) and the first reproductive (2012) years. The following traits were measured immediately prior to harvest: plant height, number of flower stalks, percent survival, percent flowering, above ground non- flowering dry weight, flower dry weight, and total dry weight. Percent survival was defined as the percent of plants in the sub-sub plot that were alive at harvest and percent flowering was defined as the percentage of those plants that displayed floral characteristics. Flower dry weight was defined as the area of the plant that contained reproductive organs. On November 11th, 2011 all surviving plants from each row were harvested. All plant materials were dried at 80°C for 48 hours and weighed.

Flowering did not occur in the Elora trial in the vegetative year and consequently no flowering data were collected.

Data collection for reproductive year

In the reproductive year (2012), measurements collected included plant height, number of flower stalks, flowering area length, percent survival, percent flower, date of first bloom (50% of the plants in a row displayed flowers), date of full bloom (90% of plants in a row displayed flowers), date of bloom ending (90% of flowered plants no longer displayed flowering), above ground material (excluding flowering material) dry weight, flower dry weight, and total dry weight. Plants were monitored bi-weekly (Tuesday & Thursday) to determine

bloom date. On September 30th, 2012, all surviving plants from each row were harvested.

Flowering portions of the stem were separated from the remaining above ground plant material dried at 80°C for 48 hours and weighed.

Data analysis

All data were analyzed in SAS v9.2 (SAS Institute Inc., Cary, NC, USA, 2009) using general linear model procedures for ANOVA tables. Means comparisons were done using a

Tukey’s Studentized range test at P<0.05 level. Analysis of variance results are presented in

Appendix A.

Results

During the 2011 growing season (July 18- October 22), the GTI trial received 177 mm of rainfall (Figure 3.1). The rainfall patterns during this season were irregular but were sufficient to avoid drought and plant wilting. Total irrigation water added to plants under SW was 205 mm. In the GTI trial in the SW and NW treatments, plants received 381 mm and 177 mm of water, respectively. In the 2012 (Figure 3.2) growing season (June 5 – September 21), the rainfall pattern was substantially different from the 2011 season. The total rainfall in August and

September (239mm) was nearly twice as much as June and July combined (126mm). As well, during the months of June and July (2012), there were two occurrences of 15-day periods with no rainfall. On July 5th, 2012, drought conditions caused some plant species to display significant wilt. To prevent plant desiccation and death, 2.25 cm of water was supplied to the NW plots using an overhead sprinkler system. In total, rainfall in the 2012 season was 366 mm and plants in the SW treatment received an additional 249 mm through irrigation, totaling 615 mm of water received.

The Elora trial did not incorporate water as a treatment; however, rainfall was measured during both growing seasons. In 2011, the establishment season, the Elora trial received 196 mm of rainfall (Figure 3.3). In the 2012 season (May 1 – September 21), plants in the Elora trial received 280 mm of rainfall (Figure 3.4). Rainfall patterns in Elora were similar to those at the

GTI in that extensive drought periods between rain events were common for the 2012 season.

During the month of May, a seventeen-day drought period occurred. An even more severe drought occurred during the months of June and July with 43 days between major rain events.

During the second, longer drought, only 8.5 mm of rain fell on seven separate days, with 3 mm being the largest event. Also, May, June and July received a total 143.5 mm, with 35.5% of that

(51 mm) occurring during one rain event (June 4th), while August and September received 143 mm.

Total Dry Weights

For ease of explanation, species were evaluated by total above ground dry weight and grouped in their response to SF and then to SW in the 2012 or reproductive year. Those groups were then used to describe results for the remaining characteristics and previous year. Total dry weights were measured in both 2011 and 2012 seasons.

GTI trial. All species displayed an increase in total above ground dry weight under the

SW treatment in 2011. L cylindracea had the smallest increase in dry weight in 2011 under the

SW treatment. In general, under the SW treatment in 2012, all species showed an increase in total above ground dry weight with L. cylindracea. L. spicata, B. australis, and L scariosa displaying the greatest increases of 94%, 74%, and 71%, respectively, all of which were significant compared to NW (Table 3.2). L. aspera and L. pycnostachya also displayed significant increases of 65% and 63%, respectively. L. cylindracea, the exception, displayed a

non-significant decrease of 6%. Therefore, response groups for the SW treatment were ranked as follows: 1. L. spicata, B. australis, L. scariosa (high response) 2. L. aspera and L. pycnostachya

(medium high response) 3. A. tabernaemontana and T. caroliniana (medium low response), and

4. L. cylindracea (low response).

In contrast to the positive effect of the SW treatment, no significant differences were observed under the SF treatment in 2011 or 2012. However, some trends were seen that are worth noting. L. spicata L. cylindracea displayed the greatest response to SF in 2011 with increases of 27% and 24%, respectively (Table 3.4). The 2011 and 2012 above ground dry weight response to fertilizer was similar in both years with all species displaying an increase in response of up to a 25%. In 2012, T. caroliniana, B. australis, and A. tabernaemontana all displayed similar increases in total above ground dry matter under the SF treatment of 21%,

24%, and 23%, respectively (Table 3.6). This was the greatest dry weight increase within the SF treatment. Thus ratings of species response to SF are as follows: high (T. caroliniana, B. australis, and A. tabernaemontana), low (L. aspera and L. cylindracea), and negligible (L. pycnostachya, L. spicata, and L. scariosa).

Elora trial. Total dry weight for all species within the Elora trial in the vegetative year presented no significant differences between fertilizer treatments. A. tabernaemontana and L. cylindracea displayed essentially no change when subjected to each fertilizer treatment (Table

3.8). Interestingly, a trend was observed for L. pycnostachya, L. spicata, and T. caroliniana in which NF and MLF displayed the greatest dry weights. As well, within these species, the NF and

MF fertilizer treatments produced substantially lower dry weights. Another interesting trend observed was that L. aspera and B. australis, when subjected to NF, LF, and MLF had similar dry weights for each treatment. In addition, the high fertilizer treatment for those species

exhibited a substantially lower dry weight. Finally, L. scariosa was the only species in which a trend of increasing dry weight was observed with increasing supplemental fertilizer.

During the reproductive year, one noticeable trend in Elora for six of the eight species was the fact that the NF treatment displayed the greatest dry weight. This was consistent for A. tabernaemontana, L. aspera, B. australis, L. cylindracea, L pycnostachya, and L. spicata (Table

3.9). The difference between all other treatments and the NF treatment was substantial with the exception of A. tabernaemontana. Interestingly, MLF treatments for L. pycnostachya and L. spicata resulted in the second highest dry weight within those species. For the remaining species,

L. scariosa and T. caroliniana, dry weight did not respond to increasing fertilizer.

Foliage dry weight

GTI trial. SW treatment caused a large response in foliage dry weight in 2011.

Interestingly, only one (B. australis) of the three species in the high response group ranked in the top three of increased foliage dry weight under SW. The remaining two species from the high response group, L. scariosa and L. spicata, displayed changes of only 9% and 21%, respectively

(Table 3.10). A. tabernaemontana and T. caroliniana displayed comparatively large changes of

44% and 36%, respectively. The only species to exhibit a negative change under SW in 2011 was

L. cylindracea. In 2012, SW had an even larger impact on foliage dry weight compared to 2011.

B. australis (high response group) had the largest increase in foliage dry weight of 74% (Table

3.2). This was followed by L. spicata (high response group), A. tabernaemontana (medium low response group), and L. scariosa (high response group) with increases of 48%, 39%, and 37%, respectively. Once again, L. cylindracea displayed the only negative response to SW with a decrease in foliage dry weight of 2%.

The SF treatment produced low and non-significant responses from foliage dry weight in

2011 with five of the eight species displaying changes between -7% and 9% (Table 3.4). The remaining species, A. tabernaemontana (high response group), T. caroliniana (high response group), and L. spicata (negligible response group), displayed similar increases between 14%, and

16% for foliage dry weight. In 2012, a similar response of foliage dry weight for the majority of the species was observed. Three species, A. tabernaemontana, B. australis, and T. caroliniana, of the high response group, displayed the greatest changes in foliage dry weight of 23%, 24%, and 18%, respectively (Table 3.6).

Elora trial. Foliage dry weight in Elora responded in a similar manner to total dry weight at the

GTI in that the same six of eight species produced the greatest foliage dry weights under NF. The species that displayed this trend included A. tabernaemontana, L. aspera, B. australis, L. cylindracea, L. pycnostachya, and L. spicata. For all of these species, with the exception of A. tabernaemontana, the difference between NF and the other fertilizer treatments was comparatively large. For example, L. aspera displayed a foliage dry weight of 26.8g under the

NF treatment (Table 3.9), a 21% increase compared to MLF.

Flower Dry Weight

Although many of the plants in the GTI trial displayed floral characteristics in the establishment year, no floral characteristics were displayed in the Elora fertilizer trial in 2011. As well, within the GTI establishment year, A. tabernaemontana, B. australis, and T. caroliniana displayed no floral characteristics. Consequently, floral measurements were collected on five of the eight species within the GTI trial in 2011. Also, the species B. australis displayed no floral characteristics in either growing season. A. tabernaemontana displayed floral characteristics very

early in the season. As a result, a flower count based on seedpods collected from A. tabernaemontana at trial’s end was used to establish floral differences between treatments.

GTI trial. Similar to results for total dry weight, no significant differences between SW or SF treatments were seen in flower dry weights in 2011. In 2012, four of the six species had floral dry weight increases of 100% or more under SW (Table 3.2). Species from the high response group, L. spicata and L. scariosa increased floral dry weight by 270% and 160%, respectively. Species from the medium high response group, L. aspera and L. pycnostachya exhibited increases of 100% and 316%, respectively. Even the species within the medium low response group, T. caroliniana, displayed an increase of 89%. L. cylindracea, the single species in the low response group to SW, exhibited no significant change in floral dry weight. As previously mentioned, no significant differences were seen under SF within the GTI trial in

2011. In 2012, the only species to exhibit a significant positive change in floral dry weight to SF was T. caroliniana (high fertilizer response group), with an increase of 49% (Table 3.6). All other species ranged from -3% to 11% under SF.

Elora trial. Displaying similar trends to total dry weight in 2012 at Elora, five of the six species produced the greatest flower dry weight under the NF treatment. However, these increases were not as high as total dry weight when comparing the NF treatment to the other treatments, with the exception of T. caroliniana. The responses to the other levels of fertilizer were variable and species-dependent (Table 3.9).

Total dry weight : Flower Ratio

To determine how supplemental fertilizer and water affected ornamental potential and above ground growth, total above ground dry weight and flower dry weight measurements were

used to calculate a plant:flower ratio (P:F). The ratio is a display of how water affected dry matter partitioning between above ground foliage dry weight to flower dry weight.

GTI trial. The SW treatment within the GTI trial in 2012 caused substantial increases in

P:F. The largest increase, although non-significant, was seen in T. caroliniana with a 960% increase under SW (Table 3.2). With the exception of L. cylindracea, all Liatris spp. displayed a significant and positive response to SW. Ratio increases were seen for L. aspera [1.6(59%)], L. pycnostachya [0.6(249%)], L. scariosa [1.3(83%)], and L. spicata [0.5(150%)]. In contrast to the higher ratios observed with SW, SF caused a relatively unchanged P:F ratio in 2012. The only exception to this was T. caroliniana, which increased its P:F ratio by 264%. The P:F ratio actually decreased (23%) for L. cylindracea under SF.

Elora trial. Similar to the SF treatment at the GTI in 2012, fertilizer treatments at the

Elora trial produced no significant response. However, general increases were observed with supplemental fertilizer under all treatments for L. aspera and L. spicata, ranging from 13% to

40% and 36% to 70%, respectively (Table 3.9). However, some species such as T. caroliniana and L. scariosa exhibited a decreased P:F ratio in all supplemental fertilizer treatments ranging from -19% to -44% and -16% to -37%, respectively. The other species such as L. cylindracea and L. pycnostachya, exhibited responses ranging from -11% to +21% and -27% to +16%, respectively.

Plant Height

GTI trial. The SW treatments increased plant height for all species in 2011 and 2012. In the 2011 growing season T. caroliniana exhibited a significant height increase of 35% under the

SW treatment in the GTI trial (Table 3.10). The remaining species displayed no significant height changes. SW treatment had a much more profound effect on plant height in 2012 as

compared to 2011, exhibiting significant changes in L. aspera, L. pycnostachya, L. scariosa, and

L. spicata. On average, species in the high response group increased plant height by at least 26%

(Table 3.2). L. spicata (high response group) exhibited the greatest increase of 74%. The second greatest height increase (65%) was seen in L. pycnostachya (medium high response group). Once again, L. cylindracea displayed a negative growth response under SW treatment.

In general, seven out of eight species showed a non-significant response to SF treatment in both years (Table 3.5 & 3.7). In 2012, the response of plant height to SF was negative in seven of the eight measured species. The only species to show positive growth response in 2012 was T. caroliniana (high response group) and L. scariosa (low response group) in 2011.

Elora trial. Fertilizer treatment at Elora exhibited minimal effect on plant height across all species (Table 3.9). L. cylindracea and T. caroliniana demonstrated greater plant height with lower fertilizer levels. The other species had no response to fertilizer or a slightly lower height.

Percent Survival

The survival of each species within the treatments is an important factor to account for as the economics of replanting plants within urban landscapes as well as replacement of plants within production scenarios can negate the benefits of implementing certain native perennial ornamentals. Therefore, an examination of each species’ survival under the imposed conditions was conducted.

GTI trial. In 2011, survivability within the SW treatment was very high. Only slight fluctuations in percent survivability (±10.0% range) were seen for nearly all species (Table 3.10).

This kind of variation in survivability is to be expected when working with native species in an open system experiment. The exception to this range was L. cylindracea. Under the SW regime,

L. cylindracea displayed a decrease in survivability of 31.6%. This result is consistent with other

negative trends seen by L. cylindracea and supports the idea that this species has a decreased tolerance to the SW. In 2012, the same general trend observed in 2011 was repeated with minimal change in percent survivability displayed across all species (Table 3.2). However, in

2012, L. cylindracea showed no further decline in survivability.

Supplemental fertilizer in both 2011 and 2012 had minimal effect on survivability across all species. The greatest changes were seen by L. cylindracea in 2011 and L. aspera in 2012 with changes of -12.3% and 10.0%, respectively (Table 3.4 & 3.8).

Elora trial. Varying levels of fertilizer at the Elora field trial caused minimal to no significant changes in percent survival of all species in both 2011 and 2012 (Table 3.8 & 3.9).

Flower stalks

Throughout the trial, various reproductive characteristics were measured to observe species-specific water and fertilizer responses. Floral measurements identify those species able to maintain aesthetic appeal and reproduce in low input environments. The number of flower stalks produced by a plant while exposed to lower input conditions is an important factor when determining species’ potential as an ornamental. Floral measurements collected include number of flower stalks, number of flowers (A. tabernaemontana), length of stalk flowering area, flowering period length, and percent flowering.

GTI trial. At the end of the trial, the number of flower stalks (panicles) was collected for all Liatris species. In the case of A. tabernaemontana flower numbers were collected on the basis of number of seedpods produced by the end of the trial period. In 2011, flower stalk number was not significantly affected by SW (Table 3.10). As well, L. cylindracea decreased its flowering from 0.25/plant to 0 stalks/plant, while under the SW treatment. However, this follows the common trend of L. cylindracea performing better under NW. During the reproductive growth

season a 135% increase on L. pycnostachya and a 26% decrease on L. cylindracea under SW were observed (Table 3.2). Notably, L. aspera and L. spicata increased their number of flower stalks by 31% and 28%, respectively.

SF had no significant effect on flower stalks in 2011 or 2012 (Table 3.5 & 3.7).

Elora trial. At Elora the response of flower stalks was mixed and did not increase with increasing levels of fertilizer. Overall, the highest flower stalk numbers across the species were produced in the LF treatment. L. scariosa (2.6 stalks), L. pycnostachya (15.2 stalks), and L. cylindracea (3.1 stalks) all produced the greatest number of stalks under NF (Table 3.9).

Flower Stalk Lengths

GTI trial. Within the SW treatment, L. aspera, L, pycnostachya, L scariosa, and L. spicata (all in the high to medium-high response groups) displayed significant increases in flower stalk length while L. cylindracea and T. caroliniana exhibited comparatively minor changes. Similar to plant height, L. pycnostachya and L. spicata displayed the greatest increase in flower length with a fivefold and threefold increase, respectively, under SW. L. aspera and L. scariosa displayed similar responses to SW with 116% and 101% increases, respectively (Table

3.2).

Interestingly, although they exhibited minimal response to SW, T. caroliniana with 33% and L. cylindracea with 41%, displayed the only increases in flower length within the SF treatment (Table 3.6). All other species displayed little to no change in flower length in the SF treatment.

Elora trial. Fertilizer treatment produced minimal changes to flower stalk lengths. For three of the five species measured, L. aspera, L. spicata, and T. caroliniana, variability between

treatments was negligible. However, for L. pycnostachya and L. scariosa MLF displayed the greatest height while LF exhibited the lowest (Table 3.9).

Percent Flowering

GTI trial. In 2011 at the GTI trial, flowering percentage was not affected by SW except for L. aspera. Flowering percentage decreased 13.5% for L. aspera in the NW as compared to

SW (Table 3.10). In contrast, other Liatris species such as L. cylindracea, L. scariosa and L. aspera displayed no change in flowering percentage under SW treatment in 2012. However, L. pycnostachya, L. spicata, and T. caroliniana decreased flowering percentage by 38.9%, 9.2% and 4.6%, respectively, under only the rain fed control (Table 3.2). Percent flowering was not significantly affected by SF treatment in either 2011 or 2012.

Elora trial. Overall, minimal response in flowering percentage was seen across fertilizer treatments for all species. The greatest decrease, although non-significant, was seen in T. caroliniana (81.3%) (Table 3.9).

Bloom Dates

GTI trial. SW had more impact on flowering time than SF and in general caused earlier flowering. This was most apparent for L. aspera, L. scariosa, and L. spicata where first bloom was 6, 7, and 11 days earlier, respectively (Table 3.9). For full bloom, L. spicata displayed the greatest change by reaching full bloom 17 days earlier while the remaining species reached full bloom between 0 and 7 days earlier.

In general, SF caused little to no effect on bloom dates and timing, with the species measured seeing a shift of ±3 days (Table 3.10).

Elora trial. As with SF at the GTI trial, fertilizer treatments at the Elora trial exhibited minimal effect on in bloom dates and total time in bloom. For first bloom, L. scariosa was five

days later under MLF and four days earlier under the MF treatment (Table 3.13). Fertilizer played a slightly stronger role in full bloom; however, no strong trends emerged. The only species to display a trend in relation to increased fertilizer was L. cylindracea, which reached full bloom five days earlier with increased fertilizer. No significant trends were exhibited in last bloom and bloom time across all other species. Only T. caroliniana demonstrated minor changes under HF, displaying a delay of six days.

Water by Fertilizer interaction

Within the GTI trial, the interaction between water and fertilizer was investigated, resulting in few significant differences. However, some trends were seen. Interaction between

SW and SF provoked minor trends in dry weight (Table 3.14 & 3.15). For example, for five of the eight species plants exhibited a greater increase in total dry weight from the SF and SW combination. These trends stayed relatively consistent for foliage dry weight and flower dry weight. However, plant height, flower length, and number of flower stalks did not follow this trend.

Discussion

The purpose of the Elora and GTI field trials conducted over 2011 and 2012 were to characterize traits of vegetative growth of eight native ornamental perennial species from different native habitats to identify their adaptations to low water and fertility environments. The results of these trials demonstrated differences between species’ responses to high and low water and fertilizer treatments in order to mimic high and low input environments. Species’ responses to SW were greater than their responses to the SF treatments.

Until recently, research investigating the effects of low input environments on native ornamental perennials was sparse. However, with growing interest in resource management

around urban landscapes (Erickson et al., 1999; Hilaire et al., 2008; Shober et al., 2010), the potential to utilize native ornamentals to help reduce the need for urban landscape inputs has been investigated (Younis et al., 2009). The research conducted in the current trials supplements this research to gain further understanding of proper utilization of native ornamentals in landscapes. Recent studies have utilized a variety of methods to impose low input conditions on ornamental species: using different types of fertilizer (Thetford et al., 2011); applying low fertilizer input over multiple years (Thetford et al., 2009); using deficit irrigation in containers

(Álvarez et al., 2009); instituting interval irrigation (Zhang et al., 2011; Zollinger et al., 2006); supplying a specific percentage of available water to the plant (Hassen et al., 2007); and employing complete irrigation cessation until plant wilt (Kjelgren et al., 2009). The current study looked to incorporate long term growth (2 years) with interval irrigation and long term irrigation cessation as well as minimal and no supplemental fertilizer treatments. These treatments were selected, as they would likely be two methods used within urban landscapes. Thomas and

Schrock (2004) investigated the effects of long-term low input environments on 67 native species. The species were planted in a drought prone field site in Missouri and observed annually for six years. Measurements included plant height and width, flower size and quality as well as other parameters. Interestingly, L. aspera, L. pycnostachya, and B. australis were also involved in this trial. The trial concluded that B. australis was a suitable candidate for low input landscapes due to its floral quality and ability to survive. As well, the Liatris spp. had notable performance even though L. aspera did not survive past the establishment year. No detailed results of L. pycnostachya response were outlined.

The selection of species for the current research was based on their distinctive North

American habitat and ornamental potential (aesthetics). The ornamental potential of a species

can be based on many factors (Younis et al., 2009), and within this study, emphasis was placed on floral characteristics. Additionally, the species selected originate from a variety of native habitats ranging from prairie to woodlands and stream banks. With such variability in natural habitat, it is possible that certain species have developed specialized characteristics that allow them to flourish under varying low input conditions that may occur within these habitats. For this reason, species’ response to the imposed water and fertilizer treatments may vary greatly.

Overall, SW at the GTI trial produced a general increase in growth characteristics for most species. In 2011, seven out of eight species saw an increase in total dry weight of at least

36% up to an increase of 94%. Increases under the water regime were larger in 2012 with five of the eight species displaying total dry weight increases over 63%. The remaining species, A. tabernaemontana, L. cylindracea, and T. caroliniana, exhibited changes of 39%, -6%, and 22%, respectively.

A plant’s ability to maintain high internal water potential is related to its potential drought tolerance (Chapman and Augé, 1994). This high water potential is maintained using a variety of internal plant functions as well as morphological growth characteristics (Taiz and Zeiger, 2006).

Stomatal function and soil water deficit are often related (Davies and Zhang, 1991; Gowing et al., 1990). As plants’ roots experience dehydration, an increase in ABA synthesis occurs that triggers long distance signaling to the leaves, leading to stomatal closure (Chaves, 2002). This leads to an eventual reduction of internal CO2 and a decrease in carbon assimilation. Therefore, it can be concluded that the species which displays larger total dry weight differences between no supplemental and supplemental water treatments, possesses a more rapid stomatal closure response to soil with high water potential and increased effectiveness of ABA signaling. Group 1 species, B. australis, L. scariosa, and L. spicata, exhibited the greatest change when subjected to

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supplemental water, with greater total dry weight compared to no supplemental water. Even though B. australis and L. spicata grow naturally in high moisture habitats, they may possess physiological characteristics allowing them to thrive within low input environments. For L. scariosa, a drier adapted species, these results may have been expected, as a physiological adaptation (i.e. increased stomatal response and possible increased root:shoot ratio) for low water environments would likely be present in this species (Chaves, 2002). Another plausible theory could be that these species may also be broadly adapted for varying water conditions. This increased potential breadth of adaptation might allow the species to flourish under supplemental water and to appropriately manage internal water potential. Group 3 species, A. tabernaemontana and T. caroliniana, displayed the smallest change in dry weight when subjected to NW treatment. It is likely that these species are less physiologically responsive to decreased water potentials, causing a lack of stomatal closure (Taiz and Zeiger, 2006). However, it is also possible that the length of drought period and the variability between plant species could create compounding effects of the low water and the species’ capability to withstand the conditions. For example, a drought-tolerant/avoiding species may be able to postpone physiological and morphological damage for longer periods than a drought-susceptible species.

However, after a sustained period of drought, both types of species would be expected to display damage and reduction of growth.

L. cylindracea (group 4), which is adapted to prairie environments, displayed (non- significant) minor negative changes in response to SW. These results may relate to the species’ inability to thrive in ample moisture conditions. A study conducted by Houle and Belleau (2000) demonstrated that certain species of Aster can maintain proper photosynthetic function under waterlogged conditions, while species such as maize (Yordanova and Popova, 2007) are more

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sensitive to flooding. Therefore, it could be that SW led to restricted photosynthetic capabilities in L. cylindracea, resulting in a decrease in total dry weight under SW versus NW.

Overall, it can be concluded that all of these species hold some level of adaptability to both supplemental water and low water conditions. It is very possible that some of these species are opportunistic low input species. In other words, these species may possess the necessary physiological adaptations to thrive in low input environments and be able to respond to water with substantially increased plant growth and flowering characteristics.

SW generated substantial increases in flowering characteristics in both 2011 and 2012. Three

(L. scariosa, L pycnostachya, and L. spicata) of the species increased flower dry weight by at least 160% in both 2011 and 2012. The species L. pycnostachya and L. spicata originate from more moist habitats while L. scariosa is native to drier prairie lands. Therefore, it is likely that L. scariosa is a more opportunistic species, increasing its reproductive organs substantially under

SW treatment. In contrast, L. spicata and L. pycnostachya are accustomed to higher input conditions and will flourish under the SW treatment. It should be noted that based on the increases in floral stalk length, the increase in flower dry weight can be linked to a much larger flowering area for L. scariosa and L. spicata, as their stalk number did not change as much as L. pycnostachya. They exhibited a substantial increase in both floral length as well as number of flower stalks in the SW treatment.

In general, the large majority of species displayed a substantial decrease in flowering characteristics under the NW treatment. Therefore, it could be concluded that aesthetic quality would be reduced under low input conditions. This aligns with research conducted by Zhang

(2011), who determined that water stress reduced the floral quality of Oriental Lily through decreased flower length and flower diameter. This is also supported by other recent research

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investigating the effects of water stress on ornamental species (Álvarez et al., 2009; Kjelgren et al., 2009). However, some species can maintain floral growth under drought conditions. In a study conducted by Starman and Lombardini (2006), deficit irrigation consisting of two 10-day drought cycles, similar to the drought cycle in the current study, caused no change in floral characteristics of Lantana camara, Lobelia cardinalis, Salvia farinacea, and Scaevola aemula.

The study measured both inflorescence number and flower number. These studies demonstrate that there is great variation in the response of perennial ornamentals to water stress. Interestingly, research done by Zollinger (2006), utilized a different method of visual rating of ornamental species subjected to water stress. By visually rating the ornamental quality on a scale of 1-5,

Zollinger (2006) determined that some species will display reduced visual quality while others will maintain visual quality. This subjective method of visual rating is well suited for ornamental species in future trials as ultimately, it is the consumer who will determine the aesthetic quality of the plant. A. tabernaemontana, L. aspera, L. cylindracea, L. scariosa, L. spicata, and T. caroliniana all maintained acceptable numbers of flower stalks under low water treatment at the

GTI in 2012. For example, the number of flower stalks of A. tabernaemontana and L spicata changed from 26.7 to 22.5 and 8.2 to 10.5 flower stalks, respectively, which would be considered as maintenance of aesthetic quality. The majority of the species (with the exception of L. cylindracea) also displayed fluctuations in number of flower stalks and would be considered aesthetically acceptable at first glance. This trend could also be seen in the length of flowering area for both water and fertilizer treatments at the GTI in 2012.

Current research investigating the effects of fertility on native perennial ornamental species is also limited. Some studies have demonstrated a wide range of plant responses when implementing different fertilizer types, application methods, and timing regimes (Chen et al.,

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2011; Iapichino and Camerata Scovazzo, 2012; Moore et al., 2014; Palmer et al., 2014;

Contreras et al., 2009). In a recent study, Thetford (2011) demonstrated that the addition of supplemental fertilizer provided no competitive or growth advantage on native ornamental species. Another study on four native herbaceous perennials (Giallardia pulchella, Solidago chapmanii, Ophiopogon japonicas, and Salvia longspicata x farinacea) determined that certain species of herbaceous perennials had a greater response to increased nitrogen than others (Moore et al., 2014). For example, Gaillardia pulchella displayed no increase in aesthetic quality with increased nitrogen while Salvia longspicata x farinacea exhibited both increased shoot dry weight (36.2 g to 67.6 g from 0.45 kg to 2.27 kg of N/93 m2) and aesthetic quality (3.3 to 4.2 increase from 0.45 kg to 2.27 kg of N/93 m2 observed 18 weeks after planting). Aesthetic quality was a visual rating based on canopy density, flower quality, and nutrient deficiency symptoms

(Moore et al., 2014). With such documented variability in response to additional fertilizer by native perennials, it comes as no surprise that the species in the current study also displayed different responses.

In 2011, only L. cylindracea and L. spicata displayed a substantial increase in dry weight under SF at the GTI. This result was associated with an increase in flower dry weight. Fertilizer exhibited a similar influence in both 2012 and 2011 with some of the species displaying changes greater than ±20% total dry weight. Species’ flowering characteristics (flowing stalk length, stalk number, percent flowering, and plant: flower ratio) exhibited varying responses to the supplemental fertilizer treatment. When investigating visual quality, flowering length and number of flower stalks could be utilized as characteristics to rank the species. Both of these characteristics displayed a wide range of responses across species with L. cylindracea generally

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displaying a larger increase. Chen (2011) also demonstrated that supplemental fertilizer could lead to short term increases in aesthetic appeal with some species, and no change with others.

At Elora with multiple fertilizer levels, there was no general positive response to fertilizer among these species. Any changes that were observed were species and trait- specific and not considered to have significant value. One of the reasons for the variability in response may be the genetic variability amoung the plants of each species. For instance, the Liatris spp. seeds were collected from wild populations and were likely highly heterogeneous. The response to supplemental fertilizer might be variable because of this and even within a plot this could explain some of the variability observed. This has been noted as a potential source of variability that would affect certain growth characteristics of plant species within research trials (Long and

Jones, 1996; Reich et al., 1994). This variability was seen in both the first and second growing season. Species in this trial were not selected based on genetics or populations. As well, soil samples taken prior to initiation of the trial displayed higher levels of phosphorus and potassium at the GTI as compared to Elora. Therefore, it would be expected that supplemental fertilizer in the Elora trial would have had a greater opportunity to generate a species response but it did not have a big effect. It could be concluded that these species are generally non-responsive to supplemental fertilizer.

As with growth characteristics, fertilizer caused minimal change in the flowering characteristics of most species. The only species that displayed an increase in flower dry weight under SF was T. caroliniana. Interestingly, as a legume, this species was the only species treated with rhizobia, which should help to supply atmospheric nitrogen to the plant. It would be expected that this species would be the least responsive to SF, assuming the rhizobia survived and colonized the roots. The lack of response of floral characteristics to SF from the majority of

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species parallels recent research by Moore (2014). One (Gaillardia pulchella) of the two perennial species subjected to supplemental fertilizer displayed no change in aesthetic floral characteristics including dense leaf canopy, high quality flowers, and no nutrient deficiencies when treated with 0.45, 1.36, 2.27 and 3.18 kg N/93 m2. A contrasting study conducted by

Iapichino and Camerata Scovazzo (2012) measured the floral and growth changes of Iberis semperflorens, a woody ornamental perennial, in pots fertilized with 16N-8P-10K at 0, 0.75, 1.5, and 3.5 g N l-1. When treated with 3.5 N g l-1, inflorescence number increased substantially.

Therefore, this and previous studies (Iapichino and Camerata Scovazzo, 2012; Scoggins, 2005;

Contreras et al., 2009; Shurberg et al., 2012; Thetford et al., 2011), demonstrated that the response of ornamental perennials to fertilizer is minimal and depends on the species. For the species in this study, under field conditions, all species displayed adequate productivity in low input environments where fertility levels were low.

More research is necessary on these plants in field conditions to further understand their adaptability to low input landscapes. Measurement of soil water potential in the field in conjunction with photosynthetic measurements would give a greater understanding of the physiological response to high and low input conditions. As well, tracking plant nutrient levels throughout the season would help to contribute to our understanding of nutrient utilization by native species. In terms of aesthetic appeal and functionality in a low input urban landscape, a more visual or quantitative rating system would be beneficial. If outside parties were asked to rate the aesthetic quality of plant species, a stronger understanding of acceptable floral quality would be expected.

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Conclusion

In conclusion, all species displayed a general tolerance to low input conditions, displaying growth and floral display under NF and NW treatments. In the field, A. tabernaemontana, L. cylindracea, and T. caroliniana exhibited growth (total dry weight) under

NW similar to that of growth seen in SW. These species also displayed the lowest decrease in number of flower stalks and flower height in response to NW. Therefore, these species could be considered the most adapted to field conditions within this trial. The Liatris spp. displayed the least change when subjected to NF within the GTI trial as well as the smallest change in flower dry weight. Therefore, these species would be considered as the most adapted to low fertility field conditions.

Nearly all species displayed increased growth when treated with supplemental water at the GTI trial. L. spicata, L. pycnostachya, and B. australis had the greatest increase in growth when treated with SW. In areas with excess water, these species would exhibit the greatest advantage. In contrast, L. cylindracea displayed only minor decreases when supplemental water was added and is not a candidate for environments with ample water or poorly drained soils.

In general, all species were able to maintain a reasonable floral display under low input conditions. Even though decreases were seen when subjected so reduced water, visual quality was still maintained for A. tabernaemontana, L. aspera, L. scariosa, and T. caroliniana under

NW. L. spicata and L. pycnostachya seemed to suffer the greatest decrease in aesthetic appeal, which can be related to their substantial decrease in length of flowering area. The NF treatment did not cause any substantial changes in floral quality for any species except L. cylindracea, which displayed a large reduction in flowering length at the GTI.

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For the majority of the species, natural habitat seems related to the plants’ characteristics with regard to coping with different input treatments. Wet adapted species, L. spicata and L. pycnostachya, exhibited the greatest decreases in total dry weight and floral characteristics while species such as A. tabernaemontana, L. aspera, L. cylindracea, and L. scariosa, adapted to drier or well drained habitats, exhibited smaller decreases in overall growth and floral quality.

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Tables and Figures

Figure 3.1 Cumulative rainfall, irrigation, and rainfall plus irrigation received (mm) at the GTI trial during the 2011 growing season.

500.

400.

Rainwater 300. Irrigation Water 200. Irrigation + Rainfall

100. Water Water Recieved (mm)

0. 19-Jul-15 6-Aug-15 24-Aug-15 11-Sept-15 29-Sept-15 17-Oct-15 Date

Figure 3.2 Cumulative rainfall, irrigation, and rainfall plus irrigation received (mm) at the GTI trial during the 2012 growing season.

700.

525. Rainwater

Irrigation Water

350. Irrigation + Rainfall

175. Water Water Recieved (mm)

0. 6-Jun 20-Jun 4-Jul 18-Jul 1-Aug 15-Aug 29-Aug 12-Sept Date

113

Figure 3.3 Cumulative rainfall (mm) received at the Elora trail site during the 2011 growing season.

250

200

150

100

Water Water Recieved (mm) 50

0 19-Jul-15 6-Aug-15 24-Aug-15 11-Sept-15 29-Sept-15 17-Oct-15 Date

Figure 3.4 Cumulative rainfall (mm) received at the Elora trail site during the 2012 growing season.

375.

300.

225. Rainfall

150.

Water Recieved (mm) 75.

0. 2-May 19-May 5-Jun 22-Jun 9-Jul 26-Jul 12-Aug 29-Aug 15-Sept Date

114

Table 3.1 Seed sources for species used in GTI & Elora trials in 2011 and 2012. Species Source Location Prairie Moon Winona, Liatris spicata Nursery MN

Prairie Moon Winona, Liatris cylindracea Nursery MN

Prairie Moon Winona, Liatris aspera Nursery MN

Prairie Moon Winona, Liatris pycnostachya Nursery MN

Prairie Moon Winona, Liatris scariosa Nursery MN

Thompson & Ipswich, Amsonia tabernaemontana Morgan Suffolk

Prairie Moon Winona, Baptisia australis Nursery MN

Prairie Moon Winona, Thermopsis caroliniana Nursery MN

115

Table 3.2 Effects of supplemental water (SW) (rainfall plus irrigation up to 25 mm/week) on growth characteristics of eight native perennial ornamental species in 2012 in reproductive growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario, represented as percent change. Values indicate percent change from the rainfall control.

Total Foliage Flower Plant to Number of Water Plant Flower Percent Percent Species Dry Dry Dry Flower Flower Treatment Height Height Flowering Survival Weight Weight Weight Ratio stalks Amsonia tabernaemontana SW 39% 39% N/A N/A 26% 19% N/A N/A 1%

Liatris aspera SW 65% 30% 100% 59% 39% 31% 116% 1% -1%

Baptisia australis SW 74% 74% N/A N/A 26% N/A N/A N/A 8%

Liatris cylindracea SW -6% -2% -4% 10% -6% -26% -1% -11% 4%

Liatris pycnostachya SW 63% 20% 316% 249% 65% 135% 504% 64% 2%

Liatris scariosa SW 71% 37% 160% 83% 37% -13% 101% -2% -10%

Liatris spicata SW 94% 48% 270% 150% 74% 28% 306% 10% 1%

Thermopsis caroliniana SW 22% 16% 89% 960% 11% 8% 24% 3% 4%

116

Table 3.3a Effects of supplemental water (SW) (rainfall plus irrigation up to 25 mm/week) and no supplemental water (NW) on growth characteristics of eight native perennial ornamental species in 2012 in reproductive growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario. Statistical analysis appended in Tables A.33, A.34, A.35, A.39, and A.40.

Total Dry Foliage Dry Flower Dry Plant to Plant Species Treatment Weight (g) Weight (g) Weight (g) Flower Ratio Height (cm) Amsonia NW 26.5 bc 26.5 ab n/a n/a 43.9 de tabernaemontana SW 36.9 bd 36.9 abc n/a n/a 55.3 df

Liatris aspera NW 44 bd 21.7 ad 22.3 ad 1 de 50.1 dg SW 72.8 af 28.2 ab 44.6 ce 1.6 f 69.6 af

Baptisia australis NW 23.3 bc 23.3 ab n/a n/a 49.4 dg SW 40.5 bd 40.5 bci n/a n/a 62.1 fgh

Liatris cylindracea NW 8.1 c 4.5 d 3.6 b 0.8 abe 34.4 e SW 7.6 c 4.4 d 3.5 b 0.9 be 32.3 e

Liatris pycnostachya NW 56.1 df 47.9 ch 8.3 b 0.2 c 58.8 dfj

SW 91.6 a 57.3 ghi 34.3 cd 0.6 ab 96.7 bi

Liatris scariosa NW 80.4 af 47.6 ch 32.8 cd 0.7 ab 73.1 ahj SW 137.7 e 65.4 egh 85.4 f 1.3 d 100.4 i

Liatris spicata NW 82.4 a 67.7 eg 14.7 ab 0.2 c 66.4 fh SW 160 e 100.3 f 54.3 e 0.5 a 115.5 c

Thermopsis caroliniana NW 71.2 af 66.4 egh 5.2 b 0 c 74.9 ah SW 86.8 a 77.1 e 9.7 ab 0.1 c 83.5 ab Identical letters within a measured characteristics indicate that results are not significantly different at p=0.05.

117

Table 3.3b Effects of supplemental water (SW) (rainfall plus irrigation up to 25 mm/week) and no supplemental water (NW) on growth characteristics of eight native perennial ornamental species in 2012 in reproductive growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario. Statistical analysis appended in Tables A.36, A.37, A.38, and A.41.

Length of Number of Flower Flowering Survival Species Treatment Flowering Area stalks (%) (%) (cm)

Amsonia 22.5 abce n/a n/a 93.1 ab tabernaemontana NW

SW 26.7 a n/a n/a 93.8 a

Liatris aspera NW 5.1 cd 16.8 a 98.3 a 77.5 bcd

SW 6.6 bcd 36.2 c 99.3 a 76.9 cd

Baptisia australis NW n/a n/a n/a 91.3 abc

SW n/a n/a n/a 98.8 a

Liatris cylindracea NW 20.1 ab 2.3 d 92.8 a 70.6 d

SW 14.9 abc 2.3 d 82.8 ab 73.8 de

Liatris pycnostachya NW 5 de 5.1 bd 60.7 b 96.9 a

SW 11.7 abc 30.5 c 99.4 a 98.8 a

Liatris scariosa NW 3.2 d 27.5 c 99.3 a 83.8 abcd

SW 2.8 d 55.3 e 97.6 a 75 de

Liatris spicata NW 8.2 abcd 8.9 abd 89 a 95.6 a SW 10.5 abce 36.3 c 98 a 96.9 a

Thermopsis 6 cd 10 abd 96.3 a 83.8 abcd caroliniana NW SW 6.5 bcd 12.4 ab 99.3 a 86.9 abce Identical letters within a measured characteristics indicate that results are not significantly different at p=0.05.

118

Table 3.4 Effects of supplemental fertilizer (SF) (20-10-10 at 135g N/6 m row) and no supplemental fertilizer (NF) on growth characteristics of eight native perennial ornamental species in 2011 in vegetative growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario, represented as percent change. Values indicate percent change relative to the unfertilized control.

Total Foliage Flower Plant Number Dry Dry Dry Flowering Survival Species Treatment Height of Weight Weight Weight (%) (%) (cm) Stalks (g) (g) (g) Amsonia tabernaemontana SF 16% 16% N/A -3% N/A N/A 3%

Liatris aspera SF 11% -4% 25% -31% -6% 5% -7%

Baptisia australis SF 9% 9% N/A -2% N/A N/A 3%

Liatris cylindracea SF 24% -7% N/A -13% 0% -41% -12%

Liatris pycnostachya SF 5% -5% 37% -8% 4% -3% 1%

Liatris scariosa SF -4% -1% -7% 14% -7% -7% -2%

Liatris spicata SF 27% 14% 64% -3% 11% 4% 0%

Thermopsis caroliniana SF 15% 15% N/A -1% N/A N/A 3%

119

Table 3.5 Effects of supplemental fertilizer (SF) (20-10-10 at 135g N/6 m row) and no supplemental fertilizer (NF) on growth characteristics of eight native perennial ornamental species in 2011 in vegetative growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario. Statistical analysis appended in Tables A.26 to A.32.

Foliage Flower Plant Total Dry Number Flowering Survival Species Treatment Dry Dry Height Weight (g) of Stalks (%) (%) Weight (g) Weight (g) (cm) Amsonia tabernaemontana NF 7.3 fg 7.3 e n/a 21.2 c 0.0 c 0.0 c 95.0 a SF 8.4 fg 8.4 e n/a 20.5 c 0.0 c 0.0 c 97.5 a

Liatris aspera NF 17.9 de 8.8 e 9.1 b 11.2 d 2.6 a 66.9 a 92.5 a SF 19.8 d 8.4 e 11.4 b 7.7 d 2.5 a 70.0 a 85.6 ab

Baptisia australis NF 10.3 ef 10.3 e n/a 21.9 c 0.0 c 0.0 c 94.4 a SF 11.1 ef 11.1 de n/a 21.4 c 0.0 c 0.0 c 97.5 a

Liatris cylindracea NF 1.1 g 0.9 f n/a 9.1 d 0.1 c 1.3 c 70.6 bc SF 1.4 g 0.9 f n/a 8.0 d 0.1 c 0.8 c 61.9 c

Liatris pycnostachya NF 24.0 cd 18.5 bc 5.5 b 24.4 bc 1.6 b 28.9 b 99.4 a SF 25.2 cd 17.6 bc 7.5 b 22.3 c 1.7 b 28.1 b 100.0 a

Liatris scariosa NF 40.0 a 16.5 c 23.6 a 9.7 d 1.7 b 73.8 a 92.5 a SF 38.4 a 16.4 cd 22.0 a 11.1 d 1.6 b 68.4 a 90.6 a

Liatris spicata NF 28.7 bc 21.3 abc 7.5 b 24.9 abc 1.3 b 13.9 bc 99.4 a SF 36.4 ab 24.2 a 12.2 b 24.2 c 1.5 b 14.5 bc 99.4 a

Thermopsis caroliniana NF 19.1 d 19.1 abc n/a 30.6 a 0.0 c 0.0 c 95.6 a SF 22.1 cd 22.1 ab n/a 30.2 ab 0.0 c 0.0 c 98.8 a Identical letters within a measured characteristics indicate that results are not significantly different at p=0.05.

120

Table 3.6 Effects of supplemental fertilizer (SF) (20-10-10 at 135g/row) on growth characteristics of a eight native perennial ornamental species in 2012 in reproductive growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario, represented as percent change. Values indicate percent change from the unfertilized control.

Foliage Flower Plant Fert Total Dry Flower Flower Percent Percent Species Dry Dry Flower Height Treatment Weight stalks Height Flowering Survival Weight Weight Ratio Amsonia tabernaemontana SF 23% 23% N/A N/A -4% 23% N/A N/A 6%

Liatris aspera SF 11% 12% 10% 2% -10% 26% -12% 1% -10%

Baptisia australis SF 24% 24% N/A N/A -7% N/A N/A N/A 7%

Liatris cylindracea SF 7% 9% -3% -23% -9% 70% 41% 10% -4%

Liatris pycnostachya SF 0% 0% 3% 4% -7% -4% -11% -2% -2%

Liatris scariosa SF -4% 5% 11% -2% -15% -6% -7% 3% -8%

Liatris spicata SF -1% 5% 1% -11% -11% 12% -7% -5% 3%

Thermopsis caroliniana SF 21% 18% 49% 264% 8% 18% 33% 0% 8%

121

Table 3.7 Effects of supplemental fertilizer (SF) (20-10-10 at 135g N/6 m row) and no supplemental fertilizer (NF) on growth characteristics of a eight native perennial ornamental species in 2012 in reproductive growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario. Statistical analysis appended in Tables A.33 to A.41.

Total Foliage Flower Number Plant to Plant Length of Dry Dry Dry of Flowering Survival Species Treatment Flower Height Flowering Weight Weight Weight Flower (%) (%) Ratio (cm) Area (cm) (g) (g) (g) stalks Amsonia NF 28.4 dg 28.4 a 50.5 cd 22.0 bc 90.6 abc tabernaemontana n/a n/a n/a n/a SF 35.0 bd 35.0 ad n/a n/a 48.7 cd 27.2 bc n/a n/a 96.3 ab

Liatris aspera NF 55.3 ab 23.5 a 31.8 cde 1.3 ce 63.0 ac 5.2 ac 28.2 d 98.5 a 81.3 bcef SF 61.4 ac 26.4 a 35.0 c 1.3 c 56.8 c 6.5 ac 24.8 cd 99.1 a 73.1 ef

Baptisia australis NF 28.5 dg 28.5 a n/a n/a 57.9 c n/a n/a n/a 91.9 abc SF 35.2 bd 35.2 ad n/a n/a 53.6 c n/a n/a n/a 98.1 ad

Liatris cylindracea NF 7.6 g 4.3 f 3.6 a 1.0 d 34.9 df 13.0 bc 1.9 b 83.8 a 73.8 ef SF 8.1 g 4.7 f 3.5 a 0.7 d 31.8 f 22.1 b 2.7 b 91.9 a 70.6 f

Liatris pycnostachya NF 73.7 ac 52.7 de 21.0 be 0.4 ab 80.4 bg 8.5 ac 18.9 acd 80.8 a 98.8 a SF 74.0 ac 52.5 de 21.6 bd 0.4 a 75.0 ab 8.2 ac 16.7 ac 79.2 a 96.9 ab

Liatris scariosa NF 111.1 ef 55.1 e 56.1 f 1.0 de 93.6 eg 3.1 a 42.9 f 97.0 a 82.5 bcdef SF 106.9 ef 57.9 e 62.1 f 1.0 d 79.9 bg 2.9 a 39.9 f 100.0 a 76.3 cef

Liatris spicata NF 121.8 f 81.9 bc 34.4 cd 0.4 a 96.0 e 8.8 ab 23.5 cd 95.9 a 95.0 ab SF 120.6 f 86.0 c 34.6 cd 0.4 ab 85.9 be 9.9 bc 21.7 cde 91.1 a 97.5 ad

Thermopsis NF 71.4 ac 65.8 be 6.0 a 0.0 b 76.3 ab 5.7 ac 9.6 ab 97.9 a 81.9 bcdef caroliniana SF 86.7 ce 77.8 bc 8.9 ab 0.1 ab 82.1 be 6.8 ac 12.8 ae 97.7 a 88.8 abce Identical letters within a measured characteristics indicate that results are not significantly different at p=0.05.

122

Table 3.8 Effects of three separate fertilizer treatments (0 (NF), 81(LF), 122.4 (MLF), and 163.2 (MF) g N/ 3.5 m row) on growth characteristics of eight native perennial ornamentals located in a field trial at the Elora Research Station in Elora, Ontario in 2011 in vegetative growth year. Statistical analysis appended in Tables A.46 & A.47. Treatment (g Dry Survival Species N/12 plants) Weight(g) (%) Amsonia tabernaemontana NF 9.4 cd 100 a LF 8.1 cd 100 a MLF 8.2 cd 100 a MF 7.4 cd 95.8 a

Liatris aspera NF 13.7 abcd 75 abc LF 12.3 bcd 50 abc MLF 9.9 cd 58.3 abc MF 6.9 cd 54.2 abc

Baptisia australis NF 16.1 abcd 100 a LF 15.8 abcd 100 a MLF 15.1 abcd 100 a MF 9.9 cd 95.8 a

Liatris cylindracea NF 0.9 d 58.3 abc LF 0.7 d 20.8 c MLF 0.7 d 29.2 bc MF 0.7 d 25 c

Liatris pycnostachya NF 17.4 abcd 95.8 a LF 10.6 bcd 95.8 a MLF 18.2 abcd 100 a MF 10.4 bcd 95.8 a

Liatris scariosa NF 21.1 abc 45.8 abc LF 17.9 abcd 29.2 bc MLF 27.9 ab 62.5 abc MF 30.7 a 25 c

Liatris spicata NF 12.8 bcd 95.8 a LF 8 cd 100 a MLF 12.8 bcd 100 a MF 8.1 cd 87.5 ab

Thermopsis caroliniana NF 21.7 abc 100 a LF 17.5 abcd 100 a MLF 20.3 abc 100 a MF 16.3 abcd 91.7 a

Identical letters within a measured characteristics indicate that results are not significantly different at p=0.05.

123

Table 3.9a Effects of three separate fertilizer treatments (0 (NF), 81(LF), 122.4 (MLF), and 163.2 (MF) g N/ 3.5 m row) on growth and flowering characteristics of eight native perennial ornamentals located in a field trial at the Elora Research Station in Elora, Ontario in 2012 in reproductive growth year. Statistical analysis appended in Tables A.48 to A.50, A.53, and A.55.

Treatment (g N/12 Total Dry Foliage Dry Flower Dry Plant Flower Survival Species plants) Weight (g) Weight (g) Weight (g) Ratio (%) Amsonia NF 25.4 ghijk 25.4 defghijkl n/a n/a 91.7 a tabernaemontana LF 22.5 hijk 22.5 fghijkl n/a n/a 100 a MLF 23.9 hijk 23.9 defghijkl n/a n/a 100 a MF 21 hijk 21 hijkl n/a n/a 91.7 a

Liatris aspera NF 55 bcdefgh 26.8 defghijkl 28.2 abcdef 1 abcd 91.7 a LF 32.6 fghijk 14.5 kl 18.1 abcdefg 1.3 abcd 62.5 a MLF 48.3 defghijk 22.1 ghijkl 26.2 abcdefg 1.2 abcd 79.2 a MF 44.2 efghijk 18.4 ijkl 25.8 abcdefg 1.5 abcd 87.5 a

Baptisia australis NF 51.8 cdefghi 51.8 abcde n/a n/a 100 a LF 44.4 efghijk 44.4 bcdefghij n/a n/a 100 a MLF 43.9 efghijk 43.9 bcdefghij n/a n/a 100 a MF 39 efghijk 39 bcdefghijk n/a n/a 91.7 a

Liatris cylindracea NF 10.5 ijk 5.4 l 5.1 defg 0.9 abcd 54.2 a LF 6.7 k 3.3 l 3.4 fg 1.1 abcd 41.7 a MLF 6.8 k 3.8 l 3 g 0.8 abcd 50 a MF 8.9 jk 4.4 l 4.6 efg 1.1 abcd 58.4 a

Liatris pycnostachya NF 107.1 a 77.3 a 29.9 abcd 0.4 cd 95.9 a LF 67.7 abcdefg 52.7 abcd 15 abcdefg 0.3 cd 100 a MLF 90.6 abcd 61.7 abc 28.9 abcde 0.5 bcd 100 a MF 67 abcdefg 47.2 bcdefghi 19.9 abcdefg 0.4 bcd 100 a

Liatris scariosa NF 54.7 bcdefgh 17.5 jkl 37.2 a 2.1 a 87.5 a LF 35.1 efghijk 15.8 jkl 19.4 abcdefg 1.3 abcd 87.5 a MLF 51.5 cdefghij 19.7 hijkl 31.8 abc 1.8 ab 58.4 a MF 59.8 bcdefgh 23.2 efghijkl 36.6 a 1.6 abc 75 a

Liatris spicata NF 95 ab 67.9 ab 27.2 abcdefg 0.4 cd 100 a LF 77.7 abcde 50.5 abcdefg 27.2 abcdefg 0.5 bcd 95.9 a MLF 94 abc 58.9 abc 35.2 ab 0.6 bcd 95.9 a MF 72.3 abcdef 43.2 bcdefghijk 29.1 abcde 0.7 bcd 91.7 a

Thermopsis NF 58.5 bcdefgh 48.3 abcdefgh 10.3 bcdefg 0 .2 cd 95.9 a caroliniana LF 59.2 bcdefgh 51.4 abcdef 7.8 cdefg 0.2 d 100 a MLF 44.5 efghijk 37.5 cdefghijk 7 cdefg 0.2 d 100 a MF 53.6 bcdefgh 47.8 bcdefgh 5.7 defg 0.1 d 100 a Identical letters within a measured characteristics indicate that results are not significantly different at p=0.05.

124

Table 3.9b Effects of three separate fertilizer treatments (0 (NF), 81(LF), 122.4 (MLF), and 163.2 (MF) g N/ 3.5 m row) on growth and flowering characteristics of eight native perennial ornamentals located in a field trial at the Elora Research Station in Elora, Ontario in 2012 in reproductive growth year. Statistical analysis appended in Tables A.51, A.52, A.54, and A.56.

Treatment (g N/12 Plant Height Number of Flower Length of Flower stalk Flowering Species plants) (cm) stalks/Plant Area (%) Amsonia NF 38.5 defg n/a n/a n/a tabernaemontana LF 38.5 defg n/a n/a n/a MLF 40 defg n/a n/a n/a MF 40 defg n/a n/a n/a

Liatris aspera NF 69 abcd 5.9 efghi 33.5 abc 100 a LF 55.5 abcdef 4.3 fghijk 30.1 abc 100 a MLF 66.5 abcde 6.5 defg 28.7 abc 100 a MF 60 abcdef 4.3 fghijk 31.4 abc 100 a

Baptisia australis NF 50 bcdefg n/a n/a n/a LF 40 defg n/a n/a n/a MLF 42 defg n/a n/a n/a MF 42.5 cdefg n/a n/a n/a

Liatris cylindracea 0 32.7 efg 3.1 ghijk n/a 100 a 81 27 fg 1.6 k n/a 100 a 122.4 28.4 fg 1.3 k n/a 90 a 163.2 19 g 1.9 jk n/a 100 a

Liatris pycnostachya 0 87 a 15.2 a 19 c 95.9 a 81 72.5 abcd 10.3 bcd 13.6 c 100 a 122.4 87.5 a 11.6 abc 25.9 bc 100 a 163.2 73 abcd 14 ab 16.2 c 100 a

Liatris scariosa 0 81.5 ab 2.6 hijk 44.2 ab 100 a 81 66.5 abcde 1.6 k 32 abc 100 a 122.4 81 ab 2.1 ijk 52.2 a 100 a 163.2 78 abc 1.6 k 44.4 ab 100 a

Liatris spicata 0 90.5 a 7.2 def 25.9 bc 100 a 81 82.5 ab 6.6 defg 21.8 bc 95.9 a 122.4 91 a 8.6 cde 26.6 bc 100 a 163.2 91 a 6 efgh 23.7 bc 100 a

Thermopsis caroliniana 0 86.5 a 5.1 efghijk 14.2 c 95.9 a 81 79 ab 7.8 cdef 11.2 c 100 a 122.4 81.5 ab 5.5 efghij 13 c 81.3 a 163.2 72 abcd 5.9 efghi 11.3 c 95.9 a Identical letters within a measured characteristics indicate that results are not significantly different at p=0.05.

125

Table 3.10 Effects of supplemental water (SW) (rainfall plus irrigation up to 25 mm/week) on growth characteristics of eight native perennial ornamental species in 2011 in vegetative growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario, represented as percent change. Values indicate percent change from the rainfall control.

Foliage Flower Total Dry Plant Dry Dry Number Flowering Survival Species Treatment Weight Height Weight Weight of Stalks (%) (%) (g) (cm) (g) (g) Amsonia tabernaemontana SW 44% 44% N/A 15% N/A N/A 3%

Liatris aspera SW 36% 16% 55% 8% 12% 18% 7%

Baptisia australis SW 59% 59% N/A 15% N/A N/A 6%

Liatris cylindracea SW 11% -20% N/A 28% -100% -41% 0%

Liatris pycnostachya SW 52% 20% 227% 20% -3% -3% 1%

Liatris scariosa SW 94% 9% 213% 20% 17% 1% 5%

Liatris spicata SW 50% 21% 164% 25% 6% -20% 0%

Thermopsis caroliniana SW 36 % 36% N/A 35% N/A N/A 5%

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Table 3.11 Effects of supplemental water (SW) (rainfall plus irrigation up to 25 mm/week) and no supplemental water (NW) on growth characteristics of eight native perennial ornamental species in 2011 in vegetative growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario. Statistical analysis appended in Tables A.26 to A.32.

Total Foliage Flower Plant Dry Dry Dry Number of Flowering Survival Species Treatment Height Weight Weight Weight Stalks (%) (%) (cm) (g) (g) (g) Amsonia tabernaemontana NW 6.5 hi 6.5 e n/a 19.5 d 0.0 d 0.0 c 95.0 a SW 9.3 gh 9.3 de n/a 22.3 bcd 0.0 d 0.0 c 97.5 a

Liatris aspera NW 16.0 efg 8.0 de 8.0 bcd 9.1 e 2.4 ab 62.7 a 86.3 a SW 21.7 de 9.3 de 12.4 bc 9.8 e 2.7 a 74.2 a 91.9 a

Baptisia australis NW 8.3 ghi 8.3 de n/a 20.1 cd 0.0 d 0.0 c 93.1 a SW 13.1 fgh 13.1 cd n/a 23.1 bcd 0.0 d 0.0 c 98.8 a

Liatris cylindracea NW 1.2 i 1.0 f n/a 7.5 e 0.3 d 1.3 c 66.3 b SW 1.3 i 0.8 f n/a 9.6 e 0.0 d 0.8 c 66.3 b

Liatris pycnostachya NW 19.5 def 16.4 bc 3.1 d 21.3 cd 1.6 bc 28.9 b 99.4 a SW 29.7 c 19.7 ab 10.0 bcd 25.4 bc 1.6 bc 28.1 b 100.0 a

Liatris scariosa NW 26.7 cd 15.7 bc 11.0 bc 9.4 e 1.6 bc 70.6 a 89.4 a SW 51.7 a 17.2 bc 34.6 a 11.3 e 1.8 bc 71.6 a 93.8 a

Liatris spicata NW 26.0 cd 20.6 ab 5.4 cd 21.8 bcd 1.4 c 15.8 bc 99.4 a SW 39.1 b 24.9 a 14.3 b 27.3 b 1.4 c 12.6 bc 99.4 a

Thermopsis caroliniana NW 17.5 ef 17.5 bc n/a 25.8 bc 0.0 d 0.0 c 95.0 a SW 23.7 cde 23.7 a n/a 35.0 a 0.0 d 0.0 c 99.4 a Identical letters within a measured characteristics indicate that results are not significantly different at p=0.05.

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Table 3.12 Effects of supplemental fertilizer (SF) (20-10-10 at 135g N/6 m row) and no supplemental fertilizer (NF)on growth characteristics of eight native perennial ornamental species in 2011 in vegetative growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario. Statistical analysis appended in Tables A.26 to A.27.

Liatris aspera NF 17.9 de 8.8 e 9.1 b 11.2 d 2.6 a 66.9 a 92.5 a SF 19.8 d 8.4 e 11.4 b 7.7 d 2.5 a 70.0 a 85.6 ab

Baptisia australis NF 10.3 ef 10.3 e n/a 21.9 c 0.0 c 0.0 c 94.4 a SF 11.1 ef 11.1 de n/a 21.4 c 0.0 c 0.0 c 97.5 a

Liatris cylindracea NF 1.1 g 0.9 f n/a 9.1 d 0.1 c 1.3 c 70.6 bc SF 1.4 g 0.9 f n/a 8.0 d 0.1 c 0.8 c 61.9 c

Liatris pycnostachya NF 24.0 cd 18.5 bc 5.5 b 24.4 bc 1.6 b 28.9 b 99.4 a SF 25.2 cd 17.6 bc 7.5 b 22.3 c 1.7 b 28.1 b 100.0 a

Liatris scariosa NF 40.0 a 16.5 c 23.6 a 9.7 d 1.7 b 73.8 a 92.5 a SF 38.4 a 16.4 cd 22.0 a 11.1 d 1.6 b 68.4 a 90.6 a

Liatris spicata NF 28.7 bc 21.3 abc 7.5 b 24.9 abc 1.3 b 13.9 bc 99.4 a SF 36.4 ab 24.2 a 12.2 b 24.2 c 1.5 b 14.5 bc 99.4 a

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Table 3.13 Effects of supplemental water (SW) (rainfall plus irrigation up to 25 mm/week) and no supplemental water (NW) on flowering time of eight native perennial ornamental species in 2012 in reproductive growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario. Statistical analysis appended in Tables A.42 to A.45.

First Full Last Bloom Dependent Treatment Bloom Bloom Bloom Time (DAT) (DAT) (DAT)

Amsonia tabernaemontana NW -4 2 d 14 a 19 a SW -3 2 d 14 a 18 a

Liatris aspera NW 92 e 100 e n/a n/a SW 86 eg 93 h n/a n/a

Baptisia australis NW n/a n/a n/a n/a SW n/a n/a n/a n/a

Liatris cylindracea NW 58 b 69 g n/a n/a SW 58 b 69 g n/a n/a

Liatris pycnostachya NW 51 b 57 bc 92 c 41 bc SW 50 b 53 b 84 e 34 b

Liatris scariosa NW 94 e 106 e n/a n/a SW 87 e 101 e n/a n/a

Liatris spicata NW 71 fg 83 f n/a n/a SW 60 bf 66 cg 101 g 41 c

Thermopsis caroliniana NW 12 a 19 a 34 b 22 a SW 11 a 18 a 34 b 22 a Identical letters within a measured characteristics indicate that results are not significantly different at p=0.05.

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Table 3.14 Effects of supplemental fertilizer (SF) (20-10-10 at 135g N/6 m row) and no supplemental fertilizer (NF) on flower timing of eight native perennial ornamental species in 2012 in reproductive growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario. Statistical analysis appended in Tables A.42 to A.45.

First Full Last Bloom Species Treatment Bloom Bloom Bloom Time (DAT) (DAT) (DAT)

Amsonia NF -4 2 b 13 b 18 a tabernaemontana

SF -3 2 b 15 b 19 a

Liatris aspera NF 89 d 95 d n/a n/a

SF 90 d 97 df n/a n/a

Baptisia australis NF n/a n/a n/a n/a

SF n/a n/a n/a n/a

Liatris cylindracea NF 57 ce 69 h n/a n/a

SF 59 ce 69 h n/a n/a

Liatris pycnostachya NF 51 c 55 c 85 c 35 b

SF 51 c 55 c 91 c 40 b

Liatris scariosa NF 89 d 104 e n/a n/a

SF 91 d 103 ef n/a n/a

Liatris spicata NF 65 e 71 gh 100 d 36 b

SF 66 e 78 g n/a n/a

Thermopsis NF 12 a 17 a 33 a 21 a caroliniana

SF 11 a 19 a 35 a 22 a

Identical letters within a measured characteristics indicate that results are not significantly different at p=0.05.

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Table 3.15 Effects of three separate fertilizer treatments (0(NF), 81(LF), 122.4(MLF), and 163.2(MF) g N/ 3.5 m row) on flowering time of eight native perennial ornamentals located in a field trial at the Elora Research Station in Elora, Ontario in 2012 in reproductive growth year. Statistical analysis appended in Tables A.57 to A.60.

First Full Last Species Treatment (g Bloom Bloom Bloom Time N/12 plants) (DAT) (DAT) (DAT) Amsonia tabernaemontana NF n/a n/a n/a n/a LF n/a n/a n/a n/a MLF n/a n/a n/a n/a MF n/a n/a n/a n/a

Liatris aspera NF 84 a 90 c 116 a 32 a LF 83 a 90 c 115 a 32 a MLF 84 a 94 bc 116 a 32 a MF 84 a 97 abc 113 ab 29 a

Baptisia australis NF n/a n/a n/a n/a LF n/a n/a n/a n/a MLF n/a n/a n/a n/a MF n/a n/a n/a n/a

Liatris cylindracea NF 61 b 69 d 97 bc 36 a LF 62 b 67 de 95 cd 33 a MLF 59 b 64 def 97 bc 38 a MF 63 b 64 def 95 cd 32 a

Liatris pycnostachya NF 50 b 55 ef 80 e 30 a LF 51 b 54 f 79 e 29 a MLF 52 b 55 ef 83 de 32 a MF 51 b 56 ef 80 e 29 a

Liatris scariosa NF 84 a 98 abc n/a n/a LF 88 a 106 a n/a n/a MLF 89 a 103 ab n/a n/a MF 81 a 96 abc n/a n/a

Liatris spicata NF 57 b 64 def 96 bcd 39 a LF 59 b 69 d 95 cd 36 a MLF 56 b 67 de 97 bc 41 a MF 58 b 64 def 97 bc 39 a

Thermopsis caroliniana NF 6 c 12 g 32 f 26 a LF 6 c 10 g 32 f 26 a MLF 10 c 13 g 33 f 23 a MF 6 c 10 g 37 f 31 a Identical letters within a measured characteristics indicate that results are not significantly different at p=0.05.

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Table 3.16a Effects of supplemental fertilizer (SF) (20-10-10 at 135g N/6 m row) with no supplemental water (NW), supplemental water (SW) (rainfall plus irrigation up to 25 mm/week) with no supplemental fertilizer (SF), and supplemental water with supplemental fertilizer on plant growth characteristics of eight native perennial ornamental species in 2011 in vegetative growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario. Statistical analysis appended in Tables A.27, and A.30 to A.32

Foliage Flower Plant Total Dry Species Water Fertilizer Dry Dry Height Weight (g) Weight (g) Weight (g) (cm) Amsonia NW NF 6.3 jklm 6.3 lm n/a 20.1 cdef tabernaemontana NW SF 6.6 jklm 6.6 lm n/a 18.8 cdefgh SW NF 8.3 ijklm 8.3 ijklm n/a 22.3 cd SW SF 10.2 ghijklm 10.2 fghijkl n/a 22.3 cd

Liatris aspera NW NF 13.9 fghijk 7.8 klm 6.1 bc 10.5 ghi NW SF 18.1 efghij 8.1 jklm 10 bc 7.6 i SW NF 21.9 defg 9.8 ghijkl 12.1 bc 11.8 efghi SW SF 21.5 defg 8.8 hijklm 12.7 bc 7.8 i

Baptisia NW NF 7.8 ijklm 7.8 klm n/a 19.7 cdefg australis NW SF 8.7 hijklm 8.7 hijklm n/a 20.6 cdef SW NF 12.7 ghijklm 12.7 efghijkl n/a 24.1 c SW SF 13.6 fghijkl 13.6 defghijkl n/a 22.2 cd

Liatris NW NF 1.4 lm 1 m n/a 8.2 i cylindracea NW SF 1 m 1 m n/a 6.8 i SW NF 0.8 m 0.8 m n/a 10.1 hi SW SF 1.8 klm 0.8 m n/a 9.1 i

Liatris NW NF 19.7 defghi 16.5 bcdefgh 3.1 c 21.8 cd pycnostachya NW SF 19.3 defghi 16.3 bcdefghij 3 c 20.7 cde SW NF 28.3 cde 20.5 abcde 7.8 bc 26.9 abc SW SF 31 bcd 18.9 abcde 12.1 bc 23.9 c

Liatris scariosa NW NF 27.6 cde 15.4 cdefghijk 12.2 bc 11.2 fghi NW SF 25.8 cdef 15.9 bcdefghijk 9.8 bc 7.7 i SW NF 52.4 a 17.5 abcdefg 34.9 a 8.2 i SW SF 51 a 16.8 bcdefgh 34.2 a 14.5 defghi

Liatris spicata NW NF 20.9 defgh 18.4 abcdef 2.5 c 22.6 cd NW SF 31.1 bcd 22.8 abc 8.3 bc 21 cde SW NF 36.5 bc 24.1 ab 12.4 bc 27.2 abc SW SF 41.7 ab 25.6 a 16.2 b 27.4 abc

Thermopsis NW NF 16.5 efghij 16.5 bcdefghi n/a 26.1 abc caroliniana NW SF 18.5 efghij 18.5 abcdef n/a 25.6 bc SW NF 21.8 defg 21.8 abcd n/a 35 a SW SF 25.7 cdef 25.7 a n/a 34.9 ab Identical letters within a measured characteristics indicate that results are not significantly different at p=0.05. -W indicates no supplemental water -F indicates no supplemental fertilizer +W indicates supplemental water +F indicates supplemental fertilizer

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Table 3.16b Effects of supplemental fertilizer (SF) (20-10-10 at 135g N/6 m row) with no supplemental water (NW), supplemental water (SW) (rainfall plus irrigation up to 25 mm/week) with no supplemental fertilizer (NF), and supplemental water with supplemental fertilizer on plant growth characteristics of eight native perennial ornamental species in 2011 in vegetative growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario. Statistical analysis appended in Tables A.26, A.28, and A.29.

Number of Survival Species Water Fertilizer Flowering (%) Stalks (%) Amsonia tabernaemontana NW NF 0 f 0 d 93.8 ab NW SF 0 f 0 d 96.3 ab SW NF 0 f 0 d 96.3 ab SW SF 0 f 0 d 98.8 a

Liatris aspera NW NF 2.4 abc 58.3 ab 90 abc NW SF 2.4 abc 67 a 82.5 abcd SW NF 2.9 a 75.4 a 95 ab SW SF 2.5 ab 73 a 88.8 abc

Baptisia australis NW NF 0 f 0 d 91.3 abc NW SF 0 f 0 d 95 ab SW NF 0 f 0 d 97.5 a SW SF 0 f 0 d 100 a

Liatris cylindracea NW NF 0.3 ef 2.6 d 68.8 bcd NW SF 0.3 ef 0 d 63.8 cd SW NF 0 f 0 d 72.5 abcd SW SF 0 f 1.6 d 60 d

Liatris pycnostachya NW NF 1.5 cd 34 bc 98.8 a NW SF 1.8 abcd 23.8 cd 100 a SW NF 1.7 bcd 23.8 cd 100 a SW SF 1.5 bcd 32.5 bc 100 a

Liatris scariosa NW NF 1.5 bcd 71.3 a 95 ab NW SF 1.6 bcd 69.8 a 83.8 abcd SW NF 2 abcd 76.3 a 90 abc SW SF 1.7 bcd 66.9 a 97.5 a

Liatris spicata NW NF 1.2 de 14.1 cd 98.8 a NW SF 1.5 bcd 17.5 cd 100 a SW NF 1.4 cd 13.8 cd 100 a SW SF 1.5 cd 11.5 cd 98.8 a

Thermopsis caroliniana NW NF 0 f 0 d 92.5 ab NW SF 0 f 0 d 97.5 a SW NF 0 f 0 d 98.8 a SW SF 0 f 0 d 100 a Identical letters within a measured characteristics indicate that results are not significantly different at p=0.05. -W indicates no supplemental water -F indicates no supplemental fertilizer +W indicates supplemental water +F indicates supplemental fertilizer

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Table 3.17 Effects of supplemental fertilizer (SF) (20-10-10 at 135g N/6 m row) with no supplemental water (NW), supplemental water (SW)(rainfall plus irrigation up to 25 mm/week) with no supplemental fertilizer (SF), and supplemental water with supplemental fertilizer on plant growth characteristics of eight native perennial ornamental species in 2012 in reproductive growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario. Statistical analysis appended in Tables A.33 to A.41.

Total Foliage Flower Length of Plant Water Fertilizer Dry Dry Dry Flower Flowering Survival Plant:Flower Species Flowering Height Treatment Treatment Weight Weight Weight stalks (%) (%) Ratio Area (cm) (cm) (g) (g) (g)

Amsonia NW NF 24.7 cde 24.7 cd n/a n/a 14.1 ab 44.8 defk 88.8 abcde n/a tabernaemontana NW SF 28.3 cdef 28.3 cde 30.9 b 43.1 def 97.5 bde n/a n/a n/a SW NF 32.1 cdef 32.1 cdej n/a n/a 30.0 bc 56.3 deklmn 92.5 abde n/a SW SF 41.7 cdefg 41.7 cefhi n/a n/a 23.5 ab 54.3 defklm 95.0 abde n/a

Liatris aspera NW NF 45.3 cdefg 22.2 cd 23.1 defg 18.3 cdeh 4.8 a 50.6 defkl 98.3 a 81.3 abcde 1.0 abde NW SF 42.7 cdefg 21.3 dh 21.4 defg 15.2 bcde 5.3 a 49.6 defkl 98.2 a 73.8 abcd 1.0 abd SW NF 65.4 af 24.8 cd 40.5 acg 38.1 a 5.5 a 75.4 bcjm 98.7 a 81.3 abcde 1.6 c SW SF 80.2 ag 31.6 cdej 48.6 aci 34.4 a 7.7 ab 63.9 bcd 100.0 a 72.5 abc 1.6 c

Baptisia australis NW NF 18.5 de 18.5 di n/a n/a n/a 51.6 defkl 86.3 abcde n/a NW SF 28.1 cdef 28.1 cde n/a n/a n/a 47.1 defkl 96.3 abde n/a SW NF 38.5 cdefh 38.5 cehijl n/a n/a n/a 64.1 bcd 97.5 bde n/a SW SF 42.4 cdefg 42.4 cefhi n/a n/a n/a 60.0 cd 100.0 e n/a

Liatris NW NF 8.3 e 4.7 d 3.6 d 1.8 b 12.3 ab 36.5 ef 91.1 ab 76.3 abcde 0.8 abde cylindracea NW SF 8.0 e 4.4 d 3.6 d 2.8 b 28.0 bc 32.4 fo 94.6 ab 65.0 c 0.8 abde SW NF 7.0 e 4.0 d 3.6 d 2.0 b 13.7 ab 33.4 ef 76.5 ab 71.3 ac 1.1 abc SW SF 8.3 e 4.9 d 3.4 d 2.6 b 16.1 ab 31.2 f 89.1 ab 76.3 abcde 0.7 adef

Liatris NW NF 54.7 cdfgj 47.3 cefhk 7.4 d 4.8 bc 5.1 a 54.8 deklmo 61.6 bc 97.5 bde 0.2 ghi pycnostachya NW SF 57.5 acd 48.4 cefhk 9.1 de 5.3 bc 4.9 a 62.8 cdh 59.7 b 96.3 abde 0.2 ghij SW NF 92.7 aj 58.1 afj 34.6 cf 32.9 ah 11.9 ab 106.0 gi 100.0 a 100.0 e 0.6 adefg SW SF 90.5 aj 56.5 ae 34.0 cf 28.2 aef 11.5 ab 87.3 abg 98.8 a 97.5 bde 0.6 adefg

Liatris scariosa NW NF 87.3 aj 50.6 cefk 36.8 cf 30.3 ae 3.6 a 83.3 abcg 98.7 a 90.0 abcde 0.7 adef NW SF 73.4 agh 44.6 cefhik 28.9 efgi 24.7 ad 2.8 a 63.0 cdh 100.0 a 77.5 abcde 0.7 adefj SW NF 135.0 bi 59.6 afj 75.4 bh 55.5 g 2.6 a 104.0 agi 95.3 ac 75.0 abcde 1.3 bc SW SF 140.5 i 71.2 agk 95.4 h 55.1 g 3.0 a 96.8 agj 100.0 a 75.0 abcde 1.3 bc

Liatris spicata NW NF 88.0 aj 69.3 afg 18.8 def 8.6 bc 7.1 ac 67.3 bck 94.6 ab 92.5 abde 0.3 fghi NW SF 76.7 agh 66.1 afgl 10.6 de 9.3 bcd 9.4 ab 65.5 bcd 83.5 ab 98.8 de 0.2 ghi SW NF 155.6 i 94.6 bg 50.0 ac 38.4 a 10.6 ab 124.8 i 97.2 a 97.5 bde 0.5 efghi SW SF 164.5 i 105.9 b 58.6 ab 34.1 a 10.5 ab 106.3 gi 98.7 a 96.3 abde 0.6 defgh

Thermopsis NW NF 65.5 ac 61.9 afj 4.3 d 8.0 bcd 5.2 ac 70.8 bcl 97.2 ab 82.5 abcde -0.1 i caroliniana NW SF 77.0 agh 70.9 agk 6.0 d 12.0 bcd 6.8 ac 79.0 bcjn 95.5 ac 85.0 abcde 0.1 hi SW NF 77.3 agh 69.6 afg 7.7 d 11.2 bcd 6.3 a 81.8 abc 98.7 a 81.3 abcde 0.1 ghi SW SF 96.4 ab 84.6 ab 11.8 de 13.6 bcdf 6.8 ac 85.3 abgh 100.0 a 92.5 abde 0.1 ghi Identical letters within a measured characteristics indicate that results are not significantly different at p=0.05. -W indicates no supplemental water -F indicates no supplemental fertilizer +W indicates supplemental water +F indicates supplemental fertilizer

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Table 3.18 Effects of supplemental fertilizer (SF) 20-10-10 at 135g N/6 m row) with no supplemental water (NW), supplemental water (SW)(rainfall plus irrigation up to 25 mm/week) with no supplemental fertilizer (NF), and supplemental water with supplemental fertilizer on flowering time of eight native perennial ornamental species in 2012 in reproductive growth year located in a field trial at the Guelph Turfgrass Institute in Guelph, Ontario. Statistical analysis appended in Tables A.42 to A.45.

First Full Last Water Fertilizer Bloom Species Bloom Bloom Bloom Treatment Treatment Time (DAT) (DAT) (DAT)

Amsonia NW NF -5 e 2 f 13 b 17 e tabernaemontana NW SF -4 e 2 f 16 b 20 ce SW NF -4 e 2 f 14 b 18 e SW SF -3 e 2 f 15 b 18 e

Liatris aspera NW NF 92 f 99 ch n/a n/a NW SF 92 f 101 ch n/a n/a SW NF 86 f 91 c n/a n/a SW SF 87 f 94 ci n/a n/a

Baptisia australis NW NF n/a n/a n/a n/a NW SF n/a n/a n/a n/a SW NF n/a n/a n/a n/a SW SF n/a n/a n/a n/a

Liatris cylindracea NW NF 57 c 70 bd n/a n/a NW SF 60 c 68 bd n/a n/a SW NF 57 c 68 bd n/a n/a SW SF 59 c 70 bd 95 cd 39 abdf

Liatris pycnostachya NW NF 52 c 58 dg 88 d 38 abd NW SF 51 c 57 dg 97 cd 45 ab SW NF 50 c 53 g 82 d 32 bdf SW SF 50 c 54 g 86 d 36 abd

Liatris scariosa NW NF 94 f 106 h NW SF 94 f 106 h SW NF 85 f 103 hi SW SF 88 f 100 ch

Liatris spicata NW NF 71 ab 77 ab 100 c 31 abc NW SF 72 a 90 ac SW NF 60 c 65 d 100 c 41 ab SW SF 61 bc 67 bd 102 c 42 a

Thermopsis NW NF 14 d 18 e 34 a 20 ce caroliniana NW SF 11 d 19 e 34 a 23 cef SW NF 11 d 16 e 32 a 22 cef SW SF 12 d 20 e 36 a 21 cde Identical letters within a measured characteristics indicate that results are not significantly different at p=0.05.

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Chapter 4 Effect of deficit irrigation on root and shoot growth of eight native ornamental perennial species Abstract

Increased consumer interest in “green” living and reduced water usage is generating a desire for landscapes with decreased input needs. A potential fit for this niche is the use of native plant species that are naturally adapted to low input environments such as prairie landscapes. The current study investigated the effects of supplemental irrigation (SI) and deficit irrigation (DI) on the species Liatris aspera, Liatris cylindracea, Liatris pycnostachya, Liatris scariosa, Liatris spicata, Baptisia australis, Thermopsis caroliniana, and Amsonia tabernaemontana in container grown conditions. These species were selected based on their varying natural habitats. SI supplied the plants with 100% of the water lost through evapotranspiration while DI supplied only 50% of the water lost. In general, minimal response was seen between watering treatments within species. Between treatments, a general trend of decreased total dry weight was seen within the DI treatment. Increases in root:shoot ratio were seen within L. aspera, L. scariosa, L. spicata, and T. caroliniana under DI. As well, Liatris spp. displayed greater loss in corm dry weight than root dry weight under DI, indicating these species will sacrifice storage organs to maintain ground resource uptake. Root analysis indicated a decrease in root tips and crosses under DI. No significant differences were seen between species native to dry land habitat as compared to species native to habitats with more abundant water.

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Introduction

Predictions of climate change foresee increased instances of drought and moisture stress throughout the world (Houghton et al., 2001). These predictions pose a serious barrier to plant production and growth, and certain regions will be more susceptible than others. Fortunately, over the past few decades, significant research has been invested toward mitigating future issues related to water availability (Hoekstra et al., 2012; Houghton et al., 2001; Klik and Rosner, 2009;

Rockström et al., 2010). In addition, consumer trends towards reducing or eliminating environmental impact are continuing to mature (Chen and Chai, 2010; Fox, 2008). These attitudes are reflected in consumer purchasing habits as well as consumer’s desire to live in

‘green’ communities (Hostetler et al., 2008; Noiseux and Hostetler, 2010). However, these trends are likely to clash with common landscape management practices. The majority of landscaping in urban areas is designed around utilization of turf or non-native ornamental species (Kaufman and Barnes, 2009). These two, environmentally damaging, non-natural landscaping styles commonly require high levels of inputs (Nassauer, 1993). With consumers choosing more environmentally friendly lifestyles and likelihood of reduced water availability in the near future, low-input gardening becomes a potential solution. The utilization of highly adaptive native species is often associated with low-input landscapes (McMahan, 2006). Additional research in this area could benefit utilization and adoption of this technology.

Native species have the capacity to adapt to a wide range of conditions (Franco et al.,

2006) including low-input drought prone environments (De Herralde et al., 1998). However, some native species lack the desired aesthetic attributes valued by consumers. Consumers interested in cultivating low-input landscapes and gardens for reasons of environmental conservation are selective in their choices of plants. Numerous studies investigating consumers

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interest in native low-input gardens have demonstrated that although low input plants are desirable at an environmental level, they must have the ornamentally desirable traits (i.e. plentiful flowers, flower colour, and plant shape) that traditional water loving species possess

(Gobster et al., 2007; Helfand et al., 2006; Nassauer, 1993). Another factor restricting the increased use of native plants in low-input landscapes is lack of species variety (Brzuszek et al.,

2010) and consumer marketing for those species (Brzuszek and Harkess, 2009; Kauth and Perez,

2011; Yue et al., 2011).

In attempts to increase public awareness of the potential of native species as low-input plant option and increase native plant availability for ornamental production, research investigating the response of native species to low-input enviornments has been increasing.

Research conducted on wildflowers (Chapman and Augé, 1994; De Herralde et al., 1998; Franco et al., 2001; Kjelgren et al., 2009), shrubs (Scheiber et al., 2008), and ornamental grasses

(Thetford et al., 2011, 2009) demonstrated that native species have characteristics that allow survival under low input conditions. These characteristics include rapid stomatal closure, osmotic adjustment sensitivity, leaf rolling/shedding/enhanced wax cuticle, and increased root:shoot ratio. Moreover, when investigating characteristics that contribute to growth under water stress, natural habitat was occasionally correlated to the ability of a species to grow in droughty environments (Chapman and Augé, 1994). In essence, plants native to arid regions are more likely to have the characteristics that restrict water loss and maximize water uptake. Plants native to regions with short time periods of abundant water availability have characteristics of drought avoiders (i.e. shorter life cycle and dieback) or minimal water stress tolerance. In other words, these species look to avoid growth during times of limited water availability.

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When investigating species response to water stress, root characteristics are key factors relating to maintenance of growth and survivability during long-term drought (Lynch, 1995).

Soil environments and resources can be extremely variable depending on the habitat in which plants are grown (Hodge, 2004). In response, plants have adopted a variety of root architectures that allow them to extract necessary resources from their environments (Rundel et al., 1991).

Root architecture is one of the more important factors responsible for these adaptations.

Investigation into water stress has revealed diverse characteristics that contribute to adaptation to drought in numerous plant species. When comparing wheat genotypes with contrasting drought tolerance in environments with water stress, strong architectural differences in lateral root spread were observed (Manschadi et al., 2006). Reduced lateral spread likely suggests a narrow root angle, which results in deeper roots that may attain otherwise unavailable water. Research on common bean (Ho et al., 2003) and cowpea (Matsui and Singh, 2003) demonstrated similar results when investigating water acquisition . These ideas have recently been challenged by evidence suggesting that plants growing in subhumid regions have deeper rooting systems compared to plants in arid regions (Hodge et al., 2009). This is explained using relative and absolute rooting depth as described by Schenk and Jackson (2002). Absolute rooting depth is described as the maximum depth a plant can root under optimum conditions. In comparison, relative rooting depth is a measure relating to plant size. Absolute rooting depth decreases in arid regions as compared to sub humid regions. However, rooting depth relative to canopy size increased in arid regions (i.e. root depth in relation to canopy height increases substantially in arid regions).

Native plants, adapted to a large diversity of environments have the potential to possess specialized rooting characteristics that allow the plant to maintain growth during drought stress.

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Research conducted on root growth of native plants in water stress environments is currently limited. The majority of research has investigated the response of field crop species to drought environments (de Dorlodot et al., 2007). Research conducted on the response of perennial ornamentals to water stress conditions demonstrated common trends such as increased root:shoot ratio (Álvarez et al., 2009; Prevete et al., 2000) and deeper root systems (Kjelgren et al., 2009).

However, this was not always the case when species were subjected to water stress within a confined container system. A study done by Zollinger et al. (2006) in which six ornamental herbaceous perennials were subjected to drought provides an example. The majority of the species native to drier habitats displayed increases in root:shoot ratio with the exception of

Lavandula angustifolia which displayed no significant change during the first two drought treatments and died during the longest drought treatment. Although the growth environment (i.e. container) may have restricted the plant’s natural response to drought, these results suggest natural habitat may not always be a good predictor of plant response to drought.

The purpose of this study was to investigate the effects of DI on the root architecture of eight native ornamental perennials. Species selected for the trial were Liatris spicata, L. cylandracea, L. aspera, L. pycnostachya, L. scariosa, Thermopsis caroliniana, Amsonia tabernaemontana and Baptisia australis. Species (Table 3.1) were selected to represent a variety of natural habitats (described in Chapter 2). The extensive range of natural habitat of these species may present an opportunity to distinguish those species that have water-stress tolerant root characteristics. Specific objectives of the study were:

1. Characterize the vegetative growth parameters of eight native ornamental

perennials under DI conditions

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2. Characterize root architecture of eight native ornamental perennials under DI

conditions

3. Determine root plasticity of eight native ornamental perennials under DI

conditions.

4. Determine if natural habitat is linked to drought tolerance through root

architecture changes

Materials and Methods

Seed sources, germination and establishment

Seeds of Liatris aspera, Liatris scariosa, Liatris spicata, Liatris pycnostachya, Liatris cylindracea, Amsonia Tabernaemontana, Baptisia australis, and Thermopsis caroliniana, were purchased from commercial sources (Table 3.1). Germination and establishment were carried out over the same time period using the same methods as the field trials (Refer to GTI and Elora

Seed sources, germination and establishment section 3.3). Plant material selected for the root analysis trial remained in 50 cell flats under greenhouse conditions (22°C/18°C daytime/nighttime temperatures). Plants were watered daily as needed. Once per week, water- soluble fertilizer (20N-8P-20K 250ppm 1.25 g/L pH adjusted 6.0 and E.C. 2.5) was applied during watering. Four weeks after germination, plants were transplanted into 23 L containers

(15.5 inch and 7.5 inch top and bottom diameters, respectively) filled with brick sand (Gro-Bark,

Caledon, ON, Canada) and transferred on July 10th, 2011 into a cold frame covered with clear polyethylene to exclude rainwater. Containers were watered daily as needed and fertilized once per week using water-soluble fertilizer described above.

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Experimental design

The root analysis trial consisted of a split plot design with three replications and was conducted over an 11-week period (August 15th 2011- October 31st 2011). Two watering treatments were imposed; DI (Each container was weighed every week and had its weight compared was to the saturated weight of the container collected in week one. The difference in weight was considered the loss of water through evapotranspiration that week and 50% of the weight difference was applied as water each week) and SI (plants received 100% of the water lost once per week every week, based on weight change). Water treatments were randomized as the main plot with species randomized to the sub-plots. At the start of the trial, containers were hand watered to capacity and weighed after excess water had drained. At the end of the first seven-day drying period, the plants were weighed again to determine the gravimetric water loss through evapotranspiration. Containers under SI treatment were re-watered to saturation while

DI plants were supplied with the species-specific water loss for that week. This process was repeated each week for the 11-week period.

Root extraction

At the end of the eleven-week period, above ground plant material was cut from the root system at soil level or at the point of stem initiation from the corm depending on the species.

Above ground plant material was dried at 80°C for 48 hours and weighed. Sand was carefully washed from the roots and care was taken to reduce loss of smaller root material. Once the roots were thoroughly washed, the corms were cut from the root system and dried at 80°C for 5 days then weighed.

To maintain root tissue stability during long-term storage, roots were stored in a 5:1 water: ethanol solution and placed in a sealed plastic bag and stored at -15°C.

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Root analysis

Roots selected for analysis were removed from cold storage the night prior to analysis to allow full thawing. Once thawed, roots were drained, and excess water was removed using a salad spinner for 20-30 seconds. Root fresh weight was collected for each root system. To accommodate their large size, the root systems were then cut into quarters or half longitudinally and verified by weight. After root system partitioning, each primary root within the selected 25% or 50% section was removed from the main root system. All primary roots were removed and classified by length (i.e. 0-5 cm, 5-10 cm, 10-15 cm, etc.). The number of primary roots within each category was counted. Primary roots were cut into 10 cm intervals (0-10 cm, 10-20 cm, 20-

30 cm, etc.) and dried in separate length groupings for 48 hours at 80°C. After drying, secondary and tertiary roots were carefully removed from the primary roots and weighed separately as primary or secondary and tertiary dry weights within the each length grouping separately.

Prior to root sectioning (described above), ten randomly selected primary roots were scanned using WinRHIZO (Regent Instruments Inc. Ch Ste-Foy, QC, Canada). Scanned roots were then cut into sections to be dried and scanned separately using the same methods as described above (Figures 4.1 & 4.2). Measurements collected included number of crosses, number of forks, number of tips (crosses, forks, and tips of roots displayed in Figure 4.3), total root length, surface area, and root volume. Root:shoot ratio was calculated using the below ground dry weight (minus the weight of any corm) and above ground dry weight.

Statistical analysis

All data were analyzed in SAS v9.2 (SAS Institute Inc., Cary, NC, USA, 2009) using general linear model procedures for ANOVA tables. Means comparisons were done using a Tukey’s

Studentized range test at P<0.05 level. Analysis of variance results are presented in Appendix A.

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Results

Dry Weight Measurements

Dry Weight. A significant decrease was observed in total dry weight (60.3 g to 44.4 g), total below ground dry weight (38.7 g to 30.5 g), corm dry weight (27 g to 19.4 g), and above ground dry weight (21.6 g to 13.9 g) across all species in response to DI (Table 4.1).

Interestingly, root dry weight remained relatively constant between treatments (11.8 g to 11.1 g).

Within species, a general decrease in total dry weight was observed within the DI treatment with the exception of A. tabernaemontana (12% increase) (Table 4.2). The greatest loss was observed for L. aspera (-46%) and L. cylindracea (-59%). The remaining species displayed decreases between -22% to -38%. Above and below ground dry weights also followed this trend.

Interestingly, six of the eight species displayed a greater percent loss in above ground dry weight than below ground dry weight (Table 4.2). For the Liatris spp., corm dry weight played a role in dry weight partitioning. For L. cylindracea, L. scariosa, and L. spicata, the dry weight in roots increased (66%, 66%, and 75%, respectively) while the dry weight in the corm decreased (-61%,

-32%, and -30%, respectively). For L. aspera, the percent loss in below ground dry weight was the same in both roots and corm. However, corm dry weight was a larger proportion of below ground dry weight than roots. For example, L. scariosa exhibited an increase of 3.1 g (66%) to

7.9 g of root dry weight under DI. However, corm dry weight was decreased by 8.7 g (-32%) to

18.2 g.Thus, root dry weight appears to have increased at the expense of corm dry weight (Table

4.3). Figures 4.4-4.11 depict randomly selected roots systems complete with corms immediately prior to washing and storage.

Root:Shoot Ratio. Overall, root:shoot ratio displayed no change between DI (2.6) and SI

(2.7) (Table 4.1). Root:shoot ratio response to DI was species-dependent. T. caroliniana, L.

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spicata, L. scariosa, and L. aspera all displayed increases in root:shoot ratio within the DI treatment. Increases observed for these species were 1.0 to 2.1 (100%), 3.0 to 3.3 (11%), 1.0 to

1.3 (32%) and 1.2 to 3.0 (143%), respectively (Table 4.3). The remaining species displayed a decrease in root:shoot ratio when exposed to DI.

Root Architecture

Root dry weights by depth. No significant differences were observed between treatments when comparing primary and secondary root dry weights at different lengths (Table 4.4). In general, root dry weight distribution was similar under DI and SI. However, there was a difference in the distribution of dry weight between primary and secondary roots within the top

10 cm of growth. Under SI, a larger portion of root dry weight was present in the primary roots

(4.4 g) compared to secondary roots (1.9 g). Comparatively, dry weight distribution was more balanced under DI with root dry weights at 2.1 g and 2.2 g for primary and secondary roots, respectively. When comparing irrigation treatment within species, differences were observed but they were non-significant (Table 4.4 & 4.5). For example, the dry weight of primary roots in the

0-10 cm depth for A. tabernaemontana and T. caroliniana was decreased from 16.9 g to 2.6 g and 12.2 g to 7.7 g, respectively.

Number of primary roots. In general, the number of primary roots at specific depths was not significantly affected by DI. However, an interesting trend was observed as the majority of roots had lengths of 5-10 cm (132 and 87 for DI and SI, respectively) (Table 4.6). When comparing the treatments within species, this trend continued and expanded with a high proportion of primary roots in the range of 5-15cm in length (Table 4.6 & 4.7). The majority of species displayed no significant differences in number of primary roots of different lengths with the exception of L. spicata. L. spicata, which had significant increases of roots at 5-10 cm in

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length from 212 to 577 and 10-15 cm length roots from 197 to 443 under SI and DI, respectively.

Interestingly, L. aspera and L. pycnostachya displayed a decreased number of primary roots between 0-20 cm and a general increase in number of roots greater than 15-20 cm in length.

Comparatively, B. australis, L. cylindracea, L. scariosa, and L. spicata displayed increases for all root lengths under DI. A. tabernaemontana and T. caroliniana displayed no general trends. In general, A. tabernaemontana, L. aspera, and T. caroliniana can be grouped as deeper rooting plants while L. cylindracea, L. pycnostachya, L. scariosa, and L. spicata can be grouped as more shallow rooted plants with a greater portion of roots between 20-40 cm. B. australis displayed a more even distribution of root growth through the soil profile.

WinRHIZO root analysis. Two characteristics displaying significant changes under DI were number of tips and number of crosses, which were reduced from 43717 to 31586 and 15503 to 10182, respectively (Table 4.8). Interestingly, B. australis, L. pycnostachya, and L. spicata displayed reductions in all measured characteristics under DI (Table 4.9). Conversely, L. scariosa and T. caroliniana displayed increases in all measured characteristics when subjected to

DI. L. aspera displayed minimal changes under DI. A. tabernaemontana and L. cylindracea displayed their greatest decreases in the number of crosses (48% and 76%, respectively) and number of forks (27% and 13%, respectfully) as compared to other characteristics under DI

(Table 4.10).

Discussion

The purpose of the DI container trial was to investigate the effects of reduced water input on overall plant growth as well as investigate the effects, if any, DI has on general root architecture of L. aspera, L. scariosa, L. cylindracea, L. spicata, L. pycnostachya, T. caroliniana,

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A. tabernaemontana, and B. australis. The species were selected for this study because they were native to North America and were adapted to different habitats.

When exposed to DI, a general trend of decreased total dry weight was observed. This was to be expected as a reduction in available water would lead to an initial reduction in cell expansion followed by a reduction in stomatal opening and photosynthate production (Taiz and

Zeiger, 2006). The only species that did not follow this trend was A. tabernaemontana. This could be due to its habitat preference for well drained soils (Scocco et al., 1997). In addition the soil (brick sand) used for these trials may have compounded the negative effects of heavy watering on plant growth. Due to the nature of the SW treatment, in which each pot was resaturated each week, it is possible that due to the container filter that the plants were subjected to periods of water saturation. This could have possibly created an anaerobic environment for the roots which would have subsequently reduced growth.

With the exception of B. australis, all species displayed a greater percent loss in above ground dry weight compared to below ground dry weight. This aligns with current understanding of plant dry weight allocation in response to drought. As plants encounter periods of low available water, ABA influx (Sharp and LeNoble, 2002) and stomatal response (Taiz and Zeiger,

2006; Ludlow et al., 1980) lead to an increased allocation of assimilates to below-ground organs.

However, even though percent loss was greater in above-ground organs, root:shoot ratio increases were only observed in four (L. aspera, L. scariosa, L. spicata, and T. caroliniana) of the eight species. The root:shoot ratio response did not seem to relate to natural habitat. As examples, L. scariosa and L. cylindracea, which are both from low input prairie landscapes, displayed a 32% increase and 34% decrease in root:shoot ratio, respectively. Dead roots were not measured in this trial, therefore it is possible that root desiccation played a roll in these variable

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results in the species native to drier habitats. Root desiccation is a tactic used at varying levels by different species in response to DI and rewatering. Huang and Gao (2000) investigated the effects of water deficit on different tall fescue cultivars (Kentucy-31, Falcon II, Houndog V,

Pheonix, Rebel Jr., and Bonsai) and found root mortality to vary between cultivars. This variability of root desiccation may have played a role in some of the results seen.

One interesting trend seen with Liatris spp. was the higher percentage decrease in corm weight as compared to the non-significant decrease in root weight. The DI treatment may have generated enough water stress to cause a change in allocation of plant carbon. Instead of allocating resources to the storage organ for future use in subsequent years, the species may have prioritized first year growth and reproduction in order to continue the progeny line.

Root dry weight changes under DI were species-dependent. A. tabernaemontana, L. cylindracea, and L. pycnostachya maintained similar root dry weights under both treatments. B. australis, L. aspera, and T. caroliniana had slight decreases in root dry weight under DI while L. spicata and L. scariosa had decreases. Once again, these trends did not relate to species natural habitat and may have been influenced by root desiccation. Some species have the capability to generate significant increases in lateral and fine roots when under water deficit. Typically, this is in combination with the ability to desiccate those roots when water becomes abundant again

(Jupp and Newman, 1987). However, research relating to water stress impacts on root desiccation is rather limited (Blum, 1996). It is entirely possible that some of the species in this study showed variability in root desiccation. Consequently, if some species desiccated roots prior to extraction while others maintained their roots, this would have contributed to the variability observed.

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Plants are capable of investing energy in root growth into areas of soil where resources are present. For example, in lighter soils with frequent small rainfalls, root growth will be invested largely toward the upper layers of soil, as water absorption in deeper layers will not be as essential. Soils with harder surfaces with lower rainfall occurrences will lead to deeper root growth and increased secondary root growth at the deeper layers, as resources in the upper soil layers will not be available or accessible (Blum, 1996). In the current study, water was applied to the soil surface. Therefore, depending on the volume of water applied, it may be expected that plants in the DI would respond with increased lateral root dry weight in the top layers of soil as the irrigation water would be less likely to reach the lower soil levels. Interestingly, no differences were observed among treatments at any soil depth. As well, no interaction was seen between treatments and species. The type of media used may have been a contributing factor to this. In natural landscapes, variability in soil characteristics would be expected at different depths. For example, the top layers may be composed of coarser particles and be less compact while the deeper layers (greater than 15cm) may be more compact and contain finer soil particles. This could lead to greater exploration of the top 15cm of soil by plant roots due to the greater amount of resources available there. A study conducted by Jupp and Newman (1987) imposed drought conditions on Lolium perenne L. which responded with increased lateral root growth in the upper layers of soil. This result was linked to possible desiccation of root tips in the deeper areas of soil, causing increased lateral root growth. It is possible that the DI treatment along with the soil media did not lead to a low enough water potential to cause desiccation of root tips and greater lateral root growth. Like secondary root dry weights, the number of primary roots in different soil levels remained unchanged between treatments as well as within species.

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Only L. spicata displayed a significant increase in the number lateral roots in the upper levels (5-

15cm) of soil. Interestingly, this species is known to grow in more water abundant-habitats.

Based on previous studies, it would be expected that the species native to drier landscapes would display greater drought tolerance qualities. One of the main drought tolerance features measured is an increase in root:shoot ratio. In the current study, no significant increases in root:shoot ratio were measured. A study conducted by Scheiber (2008) found some species native to drier habitats exhibited drought tolerance mechanisms while other species also native to dry habitat did not. These results may indicate that although a species is native to low water habitats and may display those features in that habitat, imposed trial conditions may not always provoke those responses. Therefore, as much as native habitat may play a role in their drought tolerance, it is important to note that container trials and urban landscapes are not the same as native habitat and other factors may play a role in the results.

Conclusion

The objectives of the current study were to investigate the response of eight container grown native perennial ornamental species to deficit irrigation. The study looked to characterize vegetative growth, root architecture, root plasticity, and how native habitat related to study results. Water deficit conditions were successfully imposed on all eight species. In general, results of the study exhibited no significant differences between treatments within species. Total dry weight, total below ground dry weight, above ground dry weight, and corm dry weight all exhibited significant decreases when plants were subjected to DI. This aligns with other studies conducted on native perennials looking at reduced water availability.

Treatment differences within species displayed trends or reduced dry weight under DI, however the results were not significant. This may have been a result of genetic variation with

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species as well as experimental design. An increased sample size may have generated stronger results as the variability within the species could have dampened the experimental results.

Investigation of root architecture and root plasticity exhibited similar results to dry weight results in that nearly all changes between treatments within species were non-significant.

However, interesting root features for each species were seen. For example, A. tabernaemontana,

L. aspera, and T. caroliniana displayed deeper root systems than other species within the trial, under both SI and DI. This creates a greater understanding of where each species prefers to extract resources in soil from within the given conditions. Although root analysis through

WinRHIZO exhibited no significant changes between treatments with species, it displayed possible indicators of root architecture changes of each species. However, when species were grouped, number of root tips and number of root crosses were significantly reduced under DI.

As there was minimal response to the watering treatments within species, it is difficult to relate natural habitat to root architecture response from deficit irrigation. A. tabernaemontana, the only species to stand out in its response to the imposed watering treatments, displayed a negative response to SI. Species native to drier habitats did not display a significant advantage or lack of disadvantage to the DI treatment. Although there was some significance displayed (total dry weight) between treatments, this failed to extend within species and between species adapted to contrasting habitats.

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Tables and Figures Figure 4.1 One primary root image of Amosonia tabernaemontana scanned for analysis using WinRHIZO.

Figure 4.2: One primary root image of Baptisia australis scanned for analysis using WinRHIZO.

Figure 4.3: Diagram of crosses (a), forks (b), and tips (c) of root system as measured by WinRHIZO

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Table 4.1 Effects of deficit (DI)(1/2 of water loss through transpiration) and supplemental (SI)(100% of water loss from transpiration) irrigation on several growth characteristics of eight native ornamental perennial species at the University of Guelph (Guelph, Ontario, Canada) in 2011. Data presented are the mean of eight species. Statistical analysis appended in Tables A.61 to A.66. SI DI Above Ground Dry Weight (g) 21.6 a 13.9 b Corm Dry Weight (g) 27 a 19.4 b Root Dry Weight (g) 11.7 a 11.1 a Total Below Ground Dry 38.7 a 30.5 b Weight (g) Total Dry Weight (g) 60.3 a 44.4 b Root:Shoot Ratio 2.7 a 2.6 a Means followed by the same letter within a row are not significantly different at p≤0.05 using tukeys test.

Table 4.2 Differences between deficit (1/2 of water loss through transpiration) and supplemental (100% of water loss from transpiration) irrigation on percent change of several growth characteristics of eight native ornamental perennial species at the University of Guelph (Guelph, Ontario, Canada) in 2011. Data represented as percent change from check.

Total Root Total Above Below Corm Dry Dry Dry Root:Shoot Species Ground Dry Ground Weight (g) Weight Weight Ratio Weight (g) Dry (g) (g) Weight (g) Amsonia 21% N/A 8% 8% 12% -28% Tabernaemontana Baptisia australis -31% N/A -42% -42% -38% -32%

Liatris aspera -63% -32% -33% -32% -46% 143%

Liatris cylindracea -71% -61% 66% -57% -59% -34% Liatris -26% -18% -4% -17% -20% -18% pycnostachya Liatris scariosa -34% -32% 66% -17% -26% 32%

Liatris spicata -30% -30% 75% -18% -22% 11% Thermopsis -38% N/A -33% -33% -35% 100% caroliniana

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Figure 4.4: Full root system of Liatris aspera at conclusion of container trial in which the species was exposed to 100% replacement of water lost based on weight (SI) and 50% replacement of water lost based on container weight (DI).

Figure 4.5: Full root system of Liatris spicata at conclusion of container trial in which the species was exposed to 100% replacement of water lost based on weight (SI) and 50% replacement of water lost based on container weight (DI).

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Figure 4.6: Full root system of Thermopsis caroliniana at conclusion of container trial in which the species was exposed to 100% replacement of water lost based on weight (SI) and 50% replacement of water lost based on container weight (DI).

Figure 4.7: Full root system of Amsonia tabernaemontana at conclusion of container trial in which the species was exposed to 100% replacement of water lost based on weight (SI) and 50% replacement of water lost based on container weight (DI).

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Figure 4.8: Full root system of Liatris pycnostachya at conclusion of container trial in which the species was exposed to 100% replacement of water lost based on weight (SI) and 50% replacement of water lost based on container weight (DI).

Figure 4.9: Full root system of Liatris scariosa at conclusion of container trial in which the species was exposed to 100% replacement of water lost based on weight (SI) and 50% replacement of water lost based on container weight (DI).

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Figure 4.10: Full root system of Liatris cylindracea at conclusion of container trial in which the species was exposed to 100% replacement of water lost based on weight (SI) and 50% replacement of water lost based on container weight (DI).

Figure 4.11: Full root system of Baptisia australis at conclusion of container trial in which the species was exposed to 100% replacement of water lost based on weight (SI) and 50% replacement of water lost based on container weight (DI).

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Table 4.3 Effects of deficit (DI) (1/2 of water loss through transpiration) and supplemental (SI) (100% of water loss from transpiration) irrigation on several growth characteristics of eight native ornamental perennial species at the University of Guelph (Guelph, Ontario, Canada) in 2011. Statistical analysis appended in Tables A.61 to A.66. Total Above Below Total Dry Irrigation Ground Corm Dry Root Dry Root:Shoot Species Ground Weight Treatment Dry Weight (g) Weight (g) Ratio Dry (g) Weight (g) Weight (g)

Amsonia DI 10.5 bcde n/a 17.1 abcd 17.1 cdef 27.6 defg 1.7 b Tabernaemontana

SI 8.7 cde n/a 15.9 bcd 15.9 cdef 24.6 efg 2.3 b

Baptisia australis DI 4.5 de n/a 6.8 bcd 6.8 ef 11.3 g 1.3 b SI 6.5 cde n/a 11.7 bcd 11.7 def 18.2 fg 1.9 b

Liatris aspera DI 12.7 bcde 24.4 de 3 cd 27.4 bcdef 40.1 cdefg 3 b SI 34.4 ab 35.6 cde 4.6 bcd 40.2 bcd 74.6 bcd 1.2 b

Liatris cylindracea DI 0.2 e 0.9 f 0.1 d 1 f 1.2 g 5.4 ab SI 0.5 de 2.2 f 0.1 d 2.3 f 2.8 g 8.1 a

Liatris DI 18.8 abcde 41.5 cd 5.7 bcd 47.1 bc 65.9 cde 2.6 b pycnostachya SI 25.4 abcd 50.6 bc 5.9 bcd 56.5 b 81.9 bc 3.2 b

Liatris scariosa DI 19.9 abcde 18.2 ef 7.9 bcd 26.2 bcdef 46.1 cdefg 1.3 b SI 30.2 abc 26.9 de 4.8 bcd 31.7 bcdef 61.9 cdef 1 b

Liatris spicata DI 29.6 abc 70.3 b 22.4 abc 92.7 a 122.3 ab 3.3 b SI 42.5 a 100.5 a 12.8 bcd 113.3 a 155.8 a 3 b

Thermopsis DI 15.3 bcde n/a 25.6 ab 25.6 bcdef 40.9 cdefg 2.1 b caroliniana SI 24.6 abcde n/a 38.2 a 38.2 bcde 62.9 cdef 1 b Means followed by the same letter within a row are not significantly different at p≤0.05 using tukeys test.

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Table 4.4 Effects of deficit (DI) (1/2 of water loss through transpiration) and supplemental (SI) (100% of water loss from transpiration) irrigation on the dry weight of primary and tertiary roots at three different depths of eight container grown native ornamental perennial species at the University of Guelph (Guelph, Ontario, Canada) in 2011. Statistical analysis appended in Tables A.82 to A.87. Primary Tertiary Primary Tertiary All Roots All Roots Irrigation Roots Roots Species Roots (0- Roots (0- (20- (30- treatment (10- (10- 10cm)g 10cm)g 30cm)g 40cm)g 20cm)g 20cm)g Amsonia DI 2.6 a 2 bcd 1.4 bc 3.2 abc 3.7 ab 1.5 a tabernaemontana SI 16.9 a 1.9 bcd 1.2 bc 3.2 abc 3 abc 0.9 ab

Baptisia australis DI 2.6 a 1 cd 1.3 bc 0.8 bc 1.1 bc 0.2 b SI 3.1 a 1.3 bcd 1.7 abc 1.1 bc 1.3 bc 0.5 ab

Liatris aspera DI 0.2 a 0.6 cd 0.1 c 0.7 c 0.8 bc 0.1 b SI 0.3 a 0.8 cd 0.1 c 0.9 bc 0.4 c 0.1 b

Liatris cylindracea DI -0.1 a 0 d -0.2 bc 0 c 0 c 0 b SI 0 a 0 d 0 c 0 c 0 c 0 b

DI 0.9 a 1.5 bcd 0.2 c 1.9 bc 0.7 bc 0 b Liatris pycnostachya SI 0.6 a 1.7 bcd 0.1 c 1.9 bc 1 bc 0.1 b

Liatris scariosa DI 0.9 a 2 bcd 0.3 c 2.4 abc 1 bc 0.2 b SI 0.6 a 1.3 bcd 0.2 c 1.3 bc 0.4 c 0 b

Liatris spicata DI 2.5 a 6 a 0.9 bc 6.7 a 2.7 abc 1.1 ab SI 1.6 a 3.1 abcd 0.5 bc 3.8 abc 2.2 abc 0.5 ab

Thermopsis DI 7.7 a 4.1 abc 3.1 ab 3 abc 2.5 abc 0.6 ab caroliniana SI 12.2 a 4.8 ab 4.5 a 5.5 ab 4.5 a 0.9 ab Means followed by the same letter within a row are not significantly different at p≤0.05 using tukeys test.

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Table 4.5 Effects of deficit (DI)(1/2 of water loss through transpiration) and supplemental (SI)(100% of water loss from transpiration) irrigation on percent change in the dry weight of primary and tertiary roots at three different depths of eight container grown native ornamental perennial species at the University of Guelph (Guelph, Ontario, Canada) in 2011. Data represented as percent change from check.

Primary Tertiary Irrigation Primary Roots Tertiary Roots All Roots (20- All Roots (30- Species Roots (0- Roots (0- treatment (10-20cm)g (10-20cm)g 30cm)g 40cm)g 10cm)g 10cm)g

DI -85% 6% 20% 0% 23% 77% Amsonia tabernaemontana

Baptisia australis DI -18% -23% -23% -33% -20% -50%

Liatris aspera DI -29% -22% -26% -27% 124% -13%

Liatris cylindracea DI -1011% 166% 2559% 59% -15% -29%

DI 47% -11% 178% -2% -29% -45% Liatris pycnostachya

Liatris scariosa DI 55% 49% 82% 85% 154% 395%

Liatris spicata DI 62% 92% 67% 77% 22% 104%

DI -37% -15% -29% -45% -43% -27% Thermopsis caroliniana

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Table 4.6 Effects of deficit (DI)(1/2 of water loss through transpiration) and supplemental (SI)(100% of water loss from transpiration) irrigation on the number of primary roots at different depths of eight container grown native ornamental perennial species at the University of Guelph (Guelph, Ontario, Canada) in 2011. Statistical analysis appended in Tables A.74 to A.81.

Irrigation 0- 5- 10- 15- 20- 25- 30- 35-

Species treatment 5cm 10cm 15cm 20cm 25cm 30cm 35cm 40cm Amsonia DI 2.8 b 2.5 b 2.0 b 5.1 bc 4.7 d 3.8 c 5.6 bc 1.8 ab tabernaemontana SI 2.6 b 1.6 b 5.2 b 4.7 bc 7.4 cd 7.9 c 5.2 bc 1.3 ab

Baptisia australis DI 1.3 b 9.2 b 9.9 b 6.3 bc 6.4 cd 10.7 c 3.9 bc 2.2 ab SI 1.2 b 0.2 b 1.2 b 2.2 c 3.2 d 5.4 c 3.0 bc 1.0 ab

Liatris aspera DI 6.7 b 72.3 b 85.1 b 74.1 bc 44.7 bcd 36.7 bc 10.4 bc 3.0 ab SI 19.1 b 99.7 b 103.2 b 85.1 bc 37.0 bcd 29.3 bc 5.9 bc 2.7 ab

Liatris DI 4.5 b 14.7 b 12.0 b 9.2 bc 7.2 cd 2.8 c 1.0 c 0.2 b cylindracea SI 1.2 b 5.3 b 2.8 b 3.5 bc 2.3 d 2.2 c 0.7 c 0.2 b

Liatris DI 33.1 ab 182.5 b 129.2 b 105.8 bc 45.9 bcd 37.9 bc 4.6 bc 0.0 b pycnostachya SI 59.7 ab 239.1 b 180.0 b 93.0 bc 41.8 bcd 21.1 bc 3.5 bc 0.0 b

Liatris scariosa DI 22.3 b 195.8 b 137.6 b 145.4 ab 85.0 abc 52.6 bc 22.1 abc 1.8 ab SI 10.3 b 133.7 b 115.1 b 89.3 bc 67.4 abcd 52.0 bc 13.0 bc 1.3 ab

Liatris spicata DI 99.2 a 577.6 a 443.1 a 266.1 a 130.5 a 145.8 a 42.5 a 19.5 a

SI 38.9 ab 212.4 b 197.7 b 133.3 abc 90.1 ab 86.6 ab 29.9 ab 11.9 ab

Thermopsis DI 1.9 b 7.2 b 14.7 b 20.6 bc 24.4 bcd 35.1 bc 8.5 bc 3.2 ab caroliniana SI 2.0 b 9.5 b 11.9 b 21.4 bc 18.4 bcd 33.0 bc 14.8 abc 4.0 ab Means followed by the same letter within a row are not significantly different at p≤0.05 using tukeys test.

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Table 4.7 Effects of deficit (DI)(1/2 of water loss through transpiration) and supplemental (SI)(100% of water loss from transpiration) irrigation on percent change in the number of primary roots at different depths of eight container grown native ornamental perennial species at the University of Guelph (Guelph, Ontario, Canada) in 2011. Data represented as percent change from check.

Species Irrigation treatment 0-5cm 5-10cm 10-15cm 15-20cm 20-25cm 25-30cm 30-35cm 35-40cm Amsonia DI 8% 54% -62% 9% -37% -52% 7% 45% tabernaemontana

Baptisia australis DI 13% 5381% 752% 187% 99% 98% 30% 116%

Liatris aspera DI -65% -27% -17% -13% 21% 25% 76% 12%

Liatris cylindracea DI 286% 175% 324% 162% 207% 31% 50% 0%

Liatris pycnostachya DI -45% -24% -28% 14% 10% 80% 32% 0%

Liatris scariosa DI 116% 46% 20% 63% 26% 1% 71% 38%

Liatris spicata DI 155% 172% 124% 100% 45% 68% 42% 64%

Thermopsis caroliniana DI -5% -24% 23% -4% 33% 6% -43% -19%

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Table 4.8 Effects of deficit (DI)(1/2 of water loss through transpiration) and supplemental (SI)(100% of water loss from transpiration) irrigation on several root growth characteristics of eight container grown native ornamental perennial species at the University of Guelph (Guelph, Ontario, Canada) in 2011. Statistical analysis appended in Tables A.67 to A.78. Total Root Average Number Projected Surface Irrigation Number Number Root Volu Species Diameter of Area Area Treatment of Forks of Tips Length me (mm) Crosses (cm2) (cm2) (cm) (cm3) Amsonia DI 2.2 a 15958 abc 78507 bc 1142 ab 3586 ab 28123 bc 26396 bc 39 abcd Tabernaemontana SI 2.3 a 30844 ab 107213 ab 1205 ab 3785 ab 38350 bc 27180 bc 44 ab

Baptisia australis DI 1.8 abcd 3086 c 25609 bc 375 bcd 1179 bcd 21582 bc 7098 bc 16 bcdef SI 1.9 ab 3950 c 28352 bc 540 bcd 1696 bcd 17680 bc 10149 bc 23 abcdef

Liatris aspera DI 0.7 de 14251 abc 56042 bc 642 bcd 2017 bcd 40415 bc 21466 bc 15 cdef SI 0.6 de 14743 abc 58720 bc 591 bcd 1856 bcd 55582 bc 21426 bc 13 bcdef

Liatris cylindracea DI 0.5 e 3114 c 12075 c 134 d 420 d 11745 bc 4844 c 3 f SI 0.4 e 12780 abc 13952 c 109 cd 341 cd 3889 c 3678 c 3 f

Liatris DI 0.9 bcde 7053 bc 39269 bc 381 bcd 1196 bcd 25063 bc 10337 bc 11 def pycnostachya SI 0.8 cde 11698 bc 64798 bc 544 bcd 1710 bcd 46083 bc 15991 bc 15 cdef

Liatris scariosa DI 0.9 bcde 9144 bc 44570 bc 586 bcd 1842 bcd 34968 bc 17434 bc 16 cdef SI 0.8 cde 6356 bc 28742 bc 348 bcd 1095 bcd 27234 bc 11026 bc 9 ef

Liatris spicata DI 0.7 cde 21595 abc 93253 abc 1013 abc 3184 abc 62485 b 32078 b 25 abcdef SI 0.9 bcde 38854 a 170727 a 1920 a 6031 a 140258 a 58650 a 50 a

Thermopsis DI 1.9 abc 7256 bc 51018 bc 1095 ab 3441 ab 28307 bc 21521 bc 44 abc caroliniana SI 2.4 a 4808 c 34486 bc 798 bcd 2508 bcd 20668 bc 14696 bc 34 abcde Means followed by the same letter within a row are not significantly different at p≤0.05 using tukeys test.

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Table 4.9 Effects of deficit (1/2 of water loss through transpiration) and supplemental (100% of water loss from transpiration) irrigation on percent change of several root growth characteristics of eight container grown native ornamental perennial species at the University of Guelph (Guelph, Ontario, Canada) in 2011. Data represented as percent change from check.

Total Average Number Projected Surface Root Irrigation Number Number Root Species Diameter of Area Area Volume of Forks of Tips Length Treatment (mm) Crosses (cm2) (cm2) (cm3) (cm)

Amsonia DI -2% -48% -27% -5% -5% -27% -3% -12% Tabernaemontana

Baptisia australis DI -5% -22% -10% -30% -30% 22% -30% -30%

Liatris aspera DI 13% -3% -5% 9% 9% -27% 0% 16%

Liatris cylindracea DI 35% -76% -13% 23% 23% 202% 32% 7%

Liatris pycnostachya DI 14% -40% -39% -30% -30% -46% -35% -24%

Liatris scariosa DI 16% 44% 55% 68% 68% 28% 58% 77%

Liatris spicata DI -15% -44% -45% -47% -47% -55% -45% -50%

Thermopsis DI -20% 51% 48% 37% 37% 37% 46% 29% caroliniana

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Table 4.10 Effects of deficit (DI) (1/2 of water loss through transpiration) and supplemental (SI)(100% of water loss from transpiration) irrigation on root architecture in a container trial at the University of Guelph (Guelph, Ontario, Canada) on eight native ornamental perennial species in the reproductive year in 2011. Data represented as the mean of eight species. Statistical analysis appended in Tables A.67 to A.78. SI DI Average Diameter (mm) 1.2 a 1.2 a Number of Crosses 15504 a 10182 b Number of Forks 63374 a 50043 a Projected Area (cm2) 757 a 671 a Surface Area (cm2) 2378 a 2108 a Number of Tips 43718 a 31586 b Total Root Length (cm) 20350 a 17647 a Root Volume (cm3) 24 a 21 a Means followed by the same letter within a row are not significantly different at p≤0.05 using tukeys test.

Table 4.11 Seed sources for species used in University of Guelph (Guelph, Ontario Canada) deficit irrigation container trials in 2012.

Species Source Location Prairie Moon Liatris spicata Winona, MN Nursery Prairie Moon Liatris cylandracea Winona, MN Nursery Prairie Moon Liatris aspera Winona, MN Nursery Prairie Moon Liatris pycnostachya Winona, MN Nursery Prairie Moon Liatris scariosa Winona, MN Nursery Amsonia Thompson & Ipswich, tabernaemontana Morgan Suffolk Prairie Moon Baptisia australis Winona, MN Nursery Prairie Moon Thermopsis caroliniana Winona, MN Nursery

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Chapter 5: General discussion

One of the objectives of the ornamental breeding program at the University of Guelph is the production of plants adapted to low input environments. The current study was designed to evaluate the physiological and morphological responses of eight native species (A. tabernaemontana, T. caroliniana, B. australis, L. spicata, L. pycnostachya, L. aspera, L. cylindracea, and L. scariosa) in greenhouse, outdoor container, and field trial environments. The main objectives of the current studies were to investigate growth, development, and photosynthetic response of the eight native ornamental perennial species under water stressed conditions. In addition, the relationship between native habitat and response to drought was also characterized. Each trial contained a distinct set of treatments to obtain a broad understanding of the response of each species to both water and fertilizer stress. The greenhouse trial subjected species to three water regimes; High Water (HW) (maintenance of 55%-70% volumetric water content (VWC)), Low Water (LW) (maintenance of 23%-40% VWC), and Cyclic Drought

(CDW) (soil saturation followed by a period of water cessation until wilt). The field trials conducted over two years imposed fertilizer treatments at the Elora site (4 g N/plant, 6.1 g

N/plant, and 8.2 g N/plant) and water and fertilizer treatments at the GTI site (i.e. no supplemental water and supplemental water up to 25 mm/week as well as no supplemental fertilizer and 6.75 g N/plant). Finally, the container trial imposed Supplemental Irrigation (SI) and Deficit Irrigation (DI) where 100% and 50% of water lost by weight, respectively, through transpiration was replaced through weekly irrigation. Although there are numerous studies investigating the effect of low input environments on native species (Bolger et al., 2005;

Chapman and Augé, 1994; Zollinger et al., 2006; Kummerow, 1980; Long and Jones, 1996; Reid and Oki, 2008; Scheiber et al., 2008; Smika et al., 1965; Thomas and Schrock, 2004), very few

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trials have investigated the response of these species to low input environments (Thomas and

Schrock, 2004). The majority of information regarding the tolerance these species to low input conditions is anecdotal and found in gardening literature (King and Robinson, 1987; Brickell and

Zuk, 1997; Dole and Wilkins, 1999; McLaughlin, 1982; Scocco et al., 1997; Endress and

Bruyns, 2000).

All species maintained some level of growth under stress conditions. However, some species were better adapted to the various levels of water stress than others. One trend observed across all water treatments was the negative response of A. tabernaemontana and L. cylindracea to supplemental water conditions. Within the greenhouse trial, both of these species displayed either no response or decreased dry weight while under HW or LW as compared to CDW.

Therefore, although these species thrive under lower water conditions in their natural habitat, extended periods of drought followed by soil saturation have a greater negative impact than persistent soil saturation. Their preference for low water availability conditions was further supported by the increased CER measurements observed for the LW treatment in the greenhouse trial. This trend also continued for A. tabernaemontana in the container trial where it exhibited a decrease in below and above ground dry weight (12% decrease in total dry weight) under the high water treatment.

In general, there was a lack of response to fertilizer by all species within both the GTI and Elora field trials. This may be expected as the majority of these species are adapted to areas with minimal soil nutrients (Dole and Wilkins, 1999; McLaughlin, 1982; Brickell and Zuk,

1997). Therefore, it is possible that even when supplemental fertilizer is applied, the plant’s nutrient requirements are low enough that extra fertilizer is not utilized. It is also possible that the sites utilized for fertilizer trials contained residue amounts of nutrients (Appendix 2.4 & 2.5).

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Therefore, supplemental fertilizer added would not lead to a response from these species.

Previous studies have also indicated that native species do not respond well to additional nutrients (Moore et al., 2014; Thetford et al., 2011)

Species were selected for this study based, in part, on their native habitats. L. aspera, L. cylindracea, L. scariosa, and T. caroliniana are all native to drier, well-drained habitats. L. pycnostachya, L. spicata, and B. australis are native to habitats with abundant soil moisture. A. tabernaemontana is native to well drained river-banks. It would be expected that the species native to drier habitats would thrive under treatments with minimal available water and the species adapted to wetter habitats would perform better under treatments with higher water.

However, it should be acknowledged that some smaller streams can actually dry up in the summer and are not consistently wet environments. Within the greenhouse and container trials, the total dry weights of L. cylindracea and A. tabernaemontana were either negatively impacted by supplemental water or showed the lowest negative reaction to low water treatments.

Supporting this, both CER (significant) and Chltot (non-significant) measurements increased when water availability was reduced. These results align with research on mungbean and maize in which excessive water caused a reduction in CER and Chltot (Pociecha et al., 2008; Yordanova and Popova, 2007). The species adapted to wetter habitats, in general, displayed some of the greatest negative impacts on growth and photosynthetic capability when exposed to drought. B. australis, L. spicata, and L. pycnostachya exhibited some of the highest percentage dry weight losses within the greenhouse study. As well, these species displayed only minor changes in root:shoot ratio in the greenhouse and container trials. The drier adapted species, L. aspera and

L. scariosa, also exhibited reduced growth when subjected to reduced water availability. In some cases, these reductions were similar to those of the wet adapted species. For example, L.

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scariosa, L. pycnostachya, and L. spicata displayed similar reductions of 46%, 49%, and 49%, respectively. As well, L. aspera had a 60% reduction in CER under CDW while B. australis and

L. pycnostachya had reductions of 45% and 28%, respectively. However, T. caroliniana, a drier adapted species, displayed some of the greatest reductions amongst species when subjected to low water treatments. Overall, all eight species sustained vegetative growth and flower production under all water-reduced treatments. All of the species were able to survive during the trial periods and were capable of completing their life cycles. Therefore, it can be concluded that all of these species possess some level of drought tolerance. A study demonstrating the extreme case of life cycle survival under low input landscapes conducted by Thomas (2004), investigated the survival ability of 67 native perennial species under arid field conditions. Within the Thomas trial, many species did not survive the six-year trial, determining that some species may not be suitable for low input urban landscapes. The growth reduction observed in the GTI, container, and greenhouse trials may be more of an indicator of absolute growth. B. australis, T. caroliniana, L. spicata, and L. pycnostachya were all tolerant of the low water or drought treatments and may be better adapted to low input environments. However, they may be best adapted to environments with adequate water. Two species (L. cylindracea and A. tabernaemontana) performed well under drought treatments and would be better adapted to low input environments.

One of the important factors leading to potential use of these species is their capacity to produce and maintain flowers under low input conditions. In general, reduced water availability caused reductions in flower dry weight with some exceptions (for example L. aspera, L. cylindracea, and L. spicata) in the greenhouse trial. Many other floral traits were investigated and each species displayed varying responses within each trait and each treatment. This large

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variability in response is beneficial and could be used in future studies to breed and select specific responses such as length of flowering portion of the stem or number of flower stalks.

Depending on the species, an increase or decrease in the number of flower stalks could be desirable. Species acceptable for use in urban landscapes should be capable of producing floral characteristics even under moderate drought. Considering southern Ontario is rarely subject to severe and prolonged drought, all species in the current trial could be acceptable for use in urban landscapes in Southern Ontario.

One feature that has been linked to a plant’s increased drought tolerance is its shift in assimilate partitioning from above to below ground organs (Taiz and Zeiger, 2006; Prevete et al.,

2000; Chaves et al., 2003), resulting in increases in root:shoot ratio. Only three of the eight species (A. tabernaemontana, L. cylindracea, and L. scariosa) displayed substantial increases in root:shoot ratio during the greenhouse trial. The remaining species exhibited only minor changes. In contrast in the container trial, although the responses were non-significant, A. tabernaemontana and L. cylindracea exhibited decreases in root:shoot ratio while larger increases of 143% and 100% were observed for L. aspera and T. caroliniana. This inconsistency could potentially be a result of the different media used within the each trial as well as the volume of the pots available for root growth. Another potential explanation could be different morphological responses to different media types. Root characteristics have been and continue to be difficult to measure. Complications such at root destruction during extraction and cleaning, root desiccation during growth, and practicality of experimental methods pose challenging barriers that can affect results.

The study on the architecture of roots was designed to determine differences between species and the effect of deficient irrigation on the root system. The root systems of all eight

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species were generally fibrous in nature and had similar distributions of roots throughout the depth of the container. The effect of deficit irrigation on root mass was species dependent (Table

4.2) with both increases and decreases observed. In the Liatris spp., the corm played an important role in partitioning of dry matter to the roots. However, all root systems were well distributed in the container. Well branched and did not appear to be a limiting factor to the species ability to withstand low water or drought conditions.

One common trend observed in the results of all four trials was the lack of statistical significance between treatments even though large biological differences were observed. For example, in the greenhouse trial, the difference in total dry weight from HW to CDW displayed large changes of 40.2 g to 24.3 g (-39%) and 11.9 g to 6.3 g (-47%) for L. aspera and L. cylindracea, respectively. When investigating response to SW in the GTI trial, non-significant changes of 6.5 g to 9.3 g (44%) and 8.3 g to 13.1 g (59%) were observed for A. tabernaemontana and B. australis, respectively. However, within that same trial and measurement period L. spicata displayed a significant change from 26.0 g to 39.2 g (50%) in the

SW treatment. Although each species had the same number of plants, this difference in significance with similar changes between treatments may be caused by differences in variability within and between species. These kinds of results were even more evident within the container trial, where species were exposed to deficit irrigation. Changes in root dry weight were large. e.g. 22.4 g to 12.8 g (75%), 7.9 g to 4.8 g (66%), and 11.7 g to 6.8 g (-42%) for L. spicata, L. pycnostachya, and B. australis, respectively, but not statistically significant. These results may be a consequence of high variability and too few plants within each treatment. With demonstrated variability within each species, it is possible that the plant to plant variability was greater than the effects of the treatments (Long and Jones, 1996). If true, a larger number of

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plants within each treatment, especially for the container trial that had the lowest number of plants, may have produced stronger results. Further research into these species would benefit from an increased number of plants within each species.

The current study gives insight into how the species will respond under a variety of different growth conditions including greenhouse, field, and container. This can assist in selection of species for further research and consumer markets.

The current study on the eight native perennial ornamental species has generated a comprehensive understanding of how these plants will respond to different levels of water and fertilizer. Future research can build upon this foundation and focus on some of the species that thrived under low inputs (i.e. A. tabernaemontana, L. cylindracea, L. aspera, L. scariosa) with a different experimental design and a higher number of plants. With a greater understanding of the plant-to-plant variability within some of these species, it would be beneficial to investigate, while under water stress, desirable traits that are exhibited (greater flower stalk area, greater root:shoot ratio, and increased flowering time). These select plants can then be used in a breeding program for further genetic improvement. As well, it would be beneficial to do market research on the public’s opinion of the aesthetic quality of these species.

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Appendix A: ANOVA Tables List of ANOVA Tables Title Page A.1. Analysis of variance for chlorophyll of eight wildflower species under three 187 separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.80 and CV value is 26.3. Table 2.1 & 2.8. A.2. Analysis of variance for foliage dry weight of eight wildflower species under 187 three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.92 and CV value is 16.3. Table 2.1 & 2.4a. A.3. Analysis of variance for root dry weight of eight wildflower species under three 187 separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.96 and CV value is 36.2. Table 2.1 & 2.4a. A.4. Analysis of variance for survival of eight wildflower species under three separate 188 watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.42 and CV value is 20.2. Table 2.1 & 2.4b. A.5. Analysis of variance for total above ground dry weight of eight wildflower 188 species under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.86 and CV value is 24.2. Table 2.1 & 2.4a. A.6. Analysis of variance for total below ground dry weight of eight wildflower 188 species under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.85 and CV value is 25.8. Table 2.1 & 2.4a. A.7. Analysis of variance for root:shoot ratio of eight wildflower species under three 189 separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.86 and CV value is 21.1. Table 2.1 & 2.4b. A.8. Analysis of variance for root:shoot ratio without corm of eight wildflower species 189 under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.96 and CV value is 30.4. Table 2.1 & 2.4b. A.9. Analysis of variance for total dry weight of eight wildflower species under three 189 separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.90 and CV value is 19.2. Table 2.1 & 2.4a. A.10. Analysis of variance for flower dry weight of eight wildflower species under 190 three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.62 and CV value is 102.9. Table 2.1 & 2.4a. A.11. Analysis of variance for corm dry weight of eight wildflower species under 190 three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.88 and CV value is 24.2. Table 2.1 & 2.4b. A.12. Analysis of variance for percentage of flowering of eight wildflower species 190 under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.68 and CV value is 18.5. Table

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2.1 & 2.6. A.13. Analysis of variance for plant height of eight wildflower species under three 191 separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.71 and CV value is 5.0. Table 2.1 & 2.4a. A.14. Analysis of variance for flowering area height of eight wildflower species under 191 three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.51 and CV value is 19.9.Table 2.1 & 2.6. A.15. Analysis of variance for flower width of eight wildflower species under three 191 separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.95 and CV value is 10.8. Table 2.1 & 2.6 A.16. Analysis of variance for number of flower stalks of eight wildflower species 192 under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.31 and CV value is 40.5. Table 2.1 & 2.6. A.17. Analysis of variance for number of flowers of eight wildflower species under 192 three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.63 and CV value is 29.3. Table 2.1 & 2.6. A.18. Analysis of variance for total stalk number of eight wildflower species under 192 three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.33 and CV value is 33.6. Table 2.1 & 2.6. A.19. Analysis of variance for aborted stalks of eight wildflower species under three 193 separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.45 and CV value is 201.5. Table 2.1 & 2.6. A.20. Analysis of variance for first bloom date of eight wildflower species under three 193 separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.82 and CV value is 15.1. Table 2.1 & 2.7. A.21. Analysis of variance for final bloom date of eight wildflower species under three 193 separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.86 and CV value is 8.9. Table 2.1 & 2.7. A.22. Analysis of variance for time in bloom of eight wildflower species under three 194 separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.39 and CV value is 37.3. Table 2.1 & 2.7. A.23. Analysis of variance for photosynthesis of eight wildflower species under three 194 separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.58 and CV value is 32.8. Table 2.1 & 2.8. A.24. Analysis of variance for stomatal conductance of eight wildflower species under 194 three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.66 and CV value is 47.0. Table 2.1 & 2.8. A.25. Analysis of variance for water use efficiency of eight wildflower species under 195 three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.54 and CV value is 33.7. Table 2.1 & 2.8. A.26. Analysis of variance for survival of eight wildflower species under two water 195

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and two fertilizer regimes in year one of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.65 and CV value is 11.2. Table 3.5 & 3.11. A.27. Analysis of variance for foliage dry weight of eight wildflower species under 196 two water and two fertilizer regimes in year one of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.90 and CV value is 22.45. Table 3.5 & 3.11. A.28. Analysis of variance for flowering percentage of eight wildflower species under 196 two water and two fertilizer regimes in year one of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.93 and CV value is 41.8. Table 3.5 & 3.11. A.29. Analysis of variance for stalk number per plant of eight wildflower species 197 under two water and two fertilizer regimes in year one of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.94 and CV value is 30.2. Table 3.5 & 3.11. A.30. Analysis of variance for flower dry weight per plant of eight wildflower species 197 under two water and two fertilizer regimes in year one of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.88 and CV value is 37.6. Table 3.5 & 3.11. A.31. Analysis of variance for total dry weight per plant of eight wildflower species 198 under two water and two fertilizer regimes in year one of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.93 and CV value is 22.7. Table 3.5 & 3.11. A.32. Analysis of variance for height per plant of eight wildflower species under two 198 water and two fertilizer regimes in year one of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.97 and CV value is 12.1. Table 3.5 & & 3.11. A.33. Analysis of variance for foliage dry weight per plant of eight wildflower species 199 under two water and two fertilizer regimes in year two of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.91 and CV value is 23.1. Table 3.3a & 3.7. A.34. Analysis of variance for flowering dry weight per plant of eight wildflower 199 species under two water and two fertilizer regimes in year two of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.94 and CV value is 29.3. Table 3.3a & 3.7. A.35. Analysis of variance for total dry weight per plant of eight wildflower species 200 under two water and two fertilizer regimes in year two of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.93 and CV value is 22.5. Table 3.3a & 3.7. A.36. Analysis of variance for flowering area height per plant of eight wildflower 200 species under two water and two fertilizer regimes in year two of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.92 and CV value is 28.2. Table 3.3b & 3.7. A.37. Analysis of variance for percent survival of eight wildflower species under two 201 water and two fertilizer regimes in year two of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.69 and CV value is

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10.4. Table 3.3b & 3.7. A.38. Analysis of variance for percent flowering of eight wildflower species under 201 two water and two fertilizer regimes in year two of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.59 and CV value is 14.0. Table 3.3b & 3.7. A.39. Analysis of variance for plant to flower ratio per plant of eight wildflower 202 species under two water and two fertilizer regimes in year two of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.92 and CV value is 26.7. Table 3.3a & 3.7. A.40. Analysis of variance for plant height per plant of eight wildflower species under 202 two water and two fertilizer regimes in year two of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.92 and CV value is 12.7. Table 3.3a & 3.7. A.41. Analysis of variance for number of flower stalks per plant of eight wildflower 203 species under two water and two fertilizer regimes in year two of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.63 and CV value is 76. Table 3.3b & 3.7. A.42. Analysis of variance for time in bloom of eight wildflower species under two 203 water and two fertilizer regimes in year two of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.93 and CV value is 13.3. Table 3.13 & 3.14. A.43. Analysis of variance for first bloom date of eight wildflower species under two 204 water and two fertilizer regimes in year two of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.99 and CV value is 7.4. Table 3.13 & 3.14. A.44. Analysis of variance for full bloom date of eight wildflower species under two 204 water and two fertilizer regimes in year two of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.99 and CV value is 6.0. Table 3.13 & 3.14. A.45. Analysis of variance for end bloom date of eight wildflower species under two 205 water and two fertilizer regimes in year two of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.99 and CV value is 5.8. Table 3.13 & 3.14. A.46. Analysis of variance for dry weight per plant of eight wildflower species under 205 four increasing fertilizer regimes in year one of a two year trial at Elora Research Station. Elora, Ontario. R2 value for the model is 0.89 and CV value is 32.9. Table 3.8. A.47. Analysis of variance for survival percentage of eight wildflower species under 206 four increasing fertilizer regimes in year one of a two year trial at Elora Research Station. Elora, Ontario. R2 value for the model is 0.90 and CV value is 18.5. Table 3.8. A.48. Analysis of variance for foliage dry weight per plant of eight wildflower species 206 under four increasing fertilizer regimes in year two of a two year trial at Elora Research Station. Elora, Ontario. R2 value for the model is 0.95 and CV value is 20.3. Table 3.9a. A.49. Analysis of variance for flower dry weight per plant of eight wildflower species 206

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under four increasing fertilizer regimes in year two of a two year trial at Elora Research Station. Elora, Ontario. R2 value for the model is 0.88 and CV value is 30.1. Table 3.9a. A.50. Analysis of variance for total dry weight per plant of eight wildflower species 207 under four increasing fertilizer regimes in year two of a two year trial at Elora Research Station. Elora, Ontario. R2 value for the model is 0.94 and CV value is 20.8. Table 3.9a. A.51. Analysis of variance for plant height of eight wildflower species under four 207 increasing fertilizer regimes in year two of a two year trial at Elora Research Station. Elora, Ontario. R2 value for the model is 0.94 and CV value is 13.8. Table 3.9b. A.52. Analysis of variance for flowering area length of eight wildflower species under 208 four increasing fertilizer regimes in year two of a two year trial at Elora Research Station. Elora, Ontario. R2 value for the model is 0.91 and CV value is 22.8. Table 3.9b. A.53. Analysis of variance for percent survival of eight wildflower species under four 208 increasing fertilizer regimes in year two of a two year trial at Elora Research Station. Elora, Ontario. R2 value for the model is 0.77 and CV value is 16.6. Table 3.9a. A.54. Analysis of variance for percent flowering of eight wildflower species under 208 four increasing fertilizer regimes in year two of a two year trial at Elora Research Station. Elora, Ontario. R2 value for the model is 0.66 and CV value is 3.94. Table 3.9b. A.55. Analysis of variance for plant flower ratio of eight wildflower species under 209 four increasing fertilizer regimes in year two of a two year trial at Elora Research Station. Elora, Ontario. R2 value for the model is 0.87 and CV value is 39.1. Table 3.9a. A.56. Analysis of variance for flower stalk number of eight wildflower species under 209 four increasing fertilizer regimes in year two of a two year trial at Elora Research Station. Elora, Ontario. R2 value for the model is 0.98 and CV value is 15.7. Table 3.9b. A.57. Analysis of variance for first bloom date of eight wildflower species under four 209 increasing fertilizer regimes in year two of a two year trial at Elora research station. R2 value for the model is 0.99 and CV value is 6.3. Table 3.15. A.58. Analysis of variance for full bloom date of eight wildflower species under four 210 increasing fertilizer regimes in year two of a two year trial at Elora research station. R2 value for the model is 0.99 and CV value is 4.5. Table 3.15. A.59. Analysis of variance for final bloom date of eight wildflower species under four 210 increasing fertilizer regimes in year two of a two year trial at Elora research station. R2 value for the model is 0.99 and CV value is 4.0. Table 3.15. A.60. Analysis of variance for time of bloom date of eight wildflower species under 210 four increasing fertilizer regimes in year two of a two year trial at Elora research station. R2 value for the model is 0.73 and CV value is 14.7. Table 3.15. A.61. Analysis of variance for above ground dry weight of eight wildflower species 211 under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.56 and CV value is 69.1. Table 4.1 & 4.3. A.62. Analysis of variance for corm dry weight of eight wildflower species under 211

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deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.91 and CV value is 44.5. Table 4.1 & 4.3. A.63. Analysis of variance for root dry weight of eight wildflower species under 211 deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.53 and CV value is 93.5. Table 4.1 & 4.3. A.64. Analysis of variance for total below ground dry weight of eight wildflower 212 species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.82 and CV value is 44.8. Table 4.1 & 4.3. A.65. Analysis of variance for total dry weight of eight wildflower species under 212 deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.80 and CV value is 44.5. Table 4.1 & 4.3. A.66. Analysis of variance for root:shoot ratio of eight wildflower species under 212 deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.51 and CV value is 72.8. Table 4.1 & 4.3. A.67. Analysis of variance for total root length of eight wildflower species under 213 deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.60 and CV value is 62.2. Table 4.8. A.68. Analysis of variance for root surface area of eight wildflower species under 213 deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.58 and CV value is 36.2. Table 4.8. A.69. Analysis of variance for average root diameter of eight wildflower species under 213 deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.55 and CV value is 64. Table 4.8. A.70. Analysis of variance for total root volume of eight wildflower species under 214 deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.59 and CV value is 62.9. Table 4.8. A.71. Analysis of variance for number of root tips of eight wildflower species under 214 deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.64 and CV value is 67.9. Table 4.8. A.72. Analysis of variance for number of root forks of eight wildflower species under 214 deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.55 and CV value is 73.0. Table 4.8. A.73. Analysis of variance for number of root crosses without corm of eight 215 wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.47 and CV value is 100.6. Table 4.8. A.74. Analysis of variance for number of primary roots between 0-5cm of eight 215 wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.40 and CV value is 193.1. Table 4.6. A.75. Analysis of variance for number of primary roots between 5-10cm of eight 215

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wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.68 and CV value is 106.7. Table 4.6. A.76. Analysis of variance for number of primary roots between 10-15cm of eight 216 wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.65 and CV value is 105.9. Table 4.6. A.77. Analysis of variance for number of primary roots between 15-20cm of eight 216 wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.58 and CV value is 104.3. Table 4.6. A.78. Analysis of variance for number of primary roots between 20-25cm of eight 216 wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.56 and CV value is 100.1. Table 4.6. A.79. Analysis of variance for number of primary roots between 25-30cm of eight 217 wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.59 and CV value is 99.9. Table 4.6. A.80. Analysis of variance for number of primary roots between 30-35cm of eight 217 wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.46 and CV value is 127.0. Table 4.6. A.81. Analysis of variance for number of primary roots between 35-40cm of eight 217 wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.28 and CV value is 272.6. Table 4.6. A.82. Analysis of variance for dry weight of secondary roots between 0-10cm of eight 218 wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.54 and CV value is 85.3. Table 4.4. A.83. Analysis of variance for dry weight of secondary roots between 10-20cm of 218 eight wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.45 and CV value is 99.4. Table 4.4. A.84. Analysis of variance for dry weight of roots between 20-30cm of eight 218 wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.50 and CV value is 95.3. Table 4.4. A.85. Analysis of variance for dry weight of roots between 30-40cm of eight 219 wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.48 and CV value is 127.1. Table 4.4. A.86. Analysis of variance for dry weight of primary roots between 0-10cm of eight 219 wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.27 and CV value is

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278.7. Table 4.4. A.87. Analysis of variance for dry weight of primary roots between 10-20cm of eight 219 wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.52 and CV value is 130.8. Table 4.4.

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ANOVA Tables

A.1. Analysis of variance for chlorophyll of eight wildflower species under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.80 and CV value is 26.3. Table 2.8.

Source df Type 1 SS MS F value Pr > F Block 32 1 0.0 7.53 <.0001 Species 7 0 0.1 20.90 <.0001 Water Regime 2 0 0.0 0.42 0.68 Water Regime x 14 0 0.0 1.68 0.08 Species Error 61 0 0.0 Corrected Total 93 1

A.2. Analysis of variance for foliage dry weight of eight wildflower species under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.92 and CV value is 16.3. Table 2.4a.

Source df Type 1 SS MS F value Pr > F Block 32 5545 173.3 23.71 <.0001 Species 7 2197 313.9 42.95 <.0001 Water Regime 2 2519 1259.3 97.69 <.0001 Water Regime x 14 583 41.7 5.70 <.0001 Species Error 63 460 7.3 Corrected Total 95 6006

A.3. Analysis of variance for root dry weight of eight wildflower species under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.96 and CV value is 36.2. Table 2.4a.

Source df Type 1 SS MS F value Pr > F Block 32 10383 324.5 42.27 <.0001 Species 7 8314 1187.6 154.73 <.0001 Water Regime 2 494 246.9 22.98 0.00 Water Regime x 14 1467 104.8 13.65 <.0001 Species Error 63 484 7.7 Corrected Total 95 10866

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A.4. Analysis of variance for survival of eight wildflower species under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.42 and CV value is 20.2. Table 2.4b.

Source df Type 1 SS MS F value Pr > F Block 32 14277 446.2 1.41 0.12 Species 7 4367 623.8 1.97 0.07 Water Regime 2 790 394.8 1.08 0.40 Water Regime x 14 5227 373.4 1.18 0.31 Species Error 63 19906 316.0 Corrected Total 95 34183

A.5. Analysis of variance for total above ground dry weight of eight wildflower species under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.86 and CV value is 24.2. Table 2.4a.

Source df Type 1 SS MS F value Pr > F Block 32 8276 258.6 12.50 <.0001 Species 7 3699 528.4 25.54 <.0001 Water Regime 2 3295 1647.4 45.22 0.00 Water Regime x 14 758 54.1 2.62 0.00 Species Error 63 1303 20.7 Corrected Total 95 9580

A.6. Analysis of variance for total below ground dry weight of eight wildflower species under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.85 and CV value is 25.8. Table 2.4a.

Source df Type 1 SS MS F value Pr > F Block 32 5694 177.9 10.85 <.0001 Species 7 2777 396.7 24.20 <.0001 Water Regime 2 1306 652.9 41.74 0.00 Water Regime x 14 1286 91.9 5.60 <.0001 Species Error 63 1033 16.4 Corrected Total 95 6727

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A.7. Analysis of variance for root:shoot ratio of eight wildflower species under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.86 and CV value is 21.1. Table 2.4b.

Source df Type 1 SS MS F value Pr > F Block 32 14 0.4 11.67 <.0001 Species 7 8 1.1 30.31 <.0001 Water Regime 2 2 0.9 12.40 0.01 Water Regime x 14 3 0.2 6.00 <.0001 Species Error 63 2 0.0 Corrected Total 95 16

A.8. Analysis of variance for root:shoot ratio without corm of eight wildflower species under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.96 and CV value is 30.4. Table 2.4b.

Source df Type 1 SS MS F value Pr > F Block 32 36 1.1 52.88 <.0001 Species 7 34 4.8 225.73 <.0001 Water Regime 2 0 0.2 3.42 0.10 Water Regime x 14 2 0.1 5.32 <.0001 Species Error 63 1 0.0 Corrected Total 95 38

A.9. Analysis of variance for total dry weight of eight wildflower species under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.90 and CV value is 19.2. Table 2.4a.

Source df Type 1 SS MS F value Pr > F Block 32 23538 735.6 16.88 <.0001 Species 7 10382 1483.2 34.03 <.0001 Water Regime 2 8738 4369.2 59.43 0.00 Water Regime x 14 3244 231.7 5.32 <.0001 Species Error 63 2746 43.6 Corrected Total 95 26284

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A.10. Analysis of variance for flower dry weight of eight wildflower species under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.62 and CV value is 102.9. Table 2.4a.

Source df Type 1 SS MS F value Pr > F Block 23 772 33.6 2.52 0.01 Species 4 362 90.6 6.79 0.00 Water Regime 2 84 42.0 3.09 0.12 Water Regime x 8 200 25.0 1.87 0.10 Species Error 36 481 13.3 Corrected Total 59 1253

A.11. Analysis of variance for corm dry weight of eight wildflower species under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.88 and CV value is 24.2. Table 2.4b.

Source df Type 1 SS MS F value Pr > F Block 23 2538 110.4 11.49 <.0001 Species 4 1552 388.0 40.39 <.0001 Water Regime 2 340 169.8 12.78 0.01 Water Regime x 8 225 28.2 2.93 0.01 Species Error 36 346 9.6 Corrected Total 59 2884

A.12. Analysis of variance for percentage of flowering of eight wildflower species under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.68 and CV value is 18.5. Table 2.6.

Source df Type 1 SS MS F value Pr > F Block 23 16838 732.1 3.35 0.00 Species 4 2507 626.7 2.87 0.04 Water Regime 2 6463 3231.7 9.13 0.02 Water Regime x 8 3353 419.2 1.92 0.09 Species Error 36 7860 218.3 Corrected Total 59 24698

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A.13. Analysis of variance for plant height of eight wildflower species under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.71 and CV value is 5.0. Table 2.4a.

Source df Type 1 SS MS F value Pr > F Block 32 50 1.5 32.97 <.0001 Species 7 41 5.9 125.98 <.0001 Water Regime 2 5 2.4 16.83 0.00 Water Regime x 14 1 0.1 1.64 0.06 Species Error 439 21 0.0 Corrected Total 471 70

A.14. Analysis of variance for flowering area height of eight wildflower species under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.51 and CV value is 19.9.Table 2.6.

Source df Type 1 SS MS F value Pr > F Block 26 116 4.5 11.49 <.0001 Species 5 70 14.1 36.15 <.0001 Water Regime 2 23 11.6 25.79 0.00 Water Regime x 10 9 0.9 2.27 0.01 Species Error 287 112 0.4 Corrected Total 313 228

A.15. Analysis of variance for flower width of eight wildflower species under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.95 and CV value is 10.8. Table 2.6

Source df Type 1 SS MS F value Pr > F Block 26 69 2.6 182.14 <.0001 Species 5 61 12.2 838.46 <.0001 Water Regime 2 0 0.0 0.59 0.59 Water Regime x 10 0 0.0 1.61 0.10 Species Error 266 4 0.0 Corrected Total 292 73

191

A.16. Analysis of variance for number of flower stalks of eight wildflower species under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.31 and CV value is 40.5. Table 2.6.

Source df Type 1 SS MS F value Pr > F Block 26 24 0.9 5.58 <.0001 Species 5 17 3.3 19.92 <.0001 Water Regime 2 2 1.1 3.04 0.12 Water Regime x 10 3 0.3 1.69 0.08 Species Error 321 54 0.2 Corrected Total 347 78

A.17. Analysis of variance for number of flowers of eight wildflower species under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.63 and CV value is 29.3. Table 2.6.

Source df Type 1 SS MS F value Pr > F Block 17 157 9.3 15.34 <.0001 Species 2 132 65.8 109.04 <.0001 Water Regime 2 3 1.6 2.85 0.13 Water Regime x 4 7 1.8 2.95 0.02 Species Error 150 91 0.6 Corrected Total 167 248

A.18. Analysis of variance for total stalk number of eight wildflower species under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.33 and CV value is 33.6. Table 2.6.

Source df Type 1 SS MS F value Pr > F Block 23 20 0.9 5.58 <.0001 Species 4 17 4.2 26.53 <.0001 Water Regime 2 1 0.3 1.37 0.32 Water Regime x 8 1 0.1 0.68 0.71 Species Error 260 41 0.2 Corrected Total 283 61

192

A.19. Analysis of variance for aborted stalks of eight wildflower species under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.45 and CV value is 201.5. Table 2.6.

Source df Type 1 SS MS F value Pr > F Block 23 20 0.9 9.93 <.0001 Species 4 16 4.1 46.29 <.0001 Water Regime 2 1 0.5 8.38 0.02 Water Regime x 8 2 0.3 3.28 0.00 Species Error 268 23 0.1 Corrected Total 291 44

A.20. Analysis of variance for first bloom date of eight wildflower species under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.82 and CV value is 15.1. Table 2.7.

Source df Type 1 SS MS F value Pr > F Block 26 225192 8661.2 81.48 <.0001 Species 5 212520 42504.1 399.86 <.0001 Water Regime 2 2566 1282.9 13.73 0.01 Water Regime x 10 1611 161.1 1.52 0.13 Species Error 463 49216 106.3 Corrected Total 489 274407

A.21. Analysis of variance for final bloom date of eight wildflower species under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.86 and CV value is 8.9. Table 2.7.

Source df Type 1 SS MS F value Pr > F Block 26 114019 4385.4 66.65 <.0001 Species 5 96100 19219.9 292.13 <.0001 Water Regime 2 249 124.4 2.25 0.19 Water Regime x 10 1470 147.0 2.23 0.02 Species Error 287 18882 65.8 Corrected Total 313 132902

193

A.22. Analysis of variance for time in bloom of eight wildflower species under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.39 and CV value is 37.3. Table 2.7.

Source df Type 1 SS MS F value Pr > F Block 26 11795 453.7 7.04 <.0001 Species 5 8161 1632.2 25.32 <.0001 Water Regime 2 989 494.4 5.57 0.04 Water Regime x 10 1100 110.0 1.71 0.08 Species Error 285 18370 64.5 Corrected Total 311 30166

A.23. Analysis of variance for photosynthesis of eight wildflower species under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.58 and CV value is 32.8. Table 2.8.

Source df Type 1 SS MS F value Pr > F Block 104 27250 262.0 31.53 <.0001 Species 6 8365 1394.2 167.79 <.0001 Water Regime 2 2820 1410.1 14.62 0.00 Water Regime x 12 5702 475.2 57.19 <.0001 Species Error 2367 19667 8.3 Corrected Total 2471 46917

A.24. Analysis of variance for stomatal conductance of eight wildflower species under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.66 and CV value is 47.0. Table 2.8.

Source df Type 1 SS MS F value Pr > F Block 104 20 0.2 43.76 <.0001 Species 6 8 1.4 310.89 <.0001 Water Regime 2 5 2.6 45.68 <.0001 Water Regime x 12 2 0.2 37.64 <.0001 Species Error 2367 10 0.0 Corrected Total 2471 30

194

A.25. Analysis of variance for water use efficiency of eight wildflower species under three separate watering regimes in a greenhouse trial at the University of Guelph. Guelph, Ontario. R2 value for the model is 0.54 and CV value is 33.7. Table 2.8.

Source df Type 1 SS MS F value Pr > F Block 104 6803 65.4 26.49 <.0001 Species 6 2585 430.8 174.49 <.0001 Water Regime 2 2032 1015.8 214.43 <.0001 Water Regime x 6 2585 430.8 174.49 <.0001 Species Error 2367 5844 2.5 Corrected Total 2471 12648

A.26. Analysis of variance for survival of eight wildflower species under two water and two fertilizer regimes in year one of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.65 and CV value is 11.2. Table 3.11 & 3.12.

F Source df Type 1 SS MS value Pr > F Block 43 16907 393.2 3.71 <.0001 Species 7 13533 1933.2 18.25 <.0001 Water 1 267 267.4 0.64 0.48 Fertilizer 1 33 33.0 0.72 0.43 Water x Species 7 165 23.6 0.22 0.98 Water x Fertilizer 1 2 1.8 0.04 0.85 Species x Fertilizer 7 581 83.0 0.78 0.60 Species x Water x 7 431 61.6 0.58 0.77 Fertilizer Error 84 8899 105.9 Corrected Total 127 25806

195

A.27. Analysis of variance for foliage dry weight of eight wildflower species under two water and two fertilizer regimes in year one of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.90 and CV value is 22.45. Table 3.11 & 3.12.

Source df Type 1 SS MS F value Pr > F Block 43 6923 161.0 18.22 <.0001 Species 7 6187 883.8 100.02 <.0001 Water 1 289 289.2 4.73 0.12 Fertilizer 1 21 20.8 6.81 0.04 Water x Species 7 124 17.8 2.01 0.06 Water x Fertilizer 1 1 1.4 0.45 0.53 Species x Fertilizer 7 59 8.5 0.96 0.47 Species x Water x 7 18 2.6 0.30 0.95 Fertilizer Error 84 742 8.8 Corrected 127 7666

A.28. Analysis of variance for flowering percentage of eight wildflower species under two water and two fertilizer regimes in year one of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.93 and CV value is 41.8. Table 3.11 & 3.12.

Source df Type 1 SS MS F value Pr > F Block 43 108385 2520.6 27.42 <.0001 Species 7 104857 14979.5 162.96 <.0001 Water 1 33 33.3 0.18 0.70 Fertilizer 1 4 4.4 0.02 0.88 Water x Species 7 549 78.4 0.85 0.55 Water x Fertilizer 1 0 0.2 0.00 0.98 Species x Fertilizer 7 157 22.5 0.24 0.97 Species x Water x 7 593 84.8 0.92 0.49 Fertilizer Error 84 7721 91.9 Corrected 127 116107 A.29. Analysis of variance for stalk number per plant of eight wildflower species under two water and two fertilizer regimes in year one of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.94 and CV value is 30.2.

196

Table 3.11 & 3.12.

Source df Type 1 SS MS F value Pr > F Model 43 33 0.8 32.08 <.0001 Species 7 33 4.7 192.75 <.0001 Water 1 0 0.0 0.18 0.70 Fertilizer 1 0 0.0 0.01 0.94 Water x Species 7 0 0.0 1.26 0.28 Water x Fertilizer 1 0 0.0 1.11 0.33 Species x Fertilizer 7 0 0.0 0.12 1.00 Species x Water x 6 0 0.0 1.65 0.14 Fertilizer Error 84 2 0.0 Corrected 127 35

A.30. Analysis of variance for flower dry weight per plant of eight wildflower species under two water and two fertilizer regimes in year one of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.88 and CV value is 37.6. Table 3.11 & 3.12.

F Source df Type 1 SS MS value Pr > F Block 27 5964 220.9 10.23 <.0001 Species 3 2466 822.1 38.08 <.0001 Water 1 1911 1911.0 17.37 0.03 Fertilizer 1 57 56.6 10.01 0.02 Water x Species 3 887 295.7 13.70 <.0001 Water x Fertilizer 1 0 0.2 0.03 0.87 Species x Fertilizer 3 81 27.0 1.25 0.31 Species x Water x 3 37 12.5 0.58 0.63 Fertilizer Error 36 777 21.6 Corrected 63 6742

A.31. Analysis of variance for total dry weight per plant of eight wildflower species under two water and two fertilizer regimes in year one of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.93 and CV value is 22.7. Table 3. 11 & 3.12.

197

Source df Type 1 SS MS F value Pr > F Block 43 23469 545.8 27.95 <.0001 Species 7 18143 2591.8 132.73 <.0001 Water 1 2318 2318.1 9.70 0.05 Fertilizer 1 102 102.3 13.57 0.01 Water x Species 7 1702 243.1 12.45 <.0001 Water x Fertilizer 1 0 0.2 0.02 0.89 Species x Fertilizer 7 207 29.5 1.51 0.17 Species x Water x 7 64 9.1 0.47 0.86 Fertilizer Error 84 1640 19.5 Corrected Total 127 25109

A.32. Analysis of variance for height per plant of eight wildflower species under two water and two fertilizer regimes in year one of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.97 and CV value is 12.1. Table 3.11 & 3.12.

Source df Type 1 SS MS F value Pr > F Block 35 4261 121.7 23.99 <.0001 Species 7 3715 530.6 104.56 <.0001 Water 1 216 216.3 4.90 0.27 Fertilizer 1 14 13.9 6.23 0.13 Water x Species 7 98 13.9 2.75 0.03 Water x Fertilizer 1 4 4.2 1.89 0.30 Species x Fertilizer 7 28 4.0 0.78 0.61 Species x Water x 7 53 7.5 1.48 0.21 Fertilizer Error 28 142 5.1 Corrected Total 63 4403

198

A.33. Analysis of variance for foliage dry weight per plant of eight wildflower species under two water and two fertilizer regimes in year two of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.91 and CV value is 23.1. Table 3.3a & 3.7.

Source df Type 1 SS MS F value Pr > F Block 43 94763 2203.8 20.88 <.0001 Species 7 76007 10858.1 102.87 <.0001 Water 1 5387 5387.4 9.13 0.06 Fertilizer 1 615 615.5 1.42 0.28 Water x Species 7 2647 378.1 3.58 0.00 Water x Fertilizer 1 244 244.2 0.56 0.48 Species x Fertilizer 7 421 60.1 0.57 0.78 Species x Water x Fertilizer 7 442 63.1 0.60 0.76 Error 83 8761 105.6 Corrected Total 126 103524

A.34. Analysis of variance for flowering dry weight per plant of eight wildflower species under two water and two fertilizer regimes in year two of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.94 and CV value is 29.3. Table 3.3a & 3.7.

Source df Type 1 SS MS F value Pr > F Block 35 55359 1581.7 26.51 <.0001 Species 5 30643 6128.5 102.72 <.0001 Water 1 13342 13341.5 413.06 0.00 Fertilizer 1 106 105.7 0.54 0.49 Water x Species 5 7458 1491.7 25.00 <.0001 Water x Fertilizer 1 468 467.6 2.38 0.17 Species x Fertilizer 5 106 21.2 0.36 0.88 Species x Water x Fertilizer 5 630 126.0 2.11 0.08 Error 57 3401 59.7 Corrected Total 92 58760

199

A.35. Analysis of variance for total dry weight per plant of eight wildflower species under two water and two fertilizer regimes in year two of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.93 and CV value is 22.5. Table 3.3a & 3.7.

Source df Type 1 SS MS F value Pr > F Block 43 244078 5676.2 27.39 <.0001 Species 7 173763 24823.2 119.78 <.0001 Water 1 28929 28928.5 49.26 0.01 Fertilizer 1 450 450.3 0.34 0.58 Water x Species 7 18878 2696.9 13.01 <.0001 Water x Fertilizer 1 469 469.1 0.36 0.57 Species x Fertilizer 7 1015 144.9 0.70 0.67 Species x Water x Fertilizer 7 768 109.8 0.53 0.81 Error 83 17201 207.2 Corrected Total 126 261279

A.36. Analysis of variance for flowering area height per plant of eight wildflower species under two water and two fertilizer regimes in year two of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.92 and CV value is 28.2. Table 3.3b & 3.7.

Source df Type 1 SS MS F value Pr > F Block 35 25604 731.5 22.10 <.0001 Species 5 14331 2866.2 86.59 <.0001 Water 1 6890 6889.8 193.07 0.00 Fertilizer 1 26 26.2 0.82 0.40 Water x Species 5 3142 628.4 18.98 <.0001 Water x Fertilizer 1 9 9.2 0.29 0.61 Species x Fertilizer 5 121 24.2 0.73 0.60 Species x Water x Fertilizer 5 74 14.8 0.45 0.81 Error 59 1953 33.1 Corrected Total 94 27557

200

A.37. Analysis of variance for percent survival of eight wildflower species under two water and two fertilizer regimes in year two of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.69 and CV value is 10.4. Table 3.3b & 3.7.

Source df Type 1 SS MS F value Pr > F Block 43 14706 342.0 4.20 <.0001 Species 7 10949 1564.1 19.19 <.0001 Water 1 33 32.6 0.48 0.54 Fertilizer 1 2 1.7 0.02 0.90 Water x Species 7 598 85.5 1.05 0.40 Water x Fertilizer 1 23 23.4 0.21 0.66 Species x Fertilizer 7 953 136.1 1.67 0.13 Species x Water x Fertilizer 7 624 89.1 1.09 0.38 Error 83 6766 81.5 Corrected Total 126 21472

A.38. Analysis of variance for percent flowering of eight wildflower species under two water and two fertilizer regimes in year two of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.59 and CV value is 14.0. Table 3.3b & 3.7.

Source df Type 1 SS MS F value Pr > F Block 35 14116 403.3 2.38 0.00 Species 5 4449 889.9 5.25 0.00 Water 1 1032 1032.2 5.39 0.10 Fertilizer 1 17 16.9 0.16 0.70 Water x Species 5 5595 1119.0 6.60 <.0001 Water x Fertilizer 1 146 146.4 1.41 0.28 Species x Fertilizer 5 364 72.8 0.43 0.83 Species x Water x Fertilizer 5 111 22.1 0.13 0.98 Error 58 9833 169.5 Corrected Total 93 23949

201

A.39. Analysis of variance for plant to flower ratio per plant of eight wildflower species under two water and two fertilizer regimes in year two of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.92 and CV value is 26.7. Table 3.3a & 3.7.

Source df Type 1 SS MS F value Pr > F Block 35 20 0.6 18.12 <.0001 Species 5 15 3.1 96.63 <.0001 Water 1 3 2.8 18.93 0.02 Fertilizer 1 0 0.0 0.42 0.54 Water x Species 5 1 0.2 5.48 0.00 Water x Fertilizer 1 0 0.0 0.59 0.47 Species x Fertilizer 5 0 0.0 1.22 0.31 Species x Water x Fertilizer 5 0 0.0 1.02 0.42 Error 56 2 0.0 Corrected Total 91 22

A.40. Analysis of variance for plant height per plant of eight wildflower species under two water and two fertilizer regimes in year two of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.92 and CV value is 12.7. Table 3.3a & 3.7.

Source df Type 1 SS MS F value Pr > F Block 43 71722 1668.0 23.26 <.0001 Species 7 43656 6236.5 86.97 <.0001 Water 1 13182 13181.5 98.98 0.00 Fertilizer 1 738 737.9 7.26 0.04 Water x Species 7 7636 1090.9 15.21 <.0001 Water x Fertilizer 1 233 233.5 2.30 0.18 Species x Fertilizer 7 904 129.1 1.80 0.10 Species x Water x Fertilizer 7 1054 150.5 2.10 0.05 Error 82 5880 71.7 Corrected Total 125 77602

202

A.41. Analysis of variance for number of flower stalks per plant of eight wildflower species under two water and two fertilizer regimes in year two of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.63 and CV value is 76. Table 3.3b & 3.7.

Source df Type 1 SS MS F value Pr > F Block 39 7192 184.4 3.01 <.0001 Species 6 5008 834.7 13.63 <.0001 Water 1 51 50.6 1.04 0.38 Fertilizer 1 161 160.6 5.69 0.05 Water x Species 6 321 53.6 0.87 0.52 Water x Fertilizer 1 190 190.1 6.73 0.04 Species x Fertilizer 6 264 43.9 0.72 0.64 Species x Water x Fertilizer 6 471 78.5 1.28 0.28 Error 68 4163 61.2 Corrected Total 107 11355

A.42. Analysis of variance for time in bloom of eight wildflower species under two water and two fertilizer regimes in year two of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.93 and CV value is 13.3. Table 3.13 & 3.14.

Source df Type 1 SS MS F value Pr > F Block 27 4429 164.0 12.10 <.0001 Species 4 2752 688.0 50.76 <.0001 Water 1 3 3.0 0.09 0.79 Fertilizer 1 51 51.5 3.20 0.12 Water x Species 3 204 68.1 5.02 0.01 Water x Fertilizer 1 16 15.9 0.99 0.36 Species x Fertilizer 3 25 8.5 0.62 0.61 Species x Water x Fertilizer 2 0 0.1 0.01 0.99 Error 22 298 13.6 Corrected Total 49 4727

203

A.43. Analysis of variance for first bloom date of eight wildflower species under two water and two fertilizer regimes in year two of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.99 and CV value is 7.4. Table 3.13 & 3.14.

Source df Type 1 SS MS F value Pr > F Block 39 124198 3184.6 214.66 <.0001 Species 6 122255 20375.8 1373.47 <.0001 Water 1 359 359.4 9.96 0.05 Fertilizer 1 18 18.2 11.28 0.02 Water x Species 6 471 78.5 5.29 0.00 Water x Fertilizer 1 4 4.0 2.48 0.17 Species x Fertilizer 6 34 5.6 0.38 0.89 Species x Water x Fertilizer 6 20 3.4 0.23 0.97 Error 69 1024 14.8 Corrected Total 108 125222

A.44. Analysis of variance for full bloom date of eight wildflower species under two water and two fertilizer regimes in year two of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.99 and CV value is 6.0. Table 3.13 & 3.14.

Source df Type 1 SS MS F value Pr > F Block 39 134947 3460.2 265.87 <.0001 Species 6 130603 21767.1 1672.50 <.0001 Water 1 485 485.2 33.43 0.01 Fertilizer 1 54 53.6 2.95 0.14 Water x Species 6 709 118.2 9.08 <.0001 Water x Fertilizer 1 3 2.9 0.16 0.71 Species x Fertilizer 6 148 24.6 1.89 0.10 Species x Water x Fertilizer 6 134 22.3 1.72 0.13 Error 60 781 13.0 Corrected Total 99 135728

204

A.45. Analysis of variance for end bloom date of eight wildflower species under two water and two fertilizer regimes in year two of a two year trial at The Guelph Turfgrass Institute. Guelph, Ontario. R2 value for the model is 0.99 and CV value is 5.8. Table 3.13 & 3.14.

Source df Type 1 SS MS F value Pr > F Block 27 66932 2479.0 241.46 <.0001 Species 4 47217 11804.2 1149.76 <.0001 Water 1 45 44.5 2.14 0.24 Fertilizer 1 80 79.8 9.16 0.02 Water x Species 3 95 31.5 3.07 0.05 Water x Fertilizer 1 2 2.0 0.23 0.65 Species x Fertilizer 3 27 9.1 0.88 0.47 Species x Water x Fertilizer 2 20 10.1 0.99 0.39 Error 22 226 10.3 Corrected Total 49 67158

A.46. Analysis of variance for dry weight per plant of eight wildflower species under four increasing fertilizer regimes in year one of a two year trial at Elora Research Station. Elora, Ontario. R2 value for the model is 0.89 and CV value is 32.9. Table 3.8.

Type 1 Source df SS MS F value Pr > F Block 35 3580 102.3 5.8 <.0001 Species 7 2809 401.4 22.77 <.0001 Fertilizer 3 127 42.2 0.61 0.6523 Species x 21 380 18.1 1.03 0.4657 Fertilizer Error 28 493 17.6 Corrected Total 63 4073

205

A.47. Analysis of variance for survival percentage of eight wildflower species under four increasing fertilizer regimes in year one of a two year trial at Elora Research Station. Elora, Ontario. R2 value for the model is 0.90 and CV value is 18.5. Table 3.8.

Type 1 Source df SS MS F value Pr > F Block 35 50698 1448.5 6.95 <.0001 Species 7 45502 6500.3 31.18 <.0001 Fertilizer 3 1618 539.3 5.94 0.0887 Species x 21 2992 142.5 0.68 0.8141 Fertilizer Error 28 5838 208.5 Corrected Total 63 56535

A.48. Analysis of variance for foliage dry weight per plant of eight wildflower species under four increasing fertilizer regimes in year two of a two year trial at Elora Research Station. Elora, Ontario. R2 value for the model is 0.95 and CV value is 20.3. Table 3.9a.

Type 1 Source df SS MS F value Pr > F Block 35 24791 708.3 14.76 <.0001 Species 7 22282 3183.2 66.34 <.0001 Fertilizer 3 848 282.6 6.35 0.0816 Species x 21 1504 71.6 1.49 0.1593 Fertilizer Error 28 1343 48.0 Corrected Total 63 26134

A.49. Analysis of variance for flower dry weight per plant of eight wildflower species under four increasing fertilizer regimes in year two of a two year trial at Elora Research Station. Elora, Ontario. R2 value for the model is 0.88 and CV value is 30.1. Table 3.9a.

Type 1 Source df SS MS F value Pr > F Block 27 6384 236.5 6.50 <.0001 Species 5 5279 1055.7 29.00 <.0001 Fertilizer 3 440 146.6 3.00 0.1954 Species x 15 517 34.4 0.95 0.5356 Fertilizer Error 20 728 36.4 Corrected Total 47 7112

206

A.50. Analysis of variance for total dry weight per plant of eight wildflower species under four increasing fertilizer regimes in year two of a two year trial at Elora Research Station. Elora, Ontario. R2 value for the model is 0.94 and CV value is 20.8. Table 3.9a.

Type 1 Source df SS MS F value Pr > F Block 35 43900 1254.3 12.04 <.0001 Species 7 38635 5519.3 52.96 <.0001 Fertilizer 3 1825 608.3 3.82 0.1501 Species x 21 2924 139.2 1.34 0.2341 Fertilizer Error 28 2918 104.2 Corrected Total 63 46818

A.51. Analysis of variance for plant height of eight wildflower species under four increasing fertilizer regimes in year two of a two year trial at Elora Research Station. Elora, Ontario. R2 value for the model is 0.94 and CV value is 13.8. Table 3.9b.

Type 1 Source df SS MS F value Pr > F Block 35 31250 892.9 12.19 <.0001 Species 7 29347 4192.5 57.22 <.0001 Fertilizer 3 914 304.6 3.13 0.1869 Species x 21 668 31.8 0.43 0.9738 Fertilizer Error 28 2052 73.3 Corrected Total 63 33302

207

A.52. Analysis of variance for flowering area length of eight wildflower species under four increasing fertilizer regimes in year two of a two year trial at Elora Research Station. Elora, Ontario. R2 value for the model is 0.91 and CV value is 22.8. Table 3.9b.

Type 1 Source df SS MS F value Pr > F Block 23 5679 246.9 7.02 0.0001 Species 4 4477 1119.2 31.82 <.0001 Fertilizer 3 310 103.3 0.59 0.6637 Species x 12 341 28.4 0.81 0.6407 Fertilizer Error 16 563 35.2 Corrected Total 39 6242

A.53. Analysis of variance for percent survival of eight wildflower species under four increasing fertilizer regimes in year two of a two year trial at Elora Research Station. Elora, Ontario. R2 value for the model is 0.77 and CV value is 16.6. Table 3.9a.

Type 1 Source df SS MS F value Pr > F Block 35 19536 558.2 2.67 0.0046 Species 7 15986 2283.7 10.92 <.0001 Fertilizer 3 165 55.2 0.23 0.8736 Species x 21 2646 126.0 0.60 0.8825 Fertilizer Error 28 5855 209.1 Corrected Total 63 25390

A.54. Analysis of variance for percent flowering of eight wildflower species under four increasing fertilizer regimes in year two of a two year trial at Elora Research Station. Elora, Ontario. R2 value for the model is 0.66 and CV value is 3.94. Table 3.9b.

Type 1 Source df SS MS F value Pr > F Block 27 564 20.9 1.39 0.2326 Species 5 141 28.1 1.87 0.1477 Fertilizer 3 120 40.2 5.39 0.1 Species x 3 4 1.3 0.09 0.9654 Fertilizer Error 19 286 15.1 Corrected Total 46 850

208

A.55. Analysis of variance for plant flower ratio of eight wildflower species under four increasing fertilizer regimes in year two of a two year trial at Elora Research Station. Elora, Ontario. R2 value for the model is 0.87 and CV value is 39.1. Table 3.9a.

Type 1 Source df SS MS F value Pr > F Block 27 15 0.5 5.03 0.0002 Species 5 13 2.7 24.64 <.0001 Fertilizer 3 0 0.0 0.32 0.8138 Species x 15 1 0.1 0.63 0.8171 Fertilizer Error 20 2 0.1 Corrected Total 47 17

A.56. Analysis of variance for flower stalk number of eight wildflower species under four increasing fertilizer regimes in year two of a two year trial at Elora Research Station. Elora, Ontario. R2 value for the model is 0.98 and CV value is 15.7. Table 3.9b.

Type 1 Source df SS MS F value Pr > F Block 27 709 26.3 31.07 <.0001 Species 5 640 128.0 151.50 <.0001 Fertilizer 3 9 2.9 1.11 0.4679 Species x 15 50 3.3 3.91 0.0026 Fertilizer Error 20 17 0.8 Corrected Total 47 726

A.57. Analysis of variance for first bloom date of eight wildflower species under four increasing fertilizer regimes in year two of a two year trial at Elora research station. R2 value for the model is 0.99 and CV value is 6.3. Table 3.15.

Type 1 Source df SS MS F value Pr > F Block 27 32838 1216.2 91.56 <.0001 Species 5 32586 6517.3 490.63 <.0001 Fertilizer 3 13 4.2 0.11 0.9504 Species x 15 121 8.1 0.61 0.8356 Fertilizer Error 20 266 13.3 Corrected Total 47 33104

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A.58. Analysis of variance for full bloom date of eight wildflower species under four increasing fertilizer regimes in year two of a two year trial at Elora research station. R2 value for the model is 0.99 and CV value is 4.5. Table 3.15.

Type 1 Source df SS MS F value Pr > F Block 27 40818 1511.8 179.79 <.0001 Species 5 40404 8080.8 961.05 <.0001 Fertilizer 3 19 6.4 0.18 0.9061 Species x 15 255 17.0 2.02 0.0705 Fertilizer Error 20 168 8.4 Corrected Total 47 40986

A.59. Analysis of variance for final bloom date of eight wildflower species under four increasing fertilizer regimes in year two of a two year trial at Elora research station. R2 value for the model is 0.99 and CV value is 4.0. Table 3.15.

Type 1 Source df SS MS F value Pr > F Block 23 29849 1297.8 118.86 <.0001 Species 4 28755 7188.7 658.40 <.0001 Fertilizer 3 23 7.6 6.56 0.0784 Species x 12 57 4.8 0.44 0.9223 Fertilizer Error 15 164 10.9 Corrected Total 38 30012

A.60. Analysis of variance for time of bloom date of eight wildflower species under four increasing fertilizer regimes in year two of a two year trial at Elora research station. R2 value for the model is 0.73 and CV value is 14.7. Table 3.15.

Type 1 Source df SS MS F value Pr > F Block 23 920 40.0 1.80 0.1212 Species 4 737 184.3 8.29 0.001 Fertilizer 3 21 7.1 0.92 0.5252 Species x 12 137 11.4 0.51 0.8748 Fertilizer Error 15 333 22.2 Corrected Total 38 1253

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A.61. Analysis of variance for above ground dry weight of eight wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.56 and CV value is 69.1. Table 4.3.

Source df Type 1 SS MS F value Pr > F Block 19 14689 773.1 5.13 <.0001 Species 7 11596 1656.6 10.99 <.0001 Water Regime 1 1418 1418.3 8.14 0.10 Water Regime x 7 1237 176.8 1.17 0.33 Species Error 76 11453 150.7 Corrected Total 95 26142

A.62. Analysis of variance for corm dry weight of eight wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.91 and CV value is 44.5. Table 4.3.

Source df Type 1 SS MS F value Pr > F Block 19 82559 4345.2 40.73 <.0001 Species 7 78203 11171.9 104.73 <.0001 Water Regime 1 1378 1377.9 5.10 0.15 Water Regime x 7 2211 315.9 2.96 0.01 Species Error 76 8107 106.7 Corrected Total 95 90666

A.63. Analysis of variance for root dry weight of eight wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.53 and CV value is 93.5. Table 4.3.

Source df Type 1 SS MS F value Pr > F Block 19 9798 515.7 4.52 <.0001 Species 7 8794 1256.3 11.01 <.0001 Water Regime 1 10 10.1 0.33 0.62 Water Regime x 7 854 122.0 1.07 0.39 Species Error 76 8675 114.1 Corrected Total 95 18474

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A.64. Analysis of variance for total below ground dry weight of eight wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.82 and CV value is 44.8. Table 4.3.

Source df Type 1 SS MS F value Pr > F Block 19 88377 4651.4 19.32 <.0001 Species 7 84799 12114.2 50.31 <.0001 Water Regime 1 1622 1622.0 6.78 0.12 Water Regime x 7 1048 149.8 0.62 0.74 Species Error 76 18299 240.8 Corrected Total 95 106676

A.65. Analysis of variance for total dry weight of eight wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.80 and CV value is 44.5. Table 4.3.

Source df Type 1 SS MS F value Pr > F Block 19 164149 8639.4 15.90 <.0001 Species 7 151786 21683.8 39.90 <.0001 Water Regime 1 6074 6073.8 7.57 0.11 Water Regime x 7 4010 572.8 1.05 0.40 Species Error 76 41299 543.4 Corrected Total 95 205449

A.66. Analysis of variance for root:shoot ratio of eight wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.51 and CV value is 72.8. Table 4.3.

Source df Type 1 SS MS F value Pr > F Block 19 254 13.3 3.67 <.0001 Species 7 201 28.7 7.91 <.0001 Water Regime 1 0 0.4 6.54 0.12 Water Regime x 7 31 4.4 1.22 0.30 Species Error 67 243 3.6 Corrected Total 86 497

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A.67. Analysis of variance for total root length of eight wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.60 and CV value is 62.2. Table 4.8.

F Source df Type 1 SS MS value Pr > F Block 19 14479402299 762073805.0 5.61 <.0001 Species 7 12586426160 1798060880.0 13.24 <.0001 Water Regime 1 161208859 161208859.0 1.19 0.28 Water Regime x 7 2140254658 305750665.0 2.25 0.04 Species Error 70 9506574820 135808212.0 Corrected Total 89 23985977119

A.68. Analysis of variance for root surface area of eight wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.58 and CV value is 36.2. Table 4.8.

Source df Type 1 SS MS F value Pr > F Block 19 176984157 9314955.6 5.16 <.0001 Species 7 152192403 21741771.9 12.05 <.0001 Water Regime 1 1600991 1600991.4 0.89 0.35 Water Regime x 7 26223287 3746183.8 2.08 0.06 Species Error 70 126287562 1804108.0 Corrected Total 89 303271720

A.69. Analysis of variance for average root diameter of eight wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.55 and CV value is 64. Table 4.8.

Source df Type 1 SS MS F value Pr > F Block 19 3512 184.8 4.57 <.0001 Species 7 2553 364.6 9.02 <.0001 Water Regime 1 24 24.4 0.60 0.44 Water Regime x 7 1051 150.1 3.71 0.00 Species Error 70 2829 40.4 Corrected Total 89 6341

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A.70. Analysis of variance for total root volume of eight wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.59 and CV value is 62.9. Table 4.8.

Source df Type 1 SS MS F value Pr > F Block 19 20000 1052.6 5.30 <.0001 Species 7 17389 2484.2 12.51 <.0001 Water Regime 1 157 157.2 0.79 0.38 Water Regime x 7 2188 312.6 1.57 0.16 Species Error 70 13902 198.6 Corrected Total 89 33901

A.71. Analysis of variance for number of root tips of eight wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.64 and CV value is 67.9. Table 4.8.

Source df Type 1 SS MS F value Pr > F Block 19 76623706000 4032826631.6 6.56 <.0001 Species 7 61145015058 8735002151.0 14.20 <.0001 Water Regime 1 3247629039 3247629039.0 5.28 0.02 Water Regime x 7 16023671960 2289095994.0 3.72 0.00 Species Error 70 43054809973 615068713.9 Corrected Total 89 119678515973

A.72. Analysis of variance for number of root forks of eight wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.55 and CV value is 73.0. Table 4.8.

F Source df Type 1 SS MS value Pr > F Block 19 141147275666 7428803982.4 4.48 <.0001 7 115100052686 9.92 <.0001 Species Water Regime 1 3921220627 3921220626.8 2.37 0.13 Water Regime x 7 18253023606 2607574800.9 1.57 0.16 Species Error 70 116059005590 1657985794.1 Corrected Total 89 257206281256

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A.73. Analysis of variance for number of root crosses without corm of eight wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.47 and CV value is 100.6. Table 4.8.

Source df Type 1 SS MS F value Pr > F Block 19 9872684297 519614963.0 3.32 0.00 Species 7 6817456373 973922339.0 6.22 <.0001 Water Regime 1 624909824 624909824.0 3.99 0.05 Water Regime x 7 1184329147 169189878.0 1.08 0.39 Species Error 70 10966434280 156663347.0 Corrected Total 89 20839118577

A.74. Analysis of variance for number of primary roots between 0-5cm of eight wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.40 and CV value is 193.1. Table 4.6.

Source df Type 1 SS MS F value Pr > F Block 19 71647 3770.9 2.68 0.00 Species 7 52784 7540.5 5.37 <.0001 Water Regime 1 504 503.5 0.35 0.61 Water Regime x 7 13449 1921.3 1.37 0.23 Species Error 75 105387 1405.2 Corrected Total 94 177034

A.75. Analysis of variance for number of primary roots between 5-10cm of eight wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.68 and CV value is 106.7. Table 4.6.

Source df Type 1 SS MS F value Pr > F Block 19 2186958 115103.1 8.22 <.0001 Species 7 1643953 234850.4 16.78 <.0001 Water Regime 1 48014 48014.2 6.64 0.12 Water Regime x 7 374975 53567.9 3.83 0.00 Species Error 75 1049976 13999.7 Corrected Total 94 3236935

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A.76. Analysis of variance for number of primary roots between 10-15cm of eight wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.65 and CV value is 105.9. Table 4.6.

Source df Type 1 SS MS F value Pr > F Block 19 1291623 67980.2 7.31 <.0001 Species 7 1022181 146025.9 15.71 <.0001 Water Regime 1 17359 17358.8 4.59 0.17 Water Regime x 7 173848 24835.5 2.67 0.02 Species Error 75 697104 9294.7 Corrected Total 94 1988728

A.77. Analysis of variance for number of primary roots between 15-20cm of eight wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.58 and CV value is 104.3. Table 4.6.

Source df Type 1 SS MS F value Pr > F Block 19 498652 26244.8 5.38 <.0001 Species 7 414894 59270.5 12.15 <.0001 Water Regime 1 14833 14833.1 13.30 0.07 Water Regime x 7 48213 6887.6 1.41 0.21 Species Error 75 365783 4877.1 Corrected Total 94 864435

A.78. Analysis of variance for number of primary roots between 20-25cm of eight wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.56 and CV value is 100.1. Table 4.6.

Source df Type 1 SS MS F value Pr > F Block 19 140994 7420.8 4.96 <.0001 Species 7 121404 17343.4 11.58 <.0001 Water Regime 1 2434 2434.2 0.91 0.44 Water Regime x 7 3797 542.4 0.36 0.92 Species Error 75 112298 1497.3 Corrected Total 94 253292

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A.79. Analysis of variance for number of primary roots between 25-30cm of eight wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.59 and CV value is 99.9. Table 4.6.

Source df Type 1 SS MS F value Pr > F Block 19 132603 6979.1 5.62 <.0001 Species 7 113854 16264.8 13.10 <.0001 Water Regime 1 2867 2866.5 1.68 0.32 Water Regime x 7 8755 1250.8 1.01 0.43 Species Error 75 93118 1241.6 Corrected Total 94 225720

A.80. Analysis of variance for number of primary roots between 30-35cm of eight wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.46 and CV value is 127.0. Table 4.6.

Source df Type 1 SS MS F value Pr > F Block 19 12546 660.3 3.40 <.0001 Species 7 11040 1577.2 8.13 <.0001 Water Regime 1 192 191.6 4.39 0.17 Water Regime x 7 724 103.5 0.53 0.81 Species Error 75 14558 194.1 Corrected Total 94 27104

A.81. Analysis of variance for number of primary roots between 35-40cm of eight wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.28 and CV value is 272.6. Table 4.6.

Source df Type 1 SS MS F value Pr > F Block 19 2506 131.9 1.57 0.09 Species 7 2201 314.4 3.74 0.00 Water Regime 1 33 32.6 4.23 0.18 Water Regime x 7 149 21.2 0.25 0.97 Species Error 75 6302 84.0 Corrected Total 94 8808

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A.82. Analysis of variance for dry weight of secondary roots between 0 -10cm of eight wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.54 and CV value is 85.3. Table 4.4.

Source df Type 1 SS MS F value Pr > F Block 19 261 13.7 4.60 <.0001 Species 7 231 33.0 11.09 <.0001 Water Regime 1 2 2.0 15.27 0.06 Water Regime x 7 26 3.7 1.25 0.29 Species Error 75 224 3.0 Corrected Total 94 484

A.83. Analysis of variance for dry weight of secondary roots between 10 -20cm of eight wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.45 and CV value is 99.4. Table 4.4.

Source df Type 1 SS MS F value Pr > F Block 19 324 17.1 3.27 0.00 Species 7 275 39.3 7.52 <.0001 Water Regime 1 0 0.3 7.63 0.11 Water Regime x 7 48 6.9 1.32 0.25 Species Error 75 392 5.2 Corrected Total 94 717

A.84. Analysis of variance for dry weight of roots between 20-30cm of eight wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.50 and CV value is 95.3. Table 4.4.

Source df Type 1 SS MS F value Pr > F Block 19 172 9.1 3.93 <.0001 Species 7 153 21.9 9.51 <.0001 Water Regime 1 0 0.0 0.03 0.88 Water Regime x 7 16 2.2 0.97 0.46 Species Error 75 173 2.3 Corrected Total 94 345

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A.85. Analysis of variance for dry weight of roots between 30-40cm of eight wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.48 and CV value is 127.1. Table 4.4.

Source df Type 1 SS MS F value Pr > F Block 19 20 1.0 3.60 <.0001 Species 7 17 2.4 8.23 <.0001 Water Regime 1 0 0.2 3.07 0.22 Water Regime x 7 2 0.3 1.16 0.33 Species Error 75 22 0.3 Corrected Total 94 41

A.86. Analysis of variance for dry weight of primary roots between 0-10cm of eight wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.27 and CV value is 278.7. Table 4.4.

Source df Type 1 SS MS F value Pr > F Block 19 2380 125.3 1.42 0.14 Species 7 1419 202.8 2.31 0.04 Water Regime 1 118 117.9 1.18 0.39 Water Regime x 7 555 79.3 0.90 0.51 Species Error 73 6421 88.0 Corrected Total 92 8800

A.87. Analysis of variance for dry weight of primary roots between 10- 20cm of eight wildflower species under deficit and supplemental irrigation in a container trial at The University of Guelph. Guelph, Ontario. R2 value for the model is 0.52 and CV value is 130.8. Table 4.4.

Source df Type 1 SS MS F value Pr > F Block 19 142 7.5 4.12 <.0001 Species 7 133 19.0 10.49 <.0001 Water Regime 1 0 0.4 0.32 0.63 Water Regime x 7 6 0.9 0.48 0.85 Species Error 71 129 1.8 Corrected Total 90 271

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Appendix B: Supplementary Tables and Figures

Appendix 2.1: Carbon exchange rate of all full measurement cycles taken each day after saturation (DAS) within greenhouse trial imposing Low Water (23-40% volumetric water content), High Water (55-70% volumetric water content), and Cyclic Drought (Soil saturation followed by a period of irrigation cessation until plants display wilt.

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Appendix 2.2: Stomatal conductance of all full measurement cycles taken each day after saturation (DAS) within greenhouse trial imposing Low Water (23-40% volumetric water content), High Water (55-70% volumetric water content), and Cyclic Drought (Soil saturation followed by a period of irrigation cessation until plants display wilt.

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Appendix 2.3: Water use efficiency (WUE) of all full measurement cycles taken each day after saturation (DAS) within greenhouse trial imposing Low Water (23-40% volumetric water content), High Water (55-70% volumetric water content), and Cyclic Drought (Soil saturation followed by a period of irrigation cessation until plants display wilt.

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Appendix 2.4: Soil sample results taken from GTI on April 10th 2011 at 6” depth with soil probe. One sample taken for every 3ft2 and then all samples mixed together for one minute. Mixed sample was sent for analysis.. Analyzed by the University of Guelph Laboratory Services Agriculture and Food Laboratory.

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Appendix 2.5: Soil sample results taken from Elora on June 29th 2011 at 6” depth with soil probe. One sample taken for every 3ft2 and then all samples mixed together for one minute. Mixed sample was sent for analysis. Analyzed by the University of Guelph Laboratory Services Agriculture and Food Laboratory.

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