Turfgrass and Environmental Research Online

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1 Turfgrss nd Environmentl Reserch Online...Using Science to Benefit Golf USGA s Turfgrss nd Environmentl Reserch Progrm jointly funded coopertive study with GCSAA s Environmentl Institute for Golf to evlute commonly used wetting gents on golf courses. Nine sites cross the US were chosen nd dt were tken for phytotoxicity, turf color, turf qulity, nd degree of soil hydrophoicity. For the ske of regulr reders of TERO, nd with permission from GCSAA, the report presented in this issue of TERO is exctly how it ppered in the April nd August issues of Golf Course Mngement, GCSAA s flgship puliction. Volume 4, Numer 1 August 1, 2

2 PURPOSE The purpose of USGA Turfgrss nd Environmentl Reserch Online is to effectively communicte the results of reserch projects funded under USGA s Turfgrss nd Environmentl Reserch Progrm to ll who cn enefit from such knowledge. Since 1983, the USGA hs funded more thn 29 projects t cost of $2 million. The privte, non-profit reserch progrm provides funding opportunities to university fculty interested in working on environmentl nd turf mngement prolems ffecting golf courses. The outstnding plying conditions of tody s golf courses re direct result of using science to enefit golf. Editor Jeff Nus, Ph.D. 132 Rogers Plce Lwrence, KS 6649 jnus@usg.org (78) (78) (fx) Reserch Director Michel P. Kenn, Ph.D. P.O. Box 2227 Stillwter, OK 7476 mkenn@usg.org (4) (4) (fx) USGA Turfgrss nd Environmentl Reserch Committee Bruce Richrds, Chirmn Julie Dionne, Ph.D. Ron Dodson Kimerly Erush, Ph.D. Ali Hrivndi, Ph.D. Michel P. Kenn, Ph.D. Jeff Krns, Ph.D. Pete Lndschoot, Ph.D. Jmes Moore Scott E. Niven, CGCS Jeff Nus, Ph.D. Pul Rieke, Ph.D. Jmes T. Snow Clrk Throssell, Ph.D. Pt Vittum, Ph.D. Scott Wrnke, Ph.D. Jmes Wtson, Ph.D. Permission to reproduce rticles or mteril in the USGA Turfgrss nd Environmentl Reserch Online (ISSN ) is grnted to newsppers, periodicls, nd eductionl institutions (unless specificlly noted otherwise). Credit must e given to the uthor(s), the rticle title, nd USGA Turfgrss nd Environmentl Reserch Online including issue nd numer. Copyright protection must e fforded. To reprint mteril in other medi, written permission must e otined fom the USGA. In ny cse, neither rticles nor other mteril my e copied or used for ny dvertising, promotion, or commercil purposes.

3 This reserch ws funded y The Environmentl Institute for Golf nd USGA. GCSAA-USGA wetting gent evlution: Updte A renlysis of the wter-droplet-penetrtion-test dt shows no iologiclly significnt chnges from the originl results. Clrk Throssell, Ph.D. In the April 2 edition of Golf Course Mngement, GCSAA relesed the results of the GCSAA-USGA Wetting Agent Evlution. Further exmintion of the results fter puliction reveled n error in the nlysis of the wter-droplet-penetrtion-test dt for the nine sites for oth 23 nd 24. Wter-droplet-penetrtion-test dt were collected on six seprte dtes ech yer t specified intervls throughout the course of the evlution. To determine the uniformity of the reserch plots, the first dte of dt collection occurred efore ny wetting gents were pplied. The other five collection dtes occurred fter the wetting gents hd een pplied. In the originl nlysis of the wterdroplet-penetrtion-test dt, dt from ll six dtes were included in the nlysis. This ws incorrect. Only the wter-droplet-penetrtion-test dt collected from the five dtes fter the ppliction of wetting gents should hve een included in the nlysis. Sttisticins from the Ntionl Turfgrss Evlution Progrm (NTEP) hve renlyzed the wter-droplet-penetrtion-test dt using only the dt collected from the five dtes fter wetting gents hd een pplied. The results of the renlysis of the wter-droplet-penetrtion-test dt for ll nine sites for oth 23 nd 24 re presented in the following pges. The renlysis of the wter-droplet-penetrtion-test dt reveled five mjor points. The reserch plots within ech of the nine evlution sites were uniform in their degree of soil hydrophoicity efore wetting gents were pplied. This uniformity is desirle ecuse it mens tht ll the The nine sites for the wetting gent evlution were distriuted cross the United Sttes. plots within ech site were in similr condition t the strt of the experiment. Becuse the plots t ech evlution site were uniform efore the wetting gents were pplied, the results of the two dt nlyses were similr. Tht is, the renlysis of the wter-droplet-penetrtion-test dt using only dt collected fter wetting gents were pplied showed only minor differences from the results of the originl dt nlysis. The reltive performnce of the wetting gents in reducing wter-droplet-penetrtion time t ech site is nerly unchnged following the renlysis of the dt. A wetting gent tht ws effective in reducing wter-droplet-penetrtion time s reported in the April issue ws still effective in reducing wter-droplet-penetrtion time when the dt were renlyzed. The reltionship mong wetting gents for their ility to reduce wter-droplet-penetrtion time t ech site is unchnged or chnged only slightly. The wter-droplet-penetrtion times reported for ech site hve chnged somewht ecuse the dt collected efore ppliction of the wetting gents ws excluded from the renlysis. The chnges in the wter-droplet-penetrtion time hve little impct on the interprettion of the results. Although the results my hve chnged little following the renlysis of the wterdroplet-penetrtion-test dt, it is only fir to ll involved to ensure tht the dt re nlyzed correctly nd the correct results re pulished. Clrk Throssell is GCSAA s director of reserch. August 2 GCM 71

4 This reserch ws funded y The Environmentl Institute for Golf nd USGA. GCSAA-USGA wetting gent evlution Superintendents cn now rep the enefits of two yers of comprtive studies of wetting gents. Clrk Throssell, Ph.D. GCSAA, through funding from The Environmentl Institute for Golf nd USGA, hs completed n evlution of selected wetting gents tht egn in spring 23. For severl yers efore the study ws initited, superintendents hd expressed strong desire for product comprison dt to help them mke informed product use nd purchsing decisions. In response, the GCSAA reserch committee developed the concept of progrm coordinted y GCSAA to evlute products tht re commonly used y superintendents ut currently receive limited evlution in university trils. The committee recommended, nd the GCSAA Bord of Directors pproved, the evlution of wetting gents for the pilot progrm. Wetting gents were chosen ecuse they re widely used y superintendents cross the country to mnge loclized dry spots, n importnt prolem on greens, nd ecuse comprison of wetting gents in side-y-side university trils hs een limited. After the results from the evlution hve een mde ville, feedck will e sought from golf course superintendents, wetting gent mnufcturers nd the university scientists who conducted the reserch to help determine the vlue of the pilot progrm. Ultimtely, the ssocition will decide whether to continue the progrm nd evlute other products. Advisory pnel To help GCSAA conduct the estpossile evlution, 1-memer dvisory pnel ws creted to define experimentl ojectives, develop the scientific protocol, select evlution sites, determine the method to use for including products in the evlution nd provide direction for disseminting the results. The pnel comprised golf course superintendents Drren Dvis; Mrk Kienert, CGCS; Roert J. Miusch, CGCS, MG; Brin Sullivn, CGCS, MG; nd Mrk Woodwrd, CGCS. Also on the pnel were three university scientists who hve conducted wetting gent reserch John Cisr, Ph.D.; Keith Krnok, Ph.D.; nd Roert Shermn, Ph.D. nd the directors of reserch for the USGA Green Section, Mike Kenn, Ph.D., nd for GCSAA, Clrk Throssell, Ph.D. Ojectives Superintendents use wetting gents to ddress mny different prolems on the golf course, ut limittions in time nd funding required the scope of the evlution to e very specific. The dvisory pnel decided the overll ojective of the evlution ws to determine the effectiveness of selected wetting gents for mnging loclized dry spots on putting greens. Specific ojectives were to determine: phytotoxicity dmge to turf following wetting gent pplictions the impct of wetting gent pplictions on turf color nd qulity the degree of soil hydrophoicity following wetting gent pplictions dew formtion following wetting gent pplictions pest dmge following wetting gent pplictions Loclized dry spots Although loclized dry spots on putting greens cn hve mny cuses, this evlution focused on hydrophoic or wter-repellent soils. An orgnic coting on the soil prticles, which my originte from plnts, microorgnisms nd decomposing orgnic mtter, cuses soil to ecome hydrophoic (1). Soil hydrophoicity is most severe in the upper 1-2 inches (2.- centimeters) of the soil profile. Symptoms of loclized dry spots re roughly circulr ptches of tn-colored, drought-stressed turf 12 inches (3. centimeters) to severl feet in dimeter. Turf within the loclized dry spots my thin out over time, nd, in severe cses, portions of the turf my die. Loclized dry spots re most severe during periods of extended high tempertures nd dry wether (2). Recommended tretments for mnging loclized dry spots cused y hydrophoic soil include cultivtion of loclized dry spots to increse wter penetrtion, hnd wtering to increse soil moisture content, nd preventive nd/or curtive ppliction of wetting gents (2). Mterils nd methods Evlution sites The dvisory pnel determined tht the evlution should e conducted t nine sites round the country tht represented rod geogrphic regions with diverse climtes nd growing conditions. Interested scientists were required to sumit site profile of the putting green tht would e used to conduct the evlution. Criteri for selecting sites 2 GCM April 2

5 The nine sites for the wetting gent evlution were distriuted cross the United Sttes. were geogrphic loction, high-snd-content root zone, history of loclized dry spots on the putting green nd the degree of soil hydrophoicity s determined y the wterdroplet-penetrtion test. Loctions for the wetting gent evlution re shown on the mp (ove). Wetting gents Becuse of funding constrints nd limited usle reserch plot spce tht met the evlution site criteri, the dvisory pnel determined tht 1 wetting gents nd n untreted control would e evluted. The pnel selected the top 1 wetting gents tht were used y superintendents, s indicted in the 22 Plnt Protectnt nd Fertilizer Usge Study, nd were commercilly ville in 23. All products were pplied ccording to lel directions nd t the highest lel rte for control/mngement of loclized dry spots. A complete list of the wettings gents, rtes nd timing of pplictions is given in Tle 1. During the two yers of the evlution, the wetting gents were identified y code. Scientists did not know the identity of the products until ll dt hd een collected. Durtion of the evlution The wetting gent evlution ws conducted over four-month period in 23 nd 24 when stress from loclized dry spots ws t its pek. Ech scientist determined when the pek stress period occurred from the presence of loclized dry spots t the site. Dt collected At ech site, dt were collected for phytotoxicity, turf color nd qulity nd degree of soil hydrophoicity. Phytotoxicity. Rtings were tken one, three nd seven dys fter ech ppliction of wetting gent. All plots were rted ech time phytotoxicity rtings were tken. The rting scle is 1-9, where 1 = rown or discolored turf, 7 = cceptle dmge nd 9 = green turf, no dmge. Turf color. Rtings were tken every two weeks eginning seven dys fter the initil ppliction of the first wetting gent tretment. The rting scle is 1-9, where 1 = rown, = medium green nd 9 = drk green. Turf qulity. Rtings were tken every two weeks eginning seven dys fter initil ppliction of the first wetting gent tretment. The rting scle is 1-9, where 1 = poor qulity, = cceptle qulity nd 9 = excellent qulity. Degree of soil hydrophoicity. The wterdroplet-penetrtion test ws used to determine soil hydrophoicity. Soil cores 1.9 centimeters (.7 inch) in dimeter were tken to depth of 6 centimeters (2.4 inches). Droplets of distilled, deionized wter were plced on soil cores t., 1., 2., 3., 4. nd. centimeters (.2,.6,.9, 1.4, 1.8 nd 2.2 inches) elow the soil surfce. The time it took for the wter droplet to penetrte into the soil core ws determined. The mximum time for wterdroplet penetrtion ws 6 seconds. Any wter droplet remining fter 6 seconds ws recorded s 6 seconds. Three to five soil cores were tken per plot. Wterdroplet-penetrtion times (WDPT) from ll April 2 GCM 3

6 Product/rte Spry volume (ounces)* Timing (gllons/1, sq. ft.) Wtering in 8 first ppliction 1 irrigte efore next mowing 8 1 week fter first ppliction 1 irrigte efore next mowing 8 once every four weeks fter second ppliction 1 irrigte efore next mowing Brillince 8 first ppliction 2 immeditely fter ppliction 8 1 dys fter first ppliction 2 immeditely fter ppliction 8 12 weeks fter second ppliction 2 immeditely fter ppliction Cse Plus 8 first ppliction 2 immeditely fter ppliction 8 1 dys fter first ppliction 2 immeditely fter ppliction 8 first ppliction 1 immeditely fter ppliction 8 two weeks fter first ppliction 1 immeditely fter ppliction 2 every two weeks fter second ppliction immeditely fter ppliction 8 first ppliction 1 immeditely wter in 8 two weeks fter first ppliction 1 immeditely wter in Nid 8 first ppliction 1 immeditely fter ppliction 8 two weeks fter first ppliction 1 immeditely fter ppliction 6 once every four weeks fter second ppliction 1 immeditely fter ppliction 6 first ppliction 2 irrigte efore next mowing 6 every four weeks following first ppliction 2 irrigte efore next mowing 1 first ppliction 8 immeditely fter ppliction 1 8 weeks fter first ppliction 8 immeditely fter ppliction 32 first ppliction 1 immeditely fter ppliction 4 every two weeks fter first ppliction 1 immeditely fter ppliction 6 first ppliction 2 immeditely wter in 6 every four weeks following first ppliction 2 immeditely wter in *2, 4, 6, 8, 1 nd 32 ounces = 9.1 milliliters,.12 liter,.17 liter,.24 liter,.3 liter nd.94 liter, respectively. 1, 2,, 8, nd 1 gllons/1, squre feet = 4.7, 81., 23.7, 326 nd 47. liters/1, squre meters, respectively. Tle 1. Wetting gents, rtes of ppliction in fluid ounces, timing of ppliction, spry volume nd post-ppliction wtering instructions used in the GCSAA/USGA wetting gent evlution. The first ppliction of ll wetting gents ws mde on the sme dte nd efore the ppernce of ny symptoms of loclized dry spots. 4 GCM April 2

7 Time (seconds) Degree of repellency none 6 slight 6 6 moderte to high 6 3,6 severe ove 3,6 Tle 2. Scle for interpreting wter-droplet-penetrtion test dt. cores from ech plot were verged y depth, nd tht verge ws used to chrcterize tht plot. Soil cores were collected for the wterdroplet-penetrtion test within five dys efore the first wetting gent ppliction nd t two, four, eight, 12 nd 16 weeks fter the first wetting gent ppliction. The scle for interpreting wter-dropletpenetrtion test dt is shown in Tle 2. Additionl dt on dew nd pest dmge were collected t some sites. Dt for these vriles re ville t Experimentl design Minimum plot size ws 3 y 3 feet (.9 y.9 meter), nd scientists were encourged to use lrger plots if sufficient uniform reserch re ws ville. Ech tretment ws replicted four times. The sme plots used for the evlution in 23 were used in 24, with the sme tretments pplied to the sme plots in oth yers. Tretments were rrnged in rndomized complete lock design. Dt nlysis Gungling Go, Ph.D., nd Kevin Morris of the Ntionl Turfgrss Evlution Progrm nlyzed dt from ll sites. Anlysis of vrince nd men seprtion were performed to determine the impct of the wetting gents. All dt were nlyzed y NTEP to ensure uniformity. Dt for ech site were nlyzed nd reported seprtely. The dt were not nlyzed nd summrized over ll loctions. Reserch site mngement The dvisory pnel required creeping extreme entgrss greens in the evlution to e mowed t mximum height of.14 inch (3.6 millimeters) t lest six dys per week. For ermudgrss greens, the mximum mowing height ws.16 inch (4 millimeters) nd the minimum mowing frequency ws six dys per week. Cultivtion tht penetrted the soil surfce ws not llowed during the four-month evlution period. Grooming nd light verticutting were llowed, provided the ldes did not penetrte the soil surfce. Topdressing with % snd ws llowed during the evlution period. Wtering prctices followed during the evlution re roken down y week. Weeks 1 through 8. Plots were wtered t 7% potentil evpotrnspirtion (ET) for ermudgrss greens nd 8% potentil ET for creeping entgrss greens. These crop coefficients were guidelines, nd djustments were permitted to meet the specific conditions t ech site. Greens were not wtered dily. To the gretest extent possile, wter ws pplied deeply nd infrequently. During weeks 1-8, greens were sujected to only slight stress from loclized dry spots on plots in the middle rnking of turf qulity. Weeks 9 through 12. Plots were irrigted so tht plots in the middle rnking of turf qulity received moderte stress from loclized dry spots. Plots were provided enough wter to keep them live. Some ut not ll plots should hve shown visile, moderte stress from loclized dry spots. Weeks 13 through 16. Plots were wtered s descried ove for weeks 1-8. Beyond the specific requirements for mowing height, mowing frequency, cultivtion, topdressing nd wtering outlined ove, the putting greens in the evlution were mintined s high-qulity putting turf using mngement prctices pproprite for the locl re. Turf plots were mintined to prevent sustntil loss of turf in the control plots. Interprettion of the results The results from ech evlution site re summrized over the next 37 pges. A tremendous volume of dt ws collected t ech site, nd spce limittions in GCM permit puliction of only the key findings from ech site nd limited mount of dt to support those findings. The wetting gents re presented in the sme order in ech grph to help reduce confusion. Reders re encourged to find the evlution site tht is most similr to their golf course in terms of loction, growing conditions nd grss species nd review the results from tht site for help in mking decisions regrding the performnce of the wetting gents. We do not think it is pproprite to drw conclusions from northern evlution site for use on golf course in the South nd vice vers. The complete set of summrized dt for ll sites nd the entire scientific protocol used to conduct the evlution re ville t Acknowledgments I would like to cknowledge the nine coopertors who conducted the study nd devoted mny hours nd untold energy to mking it success: John Cisr, Ph.D.; Br Corwin, Ph.D.; Kevin Frnk, Ph.D.; Keith Krnok, Ph.D.; Joe Krusz, Ph.D.; Bernd Leinuer, Ph.D.; Eric Miltner, Ph.D.; Sowmy Mitr, Ph.D.; nd Frnk Rossi, Ph.D. In ddition, I would like to thnk Jeff Nus, Ph.D., former director of reserch for GCSAA nd current mnger of Green Section reserch for USGA, who plyed criticl role in the development of the product evlution concept tht ws implemented in the project. Literture cited 1. Krnok, K.J., nd K.A. Tucker. 22. Wter-repellent soils. Prt I: Where re we now? Golf Course Mngement 7(6): McCrty, L.B. 21. Best golf course mngement prctices. Prentice Hll, Upper Sddle River, N.J. Clrk Throssell, Ph.D. (cthrossell@gcs.org), is GCSAA s director of reserch. April 2 GCM

8 FLORIDA Reserch coopertors: John L. Cisr, Ph.D. professor of environmentl horticulture; D.M. Prk, grdute student; nd K.E. Willims, senior iologist, University of Florid Fort Luderdle Reserch nd Eduction Center Reserch site: Otto Schmeisser Florid GCSA Reserch Green, University of Florid Fort Luderdle Reserch nd Eduction Center Photo y K.E. Willims Overview of the experimentl re on Mrch 19, 24. Construction method: USGA recommendtions Soil texture: 97.% snd, 1.9% silt, 1.% cly Root-zone orgnic mtter: 3.4% Thickness of thtch/mt:.62 inch (1.9 millimeters) Dily high ir temperture ( F) Long-term verge dily high ir temp Figure 1. Averge monthly high temperture during the months of the evlution in 23 nd 24 nd over 32-yer period from 1971 to 22. Fe Mr Apr My Jun Jul Aug Yerly verge hydrophoicity of control plots: 23, 71 seconds; 24, 14 seconds Mowing height:.16 inch (4 millimeters) Mowing frequency: 6 dys/week Cultivr: Tifdwrf ermudgrss Study dtes: April 22 Aug. 12, 23; Fe. 16 June 7, 24 Precipittion (inches) Long-term verge precipittion Fe Mr Apr My Jun Jul Aug Figure 2. Totl monthly precipittion during the months of the evlution in 23 nd 24 nd the norml monthly precipittion totl over 32-yer period from 1971 to GCM April 2

9 FLORIDA Reserch coopertors: J.L. Cisr, Ph.D. professor of environmentl horticulture; D.M. Prk, grdute student; nd K.E. Willims, senior iologist, University of Florid Fort Luderdle Reserch nd Eduction Center Reserch site: Otto Schmeisser Florid GCSA Reserch Green, University of Florid Fort Luderdle Reserch nd Eduction Center South Florid hs sutropicl climte, with wet seson from My through Octoer followed y dry seson from Novemer through April. Wet-seson wether is chrcterized y high tempertures with intense rinfll occurring frequently in the fternoons. Dry-seson wether is chrcterized y high evpotrnspirtion (ET) conditions (high tempertures nd windy) with infrequent yet intense rinfll. The rpid wetting nd drying cycles nd high ET crete n optiml environment for the development of soil wter repellency. For oth 23 nd 24, significnt differences were found mong wetting gents nd etween wetting gents nd the nontreted (control) turfgrss. Wter-droplet-penetrtion test (seconds) e Brillince Cse Plus Figure 3. Overll verge wter-droplet-penetrtion time (seconds) for smples tken t depths of., 1. nd 2. centimeters (.2,.6 nd 1. inch) cross ll smpling dtes in 23. Different letters indicte significnt differences mong wetting gents. de de d Nid c c c Wter-droplet-penetrtion test (seconds) Brillince de e Cse Plus Figure 4. Overll verge wter-droplet-penetrtion time (seconds) for smples tken t depths of., 1. nd 2. centimeters (.2,.6 nd 1. inch) cross ll smpling dtes in 24. Different letters indicte significnt differences mong wetting gents. Nid c de 72 GCM August 2

10 TEXAS Reserch coopertor: Joseph P. Krusz, Ph.D. professor nd Extension specilist, plnt pthology nd microiology, Texs A&M University, College Sttion Reserch site: Texs A&M University Turfgrss Field Lortory, College Sttion Photo courtesy of J.P. Krusz The wetting gent evlution site in Texs ws t the Texs A&M University Turfgrss Field Lortory in College Sttion. Construction method: USGA recommendtions Soil texture: 97.8% snd, 1.% silt,.6% cly Root-zone orgnic mtter: 1.3% Depth of thtch/mt:.2 inch (6.4 millimeters) Dily high ir temperture ( F) Long-term verge dily high ir temp Figure 1. Averge monthly high temperture during the months of the evlution in 23 nd 24 nd over 32-yer period from 1971 to 22. My Jun Jul Aug Sep Yerly verge hydrophoicity of control plots: 23, 8 seconds; 24, 11 seconds Mowing height:.16 inch (4 millimeters) Mowing frequency: 6 dys/week Cultivr: FlorDwrf ermudgrss Study dtes: My 2 Sept. 2, 23; My 4 Aug. 31, 24 Precipittion (inches) Long-term verge precipittion Figure 2. Totl monthly precipittion during the months of the evlution in 23 nd 24 nd the norml monthly precipittion totl over 32-yer period from 1971 to 22. My Jun Jul Aug Sep 8 GCM April 2

11 9 8 7 Turf color (1-9) Brillince Cse Plus Nid 2 1 Figure 3. Men rtings for turf color in 23 (on scle of 1-9, where 1 = rown nd 9 = drk green). There were no significnt differences mong wetting gents Turf color (1-9) Brillince Cse Plus Nid 2 1 Figure 4. Men rtings for turf color in 24 (on scle of 1-9, where 1 = rown nd 9 = drk green). There were no significnt differences mong wetting gents. April 2 GCM 9

12 TEXAS Reserch coopertor: Joseph P. Krusz, Ph.D., Texs A&M University, College Sttion Reserch site: Texs A&M University Turfgrss Field Lortory, College Sttion No significnt differences in overll visul qulity were oserved mong the tretments in either 23 or 24. Hydrophoicity ws worse in the upper soil levels (depths of. nd 1. centimeters) in 23, ut ws much less of prolem in 24, perhps ecuse of the undnt rinfll nd reltively mild tempertures in 24. In 23, when hydrophoicity ws prolem, none of the wetting gent tretments significntly reduced the hydrophoicity of the soil. In 24, when hydrophoicity ws much less of prolem compred to 23, severl wetting gent tretments, Brillince,,, nd ll significntly reduced hydrophoicity compred to the untreted check. However, the level of overll hydrophoicity ws so low s to e insignificnt, nd it is doutful tht differences mong tretments were gronomiclly significnt. In summry, none of the wetting gent tretments significntly improved turfgrss color or qulity in either 23 or 24. Wter-droplet-penetrtion test (seconds) Wter-droplet-penetrtion test (seconds) Brillince Brillince Cse Plus Cse Plus Figure. Overll verge seconds for wter-droplet penetrtion for smples tken t depths of., 1. nd 2. centimeters (.2,.6 nd 1 inch) cross ll smpling dtes in 23. There were no significnt differences mong wetting gents. Nid Figure 6. Overll verge seconds for wter-droplet penetrtion for smples tken t depths of., 1. nd 2. centimeters (.2,.6 nd 1 inch) cross ll smpling dtes in 24. Different letters indicte significnt differences mong wetting gents. Nid d c d -d -d d August 2 GCM 73

13 NEW MEXICO Reserch coopertor: Bernd Leinuer, Ph.D. Extension specilist, Extension plnt sciences, New Mexico Stte University, Ls Cruces Reserch site: New Mexico Stte University Golf Course, Ls Cruces Photo courtesy of B. Leinuer The study site ws putting green t New Mexico Stte University s golf course in Ls Cruces. Construction method: Modified Cliforni style Soil texture: 97% snd, 2% silt, 1% cly Root-zone orgnic mtter: <1% Thickness of thtch/mt:.12 inch (3.2 millimeters) Dily high ir temperture ( F) Long-term verge dily high ir temp Figure 1. Averge monthly high temperture during the months of the evlution in 23 nd 24 nd over 32-yer period from 1971 to 22. My Jun Jul Aug Sep Oct Yerly verge hydrophoicity of control plots: 23, 96 seconds; 24, 6 seconds Mowing height:.11 inch (2.8 millimeters) Mowing frequency: dily Cultivr: Penncross creeping entgrss Study dtes: June 1 Oct. 8, 23; My 17 Sept. 13, 24 Precipittion (inches) Long-term verge precipittion Figure 2. Totl monthly precipittion during the months of the evlution in 23 nd 24 nd the norml monthly precipittion totl over 32-yer period from 1971 to 22. My Jun Jul Aug Sep Oct 62 GCM April 2

14 9 8 7 Turf color (1-9) Brillince Cse Plus Nid 2 1 Figure 3. Men rtings for turf color in 23 (on scle of 1-9, where 1 = rown nd 9 = drk green). Dt re verged over ll smpling dtes for ech yer. There were no significnt differences mong wetting gents Turf color (1-9) Brillince Cse Plus Nid 2 1 Figure 4. Men rtings for turf color in 24 (on scle of 1-9, where 1 = rown nd 9 = drk green). Dt re verged over ll smpling dtes for ech yer. There were no significnt differences mong wetting gents. April 2 GCM 63

15 NEW MEXICO Reserch coopertor: Bernd Leinuer, Ph.D., New Mexico Stte University, Ls Cruces Reserch site: New Mexico Stte University Golf Course, Ls Cruces. cm* 1. cm* 2. cm Product c 7 c 2 e 61 Brillince 32 e 7 c 6 c 21 de 1 Cse Plus 4 de 6 c 83 c 27 de 7 7 e 7 c 84 c 33 de e 6 c c 27 de 9 8 Nid e c 69 c 22 de c 1 c c 12 c 91 c c 3 c 64 c 2 de Note. Numers in column followed y the sme letter re not significntly different from one nother. Tle 1. Wter-droplet-penetrtion time t depths of., 1. nd 2. centimeters (.2,.6 nd 1 inch) for 23 nd 24. Dt re verged over ll smpling dtes for ech yer. There were no sttisticl differences mong tretments for men color rtings for 23 nd 24. In oth yers, the control tretment nd plots treted with Nid nd wetting gents showed highest wter-droplet-penetrtion time (WDPT) t ll depths. In 23, the products Brillince, Cse Plus, nd, differed significntly from the control tretment t the.-centimeter (.2-inch) depth. At the 1.-centimeter depth, Brillince,, nd showed significnt difference from the control tretment for WDPT. In 24, Nid did not differ significntly from the control tretment in WDPT t depths of. centimeter nd 1. centimeters (.2 nd.6 inch) nd hd the highest reported WDPT for ll tretments. lso hd no significnt effect on WDPT compred to the control t the 1.-centimeter depth. In 23 nd 24, none of the pplied surfctnts differed significntly from the control tretment t the 2.-centimeter (1-inch) depth. Most other products in the study ppered to llevite wter repellency to vrious degrees t depths of. centimeter nd 1. centimeters (.2 nd.6 inch) s indicted y WDPTs lower thn tht of the control tretment. The support of Bruce Erhrd, 22-yer GCSAA memer nd superintendent t New Mexico Stte University s golf course; the Rio Grnde GCSA; nd the Southwest Turfgrss Assocition is gretly pprecited. Without their generous help, this study would not hve een possile. 74 GCM August 2

16 CALIFORNIA Reserch coopertor: Sowmy (Shoumo) Mitr, Ph.D. ssocite professor, deprtment of plnt science, grdute progrm coordintor, Cliforni Stte Polytechnic University, Pomon Reserch site: Monteello (Clif.) Golf Course Photo courtesy of Sowmy Mitr Russell Plum (left), grdute student t Cl Poly Pomon, collects soil cores with Jun Perez, ssistnt superintendent t Monteello GC, who conducted the 23 wetting gent test for his senior project t the university. Perez, four-yer GCSAA memer, is currently ssistnt superintendent t Vellno CC, Chino Hills, Clif. Construction method: USGA recommendtions Soil texture: 92% snd, 4.8% silt, 2.2% cly Root-zone orgnic mtter: 1.62% Thickness of thtch/mt:.7 inch (19.1 millimeters) Dily high ir temperture ( F) Long-term verge dily high ir temp Figure 1. Averge monthly high temperture during the months of the evlution in 23 nd 24 nd over 32-yer period from 1971 to 22. Jul Aug Sep Oct Nov Yerly verge hydrophoicity of control plots: 23, 234 seconds; 24, 399 seconds Mowing height:.14 inch (3.6 millimeters) Mowing frequency: 6 dys/week Cultivr: 8% Dominnt creeping entgrss lend nd 2% nnul luegrss Study dtes: July 29 Nov. 18, 23; July 22 Nov. 1, 24 Precipittion (inches) Long-term verge precipittion Figure 2. Totl monthly precipittion during the months of the evlution in 23 nd 24 nd the norml monthly precipittion totl over 32-yer period from 1971 to 22. Jul Aug Sep Oct Nov 66 GCM April 2

17 9 8 7 c c c c c c c c Phytotoxicity (1-9) Brillince d Cse Plus Nid 2 1 Figure 3. Phytotoxicity oserved in 24 on the third dy fter the first ppliction for ll wetting gents (on scle of 1-9, where 1 = rown or discolored turf nd 9 = no dmge). Different letters indicte significnt differences mong wetting gents. 9 Turf color (1-9) c Brillince c Cse Plus Nid c c c 2 1 Figure 4. Men rtings for turf color in 23 (on scle of 1-9, where 1 = rown nd 9 = drk green). Different letters indicte significnt differences mong wetting gents. April 2 GCM 67

18 CALIFORNIA Reserch coopertor: Sowmy (Shoumo) Mitr, Ph.D., Cliforni Stte Polytechnic University, Pomon Reserch site: Monteello (Clif.) Golf Course No phytotoxicity ws oserved in 23, ut significnt injury ws oserved in 24. The difference in response could e due to the chnge in wether conditions etween the two yers. In 24, Cse Plus cused the gretest phytotoxicity t one nd three dys fter tretment. The most hydrophoic regions were t depths of 1. nd 2. centimeters (.6 nd 1. inch) for oth yers. All the wetting gent tretments reduced dew formtion on the turf compred to the control. In oth yers,,,,, nd significntly reduced dew formtion seven dys fter ppliction compred to the other products in the study. Overll, sed on the verge wterdroplet-penetrtion test in 23,, Brillince, Cse Plus,, nd significntly reduced hydrophoicity compred to the control nd. There ws no difference mong the, Nid, Hydro- Wet nd tretments. In 24, ccording to the overll verge wter-droplet-penetrtion test, reduced hydrophoicity significntly compred to the control, Brillince,,, Nid,,, nd. The nd Cse Plus tretments were not significntly different. There were no significnt differences mong the Brillince, Cse Plus,,, nd tretments. I gretly pprecite the help nd support I received from Fernndo Grci, six-yer GCSAA memer nd superintendent t Monteello Golf Course; Jun Perez (Senior Project 23); Kevin White (Senior Project 24); Kent Kurtz, Ph.D.; Russell Plum; Binc Good; Himni Swmi; Pitwee Suphndrit; nd Mgdy Fm. Wter-droplet-penetrtion test (seconds) Wter-droplet-penetrtion test (seconds) e def Brillince e Brillince ef Cse Plus de Cse Plus Figure. Overll men wter-droplet-penetrtion time (WDPT) in seconds for smples tken t depths of., 1. nd 2. centimeters (.2,.6 nd 1. inch) cross ll smpling dtes in 23. Different letters indicte significnt differences mong wetting gents. -d Nid Figure 6. Overll men WDPT for smples tken t depths of., 1. nd 2. centimeters (.2,.6 nd 1. inch) cross ll smpling dtes in 24. Different letters indicte significnt differences mong wetting gents. d def c Nid f e c ef August 2 GCM 7

19 GEORGIA Reserch coopertors: Keith J. Krnok, Ph.D. professor in the deprtment of crop nd soil sciences, nd Kevin Tucker, reserch ssistnt, University of Georgi, Athens Reserch site: University of Georgi Rhizotron nd Turfgrss Fcility, Athens Photo courtesy of K.J. Krnok The study site ws locted t the University of Georgi s turfgrss fcility in Athens. Construction method: USGA recommendtions Soil texture: 96.1% snd, 2.3% silt, 1.4% cly Root-zone orgnic mtter: 1.9% Thickness of thtch/mt:.187 inches (4.8 millimeters) Dily high ir temperture ( F) Long-term verge dily high ir temp Figure 1. Averge monthly high temperture during the months of the evlution in 23 nd 24 nd over 32-yer period from 1971 to 22. Jun Jul Aug Sep Oct Yerly verge hydrophoicity of control plots: 23, 18 seconds; 24, 194 seconds Mowing height:.14 inch (3.6 millimeters) Mowing frequency: 6 dys/week Cultivr: Penncross creeping entgrss Study dtes: June 4 Oct. 1, 23; June 7 Oct. 4, 24 Precipittion (inches) Long-term verge precipittion Figure 2. Totl monthly precipittion during the months of the evlution in 23 nd 24 nd the norml monthly precipittion totl over 32-yer period from 1971 to 22. Jun Jul Aug Sep Oct 7 GCM April 2

20 9 8 7 Phytotoxicity (1-9) c c Brillince Cse Plus Nid c 2 1 Figure 3. Phytotoxicity seven dys fter tretment in 23 (on scle of 1-9, where 1 = rown or discolored turf nd 9 = no dmge. Only the first phytotoxicity rting dte is shown for 23. Different letters indicte significnt differences mong wetting gents. 9 Phytotoxicity (1-9) d d Brillince -d Cse Plus c Nid 2 1 Figure 4. Phytotoxicity seven dys fter tretment in 24 (on scle of 1-9, where 1 = rown or discolored turf nd 9 = no dmge. Only the first phytotoxicity rting dte is shown for 24. Different letters indicte significnt differences mong wetting gents. April 2 GCM 71

21 GEORGIA 9 8 Turf qulity (1-9) c Brillince Cse Plus c Nid d 2 1 Figure. Men turf qulity rtings in 23 (on scle of 1-9, where 1 = poor nd 9 = excellent). Different letters indicte significnt differences mong wetting gents. 9 Turf qulity (1-9) fg def Brillince Cse Plus e c Nid efg g 2 1 Figure 6. Men rtings for turf qulity in 24 (on scle of 1-9, where 1 = poor nd 9 = excellent). Different letters indicte significnt differences mong wetting gents. 72 GCM April 2

22 GEORGIA Reserch coopertors: Keith J. Krnok, Ph.D., nd Kevin Tucker, University of Georgi, Athens Reserch site: University of Georgi Rhizotron nd Turfgrss Fcility, Athens 4 3 Wter-droplet-penetrtion test (seconds) Brillince Cse Plus Nid c d d d Figure 7. Wter-droplet-penetrtion time (WDPT) in seconds verged over depths of., 1. nd 2. centimeters (.2,.6 nd 1 inch) nd over ll smpling dtes for 23. Different letters indicte significnt differences mong wetting gents. 4 3 Wter-droplet-penetrtion test (seconds) Brillince Cse Plus Nid c d de e de de de e Figure 8. WDPT in seconds verged over depths of., 1. nd 2. centimeters (.2,.6 nd 1 inch) nd over ll smpling dtes for 24. Different letters indicte significnt differences mong wetting gents. c 76 GCM August 2

23 The control showed the est turfgrss qulity throughout the study. Wter-repellent soils hve criticl moisture point. Aove this point, the soil will not show signs of wter repellency. Below this point, the soil will egin to repel wter, nd loclized dry spots will ecome pprent. This criticl moisture point vries mong soils. In our cse, with the irrigtion regime used nd greter-thn-norml rinfll t times, the soil moisture content ws often ove the criticl point, nd the control showed few signs of loclized dry spots. This fct does not influence the WDPT dt ecuse the soil smples were dried elow the criticl moisture point efore testing. To us, this is the true indictor of how well wetting gent relieves soil wter repellency. The qulity dt shown here most likely represent the stress the wetting gent put on the turfgrss rther thn the effects of wter-repellent soil. Certinly, different environments, culturl prctices, soil types, nd species nd cultivr of turfgrss could result in different findings., Nid, nd were the only wetting gents tht showed no significnt phytotoxicity for oth 23 nd 24., Brillince, nd showed significnt phytotoxicity compred to the control in oth yers. In most cses, the wetting gents with the gretest potentil for cusing phytotoxicity did so during the periods of gretest turfgrss summer stress., Nid, nd did not reduce turfgrss qulity compred to the control for 23 nd 24. Phytotoxicity ws most severe during the pek summer stress months., Cse Plus,, nd ll reduced turf qulity compred to the control in oth yers. The gretest soil wter repellency occurred in the top 2. centimeters (1 inch) of the soil profile. Soil wter repellency ws most severe towrd the end of summer in oth yers., Nid nd were the lest effective in reducing soil wter repellency., Brillince, Cse Plus,,, nd significntly reduced soil wter repellency in oth yers. In terms of reducing soil wter repellency, the reltive rnking of wetting gents remined essentilly the sme regrdless of soil depth or degree of wter repellency. August 2 GCM 77

24 MISSOURI Reserch coopertor: Brr S. Corwin, Ph.D. Extension ssistnt professor, Ag Extensionplnt sciences, University of Missouri, Columi Reserch site: The Clu t Porto Cim, Lke Ozrk, Mo. Photo courtesy of B. Corwin The study site ws locted on prctice putting green t the Clu t Porto Cim, Lke Ozrk, Mo. Construction method: USGA recommendtions Soil texture: 97.9 % snd,.8% silt, 1.% cly Root-zone orgnic mtter:.84% Thickness of thtch/mt:.7 inch (19. millimeters) Dily high ir temperture ( F) Long-term verge dily high ir temp Figure 1. Averge monthly high temperture during the months of the evlution in 23 nd 24 nd over 32-yer period from 1971 to 22. My Jun Jul Aug Sep Yerly verge hydrophoicity of control plots: 23, 18 seconds; 24, 18 seconds Mowing height: inch ( millimeters) Mowing frequency: dily Cultivr: G-2 creeping entgrss Study dtes: My 12 Sept. 9, 23; My 17, 24 Sept. 21, 24 Precipittion (inches) Long-term verge precipittion Figure 2. Totl monthly precipittion during the months of the evlution in 23 nd 24 nd the norml monthly precipittion totl over 32-yer period from 1971 to 22. My Jun Jul Aug Sep 76 GCM April 2

25 9 8 Turf color (1-9) Brillince c Cse Plus Nid 2 1 Figure 3. Men turf color rtings for 23 (on scle of 1-9, where 1 = rown nd 9 = drk green). Dt re verged over ll smpling dtes for one yer. Different letters indicte significnt differences mong wetting gents Turf color (1-9) Brillince Cse Plus Nid 2 1 Figure 4. Men turf color rtings for 24 (on scle of 1-9, where 1 = rown nd 9 = drk green). Dt re verged over ll smpling dtes for one yer. There were no significnt differences mong wetting gents. April 2 GCM 77

26 MISSOURI Reserch site: The Clu t Porto Cim, Lke Ozrk, Mo. Reserch coopertor: Brr S. Corwin, Ph.D., University of Missouri, Columi In 23, the verge color rting for plots treted with Cse Plus ws significntly lower thn the verge color rting for the control s well s ll other wetting gent tretments. The verge color rting for plots treted with ws significntly etter thn the verge color rting for plots treted with Brillince, Cse Plus nd HydroWet, ut did not differ significntly from the control. There were no significnt differences in color rting mong tretments in 24. The root zone of the putting green t this study site hd slight degree of wter repellency during the course of this study. Although sttisticlly significnt differences were oserved mong tretments in oth 23 nd 24, there ws only n 11-second difference in wter droplet penetrtion etween the longest men time nd the shortest men time in oth yers. It is doutful the differences in men wterdroplet-penetrtion times were gronomiclly meningful. The products tht were most effective in reducing soil hydrophoicity lso reduced turfgrss color. I would like to thnk Pul Nudet, superintendent, nd Mike Renfro, turf equipment technicin, t The Clu t Porto Cim; 23 summer interns She Nelson nd Ben Stover from Iow Stte University; nd 24 summer intern Kyle Briscoe from the University of Missouri. Wter-droplet-penetrtion test (seconds) Wter-droplet-penetrtion test (seconds) Brillince Cse Plus Nid c c c c c c c c c Figure. WDPT (seconds) verged over., 1. nd 2. centimeters (.2,.6 nd 1 inch) nd over ll smpling dtes for 23. Different letters indicte significnt differences mong wetting gents Brillince Cse Plus Nid Figure 6. WDPT (seconds) verged over., 1. nd 2. centimeters (.2,.6 nd 1 inch) nd over ll smpling dtes for 24. Different letters indicte significnt differences mong wetting gents. 78 GCM August 2

27 NEW YORK Reserch coopertor: Frnk S. Rossi, Ph.D. ssocite professor, deprtment of horticulture, Cornell University, Ithc, N.Y. Reserch site: Cornell Turfgrss nd Lndscpe Reserch Lortory, Ithc, N.Y. Photo courtesy of Frnk S. Rossi The study site ws t the Cornell Turfgrss nd Lndscpe Reserch nd Eduction Center, Ithc, N.Y. Construction method: %-snd Cliforni profile Soil texture: 98% snd, 2% silt nd cly Root-zone orgnic mtter:.9% Thickness of thtch/mt:.2 inch (6.4 millimeters) Dily high ir temperture ( F) Long-term verge dily high ir temp Figure 1. Averge monthly high temperture during the months of the evlution in 23 nd 24 nd over 32-yer period from 1971 to 22. Jun Jul Aug Sept Oct Nov Yerly verge hydrophoicity of control plots: 23, 12 seconds; 24, 2 seconds Mowing height:. inch (2. millimeters) Mowing frequency: 7 dys/week Cultivr: 8% SR 1119 creeping entgrss nd 2% nnul luegrss Study dtes: June 1 Nov. 1, 23; June Nov. 8, 24 Precipittion (inches) Long-term verge precipittion Figure 2. Totl monthly precipittion during the months of the evlution in 23 nd 24 nd the norml monthly precipittion totl over 32-yer period from 1971 to 22. Jun Jul Aug Sep Oct Nov 8 GCM April 2

28 9 8 7 Turf qulity (1-9) Brillince Cse Plus Nid 2 1 Figure 3. Averge turf qulity rtings in response to wetting gent pplictions (on scle of 1-9, where 1 = poor nd 9 = excellent). There were no significnt differences mong wetting gents. April 2 GCM 81

29 NEW YORK Reserch coopertor: Frnk S. Rossi, Ph.D., Cornell University, Ithc, N.Y. Reserch site: Cornell Turfgrss nd Lndscpe Reserch Lortory, Ithc, N.Y. In generl, the 23 nd 24 growing sesons were mong the wettest in the lst yers in centrl New York stte. Both yers experienced ove-verge rinfll; rinfll in 24 ws 12 inches (3. centimeters) ove norml for the months of the study. There were no significnt differences in men turf-qulity rtings verged over the two yers mong the tretments (Figure 3). Phytotoxicity dt (not shown) do not revel ny ovious injury ssocited with the tretments. There were significnt sttisticl differences mong the wetting gents in oth yers of the study (Figures 4, ). However, s the dt indicte, this site did not exhiit the severe wter repellency we hve oserved in yers of norml rinfll. Therefore, we do not elieve there were iologiclly meningful differences mong the tretments. The conclusion from the two-yer study t our loction suggests tht snd green historiclly prone to loclized dry spot my enefit from wetting gent use, nd some wetting gents do pper to e etter thn others. However, when rinfll is ove verge, greens do not require supplementl wetting gent tretments for wter repellency. Wter-droplet-penetrtion test (seconds) Wter-droplet-penetrtion test (seconds) Brillince Cse Plus Figure 4. Wter-droplet-penetrtion time (WDPT) in seconds verged over depths of., 1. nd 2. centimeters (.2,.6 nd 1 inch) in response to wetting gent pplictions in 23. Different letters indicte significnt differences mong wetting gents. Nid c c c c c c Brillince Cse Plus Figure. WDPT (seconds) verged over depths of., 1. nd 2. centimeters (.2,.6 nd 1 inch) in response to wetting gent pplictions in 24. Different letters indicte significnt differences mong wetting gents. Nid d d d c c d August 2 GCM 79

30 MICHIGAN Reserch coopertors: Kevin W. Frnk, Ph.D. ssistnt professor, nd Jeff Bryn, reserch technicin, deprtment of crop nd soil sciences, Michign Stte University, Est Lnsing Reserch site: Hncock Turfgrss Reserch Center, Michign Stte University, Est Lnsing Photo courtesy of Kevin Frnk The wetting gent evlution ws conducted t the Hncock Turfgrss Reserch Center on the cmpus of Michign Stte University. Construction method: USGA recommendtions Soil texture: 87.7% snd, 9.9% grvel, 1.2% silt, 1.2% cly Root-zone orgnic mtter:.29% Thickness of thtch/mt depth:.4-inch (1.2 millimeters) Dily high ir temperture ( F) Long-term verge dily high ir temp Figure 1. Averge monthly high temperture during the months of the evlution in 23 nd 24 nd over 32-yer period from 1971 to 22. My Jun Jul Aug Sept Oct Yerly verge hydrophoicity of control plots: 23, 34 seconds; 24, 322 seconds Mowing height:.16 inch (4 millimeters) Mowing frequency: 6 dys/week Cultivr: L-93 creeping entgrss Study dtes: June 16 Oct. 7, 23; My 27 Oct. 7, 24 Precipittion (inches) Long-term verge precipittion Figure 2. Totl monthly precipittion during the months of the evlution in 23 nd 24 nd the norml monthly precipittion totl over 32-yer period from 1971 to 22. My Jun Jul Aug Sep Oct 84 GCM April 2

31 9 8 Turf qulity (1-9) Brillince Cse Plus c Nid c 2 1 Figure 3. Overll men turf qulity rtings for 23 (on scle of 1-9, where 1 = poor nd 9 = excellent). Different letters indicte significnt differences mong wetting gents Turf qulity (1-9) Brillince Cse Plus Nid 2 1 Figure 4. Overll men turfgrss qulity rtings for 24 (on scle of 1-9, where 1 = poor nd 9 = excellent). Different letters indicte significnt differences mong wetting gents. April 2 GCM 8

32 MICHIGAN Reserch coopertors: Kevin W. Frnk, Ph.D., nd Jeff Bryn, Michign Stte University, Est Lnsing Reserch site: Hncock Turfgrss Reserch Center, Michign Stte University, Est Lnsing Men turfgrss qulity rtings from 23 nd 24 were similr. Nid nd the untreted control were the only tretments tht were significntly different in oth yers; they lso hd the lowest qulity rtings. Men wter-dropletpenetrtion-test results were verged over depths of., 1. nd 2. centimeters (.2,.6 nd 1 inch). 23. Plots treted with Nid,, Respond 2 nd the untreted control hd the longest wterdroplet-penetrtion times. Plots treted with, Brillince, Cse Plus,,, Primer Select nd hd the shortest times for wter penetrtion nd were sttisticlly similr. 24. Plots treted with Nid nd the untreted control hd the longest times for wter penetrtion. Plots treted with, Brillince,,, nd hd the shortest times for wter penetrtion nd were sttisticlly similr. Wter-droplet-penetrtion test (seconds) Wter-droplet-penetrtion test (seconds) Figure. Overll men WDPT (seconds) for 23. Different letters indicte significnt differences mong wetting gents. c Brillince Cse Plus Nid Figure 6. Overll men WDPT (seconds) for 24. Different letters indicte significnt differences mong wetting gents. c Brillince c Cse Plus c c c Nid c c d 8 GCM August 2

33 WASHINGTON Reserch coopertor: Eric Miltner, Ph.D. ssistnt turfgrss reserch gronomist, Wshington Stte University, Puyllup Reserch site: Wshington Stte University Puyllup Reserch nd Extension Center, Frm, Puyllup Photo y Eric Miltner The evlution site ws t the Wshington Stte University Puyllup Reserch nd Extension Center. The photo ws tken in My 24. Construction method: Snd root zone, with snd meeting USGA recommendtions Soil texture: 94.% snd, 1.8% silt, 1.7% cly Root-zone orgnic mtter:.8% Thickness of thtch/mt:.37 inch (9. millimeters) Dily high ir temperture ( F) Long-term verge dily high ir temp Figure 1. Averge monthly high temperture during the months of the evlution in 23 nd 24 nd over 32-yer period from 1971 to 22 My Jun Jul Aug Sep Yerly verge hydrophoicity of control plots: 23, 218 seconds; 24, 188 seconds Mowing height:.13 inch (3.4 millimeters) Mowing frequency: -6 dys/week Cultivr: Century creeping entgrss Study dtes: My 27 Sept 17, 23; My 18 Sept. 1, 24 Precipittion (inches) Long-term verge precipittion Figure 2. Totl monthly precipittion during the months of the evlution in 23 nd 24 nd the norml monthly precipittion totl over 32-yer period from 1971 to 22. My Jun Jul Aug Sep 88 GCM April 2

34 9 8 7 Turf qulity (1-9) Brillince Cse Plus Nid 2 1 Figure 3. Men rtings for turf qulity in 23 (on scle of 1-9, where 1 = poor nd 9 = excellent). There were no significnt differences mong wetting gents Turf qulity (1-9) Brillince Cse Plus Nid 2 1 Figure 4. Men rtings for turf qulity in 24 (on scle of 1-9, where 1 = poor nd 9 = excellent). There were no significnt differences mong wetting gents. April 2 GCM 89