USGA-SPONSORED RESEARCHHighlights of the USGA-sponsored Research Program.

by DR. MIKE KENNA

USGA Research Project Categories

Turfgrass Breeding: Plant breeding projects intended to develop turfgrasseswith better resistance to stress and pest problems.

Cultural Practices: Projects that evaluate cultural practices that have thepotential to improve the ability of golf course turf to tolerate stress.

Alternative Pest Management: Evaluation of alternative pest controlmethods for use in integrated turf management systems.

Pesticide and Nutrient Fate: Projects that determine how pesticides andfertilizers can be applied to golf courses while protecting environmentalquality.

Construction and Maintenance of Greens: Identification of the bestcombinations of putting green construction, grow-in procedures, and post-construction maintenance practices.

IN1982 the United States GolfAssociation set out on a historiccourse when it decided to signifi-

cantly increase the funding for researchto improve the grasses and the mainte-nance programs used to benefit thegame of golf. This article highlightssome of the accomplishments ofprojects completed through January1998. The overarching goals of theResearch Program are to: 1) Reduceturfgrass water requirements, pesticideuse, and maintenance costs; 2) Protectthe environment while providing goodquality playing surfaces; and 3) Encour-age young scientists to become leadersin turfgrass research. The specific areaswithin these overarching goals coveredin this article include Turfgrass Breed-ing, Cultural Practices, Alternative PestManagement, and Pesticide andNutrient Fate.

Turfgrass BreedingThe turfgrass breeding projects are

directed at reducing water and pesti-cide use through the development ofresistance to several stress and pestproblems. The programs have focusedon the improvement of bentgrass, ber-mudagrass, buffalograss, Poa annua,seashore paspalum, and zoysiagrass.The turfgrasses resulting from thesponsored research will help meet thefuture needs of golf courses. Table 1was prepared to summarize the accom-plishments ofUSGA-sponsored breed-ing projects from 1983 through 1997.

Breeding and Development ofBentgrass, Texas A&M University

After 13 years of improving bent-grass, six varieties with improved heattolerance and disease resistance werereleased, and three advanced lines areready for release (see Table 1). It isimportant to note that several youngscientists were trained and are becom-ing leaders in the turfgrass industry.New, innovative screening techniqueswere developed throughout the courseof the project. For example, methods toevaluate heat tolerance (heat bench),rooting depth (slant tube), lineargradient irrigation system (LGIS),

8 USGA GREEN SECTION RECORD

insect and disease resistance, andsalinity tolerance were developed andused.

Breeding Seed. and Vegetatively-Propagated Turf Bermudagrasses,Oklahoma State University

Two seeded, fine-textured, cold-hardy bermudagrasses were releasedthat allow greater ease in establishmentversus vegetative establishment (seeTable 1). This program developed areproducible technique for evaluatingcold tolerance of bermudagrass plantsthat shortens cultivar developmenttime and incorporated the use ofmolecular tools to identify cold-hardygenes. In addition, bermudagrassesfrom throughout the world were col-lected to add greater genetic diversityfor cold hardiness, seed yield, andacceptable turf quality. The projectreached out to other scientists in thesouthern Great Plains region to aid inthe development of bermudagrasseswith better spring-dead-spot and insectresistance. Five graduate students andtwo postdoctoral students have beentrained on the project.

Breeding, Evaluation, and Culture ofBuffalograss, University of Nebraska

This comprehensive program in-creased the awareness and interest inbuffalograss as a turfgrass species be-

cause of its inherent drought resistanceand low maintenance. The projectdeveloped six vegetative buffalograsscultivars with better turf quality, toler-ance to lower cutting heights, andextended range of adaptation (seeTable 1). Improved sod productiontechniques and sod quality of the newcultivars was achieved. Two seededvarieties were developed in coopera-tion with the Native Turfgrass Develop-ment Group. Through a team researchapproach, the project successfullydeveloped management and establish-ment studies to coincide with therelease of the cultivars. Finally, morethan 10 graduate students receivedM.S. or Ph.D. degrees during theproject.

Development of Multiple Stress-Tolerant Seashore Paspalums,University of Georgia

Seashore paspalum offers an alter-native to bermudagrass with its greatersalinity tolerance and lower nitrogenrequirement (i.e., approximately halfthat of bermuda grass). In just five years,three cultivars were selected for com-mercialization (see Table 1). The pro-gram also has directed efforts towarddeveloping management programs forthe new cultivars - specifically, exten-sive field testing for weed and insectcontrol. In addition, the extensive

worldwide collection assembled (germ-plasm) is very diverse and has greatpotential to produce outstanding varie-ties for golf courses in the future.

Breeding and Development ofZoysiagrass, Texas A&M University

Zoysiagrass fairways can produce ahigh quality golf surface in the transi-tion zone and southern United States.Some of the cultivars developed offeran alternative for partly shaded teesand surrounds and can help preventbermudagrass encroachment into bent-grass greens. Four new vegetative cul-tivars were developed with improve-ments made for fine texture, salinitytolerance, shade tolerance, and colorretention (see Table 1). Improvementsalso were made in sod productionquality (i.e., establishment rate andrecoverability after harvest). Unfortu-nately, the cold hardiness of thesevarieties is inadequate for use in theupper transition zone of the UnitedStates. The project cooperated withother scientists throughout the United

States to investigate adaptation and re-sistance to insects. Seven postdoctoralstudents worked on the project overthe last 14 years.Improvement of Poa annua for GolfCourses, University of Minnesota

After years of industry efforts toeradicate annual bluegrass from golfcourse putting greens, this project tooka new approach. Thousands of annualbluegrasses from throughout the UnitedStates were collected and evaluated inorder to develop an improved variety.After nearly 15 years of work, the firstcommercially available creeping blue-grass (Faa annua var. reptans) varietywas released for use on putting greens(see Table 1). A great deal was learnedabout the growth, seeding habit,genetics and population dynamics ofFaa annua. In addition, three Ph.D.-students received their degrees whileworking on the project.Cultural Practices

A series of research projects with theaim to reduce water use, pesticide use,

and maintenance costs were conductedin different regions of the United States.This was necessary because of regionaldifferences in climate, soil, and stressconditions. The studies have led to newscreening techniques, maintenanceprograms that conserve water, andmanagement programs for newvarieties.

Interseeding New Bentgrasses,Irrigation Management, andSelection of Bentgrasses withSuperior Drought Resistance,Texas A&M University

This project addressed interseedingnew bentgrass varieties into an oldervariety, blending bentgrass varieties,and comparing irrigation frequencyand amounts. First, interseeding a newbentgrass cultivar into Penn cross wassomewhat successful. A populationshift of 5 to 30 percent was observedfollowing a single interseeding in con-junction with minimal cultivation fol-lowed by topdressing. Second, whenestablishing new greens, blending dif-

Developing herbicide-, disease-, and stress-resistant turfgrasses using genetic engineering has a promising future. Dr. Lisa Lee,while at Rutgers University, worked on developing herbicide-resistant bentgrasses. Michigan State University also has an activeprogram that is developing genetically engineered bentgrasses under the direction of Drs. Mariam Sticklen and Joe Vargas.

NOVEMBER/DECEMBER 1998 9

Table 1Summary of USGA TurfgrassBreeding Projects - 1983 to 1997

Turfgrass

Creeping Bentgrass

Agrostis stoloniferavar. palustris

Colonial Bentgrass

Agrostis tenuis

Bermudagrass

Cynodon dactylon

C. transvaalensis

C. dactylon XC. transvaalensis

Buffalograss

Buchloe dactyloides

Alkaligrass

Puccinellia sp.

Bluegrama

Bouteloua gracilis

Fairway Crested Wheatgrass

Agropyron cristatum

Curly Mesquitegrass

Hilaria belangeri

Annual Bluegrass

Poa annua var. reptans

Zoysiagrass

Zoysia japonica andZ. matrella

Seashore Paspalum

Paspalum vaginatum

University

Texas A&M University

University of Rhode Island

Pennsylvania State University

DSIR-New Zealand andUniversity of Rhode Island

New Mexico State University

Oklahoma State University

Oklahoma State University

University of Georgia

University of Nebraska

Colorado State University

Colorado State University

Colorado State University

University of Arizona

University of Minnesota

Texas A&M University

University of Georgia

Status of Varieties

Crenshaw (Syn3-88), Cato (Syn4-88) and Mariner (Synl-88),Century (Syn92-1), Imperial (Syn92-5), Backspin (92-2) werereleased. All are entered in 1993 NTEP trials (NationalTurfgrass Evaluation Program, Beltsville AgriculturalResearch Center, Beltsville, MD 20705).

Providence was released.

Pennlinks was released.

A preliminary line, BR-1518, was entered in the NTEP trials.This line was not developed any further.

NuMex Sahara, Sonesta, Primavera, and other seed-propagatedvarieties were developed from this program.

1\vo seeded types, OKS 91-11 and OKS 91-1, were entered in the1992 NTEP trials. OKS 91-11 was released.

A release of germplasm for university and industry use is underconsideration. New triploid (2n = 3x = 27) and hexaploid(2n = 6x = 54) FI hybrids are under evaluation.

Tifton 10 and Tifton 94 (MI-40) were released; a Tifway mutant,Tifeagle (TW-72), was released for vegetative production.

Vegetative varieties 609, 315, and 378 were released. Seededvarieties Cody and Tatanka were released. Three new vegetativeselections, NE 86-61, NE 86-120, and NE 91-118, are currentlybeing processed for release.

Ten improved families were developed; nothing released.

Elite, Nice, Plus, and Narrow populations were developed;nothing released.

Narrow leafed and rhizomatous populations were developed;nothing released.

Seed increases of fine and roadside populations are availablefor germplasm release and further improvement.

Selections #42, #117,#184, #208, and #234 were released. Smallamounts of MN #184 are commercially available.

Ten vegetative selections were entered in the 1991 NTEP trials.Diamond (DALZ8502), Cavalier (DALZ8507), Crowne (DALZ-8512), and Palisades (DALZ8514) were released in 1996.

Germplasm has been assembled and is under evaluation. Twogreen types (AP 10, AP 14) and one fairway type (PI 509018-1)are being evaluated on golf courses.

10 USGA GREEN SECfION RECORD

ActualET

0.74

NewMexico

0.78

water generated higher growth ratesand raised seasonal Kc by three per-cent. Water that moved through theten-foot-deep lysimeter had negligibleamounts of fertilizer nitrogen. Tissueanalysis revealed that 30 percent of theapplied nitrogen was in clippings.

Putting Green CharacteristicsAssociated with SurfaceDepressions Caused by SelectedForms of Traffic, Rutgers University

When tested on amended-sand andsoil-base putting greens, rigid wheelchair tire (2.5 cm) traffic caused greaterdepressions than pneumatic tires (3.5cm) on the putting green surface. Arelatively inexpensive penetrometerwas used to predict the damage causedby assistive equipment. Some assistivedevices can be used by handicappedgolfers on putting greens without re-ducing putting quality. However, theimpact of these assistive devices varies,depending on green constructionmaterials, management practices, andenvironmental conditions. Wheel traf-fic caused greater ball roll deflectionthan foot traffic, and pneumatic tirescaused less damage than rigid tires. As

0.83

Figure 1Total ET - Bermudagrass

0.85

Arizona California SouthernNevada

0.91

Penman-Monteith

100.

300.

1300.

Evapotranspiration (ET) estimation methods may differ by as much as 30 percent,which demonstrates the importance of matching crop coefficients (Kc) with themethod used to estimate ET. The summer ETa was obtained from five PenmanEquations under investigation (vertical bars). Actual ET is presented as the dashedline. The number above each bar represents the appropriate seasonal crop coefficient.

sensitive bermudagrass cultivars wereidentified during cold acclimation.Biochemical analyses of total cellmembrane lipids identified importantdifferences in the fatty acid chains ofphospholipids (see Figures 1 and 2).Bermudagrasses with 18 carbon fattyacid chains and three double bondswere better able to acclimate to coldtemperatures. This was quantified bycalculating the double bond index(DBI). Considerable genetic variabilityamong bermudagrasses and seashorepaspalums was documented andshould help turfgrass breeders developcold-hardy, warm-season grasses.

Turfgrass Irrigation withMunicipal Effluent: Nitrogen Fate,Turf Crop Coefficients, and WaterRequirements, University of Arizona

The five popular methods of estimat-ing evapotranspiration (ET) differ by asmuch as 30 percent, demonstratingthe importance of matching crop co-efficient (Kc) with the method used toestimate ET (see Figure 1). Estimatedwinter crop coefficients for bermuda-grass fairways overseeded with ryegrasswere more variable than summer cropcoefficients. Turf irrigated with effluent

ferent bentgrass varieties had distincteffects on turf quality. Superior varietieshad a positive impact on the stand,while lesser varieties had a negativeimpact on the quality. Lastly, frequentirrigation caused a decrease in turfquality and an increase in algae. How-ever, some varieties proved to be moretolerant of frequent irrigation. Less fre-quent irrigation allowed a favorablewater balance in specific cultivars with-out sacrificing putting green quality.Greenhouse and field drought resis-tance results were correlated, indicatingthat plant-water-status measurements(i.e., water potential at zero turgor,osmotic potential at full turgor, relativewater content, apoplastic water frac-tion, bulk modulus of tissue elasticity,and turgid weight to dry weight ratios)could be used as a screening techniquein breeding programs.

Methods to Convert a Putting Greenfrom Penncross to a New Variety,North Carolina State University

A molecular method for measuringchange in bentgrass populations overtime was developed. The greatest con-version from Penncross putting greensplot to A4 bentgrass occurred withJobSaver@ aerification tines plusPrimo@,resulting in a conversion of 20percent. The least effective treatmentswere verticutting and verticutting plusPrimo@.Results indicated that conver-sion from Penncross is probably fea-sible, but it will take a number of years.Complete conversion from Penn crossto another variety will require fumi-gation or total renovation.

Growth and PerformanceDifferences Among NewBermudagrass CuItivars andEcotypes, Auburn University

Off-types, or ecotypes, often appearin hybrid -bermudagrass putting greensover time. Some of the off-types haveshown potential suitability as puttinggreen turfgrasses in the southeasternUnited States. However, proper thatchmanagement of ultra-dwarf cultivarsand off-types was possible only withintensive management (i.e., aerifica-tion, topdressing, grooming proce-dures, etc.). Newly released TifEagleand the ecotype Mobile 9 performedwell and showed promise in this study.

Biochemical and MolecularAnalyses of Cold Acclimation inBermudagrass, Clemson University

Differences in cell membrane com-position between cold-hardy and cold-

NOVEMBER/DECEMBER 1998 11

one would expect, moist soils resultedin more damage than dry soils.

Alternative Pest ManagementThe purpose of these research proj-

ects was to evaluate alternativemethods of pest control for use inintegrated turf management systems.Alternative pest management methodsare intended to reduce the amount ofpesticide needed to maintain golfcourse turfgrasses. An alternativemethod of pest control needs to behighly effective and must be field-testedunder realistic golf course conditionsin order to receive widespread accep-tance by golf course superintendents.

The USGA has provided fundingfor the development and evaluation ofalternative methods of pest control.Even though a great deal of time andeffort have been devoted to the area ofbiological control, there are very fewscientifically documented cases wherethese alternative controls perform aswell as their pesticide counterparts.

In addition to new biological con-trols, more information is needed onthe life cycle and behavior of commonturfgrass pests. The correct treatmentthresholds, cultural practices, use ofresistant grasses, proper pesticide tim-ing, and placement all need to be con-sidered carefully in all turfgrass man-agement programs, especially in thecase of soil-borne insect or diseaseproblems.

Development of ImprovedTurfgrass with Herbicide Resistanceand Enhanced Disease Resistancethrough Transformation,Rutgers University

Creeping bentgrass is one of themore disease-susceptible grasses main-tained for turf purposes. This projecthas produced genetically engineered(transgenic) plants with disease resis-tance, salinity tolerance, and herbicideresistance genes. There are severalherbicide- and pest-resistant plantsshowing promise in the field that areready to be integrated into the breedingprogram for cultivar development.

Genetic Engineering of CreepingBentgrass with a Disease Resistance(Chitinase) Gene and theBialaphos- Herbicide ResistanceGene, Michigan State University

This project has genetically engi-neered plants under evaluation in thefield that are ready to be integrated intoa breeding program for cultivar devel-opment. Researchers were able to in-

12 - USGA GREEN SECTION RECORD

The tawnymole cricket has

a unique Y-shapedtunneling

behavior whichallows for easyfeeding, escapefrom predators,

and selection ofcomfortable

temperature andsoil moisture

conditions.

corporate the chitinase gene into bent-grass plants. This gene has the potentialto aid in bentgrass disease resistancebecause chitinase digests the cell wallsof fungal pathogens. The bialaphosgene also was successfully incorporatedinto bentgrass plants, making themtolerant of the pesticide. Bialaphoshas both herbicidal and fungicidalproperties.

Genetic Basis of BiologicalControl in a BacteriumAntagonistic to Turfgrass Pathogens,Cornell University

Using molecular biology, a bacteriumstrain was discovered that reduced thegermination of soil-borne diseases,especially Pythium. Researchers estab-lished the relationship between seed orplant exudates and the germination ofPythium. This information can bevaluable to plant breeders for incorpo-ration into breeding programs (i.e.,breed turfgrasses with low exudatelevels). The study also provided con-vincing evidence for a biological con-trol mechanism in which the bacterialagent interacts directly with the plantand only indirectly with the pathogen.

Examples ofthe use of waxcastings to capturethe burrowing ofmole crickets inlarge soil areas.

Cultural Control, Risk Assessment,and Environmentally ResponsibleManagement of White Grubs andCutworms in Turfgrass,University of Kentucky

This project has developed effectivecontrol strategies for cutworms andwhite grubs using cultural, environ-mental, and insect behavioral con-siderations that will reduce pesticideusage. The tremendous biodiversity ofbeneficial insects in golf course turf-grasses and the importance of certainpredators in the reduction of pestpopulations were clearly demonstrated.Effective control strategies for cut-worms, such as mowing putting greensearly in the morning, not disposing ofclippings near the putting green, orcontrolling insect populations in thesurround areas, will reduce pesticideuse on golf courses. Cutworms do notlike Kentucky bluegrass as a foodsource when compared to bentgrass,ryegrass, and tall fescue (see Figure 2).Endophyte-infected cultivars did notprovide significant resistance to cut-worms. Two insecticides (Merit andMach 2) were effective control mea-sures and had low impact on beneficialand non-target arthropod species.

100

Figure 3Plot of the predicted concentration of 2,4- D in surface runoff

versus time in the 1996 buffer length experiment::<, >:< >:< Significant at alpha levels 0.05 and 0.01, respectively

Pesticide and Nutrient FateUnderstanding and quantifying the

fate of applied turfgrass pesticides andfertilizers are required to understandthe environmental impacts of golfcourses. From 1991 through 1994, theUSGA sponsored comprehensive re-search that examined the fate of pesti-cides and nutrients applied to golfcourse turfgrasses. Three key findingsfrom this research were: 1) measurednitrogen and pesticide leaching gen-erally is minimal when these materialsare applied properly; 2) the turf-soilecosystem enhances pesticide degrada-tion; and 3) current agricultural modelsneed calibration/validation in order toaccurately predict the fate of pesticidesand fertilizers applied to turfgrassesgrown under golf course conditions.

As a continuation of a responsibleand scientifically based investigationof the environmental impact of golfcourses, the USGA sponsored addi-tional research to understand theeffects of turfgrass pest managementand fertilization on water quality andthe environment.

Pasteuria sp. for Biological Controlof the Sting Nematode in Turfgrass,University of Florida

A new species (Pasteuria) of bac-terium that parasitizes the sting nema-tode (Belonolaimus longicaudatus)was discovered. Results demonstratedthat the sting nematode relationshipwith Pasteuria is density dependent.For example, as the number of nema-todes increases, so does the number ofPasteuria bacteria. The study showedthat a relatively small amount ofPasteuria-infested soil can be intro-duced into a USGA green with a highnumber of sting nematodes and bringabout suppression within about 12months .

fortable temperature and soil moistureconditions. The two species are awareof the presence of the other, but apheromone is not involved. in theirability to detect each other. Manage-ment factors (i.e., soil texture, moisture,temperature, pesticides, etc.) thatinfluence mole cricket behavior wereidentified and should be consideredtogether to achieve better insectcontrol.

ALL ALLDEAD DEAD

Adelphi Kenblue MidnightKentucky bluegrass

TFPRCBo

.....s:::t1.)Ul-<t1.)~ 20

Figure 2High survival of black cutworms reared on creeping bentgrass (CB),perennial ryegrass (PR), and tall fescue (TF), and lack of suitability

of three diverse cultivars of Kentucky bluegrass

Behavioral Studies of theSouthern and Tawny Mole Cricket,North Carolina State University

Behavioral, biological, and environ-mental factors that influence molecricket activity on golf courses wereidentified. The tawny mole cricket hasa unique Y-shaped tunneling behaviorthat allows for easy feeding, escapefrom predators, and selection of com-

_ No Buffer

-+- 16-Foot Buffer300

:2 2500..0..'-' 200s:::.91d 150l-<.....s:::~ 100s:::ou 50

o15 20 25 30 35 40 45 50 55 60 65

TIME (minutes from start of rainfall)70 75

Evaluation of Best ManagementPractices to Protect Surface Waterfrom Pesticides and FertilizerApplied to Bermudagrass Fairways,Oklahoma State University

Chemical losses in surface runofffrom turf can be reduced by maintain-ing non-treated buffers between surfacewater and areas treated with chemicals(see Figure 3). The effective bufferlength is dependent upon site condi-tions (i.e., longer buffers, in excess of 16feet, will perform better). A three-inchbuffer mowing height was more effec-tive than 0.5 or 1.5 inches. Chemicalapplications following heavy irrigation

NOVEMBER/DECEMBER 1998 13

or rainfall events should be avoided.Finally, select pesticides and nutrientswith low runoff potential (i.e., low solu-bility, high adsorption coefficient).

Evaluation of Management FactorsAffecting Volatile and DislodgeableFoliar Residues of Turfgrass Pesti-cides, University of Massachusetts

Of the 13 pesticides examined, 10were deemed safe based on U.S. Envi-ronmental Protection Agency HazardQuotients (HQ). Organophosphorousinsecticides with high vapor pressuresand inherent high toxicity (i.e., etho-prop, isazofos, and diazinon) weredeemed not completely safe to humansunder certain conditions. The criticalvapor pressure below which no turf-grass pesticide will volatilize to theextent that it will result in an inhalationHQ greater than 1.0 was found to bebetween 3.3 x 10-6and 5.6 x 10-6mm Hg.Thatch management or the use ofspreader/stickers will likely be inef-fective in mitigating unwanted pesti-cide volatilization.

Mobility and Persistence ofTurfgrass Pesticides in a USGAGreen, University of Florida

The research project found that mostpesticides are bound to the thatch.Clippings were not a major pathwayfor removal of pesticides from treatedturfgrass areas. Even after severalweeks of light, infrequent irrigation,heavy rain can still cause fenamiphosto leach. Fenamiphos was not a majorconcern from a volatility viewpoint.The amount of dislodgeable residuesdecreased rapidly after irrigation wasapplied. Finally, a synthetic coatingapplied to sand demonstrated theability to increase pesticide retention inthe rootzone.

Modeling Pesticide Transport inTurfgrass Thatch and Foliage,University of Maryland

The thatch produced by differentgrasses did not have the same ability toretain pesticides. Bentgrass thatch re-tained (or adsorbed) more pesticidethan zoysiagrass thatch. The amount ofhighly soluble 2,4-D retention to thatchand soil was less than carbaryl re-tention. Desorption losses of bothpesticides were greatest during the firstleaching event after application anddeclined with subsequent events. Therewas a significant interaction betweenthe solubility of the pesticide and themedium (soil or thatch type) to whichit was applied.

14 USGA GREEN SECTION RECORD

Evaluation of the PotentialMovement of Pesticides FollowingApplication to Golf Courses,University of Georgia

If high-sand-content putting greenrootzones are considered a worst-casescenario, pesticide transport in soilwater was not a major problem whenthe pesticides were applied correctlyand not irrigated heavily. Irrigationmanagement is an essential factor inpesticide movement. High soil moisurecontent (at or above field capacity) atthe time of application results in thegreatest potential for runoff. In thisstudy, the small buffer zone betweenthe point of application and the exitpoint did not reduce the fraction ofapplied water-soluble pesticide trans-ported from the site, but diluted thesolution concentration due to reducedarea of treatment. Pressure injection ofpesticides reduced the quantity foundin runoff. The research further docu-mented that the water solubility of thepesticide influenced the amount ofpesticide transported from the fairways.The more water-soluble pesticideswere more easily transported from thetreated fairway. The less water-solublepesticides were resistant to transportin surface runoff.

Quantifying the Effect of Turf onPesticide Fate, University of Illinois

This study compared bare soil withthree levels of turf/thatch cover. Plotswere vertically mowed so that 100, 66,and 33 percent of the turf/thatch re-mained. Pesticides were then appliedand the results document that a healthyturf with thatch prevents most of thepesticide from moving into the soil.As the amount of turf and thatchdecreased, the amount of pesticidereaching the soil increased. As wouldbe expected, the bare soil plots had thegreatest amount of pesticide found inthe soil.

Degradation of Fungicidesin Turfgrass Systems,Purdue University

Two-thirds of the applied fungicidesremained bound to the leaf surface,unavailable for microbial degradationor loss into the environment. Theamount of pesticide adsorbed to theleaf surface was dependent on thechemical characteristics of the appliedmaterial (i.e., adsorption coefficient,water solubility). Analysis of leaf.fungicide residues indicated that thedissipation rates were similar, regard-

less of application frequency. Thesimilarity of the fungicide dissipationcurves suggests that there was nochange in the loss mechanism and thatenhanced microbial degradation wasnot present on the leaf surface.Model Calibration andValidation for TurfPesticidesin Runoff and Leachate,Environmental and Turf Services

PRZM 2.0, a computer model usedto estimate pesticide fate, overesti-mated runoff and was less effective inpredicting runoff than GLEAMS. Withadjustments to the runoff curve numberand the pesticide degradation rate, theGLEAMS model was able to accuratelypredict pesticide runoff from a ber-mudagrass fairway. If a thatch layeris used in any prediction model, thephysical characteristics must be accu-rately described. Modeling leachingdata was more problematic than runoffdata; however, the new PRZM 3.0model shows more promise for accu-rate prediction of pesticide transportfrom turfgrass systems.Conclusion

The USGA will continue to fundresearch in the foreseeable future. Thegoals remain: 1) reduce turfgrass waterrequirements, pesticide use, and main-tenance costs; 2) protect the environ-ment while providing good qualityplaying surfaces; and 3) encourageyoung scientists to become leaders inturfgrass research. Rather than focusingon variety or cultivar development,breeding efforts will focus on creatingnew and innovative germ plasm forseed companies to use in their com-mercial breeding programs. Puttinggreen rootzone and golf course con-struction projects are underway andwill be emphasized in the future. Inte-grated turfgrass management (culturalpractices) and environmental researchprojects also will be continued. If youwould like more information aboutthese or other projects, please see theUSGA website (http://www.usga.org)or contact the USGA Green SectionResearch Office (405-743-3900 ormkenna@usga.org).

DR. MICHAEL P. KENNA has beenResearch Director of the USGA GreenSection since February 1990. His positionwas created out of a need to extendgreater administrative support to theUSGA's growing turfgrass and environ-mental research program, which distrib-utes more than $1.5 million in grantsannually.