TigerPrints. Clemson University. Adam Wheeler Gore Clemson University,

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1 Clemson University TigerPrints All Theses Theses Potentil Helth Benefits of Pigment-Contining Products on Creedping Bentgrss [Agrostis stolonifer L. vr plustris (Huds.)] nd Hybrid Bermudgrss [Cynodon dctylon (L.) Pers. C. trnsvlensis Burtt-Dvy] Adm Wheeler Gore Clemson University, Follow this nd dditionl works t: Recommended Cittion Gore, Adm Wheeler, "Potentil Helth Benefits of Pigment-Contining Products on Creedping Bentgrss [Agrostis stolonifer L. vr plustris (Huds.)] nd Hybrid Bermudgrss [Cynodon dctylon (L.) Pers. C. trnsvlensis Burtt-Dvy]" (2016). All Theses This Thesis is brought to you for free nd open ccess by the Theses t TigerPrints. It hs been ccepted for inclusion in All Theses by n uthorized dministrtor of TigerPrints. For more informtion, plese contct kokeefe@clemson.edu.

2 POTENTIAL HEALTH BENEFITS OF PIGMENT-CONTAINING PRODUCTS ON CREEPING BENTGRASS [Agrostis stolonifer L. vr plustris (Huds.)] AND HYBRID BERMUDAGRASS [Cynodon dctylon (L.) Pers. C. trnsvlensis Burtt-Dvy] A Thesis Presented to the Grdute School of Clemson University In Prtil Fulfillment of the Requirements for the Degree Mster of Science Plnt nd Environmentl Science by Adm Wheeler Gore My 2016 Accepted by: Dr. L.B. McCrty, Committee Chir Dr. S.B. Mrtin Dr. Christin Wells

3 ii ABSTRACT With the ever chnging mrket of the golf course industry, turfgrss mngers re constntly exploring options of promoting helthier turf while lso mintining n pproprite budget. One constnt problem is how to mnge nd relieve summer stress on bentgrss [Agrostis stolonifer L. vr plustris (Huds.)] putting greens. Appliction of pigmented products is n incresingly populr mngement prctice ttempting to relieve some of this stress ssocited with high tempertures nd light intensity. Severl of these products re lso mrketed for use on wrm-seson grsses such s hybrid bermudgrss s men of providing winter green color nd improving or hstening breking of winter dormncy. Reserch on use of these products on creeping bentgrss hs incresed in recent yers but is still limited, while reserch on wrm-seson grsses is sprse. The objective of this study ws therefore to investigte the impcts of pigment-contining products on turfgrss physiology of wrm- nd cool-seson grsses during periods of respective stress. Three pigment-contining products nd three pigment-free products were selected for testing lone nd in combintions for two field studies in 2013 nd 2014 on creeping bentgrss nd hybrid bermudgrss: Turf Screen (zinc oxide nd titnium dioxide), PAR (copper-bsed pigment), Chipco Signture (fosetyl-luminum nd copper-bsed pigment), Title Phyte (potssium phosphite), Turf Screen + Title Phyte, PAR + Title Phyte, nd Fosetyl-Al (fosetyl-luminum). Products were pplied bi-weekly for twelve weeks. Civits (minerl oil) + Hrmonizer (copper bsed pigment) nd Hrmonizer lone were dded for 2014 field study on hybrid bermudgrss. All products were used in two

4 iii seprte growth chmber studies investigting helth of bentgrss in high tempertures nd bermudgrss in freezing tempertures. All products were lso used in bermudgrss dormncy breking study. In field studies, ppliction of products cused generl increse in cnopy tempertures (~0.5 to 3 C) compred to untreted controls of both grss species. Bentgrss treted with pigmented products exhibited greter (~6 to 20 µmol CO2 cm -2 s -1 ) crbon dioxide exchnge rtes (CER) thn tht of the untreted control indicting reduction in photosynthesis. Applictions of Chipco Signture to hybrid bermudgrss in yer two resulted in more negtive CER ( µmol CO2 cm -2 s -1 ) indicting greter photosynthetic ctivity. Decresed (24-50 reltive chlorophyll) chlorophyll concentrtion in creeping bentgrss ws observed in both study yers by ll tretments compred to the untreted while no effect ws observed in bermudgrss. No effect on root mss following product use ws observed in either grss species. Tissue nd soil nlysis of creeping bentgrss indicted tht Turf Screen nd Turf Screen + Title Phyte pplictions incresed zinc concentrtion in both the plnt nd soil by n verge of 820 ppm nd 4.75 kg h -1, respectively. Applictions of PAR, PAR + Title Phyte, nd Turf Screen + Title Phyte cused n increse of ~27 ppm of copper in plnt tissue of bentgrss. Applictions to bermudgrss hd similr results with zinc in soil nd tissue nlysis. Growth chmber studies on creeping bentgrss further confirmed field studies. Appliction of tretments in study one resulted in sttisticlly greter CER thn unstressed control by n verge of ~15.4 µmol CO2 cm -2 s -1. Fluorescence rtings in

5 iv study two yielded greter (~13) Fv/Fm vlues in the unstressed control thn ny other tretment indicting reduced photosynthetic efficiency. Growth chmber studies on hybrid bermudgrss focusing on freezing stress indicted net increse (~8 to 21 µmol CO2 cm -2 s -1 ) in CER of Title Phyte, stressed control, nd Turf Screen in both studies over the unstressed control. However, overll fluorescence of ll tretments ws reduced compred to the unstressed control by Fv/Fm vlue of ~12. Spring green-up study reveled no differences mong tretments on erlier breking of dormncy of hybrid bermudgrss. The incresed bentgrss CER of treted turf indictes reduction in net photosynthesis while incresed cnopy tempertures promote more stressful environment. Results suggest tht severl products investigted my promote greter het stress on creeping bentgrss during times of hot, humid wether. Applictions to bermudgrss during the sme time period did not show negtive effects, however the concentrtion of hevy metls could crete future toxicity problems.

6 v DEDICATION I dedicte this work to my fther, mother, sister, nd brother. They hve ll set exmples throughout my life on how to live s hppily s possible. Their forgiving nture is one tht I cn never forget nd will crry throughout my life, nd their support for whtever I do is more thn I could ever sk for.

7 vi ACKNOWLEDGEMENTS I would like to thnk Dr. Bert McCrty, my mjor dvisor. Though we hve not lwys greed on the methods with which he tught, nor the wy tht I worked, his persevernce nd knowledge re things tht I will lwys crry with me. I would lso like to thnk Dr. Bruce Mrtin nd Dr. Christin Wells, the other members of my grdute committee. Dr. Mrtin, for helping me get strted in this journey with ides which helped me understnd wht I ws looking for when I myself ws unsure, nd for dditionl ides on how to further my reserch. Dr. Wells, for her willingness to work with me, even when I would not lwys know wht I ws serching for nd her teching of equipment usge. Their dvice, knowledge, nd equipment got me further long in this reserch thn I would hve been ble to lone. I m lso thnkful for the dvice nd help tht I hve gined from my friendships here t Clemson. Specil thnks to Dr. Bob Cross, Nthn Gmbrell, nd Pete Signoretti for their dvice, help, nd lughter throughout the time tht I hve spent doing this reserch.

8 vii TABLE OF CONTENTS Pge TITLE PAGE... i ABSTRACT... ii DEDICATION... v ACKNOWLEDGEMENTS... vi LIST OF TABLES... x LIST OF FIGURES... xii CHAPTER I. INTRODUCTION... 1 Creeping Bentgrss... 1 Hybrid Bermudgrss... 2 Fungicidl Effects on Plnt Helth... 2 Air nd Soil Temperture Effects... 3 Bentgrss... 3 Hybrid Bermudgrss... 4 Pigments... 5 Fluorescence... 7 Hevy Metl Toxicity... 8 Photosynthesis... 8 II. MATERIALS AND METHODS Field Studies... 10

9 viii Tble of Contents (Continued) Pge Turf Qulity Cnopy Tempertures nd Chlorophyll Content Volumetric Soil Moisture Content Roots Nutrient Anlysis Bentgrss Growth Chmber Anlysis Bermudgrss Growth Chmber Anlysis Spring Greenup Study III. RESULTS AND DISCUSSION Field Studies Bentgrss Field Studies Cnopy Tempertures Chlorophyll Content Visul Turf Qulity Normlized Difference Vegettion Index Soil Moisture Crbon Dioxide Exchnge Rte Root Weight Hevy Metls Bermudgrss Field Studies... 34

10 ix Tbles of Contents (Continued) Pge Cnopy Tempertures Chlorophyll Content Visul Turf Qulity Normlized Difference Vegettion Index Soil Moisture Crbon Dioxide Exchnge Rte Root Weight Hevy Metls Growth Chmber Studies Bentgrss Het Stress Crbon Dioxide Exchnge nd Flourescnce Bermudgrss Cold Stress Crbon Dioxide Exchnge nd Flourescence Green-up Study IV. CONCLUSION Bentgrss Bermudgrss Summry V. REFERENCES... 54

11 x LIST OF TABLES Tble Pge 2-1. Tretments nd rtes pplied to L-93 creeping bentgrss green field studies bi-weekly in 2013 nd 2014 t Clemson University, Clemson, SC Tretments nd rtes pplied bi-weekly to Tifegle bermudgrss green field studies in 2013 nd 2014 t Clemson University, Clemson, SC Tretments nd rtes pplied bi-weekly to L-93 creeping bentgrss nd Tifegle bermudgrss for growth chmber studies in 2013 nd 2014 t Clemson University, Clemson, SC Tretments nd rtes pplied bi-weekly to Tifegle bermudgrss green green-up studies in 2013 nd 2014 t Clemson University, Clemson, SC Volumetric soil wter content dt for two studies following bi-weekly pplictions of vrious nonpigmented nd pigment-contining products to creeping bentgrss Net root dry weight of creeping bentgrss following bi-weekly pplictions of vrious nonpigment nd pigment-contining products Net soil copper concentrtion dt for two bentgrss studies following bi-weekly pplictions of vrious nonpigmented nd pigment-contining products to creeping bentgrss... 34

12 xi List of Tbles (Continued) Tble Pge 3-4. Volumetric soil wter content dt for two studies following bi-weekly pplictions of vrious nonpigmented nd pigment-contining products to hybrid bermudgrss Net root dry weight of hybrid bermudgrss following bi-weekly pplictions of vrious nonpigment nd pigment-contining products to hybrid bermudgrss Net soil copper concentrtion dt for two studies following bi-weekly pplictions of vrious nonpigmented nd pigment-contining products to hybrid bermudgrss Net crbon dioxide exchnge rte of hybrid bermudgrss subjected to simulted freeze following bi-weekly ppliction of vrious nonpigmentnd pigment-contining products... 48

13 xii LIST OF FIGURES Figure Pge 2-1. Creeping bentgrss (Agrostis stolonifer L. vr plustris (Huds.)) ppernce following folir ppliction of vrious pigmented products TifEgle bermudgrss (Cynodon dctylon (L.) Pers. X C. trnsvlensis Burtt-Dvy) ppernce following folir ppliction of vrious pigmented products Cnopy temperture verges for two summer studies following bi-weekly pplictions to creeping bentgrss of vrious nonpigmented nd pigment-contining products Chlorophyll content verges for two summer studies following bi-weekly pplictions to creeping bentgrss of vrious nonpigmented nd pigment-contining products Averge visul turfgrss qulity for two summer studies following bi-weekly pplictions to creeping bentgrss of vrious nonpigmented nd pigment-contining products Normlized difference vegettion index (NDVI) verges for two summer studies following bi-weekly pplictions to creeping bentgrss of vrious... 28

14 xiii List of Figures (Continued) Figure Pge 3-5. Crbon dioxide exchnge rtes for two summer studies following bi-weekly pplictions to creeping bentgrss of vrious nonpigmented nd pigment-contining products Net plnt tissue zinc concentrtion for two summer studies following bi-weekly pplictions to creeping bentgrss of vrious nonpigmented nd pigment-contining products Net plnt tissue copper concentrtion for two summer studies following bi- weekly pplictions to creeping bentgrss of vrious nonpigmented nd pigment- contining products Net soil zinc concentrtion for two summer studies following bi-weekly pplictions to creeping bentgrss of vrious nonpigmented nd pigment-contining products Cnopy temperture verges for two summer studies following bi-weekly pplictions to hybrid bermudgrss of vrious nonpigmented nd pigment- contining products Chlorophyll content verges for two summer studies following bi-weekly pplictions to hybrid bermudgrss of vrious nonpigmented nd pigment- contining products... 36

15 xiv List of Figures (Continued) Figure Pge Averge visul turfgrss qulity for two summer studies following bi-weekly pplictions to hybrid bermudgrss of vrious nonpigmented nd pigment- contining products Normlized difference vegettion index (NDVI) verges for two summer studies following bi-weekly pplictions to hybrid bermudgrss Crbon dioxide exchnge rtes for two summer studies following bi-weekly pplictions to hybrid bermudgrss of vrious nonpigmented nd pigment- contining products Net plnt tissue zinc concentrtion for two summer studies following bi- weekly pplictions to hybrid bermudgrss of vrious nonpigmented nd pigment- contining products Net plnt tissue copper concentrtion for two summer studies following bi- weekly pplictions to hybrid bermudgrss of vrious nonpigmented nd pigment- contining products Net soil zinc concentrtion for two summer studies following bi-weekly pplictions to hybrid bermudgrss of vrious nonpigmented nd pigment- contining products... 43

16 xv List of Figures (Continued) Figure Pge Crbon dioxide exchnge rtes for two growth chmber studies t Clemson University Greenhouse Fcility following tretments with pigment-contining products on creeping bentgrss Averge FluorPen redings for growth chmber study following tretments with pigment-free nd pigment-contining products on creeping bentgrss Averge FluorPen redings for growth chmber study following tretments with pigment-free nd pigment-contining products on hybrid bermudgrss Normlize difference vegettive index for spring green up on hybrid bermudgrss treted with nonpigmented nd pigment-contining products... 50

17 1 CHAPTER I INTRODUCTION Creeping Bentgrss Creeping bentgrss [Agrostis stolonifer L. vr plustris (Huds.)] is cool seson turfgrss ntive to centrl Europe often grown in the cool nd humid environments of northern United Sttes (McCrty, 2011). Due to its bility to tolerte low mowing heights (3 mm), soft texture, superb density, nd nrrow lef blde (0.62 to 0.92 mm) (Berd nd Sifers, 1997), creeping bentgrss is the most commonly used cool seson turfgrss species on golf greens (Berd, 1982). Due to its populrity, bentgrss greens hve been constructed in wrmer regions of the United Sttes. However, s result of these higher tempertures nd greter humidity, qulity of creeping bentgrss often declines in summer months; condition referred to s summer bentgrss decline (Lucs, 1995; Crrow, 1996; Berd, 1997). Creeping bentgrss is C3 plnt which is more suited for tempertures of 15 to 24 C (Berd, 1997). Trnsitionl zones, where bentgrss hs been used, often experience tempertures greter thn 30 C in summer months. These tempertures ply mjor fctor in suppressing growth nd qulity of cool seson grsses (Crrow, 1996; Berd, 1997). This suppression is observed through root loss, incresed disese incidence, reduced vegettive growth, nd reduced shoot density (Krns nd Johnson, 1974; DiPol nd Berd, 1992; Crrow, 1996; Hung et l., 1998, b). In ddition to high tempertures, summer decline is lso intensified by improper soil wter levels, poor soil ertion, nd soil-borne disese orgnism (Lucs, 1995; Crrow, 1996).

18 2 Hybrid Bermudgrss Hybrid bermudgrss [Cynodon dctylon (L.) Pers. C. trnsvlensis Burtt-Dvy], wrm-seson turfgrss, is one of the four min turf-type bermudgrsses used s fineturf (McCrty, 2011). Ntive to the hot, dry summers in Afric round the Indin Ocen, the common type of bermudgrss [Cynodon dctylon (L.) Pers.] ws often used on ll plying surfces of golf courses prior to the mid-1940 s (McCrty, 2011). Hybrid bermudgrss is fvored over its common type form in wrm subtropicl nd tropicl climtes due to its bility to tolerte very low mowing heights (3.2 to 4 mm) while sustining dense stnd of turf nd exhibiting good recovery potentil (Turgeon, 2008; Stier et l., 2013). Though dvntgeous in climtes experiencing hotter tempertures of 27 to 38 C, bermudgrss is used less in cooler climtes due to dormncy (brown) stte tht occurs below 10 C with potentil for chilling nd freezing dmge (McCrty, 2011). Bermudgrss is lso susceptible to high thtch ccumultion due to its rpid growth, exhibits poor shde tolernce, nd is susceptible to insect nd disese problems (Brede, 2000; McCrty, 2011). Fungicidl Effects on Plnt Helth Fungicides re commonly used on creeping bentgrss during the summer, both s wy to prevent the occurrence of severl diseses s well s wy to combt summer bentgrss decline (McCrty, 2011). Dernoeden nd Fu (2008) concluded tht

19 3 pplictions of luminum tris + chlorothlonil nd potssium slts of phosphite fungicides + mncozeb improved the overll qulity of creeping bentgrss during the summer in ddition to reducing sclping injury. Though not proven, it ws suggested the fungicides modified the plnt morphology, growth hbit, nd/or rte. Lucs (1995) observed tht pplictions of luminum tris + mncozeb or luminum tris + chlorothlonil t 14 dy intervls could reduce summer bentgrss decline. Building upon tht, Lucs nd Mudge (1997) enhnced bentgrss qulity using monoester slt of phosphorous cid nd n ethylene bisdithiocrbmte fungicide. The eventul conclusion ws tht the mixture of luminum tris + mncozeb (s Fore 80WP, Rohm nd Hss compny), which contins Pigment Blue 15, provided greter qulity nd color thn ny other fungicide combintions. Pigment Blue 15 reportedly enhnced the ctivity of mncozeb nd luminum tris (Lucs nd Mudge, 1997). In ddition, sequentil pplictions of KH2PO3 (potssium phosphite), either pplied lone or in combintion with iprodione, were found to reduce the occurrence of Michrodochium nivle (Fr.) Smuels nd Hllett nd other disese such dollr spot (Sclerotini homeocrp F.T. Benn.) nd possibly Pythium (Pythium spp.), s well s improve overll qulity of turf cnopy (Dempsey et l. 2012). Air nd Soil Temperture Effects Bentgrss:

20 4 Premier tempertures for cool-seson grsses rnge from 15 to 24 C for shoot growth nd 10 to 18 C for root growth (Berd, 1973). A study on root growth of Kentucky bluegrss (Po prtensis L.) indicted n increse of soil tempertures up to 25 C hd negtive impct on root growth (Aldous nd Kufmn, 1979). Little root initition occurs t high soil tempertures except following 2 to 3 dy period of cooler soil tempertures (Berd nd Dniel, 1966). The greter sensitivity of roots to soil temperture my promote direct injury of roots s n initil fctor in plnt s response to high tempertures, thus lower soil tempertures my reduce the occurrence of summer bentgrss decline. This reduction of soil tempertures llows for better plnt helth in res of greter root growth, lef photosynthesis, nd shoot growth (Skene nd Kerridge, 1967; Aldous nd Kufmn, 1979; Kuroyngi nd Pulsen, 1988). Hybrid Bermudgrss: Optimum soil nd ir tempertures for bermudgrss growth re 24 to 35 C nd 29 to 37 C, respectively (Lovvorn, 1945). Bermudgrss is prone to low temperture injury, prticulrly in lte winter nd erly spring, nd most commonly occurs during periods of lternting freezing nd thwing nd is ggrvted by incresed crown hydrtion (Berd, 1973), shde, trffic, nd crown dessiction (McCrty, 2011). To prevent potentil dmge cused by freezing tempertures, plnts cn obtin chilling nd freezing tolernce when exposed to low tempertures tht re still greter thn freezing temperture (Hughes nd Dunn, 1996). Chilling nd freezing stress result in the reduction of photosynthetic ssimiltion of CO2 vi the reduction of stomtl conductnce, modifiction of thylkoid lipids, nd restriction of electron trnsport, s well s loss of

21 5 chlorophyll nd cesstion of growth (Miller, 1960; DiPol et l., 1981; Krnok nd Berd, 1983; Allen nd Ort, 2001; Adms et l., 2002). A 45% decrese in photosynthetic rtes ws reported by Miller (1960) when tempertures were decresed from 35 C to 15 C. Chilling injury hs been shown to increse the lekge of ions nd mino cids (McKersie nd Leshem, 1994). Additionlly, production of rective oxygen species (ROS) such s superoxide (O2 - ), hydroxyl rdicls (OH - ), nd hydrogen peroxide (H2O2) is lso induced by chilling nd freezing stress which cn cuse severe cellulr injury (Inze nd Vn Montgu, 1995). Pigments The ppliction of pigments nd dyes hs become common prctice on golf courses. Most of these products hve green-bsed color, thus, help crete more estheticlly plesing turf. However, repeted pplictions of pigment-contining products hve been reported to reduce overll stnd qulity. This my be due, in prt, to the ltering of light intensity nd spectrl qulity (Reynolds et l., 2012). Pigments consist of dry powders with vrying chemicl compositions bsed on desired color. Common pigments in white, blck, nd red pint re TiO2 (titnium dioxide), C (crbon), nd Fe2O3 (iron oxide), respectively (Reynolds et l., 2012). Mny pigments hve moleculr structure similr to chlorophyll, however, pigment centered molecules re copper ions insted of mgnesium s with chlorophyll. This similr moleculr structure of pigment molecules to chlorophyll is one possible mens of

22 6 incresing plnt s photosynthetic efficiency. Visible light nd photosyntheticlly ctive rdition (PAR) shre the sme rnge of wvelengths, 400 to 700 nm. Within PAR re two specific wvelengths, grouped by color, tht re most effectively bsorbed for photosynthesis - blue light nd red light with wvelengths of 400 to 500 nm nd 600 to 700 nm, respectively (Tiz nd Zeiger, 2006). Reynolds et l. (2013) determined tht the long-term ppliction of pigments, specificlly those of drker colors such s green, blck, nd drk blue, reflected 87 to 95% of PAR. Summer pplictions of pigmented products to creeping bentgrss decresed crbon dioxide exchnge rte s well s normlized difference vegettion index (McCrty et l., 2014). The ppliction of pigments onto plying res to provide desirble winter color is n incresing trend in lieu of overseeding. Appliction of colornt to bufflogrss (Boutelou dctyloides (Nutt.) Columbus) ws found to provide similr color nd qulity s djcent cool seson turfgrsses (Shermn et l., 2005). Applictions of pigmented products cn enhnce spring green-up when compred to trditionl overseeding prctices nd dormnt turf, due in prt to the incresed soil nd ir tempertures (Liu et l., 2007). Previous work by Kreuser nd Rossi (2014) found tht summer pplictions of minerl oil contining product, Civits, cused chlorosis nd decresed visul qulity on creeping bentgrss. They lso noted tht the use of n ccompnying pigmentcontining product, Hrmonizer, did not llevite ny symptoms nd ppered only to msk stress issues by providing green color.

23 7 Fluorescence Chlorophyll fluorescence is mens of explining photosynthetic efficiency nd the effect of biotic stresses on tht efficiency (Adms et l., 2004; Mxwell nd Johnson, 2000). Stress tht cuses the formtion of vrious ctive oxygen rdicls decreses quntum efficiency of photosystem II (Fv/Fm). The rective nture of Fv/Fm mkes for n indictor of plnt stress which cn be quntittively compred to stress responses of other plnt species (Cessn et l, 2010). The fluctution of solr rdition throughout the dy hs significnt impct on photosynthetic light rections in the thylkoid membrne system inside chloroplsts (Kirchoff, 2014). When solr rdition is bsorbed t levels tht exceed rtes of photosynthesis, n event typiclly seen mid-dy under full sun exposure, or when plnts re experiencing sub-pr environmentl conditions, excess energy is more likely trnsferred to rective oxygen species (ROS)(Demmig-Adms nd Adm, 2006). Plnts hve developed vrious forms of photoprotection s wy to prevent dmging effects of the vrious ROS. In response to high light situtions, plnts will void bsorbing excessive photons through heliotropic movements s well s reducing their chlorophyll content (Heber, 2002). Redirection of electrons from the electron trnsport chin to rections other thn the Clvin cycle such s the wter-wter cycle lso llow for the dissiption of light energy (Heber, 2002).

24 8 Hevy Metl Toxicity The presence of hevy metls in soil environment my be beneficil or toxic to plnts, depending on their concentrtions (Rout nd Ds, 2003). Zinc is required in the synthesis of growth hormones nd proteins (Mrschner, 1995) requiring rpid incorportion of the element llowing for high potentil of phototoxicity (Rout nd Ds, 2003). Zinc toxicity my result in reduced root growth, yellowing of leves, nd eventul plnt deth (Hvlin et l., 2005). A sufficient zinc level is suggested between 20 to 200 mg kg -1 in vrious turf tissues with vrition occurring between grss species (Boehle nd Lindsy, 1969; Jones, 1980; McCrty, 2011). Xu nd Mncino (2001) observed tht mintining concentrtion below 109 mg kg -1 prevented phytotoxicity in creeping bentgrss, while nnul bluegrss (Po nnu L.) ws ble to tolerte level of 200 mg kg -1. Copper is n essentil element involved in vrious redox rections (Tiz nd Zeiger, 2006). Soil concentrtions of copper my increse over time due to the repeted ppliction of Cu-contining fungicides, orgnic fertilizers, nd effluent irrigtion wter (Mrschner, 1995; Brun et l., 2001). Fust nd Christins (2000) reported soil copper levels incresing from 0 to 600 mg kg -1 cused 16% decrese in bentgrss dry clipping weight s well s 52% lower dry root mss thn the untreted. Photosynthesis Photosynthesis is n essentil plnt process, thus mking it n effective indictor of plnt helth when subjected to stress (Slisbury nd Ross, 1978). The net uptke or

25 9 efflux of CO2 from given re of turf cnopy provides mesure of net photosynthesis (Kosugi et l, 2010). Positive mesurements of CER indicte tht respirtion rtes exceed photosynthesis rtes, while negtive mesurements indicte tht photosynthesis predomintes. Mesurements of photosynthesis re often conducted with hnd-held chmbers plced over the turf cnopy nd soil nd mesure CO2 exchnge (Bremer nd Hm, 2005). The CIRAS-2 Portble Photosynthesis System (PP System, Hverhill, MA 01912) hs been used previously to mesure CO2 exchnge rtes in turfgrss scenrios. The system ws used to determine cnopy photosynthetic rtes in n ssessment of lowlight tolernce of seshore psplum (Psplum vgintum Swrtz) nd hybrid bermudgrss (Jing et l, 2004). Ambient light nd CO2 were used to mesure net cnopy photosynthetic rte in micromoles of CO2 per meter squred per second (µmol cm -2 s -1 ). To obtin mesurements, 150 millimeter dimeter cler polyethylene chmber ws firmly pressed to the turfgrss surfce to sel the chmber, llowing the CIRAS-2 two to three minutes per smple. A similr system nd method ws used in this study to test the hypothesis tht the ppliction of pigmentcontining products cuses reduced photosynthesis nd inferior turf qulity.

26 10 CHAPTER II MATERIALS AND METHODS Field Studies Field reserch ws conducted in Clemson, SC t the Clemson University Turfgrss Reserch Fcility on two 14 yer old putting greens, L-93 bentgrss nd TifEgle bermudgrss, both constructed to USGA specifictions (USGA Green Section Stff 1993). This reserch ws conducted from 24 June to 16 September, 2013 nd 7 July to 29 September, Tretments consisted of n untreted control, zinc oxide + titnium dioxide + pigment (Turf Screen) (TurfMx LLC., Erdenheim. PA) t 2.5 oz/1,000 ft 2 (7.97 L h -1 ), copper phtlocynine pigment (PAR)(Hrrell s LLC., Lkelnd, FL) t 0.37 oz/1,000 ft 2 (1.17 L h -1 ), potssium phosphite (Title Phyte) (Hrrell s LLC., Lkelnd, FL) t 4 oz/1,000 ft 2 (12.57 L h -1 ), Turf Screen nd Title Phyte t 2.5 oz/1,000 ft 2 (7.97 L h -1 ), nd 4 oz/1,000 ft 2 (12.57 L h -1 ) respectively, PAR nd Title Phyte t 0.37 oz/1,000 ft 2 (1.17 L h -1 ) nd 4 oz/1,000 ft 2 (12.57 L h -1 ) respectively, fosetylluminum (Chipco Signture + Stressgrd) (Byer CropScience AG, Monheim Am Rhein, Germny) t 6 oz/1,000 ft 2 (19.13 L h -1 ), nd Fosetyl-l (fosetyl-luminum) (Quli-Pro, Psden, TX) t 4 oz/1,000 ft 2 (12.57 L h -1 )(Tble 2-1). Minerl oil (Civits)(Petro-Cnd, Mississug,Ontrio) t oz/1000 ft 2 (1.17 L h -1 ) plus proprietry pigment (Civits Hrmonizer) (Petro-Cnd, Mississug,Ontrio) t oz/1000 ft 2 (0.073 L h -1 ) nd Civits Hrmonizer lone t oz/1000 ft 2 (0.073 L h - 1 ) were dded to 2014 bermudgrss field trils (Tble 2-2). Due to the potssium content of Title Phyte, soluble potsh derived from potssium phosphite (Stress Relefe, ) (Hrrell s LLC., Lkelnd, FL) t 4 oz/1,000 ft 2 (12.57 L h -1 ) ws dded to non-

27 11 potssium treted plots. Tretments were pplied every 14 dys for twelve weeks t the lbeled rtes using CO2 bck pck spryer delivering 20 gl/cre (187.3 L h -1 ). Plots were 2.5 x 1.5 meters nd replicted 4 times in ech experiment. Both greens were mintined t mowing heights of mm. Plots were rrnged using rndomized complete block design nd results nlyzed using Anlysis of Vrince nd Fisher s LSD (lph=0.05). Turf Qulity To quntify tretment effects on turfgrss qulity, two mesurements were recorded. The Normlized Difference Vegettion Index (NDVI) ws mesured twice weekly using Field Scout Turf Color Meter (Spectrum Technologies, Plinfield, IL). The device estimtes turf qulity by mesuring the red nd ner-infrred light reflected off of the plnt s surfce. A greener surfce is indicted by higher NDVI rtio ([ner infrred light(nir)-red light)]/[nir + Red]) (Bremer et l, 2011) mesured on 0-1 scle. Turfgrss qulity ws lso mesured visully (1-9, 9 = best) twice weekly. Cnopy Tempertures nd Chlorophyll Content Due to the presence of pigments in products tested (Figures 2-1 nd 2-2), qulity bsed on plnt color or ppernce could be misleding. Therefore, physiologicl mesurements not dependent on plnt color were lso performed. Dily cnopy tempertures ( C) were tken t pproximtely 2 pm EST (1 hour pst solr noon) using hndheld infrred thermometer (Rytek Corportion, Snt Cruz, CA). Three redings per plot were verged. Chlorophyll content ws mesured dily bsed on reltve

28 12 concentrtion of chlorophyll using Field Scout CM 1000 Chlorophyll Meter (Spectrum Technologies, Plinfield, IL) t the sme time s cnopy tempertures. Three redings per plot were verged. In ddition, CO2 exchnge rtes were mesured twice weekly using CIRAS-2 Portble Photosynthesis System (PP Systems, Hverhill, MA USA) which included the differentil CO2/H2O gs nlyzer ttchment. Two redings per plot were verged. Volumetric Soil Moisture Content Volumetric soil moisture content in the top 12 cm ws recorded from ech plot twice weekly (% volumetric wter cm soil -2 ) using FieldScout TDR 100 (Spectrum Technologies, Plinfield, IL) to indicte if turf qulity ws ssocited with soil moisture stress. Roots Root weights were collected t the beginning nd conclusion of ech field tril. Three cores (2.5 cm dimeter x 15 cm deep) were removed from ech plot. Green shoots nd the next 1.5 cm were removed. Remining vegettion ws used for root weight. To determine ctul weights, both the root lyer ws dried t 80 C for 7 dys, weighed, then incinerted t 500 C for 3 hours. Weight of sh ws then subtrcted from the dried weight to determine root mss. Nutrient Anlysis Soil nutrient nlysis ws performed by extrcting 5 cores (2 cm dimeter x 15 cm deeper) per plot, blending ech plot s respective cores, nd then plcing the mixed soil

29 13 into individul pper bgs. Tissue nlysis ws performed by obtining clippings from ech plot using stndrd wlk-behind greens mower with bucket ttchment. Three psses were mde on ech plot before removing the clippings nd plcing them in pper bgs. Due to the limited growth of the bermudgrss plots, tissue nlysis ws verged per tretment, s opposed to one nlysis per plot on the bentgrss green, thus sttisticl nlysis ws not possible since smples were combined over ll replictes, however dt is presented for comprison. Both tissue nd soil smples were sent to the Clemson University Agriculuturl Service Lbortory for hevy metl nlysis. Figure 2-1 Creeping bentgrss (Agrostis stolonifer L. vr plustris (Huds.)) ppernce following folir ppliction of vrious pigmented products.

30 14 Figure 2-2 TifEgle bermudgrss (Cynodon dctylon (L.) Pers. X C. trnsvlensis Burtt-Dvy) ppernce following folir ppliction of vrious pigmented products. Bentgrss Growth Chmber Experiment Two seprte 10 dy studies were conducted in growth chmbers (Conviron, Pembin, ND) locted in the Clemson University greenhouse fcility in Clemson, SC to determine potentil impct of pigment contining products on bentgrss helth when exposed to highly stressful environment. L-93 bentgrss plugs (10 cm dimeter x 10 cm deep) were removed from the Clemson University Turfgrss Reserch Fcilities bentgrss putting green nd plced into greenhouse pots contining 85:15 snd/pet rootzone mix. Turf ws estblished for 3 weeks in the greenhouse fcility t optimum temperture of 25 C (77 F). Turf plugs were llowed to grow to 15 cm dimeter nd 13 mm height. Estblished turf pots were then moved into the growth chmber nd mintined t 35 C

31 15 (95 F) nd 24 C (75.2 F) for 12 hours ech. To reduce the potentil for loclized effects of pot plcement in the chmber, pot positions were rotted dily. All tretments received 100 ml of wter every three dys to mintin field cpcity. Tretments included stressed nd unstressed untreted control, zinc oxide + titnium dioxide + pigment (Turf Screen) (TurfMx LLC., Erdenheim. PA) t 2.5 oz/1,000 ft 2 (7.97 L h -1 ), copper phytlocynine pigment (PAR)(Hrrell s LLC., Lkelnd, FL) t 0.37 oz/1,000 ft 2 (1.17 L h -1 ), potssium phosphite (Title Phyte) (Hrrell s LLC., Lkelnd, FL) t 4 oz/1,000 ft 2 (12.57 L h -1 ), Turf Screen plus Title Phyte t 2.5 oz/1,000 ft 2 (7.97 L h -1 ) nd 4 oz/1,000 ft 2 (12.57 L h -1 ) respectively, PAR plus Title Phyte t 0.37 oz/1,000 ft 2 (1.17 L h -1 ) nd 4 oz/1,000 ft 2 (12.57 L h -1 ) respectively, Chipco Signture (Byer CropScience AG, Monheim Am Rhein, Germny) t 6 oz/1,000 ft 2 (19.13 L h -1 ), Fosetyl-l (Quli-Pro, Psden, TX) t 4 oz/1,000 ft 2 (12.57 L h -1 ), minerl oil (Civits)(Petro-Cnd, Mississug, Ontrio) t oz/1000 ft 2 (1.17 L h -1 ) with proprietry pigment (Civits Hrmonizer) (Petro-Cnd, Mississug, Ontrio) t oz/1000 ft 2 (0.073 L h -1 ), nd Civits Hrmonizer t oz/1000 ft 2 (0.073 L h -1 ). Due to the potssium content of Title Phyte, K-contining fertilizer ws dded to the other treted plots using potssium cette (Stress Relefe, ) (Hrrell s LLC., Lkelnd FL) t 4 oz/1,000 ft 2 (12.57 L h -1 )(Tble 2-3). All tretments were replicted 3 times. The unstressed untreted control pots remined in the greenhouse fcility t n optiml temperture of 28 C (82.4 F). Crbon-dioxide exchnge rtes (CER) were mesured using CIRAS-2 Portble Photosynthesis System (PP Systems, Hverhill, MA USA) which included the differentil

32 16 CO2/H2O gs nlyzer ttchment. This system included cler polyethylene 150 mm dimeter chmber plced round the plug for 75 seconds for ech reding. These rtings were tken prior to plcement in the growth chmber, on dy 5, nd t the end of the study. Vrible chlorophyll fluorescence (Fv/Fm) of turf plugs ws documented using FluorPen FP100 (Photon Systems Instruments, Drsov, Czech Republic). Rtings on 0-1 were tken t the end of the study. Bermudgrss Growth Chmber Study Two seprte studies were conducted in the Clemson University greenhouse fcility in Clemson, SC to determine potentil impct of the pigment-contining products on bermudgrss helth when exposed to freezing tempertures. TifEgle bermudgrss plugs (10 cm dimeter x 10 cm deeper) were removed from the Clemson University Turfgrss Reserch Fcilities bermudgrss putting green nd plced into greenhouse pots contining 85:15 snd/pet rootzone mix. Turf plugs were estblished over 3 weeks in the greenhouse fcility t optiml tempertures, ~35 C (95 F) during the dy, llowing folige to grow to 15 cm dimeter nd 13 mm height. Two pplictions were then mde to folige seprted by two weeks. One week fter the second tretment, plugs were plced into growth chmbers (Conviron, Pembin, ND) t -5 C(23 F) for 3 hours simulting rpid hrd freeze on green tissue. To reduce potentil for loclized effects, pots were rotted dily.

33 17 Tretments included stressed nd unstressed untreted control, zinc oxide + titnium dioxide + pigment (Turf Screen) (TurfMx LLC., Erdenheim. PA) t 2.5 oz/1,000 ft 2 (7.97 L h -1 ), copper phytlocynine pigment (PAR)(Hrrell s LLC., Lkelnd, FL) t 0.37 oz/1,000 ft 2 (1.17 L h -1 ), potssium phosphite (Title Phyte) (Hrrell s LLC., Lkelnd, FL) t 4 oz/1,000 ft 2 ( L h -1 ), Turf Screen plus Title Phyte t 2.5 oz/1,000 ft 2 (7.97 L h -1 ) nd 4 oz/1,000 ft 2 ( L h -1 ) respectively, PAR plus Title Phyte t 0.37 oz/1,000 ft 2 (1.17 L h -1 ) nd 4 oz/1,000 ft 2 (12.57 L h -1 ) respectively, Chipco Signture (Byer CropScience AG, Monheim Am Rhein, Germny) t 6 oz/1,000 ft 2 ( L h -1 ), Fosetyl-l (Quli-Pro, Psden, TX) t 4 oz/1,000 ft 2 (12.57 L h -1 ), minerl oil (Civts)(Petro-Cnd, Mississug, Ontrio) t oz/1000 ft 2 (1.17 L h - 1 ) with proprietry pigment (Civits Hrmonizer) (Petro-Cnd, Mississug, Ontrio) t oz/1000 ft 2 (0.073 L h -1 ), nd Civits Hrmonizer t oz/1000 ft 2 (0.073 L h -1 )(Tble 2-3). Due to the potssium content of Title Phyte, K-contining fertilizer ws dded to non-potssium contining tretments using potssium cette (Stress Relefe, ) (Hrrell s LLC., Lkelnd FL) t 4 oz/1,000 ft 2 (12.57 L h -1 )(Tble 2-3). All tretments were replicted 4 times. Crbon-dioxide exchnge rtes (CER) were mesured using CIRAS-2 Portble Photosynthesis System (PP Systems, Hverhill, MA USA). This system included polythylene 150 mm dimeter chmber plced round the plug for 75 seconds for ech reding. Rtings were tken prior to plcement in chmber nd t the conclusion of the 3 hours.

34 18 Vrible chlorophyll fluorescence of plugs ws documented using FluorPen FP100 (Photon Systems Instruments, Drsov, Czech Republic). Rtings on 0-1 scle were tken t the end of the study. Spring Greenup Study Two spring field trils were performed to evlute the possible effects of pigmented products on timing of bermudgrss recovery from winter dormncy. Tretments were n untreted control, zinc oxide + titnium dioxide + pigment (Turf Screen) (TurfMx LLC., Erdenheim. PA) t 2.5 oz/1,000 ft 2 (7.97 L h -1 ), copper phytlocynine pigment (PAR) (Hrrell s LLC., Lkelnd, FL) t 0.37 oz/1,000 ft 2 (1.17 L h -1 ), potssium phosphite (Title Phyte) (Hrrell s LLC., Lkelnd, FL) t 4 oz/1,000 ft 2 (12.57 L h -1 ), Turf Screen plus Title Phyte t 2.5 oz/1,000 ft 2 (7.97 L h -1 ) nd 4 oz/1,000 ft 2 (12.57 L h -1 ) respectively, PAR plus Title Phyte t 0.37 oz/1,000 ft 2 (1.17 L h -1 ) nd 4 oz/1,000 ft 2 (12.57 L h -1 ) respectively, Fosetyl-l plus StressGrd (Chipco Signture)(Byer CropScience AG, Monheim Am Rhein, Germny) t 6 oz/1,000 ft 2 (19.13 L h -1 ), Fosetyl-l (Quli-Pro, Psden, TX) t 4 oz/1,000 ft 2 (12.57 L h -1 ), minerl oil (Civts) (Petro-Cnd, Mississug, Ontrio) t oz/1,000 ft 2 (1.17 L h -1 ) with proprietry pigment (Civits Hrmonizer) (Petro-Cnd, Mississug, Ontrio) t oz/1,000 ft 2 (0.073 L h -1 ), nd Civits Hrmonizer t oz/1,000 ft 2 (0.073 L h -1 ) (Tble 2-4). Due to the potssium content of Title Phyte, K-conting fertilizer ws dded to other treted plots using potssium cette (Stress Relefe, ) (Hrrell s

35 19 LLC., Lkelnd FL) t 4 oz/1,000 ft 2 (12.57 L h -1 ). All tretments were replicted 4 times. Applictions were mde every 14 dys beginning 7 October to 18 November, 2013 with lte winter pplictions beginning 17 Februry to 15 April, Plots were 2.5 by 1.5 meters on 14 yer old TifEgle bermudgrss green mintined to USGA specifictions. Greenup ws s mesurement of NDVI compred to the untreted. The NDVI ws mesured using Field Scout Turf Color Meter (Spectrum Technologies, Plinfield, IL). Mesurements were tken weekly. Three rtings were tken per plot nd verged.

36 20 Tble 2-1. Tretments nd rtes pplied to L-93 creeping bentgrss green field studies bi-weekly in 2013 nd 2014 t Clemson University, Clemson, SC. Tretment Rte zinc oxide + titnium dioxide + pigment (Turf Screen) 2.5 oz/1,000 ft 2 (7.97 L h -1 ) copper phytlocynine pigment (PAR) 0.37 oz/1,000 ft 2 (1.17 L h -1 ) potssium phosphite (Title Phyte) 4 oz/1,000 ft 2 (12.57 L h -1 ) Turf Screen + Title Phyte PAR + Title Phyte 2.5 oz/1,000 ft 2 (7.97 L h -1 ) + 4 oz/1,000 ft 2 (12.57 L h -1 ) 0.37 oz/1,000 ft 2 (1.17 L h -1 ) + 4 oz/1,000 ft 2 (12.57 L h -1 ) Fosetyl-Al + StressGrd (Chipco Signture) 6 oz/1,000 ft 2 (19.13 L h -1 ) Fosetyl-Al 4 oz/1,000 ft 2 (12.57 L h -1 ) All tretments not including Title Phyte received potssium supplement using potssium cette (Stress Relefe, ) (Hrrell s LLC., Lkelnd FL) t 4 oz/1,000ft 2 ( L h -1 ).

37 21 Tble 2-2. Tretments nd rtes pplied bi-weekly to Tifegle bermudgrss green field studies in 2013 nd 2014 t Clemson University, Clemson, SC. Tretment Rte zinc oxide + titnium dioxide + pigment (Turf Screen) 2.5 oz/1,000 ft 2 (7.97 L h -1 ) copper phytlocynine pigment (PAR) 0.37 oz/1,000 ft 2 (1.17 L h -1 ) potssium phosphite (Title Phyte) 4 oz/1,000 ft 2 (12.57 L h -1 ) Turf Screen + Title Phyte PAR + Title Phyte 2.5 oz/1,000 ft 2 (7.97 L h -1 ) + 4 oz/1,000 ft 2 (12.57 L h -1 ) 0.37 oz/1,000 ft 2 (1.17 L h -1 ) + 4 oz/1,000 ft 2 (12.57 L h -1 ) Fosetyl-Al + StressGrd (Chipco Signture) 6 oz/1,000 ft 2 (19.13 L h -1 ) Fosetyl-Al 4 oz/1,000 ft 2 (12.57 L h -1 ) minerl oil (Civits) + proprietry pigment (Civits Hrmonizer)* oz/1000 ft 2 (1.17 L h -1 ) oz/1000 ft 2 (0.073 L h -1 ) proprietry pigment (Civits Hrmonizer)* oz/1000 ft 2 (0.073 L h -1 ) All tretments not including Title Phyte received potssium supplement using potssium cette (Stress Relefe, ) (Hrrell s LLC., Lkelnd FL) t 4 oz/1,000ft 2 ( L h -1 ). *Tretments dded fter the end of 2013 field tril

38 22 Tble 2-3. Tretments nd rtes pplied bi-weekly to L-93 creeping bentgrss nd Tifegle bermudgrss for growth chmber studies in 2013 nd 2014 t Clemson University, Clemson, SC. Tretment Rte zinc oxide + titnium dioxide + pigment (Turf Screen) 2.5 oz/1,000 ft 2 (7.97 L h -1 ) copper phytlocynine pigment (PAR) 0.37 oz/1,000 ft 2 (1.17 L h -1 ) potssium phosphite (Title Phyte) 4 oz/1,000 ft 2 (12.57 L h -1 ) Turf Screen + Title Phyte PAR + Title Phyte 2.5 oz/1,000 ft 2 (7.97 L h -1 ) + 4 oz/1,000 ft 2 (12.57 L h -1 ) 0.37 oz/1,000 ft 2 (1.17 L h -1 ) + 4 oz/1,000 ft 2 (12.57 L h -1 ) Fosetyl-Al + StressGrd (Chipco Signture) 6 oz/1,000 ft 2 (19.13 L h -1 ) Fosetyl-Al 4 oz/1,000 ft 2 (12.57 L h -1 ) minerl oil (Civits) + proprietry pigment (Civits Hrmonizer) oz/1000 ft 2 (1.17 L h -1 ) oz/1000 ft 2 (0.073 L h -1 ) minerl oil (Civits) oz/1000 ft 2 (1.17 L h -1 ) proprietry pigment (Civits Hrmonizer) oz/1000 ft 2 (0.073 L h -1 ) All tretments not including Title Phyte received potssium supplement using potssium cette (Stress Relefe, ) (Hrrell s LLC., Lkelnd FL) t 4 oz/1,000ft 2 ( L h -1 ).

39 23 Tble 2-4. Tretments nd rtes pplied bi-weekly to Tifegle bermudgrss green green-up studies in 2013 nd 2014 t Clemson University, Clemson, SC. Tretment Rte zinc oxide + titnium dioxide + pigment (Turf Screen) 2.5 oz/1,000 ft 2 (7.97 L h -1 ) copper phytlocynine pigment (PAR) 0.37 oz/1,000 ft 2 (1.17 L h -1 ) potssium phosphite (Title Phyte) 4 oz/1,000 ft 2 (12.57 L h -1 ) Turf Screen + Title Phyte PAR + Title Phyte 2.5 oz/1,000 ft 2 (7.97 L h -1 ) + 4 oz/1,000 ft 2 (12.57 L h -1 ) 0.37 oz/1,000 ft 2 (1.17 L h -1 ) + 4 oz/1,000 ft 2 (12.57 L h -1 ) Fosetyl-Al + StressGrd (Chipco Signture) 6 oz/1,000 ft 2 (19.13 L h -1 ) Fosetyl-Al 4 oz/1,000 ft 2 (12.57 L h -1 ) minerl oil (Civits) + proprietry pigment (Civits Hrmonizer) oz/1000 ft 2 (1.17 L h -1 ) oz/1000 ft 2 (0.073 L h -1 ) proprietry pigment (Civits Hrmonizer) oz/1000 ft 2 (0.073 L h -1 ) All tretments not including Title Phyte received potssium supplement using potssium cette (Stress Relefe, ) (Hrrell s LLC., Lkelnd FL) t 4 oz/1,000ft 2 ( L h -1 ).

40 24 CHAPTER III RESULTS AND DISCUSSION Field Studies Due to the ddition of Civits nd Civits Hrmonizer in the second study, bermudgrss field studies were nlyzed spertely. In bentgrss field studies, results vried between studies, nd dt were therefore lso nlyzed seprtely. Bentgrss Field Studies Cnopy Tempertures The reduction of summer cnopy tempertures hs been shown to positively ffect overll bentgrss helth nd is mjor clim for severl helth promoting products, including severl in this study. None of the studied products, however, produced lower cnopy tempertures. In fct, treted turf exhibited higher tempertures thn the untreted controls in study two. All tretments in study one showed similr verge summer tempertures to untreted control with cnopy tempertures between 98.6 nd 100 F (37 nd 37.8 C) (Figure 3-1). In study two, the untreted control (37.6 C) exhibited significntly lower tempertures thn Turf Screen, PAR, nd PAR + Title Phyte with n verge difference of 2.8 F (~1.39 C) suggesting these tretments my ctully cuse more stressful environments.

41 25 Bentgrss Cnopy Temperture 40.5 Untreted C b b b b b Turf Screen (TS) PAR Title Phyte (TP) TS + TP PAR + TP Chipco Signture 36.5 Fosetyl-Al Study 1 Study 2 Figure 3-1. Cnopy temperture verges for two summer studies following bi-weekly pplictions to creeping bentgrss of vrious nonpigmented nd pigment-contining products. Verticl brs represent stndrd errors. Different letters indicte significnt differences between tretments within ech study by LSD test (p 0.05). Chlorophyll Content Reduced chlorophyll content is indictive of possible stress hving occurred. In both studies the untreted control exhibited significntly higher levels of chlorophyll (~30 reltive concentrtion) thn ll tretments in study one nd 24 in study two (Figure 3-2). In study one, Chipco Signture exhibited higher chlorophyll content verging 297 compred to 282 of PAR but less thn the untreted (327 reltive concentrtion). No differences were observed between Fosetyl-Al, PAR + Title Phyte, Title Phyte, Turf Screen, nd Turf Screen + Title Phyte in study one. In study two, differences were observed between Title Phyte (290), Signture (283), Fosetyl-Al (276), Turf Screen

42 26 (273), Turf Screen + Title Phyte (268), PAR (267), nd PAR + Title Phyte (262). Decresed chlorophyll concentrtion is symptomtic of plnt stress. Bentgrss Chlorophyll Content 360 Untreted Reltive Chlorophyll Concentrtion bc bc c b bc bc bc bc cde de b de e bcd Turf Screen (TS) PAR Title Phyte (TP) TS + TP PAR + TP Chipco Signture Fosetyl-Al 240 Study 1 Study 2 Figure 3-2. Chlorophyll content verges for two summer studies following bi-weekly pplictions to creeping bentgrss of vrious nonpigmented nd pigment-contining products. Verticl brs represent stndrd errors. Different letters indicte significnt differences between tretments within ech study by LSD test (p 0.05). Visul Turf Qulity Visul qulity for res treted with Title Phyte nd Fosetyl-Al verged 5.79 nd 5.46 in study one, significntly less thn ll other tretments which verged ~6.8 (Figure 3-3). In study 2, turf qulity for Fosetyl-Al ws significntly less thn Signture, PAR, untreted control, nd PAR + Title Phyte verging 5.4 compred to ~6.3 for tretments tested. However, Fosetyl-Al showed similr visul qulity to tht of Turf Screen, Turf Screen + Title Phyte, nd Title Phyte verging ~5.9.

43 27 Visul Bentgrss Turf Qulity 8 Untreted 1-9, 9 = best b b b b b b Turf Screen (TS) PAR Title Phyte (TP) TS + TP PAR + TP Chipco Signture Fosetyl-Al Study 1 Study 2 Figure 3-3. Averge visul turfgrss qulity for two summer studies following bi-weekly pplictions to creeping bentgrss of vrious nonpigmented nd pigment-contining products. Verticl brs represent stndrd errors. Different letters indicte significnt differences between tretments within ech study by LSD test (p 0.05). Normlized Difference Vegettion Index In both studies, the NDVI [(ner infrred light (NIR)- red light)/(nir + red light)] verge of the untreted control ws similr to Fosetyl-Al (~0.74 in study 1, ~0.71 in study 2) (Figure 3-4). Differences were not observed between Turf Screen, Turf Screen + Title Phyte, PAR + Title Phyte, nd PAR in either study (~0.72 in study 1, ~0.68 in study 2). Similr NDVI verges were observed between Title Phyte nd Signture in both studies (~0.73 in study 1, ~0.7 in study 2).

44 28 Normlized Difference Vegettion Index NDVI/ Reflectnce Rtio b bc cd cd bcd cd d bcd b cd d d bc b Untreted Turf Screen (TS) PAR Title Phyte (TP) TS + TP PAR + TP Chipco Signture Fosetyl-Al Study 1 Study 2 Figure 3-4. Normlized difference vegettion index (NDVI) verges for two summer studies following bi-weekly pplictions to creeping bentgrss of vrious nonpigmented nd pigment-contining products. Verticl brs represent stndrd errors. Different letters indicte significnt differences between tretments within ech study by LSD test (p 0.05). Soil Moisture Similr levels of volumetric soil wter content were observed for ll tretments in both studies. Averge volumetric soil wter content for ll tretments rnged between 9 nd 13 % in study one nd between 9 nd 11% in study two (Tble 3-1). Tble 3-1. Volumetric soil wter content dt for two studies following bi-weekly pplictions of vrious nonpigmented nd pigment-contining products to creeping bentgrss. Soil Moisture Tretment Study 1 Study % Untreted

45 29 Turf Screen (TS) PAR Title Phyte (TP) TS + TP PAR + TP Chipco Signture Fosetyl-Al NS NS Mens within columns nlyzed ccording to Fisher s protected LSD (p = 0.05). NS = nonsignificnt Crbon Dioxide Exchnge Rte Crbon dioxide exchnge rte (CER) mesures the net CO2 exchnge from the surfce of the turfgrss. A positive mesurement is indictive of respirtion exceeding photosynthesis nd negtive if photosynthesis exceeds respirtion. Differences were not observed between tretments in study one, with CER levels rnging between 2.4 nd 21.5 µmol CO2 cm -2 s -1 (Figure 3-5). In study two, significntly lower CER (10.67 µmol CO2 cm -2 s -1 ) ws mesured in the untreted control compred to PAR + Title Phyte (30.35 µmol CO2 cm -2 s -1 ), Turf Screen + Title Phyte (29.42 µmol CO2 cm -2 s -1 ), Fosetyl-Al (27.52 µmol CO2 cm -2 s -1 ), PAR (27.02 µmol CO2 cm -2 s -1 ), nd Turf Screen (22.27 µmol CO2 cm -2 s -1 ). Similr levels of CER were observed between Title Phyte (18.78 µmol CO2 cm -2 s -1 ), Signture (20.99 µmol CO2 cm -2 s -1 ), Turf Screen + Title Phyte, Fosetyl-Al, PAR, nd Turf Screen in study two. All levels indicte filure to reduce net CO2 exchnge rte suggesting tht products do not llevite summer photosynthetic stress on creeping bentgrss.