WINTER DAMAGE Control the Variables and Minimize the Loss Contents November-December 2004 Volume 42, Number 6 TEST AREA1 CARTS ALLOWED 1 anywhere ON THIS HOLE Winter Damage Control the variables that can minimize the potential for winter turf loss. BY KEITH HAPP Turfgrass Establishment on Various Rootzones A comprehensive study at Rutgers University sheds light on the efficacy of various rootzone amendments. BY JAMES A. MURPHY, HIRANTHI SAMARANAYAKE, JOSH A. HONIG.T. J. LAWSON, AND STEPHANIE L. MURPHY 11 Letting the Environment and Considerations in Numbers Tell the Story Culture Affect Bermudagrass Retrofitting a Golf Course for Recycled Water Irrigation Start thinking about preparing for the use of recycled water at your course. BY M. ALI HARIVANDI Good News for the Bottom Line and Environmentally Sensitive Golf Course Development Yes, you can have it both ways. BY NANCY RICHARDSON News Notes No, It Really Is Not Just Your Golf Course! The issues at your golf course are often being experienced by other courses in your area. BY DARIN S. BEVARD 3 8 Turf Twisters on Cart Damage Analyzing the numbers shows how golf carts damage turf in a variety of ways. BY DAVID L. WIENECKE New Tool for Biological Warfare on Cutworms? Recent discoveries by University of Kentucky scientists may make biological control of black cutworms a reality. BY CALLIE ANNE PRATER AND DANIEL A. POTTER Walking Green Mowers: Solution or Problem? Carefully analyze several factors before determining the best plan. BY BOB RANDQUIST Growth and Decline The roles temperature and shade play in ultradwarf bermudagrass health are not totally understood. BY RICHARD H. WHITE ... ) Evaluating Recycled Waters for Golf Course Irrigation To avoid problems, analyze recycled water thoroughly before starting to use it to irrigate a golf course, and monitor it regularly thereafter. BY M. ALI HARIVANDI Green Section Committee Chairman Bruce C. Richards 12202 NE 31st Place Bellevue, WA 98005 Editor James T. Snow Associate Editor Kimberly S. Erusha, Ph.D Cover Photo Turf managers should control variables where possible to minimize winter damage. USGA President Fred S. Ridley Executive Director David B. Fay Director of Communications Marty Parkes It is no coincidence that winter damage is more severe in the more shady areas of greens. To minimize the potential for future damage, remove limiting factors. Removing the tree would be a good starting point. WINTER DAMAGE Control the variables that can minimize the potential for winter turf loss. BY KEITH HAPP ■“hanks to research and advancements in turfgrass management, golf course mainte­ nance has been impacted by the intro­ duction of various technologies that have enabled turf managers to maintain higher quality condi­ tions than in the past. While technology offers a degree of control, complete control over all of the variables associated with golf course prepara­ tion is not possible. This is particularly true when it comes to various aspects of winter injury on northern golf turf. On occasion, Mother Nature lets us know exactly how much, or should I say how little control we have. Over the last decade, numerous areas within the northern tier of states have suffered great turf loss due to direct low- temperature kill, crown hydration damage, wind desiccation, and, in some rare instances, suffocation. Although there are several agronomic strategies that can be utilized to prepare for the onset of winter weather, control is not completely in the hands of the superintendent. Turf managers can control only certain aspects of turf health. Fertility strategies can be adjusted, cultural pro­ grams can be implemented in a timely fashion, plant protectants can be applied, drainage infra­ structure can be enhanced, surface drainage pat­ terns can be altered, and, most important, the growing environment can be improved by addressing limiting factors such as shade and airflow restrictions. This article will discuss some of the strategies that are being utilized to mini­ NOVEMBER-DECEMBER 2004 I mize the potential for turf loss during severe winter weather. THE HARDENING PROCESS Plants withstand freezing in the cells of crown tissue by increasing concentrations of carbo­ hydrates and other nutrient solutes within these cells as the plant hardens in the fall and early winter (Tompkins, 1995).To completely harden, turfgrass plants must freeze for a period of at least one month. This hardening process is reversed in the spring when stored energy (carbohydrates) is rapidly used.The plant dehardens (i.e., defrosts) and becomes very susceptible to low-temperature injury if the contents of cells are again exposed to low-temperature stress. If crown cells freeze after dehardening, severe damage can result. Research studies have revealed how susceptible unhardened biotypes of Poa annua can be to temperature fluctuations. Unhardened biotypes only tolerated temperatures of 23° to 28° F, while completely hardened biotypes exhibited tolerance of-13° to -25° F (Tompkins et al., 1995). As a comparison, researchers have reported that creeping bentgrass exhibits maximum hardiness levels of -40° F. Biotypes of Poa annua can rapidly deharden when subjected to temperatures of 45° F for 48 hours (Tompkins, Budar, and Ross, 1996). In many portions of the Mid-Atlantic Region, these tem­ perature fluctuations can and often do occur frequently within a short period of time. For example, during the prime hardening period of the early winter of 2003/2004, the Pittsburgh area experienced a temperature of 61° F on January 3, only to be followed by subzero tem­ peratures seven days later. Under these conditions even the most proactive measures employed prior to the temperature swings can go for naught. The question is, what can turf managers do to improve the potential for the turf surviving severe weather conditions, particularly fluctuations in temperature resulting in rapid freeze and thaw cycles? MOWING HEIGHT Turf managers, with the help of the Green Committee, have developed course setup guide­ lines for maintenance and course preparation. Major components of course setup are the mow­ ing procedures used throughout the property in general, and for the greens in particular. There are many factors that affect putting green perfor­ mance, and all too often golfers focus on mowing heights to achieve the desired playing effect. Mowing height is critical to the plant’s ability to prepare for winter weather. Excessive close mow­ ing late in the year severely compromises the turf’s natural defense mechanisms going into winter. Maximizing energy production via photosynthesis is essential to the hardening process. Surface area of the leaf is an important part of the equation. Energy is stored first in the leaves and then transported to the roots for use as winter reserves. As a first step, set limits as to how the greens will be prepared during the period of plant hardening. For example, pick a date and stop mowing the turf. Use other techniques to prepare for bonus golf late in the year. Rolling could be used rather than regular mowing practices. If mowing has to be implemented, then raise the height of cut slightly until mowing can be completely halted before winter weather prevents any play. Even though it may be late in the season, make sure the mowers are sharp so that additional cutting does not bruise or tear the turf during the critical hardening process. It is no coincidence that turf on the collars often avoids crown hydration damage when grass on the green surface is severely damaged. FERTILIZATION Adequate fertilization plays a key role in prepar­ ing the turf for winter. Researchers have examined the fertility needs of turf prior to winter weather and have found that elevated levels of potassium and phosphorus are key components to surviving cold-temperature stress (Roberts, 1993;Johansson, 1994). There are a number of different materials that can be utilized to enhance winter hardiness, and it begins with nitrogen fertilization, which is the catalyst for nutrient uptake. Studies have shown that carbohydrate reserves increase from fall fertilization. For example, researchers at Cornell University revealed the importance of nitrogen to the uptake of potassium (Woods, 2004). Additionally, Roberts (1993) reported that 30% less damage occurred on research plots treated with a 1:2 nitrogen-to- potassium regime. The least tolerant plots were those treated with nitrogen only. Treating in a controlled fashion with readily available nitrogen sources provides the oppor­ tunity to stimulate the desired level of growth without compromising root growth. All too often, large quantities of fertilizer applied late in the 2 GREEN SECTION RECORD season create a lush turf that is very susceptible to winter damage as well as disease. All fertilization programs utilized late in the season should be focused on supporting the turf’s ability to prepare itself for cold-temperature stress. That is, fertiliza­ tion should be performed to stimulate and sup­ port carbohydrate storage. These reserves are critical to the hardening process. They can be maximized by using readily available nutrient sources that offer a predictable response. TREE MANAGEMENT In the fall, autumn days get shorter and tempera­ tures decrease. These changes in environmental conditions provide a signal to turfgrass that winter is approaching. To allow the turf to use available nutrients, other essential factors must be con­ sidered. First and foremost, adequate sunlight must be provided. Availability of light is essential to photosynthesis during the hardening process (Johansson, 1994). Without sunlight, photo­ synthesis is restricted, resulting in lower carbo­ hydrate production, and this reduces storage within the root structures. Additionally, shade plays a significant role in winter freeze-and-thaw cycles, particularly severe cold-temperature stress. It is no coincidence that greens that suffer the most during winter weather are located in shadier sites. During the winter months when the sun is lower in the southern sky, radiant energy is spread over a much wider area. The impact of shade is then magnified during freeze-and-thaw cycles. Evaluate all areas of the course, particularly green complexes, for sunlight exposure, maximiz­ ing sunlight on the east and southern borders of these sites. Trees should accent and highlight the course, not interfere with proper course maintenance. DRAINAGE The importance of having adequate surface drainage characteristics during the winter cannot be overstated! Surface drainage becomes all the more important when rapid fluctuations in temperature occur. Water can collect in low-lying areas and freeze rapidly, resulting in crown hydration damage and/or direct low-temperature kill. It is not uncommon to see poor surface drainage characteristics near the interface of the collar and the putting green surface. Many turf managers are modifying these areas of their greens to help minimize the potential for any further winter damage. A sod cutter is utilized to strip the area adjacent to the putting green that is in effect creating a dam or dyke, not allowing the water to escape. The sod is removed and the subsoils are shaved with a sod cutter. When positive water flow is Follow the trail of draining water. Improving drainage to minimize standing water improves the chances of survival. NOVEMBER-DECEMBER 2004 3 There has been a resurgence of using late- season topdressing treatments. For years turf managers have practiced heavy late-season top­ dressing that provides an added degree of insula­ tion against cold-temperature stress. The theory has been that crowns will be protected from desiccation and will also enjoy improved free drainage near the active growing point of the plant. Problems occur when sand is aggressively dragged or brushed into the canopy of the turf. The best possible scenario exists when treatments are performed in a light and frequent manner. Natural precipitation events then work the sand into the profile. Eliminating dragging manages a stress variable associated with the hardening process. As topdressing accumulates, a more resilient surface can result. Footprinting is often much less noticeable due to the fact that the top­ dressing is providing a firmer surface upon which to play. Still, the critical issue is topdressing at a rate that matches the growth of the turf and protects the active growing points of the plant. To a large degree, preparing for winter weather hinges on the support of the Green Committee. We know that routine top dressing treatments provide an element of protection, insulation, and improved free drainage in the upper portion of the soil structure. However, this strategy must be balanced between trying to protect the turf and still providing an acceptable playing condition if weather allows the course to be used late in the season. Frankly, the first question to pose is whether or not bonus golf should take precedence over trying to prepare the course, in fact to pro­ tect it from potential severe weather. All too often, focus is placed on putting green performance at a time of year when excessive conditioning could easily predispose the turf to severe damage. Recently, turfgrass managers have been experi­ menting with black topdressing sand to aid in controlling the temperature near the surface of the turf. The theory is to maintain growth by stimulating higher temperatures near the soil surface. This controlled plant growth can result in greater storage of carbohydrates, and thus more reserves for greater tolerance of cold-temperature stress (Hamilton, 2003). TURF COVERS When it comes to controlling winter damage, questions are always posed regarding the use of geotextile covers. Research has indicated that the use of these tools can be beneficial if desiccation On this Poa annua green, triplex ring was a positive in this one instance.The traffic pattern resulted in less thatch in the wheel tracks and the turf was not lost to desiccation injury. established, the sod is replaced. These types of projects are normally conducted late in the fall or during early winter. The sod will heal quite rapidly and playability can be restored before the next season. This type of minor change is not noticeable for daily play. However, during periods of rain or during periods of freeze and thaw, the changes can be significant. Turf managers have also utilized intercept drains on the high side of a green that is prone to damage from runoff during precipitation or melting snow. Intercept drains, including drop inlets (Dis), can be strategically placed to capture rainfall or melting snow and ice. The position of these Dis is critical. During the winter months when soils are frozen, open stone intercept drains may not adequately accept runoff water. The excess then flows over the green, increasing the potential for crown hydration damage. The best method of positioning these Dis involves spend­ ing time on the course during a rain event. Watch the flow of the water and chart areas where additional drainage infrastructure is needed. AERATION AND TOPDRESSING Accumulations of excessive thatch will reduce the turf’s ability to survive severe winter weather. Plant crowns and other structures elevated from the soil/thatch interface are not buffered as well from temperature extremes. Excessive thatch (more than an inch) is prone to desiccation when located in a windy area and also is prone to direct low-temperature damage when located in low- lying portions of the surface. Thatch that becomes saturated during thawing events is very prone to crown hydration damage. To a large degree this variable can be controlled with core cultivation and topdressing treatments. 4 GREEN SECTION RECORD is the primary concern. These covers will help to minimize water loss from turf that is frozen and may even provide much faster growth response in the spring when the covers are removed. For information regarding the use of covers, refer to the September/October 2000 issue of the Green Section Record (“Winter Protection of Annual Bluegrass Golf Greens”). In most instances, these geotextile covers and other green blankets will protect the turf from certain cold­ temperature stresses, but the turf cannot be protected from all of the conditions that can be presented. Crown hydration damage has occurred underneath geotextile covers even when the most laborious precautions have been taken. TO REMOVE OR NOT TO REMOVE? A question often posed is whether or not to remove snow cover on an ongoing basis during the winter. Research is clear on this one point. One way to protect greens from injury in the late winter is to maintain snow cover as long as possible. The snow insulates the turf from air temperatures that may warm the soil and induce a reduction in cold tolerance. Basically, the snow cover helps to maintain a dormant state, which prolongs the tolerance to cold­ temperature stress. If snow melts rapidly, then the extent of the protection may only last a few days during the nighttime hours. However, this may still be enough to prevent major damage. Naturally, the surfaces need to be inspected to determine if ice accumulation is occurring. Ice accumulation is another story. The turf can survive under ice, but it is the initial phases of freezing that impact survival. If the plant has hardened, soils have frozen, and a gradual reduction in temperature has occurred, then the potential for damage is reduced. The worst-case scenario occurs when the soil is not frozen, there is rainfall, and the temperature plunges. Damage may then be unavoidable. Removal of ice has become much more feasible with the introduction of black topdressing sand. This material has offered a high degree of control during certain types of winter weather. Research has indicated that treatments of between 70 and 100 lbs. of actual product per 1,000 sq. ft. can rapidly melt significant accumulations of ice (Hamilton, 2003). Often, treatments performed in the middle of winter can melt through 2 to 4 inches of ice in a 24-hour period. As the snow and ice melt, the runoff must have a place to go. This reemphasizes the need for adequate drainage capacity to move the water away from the turf. CONCLUSION There are several factors that help induce natural cold hardening. Low temperature, shorter day length, and reduced soil and plant moisture are prime examples, but these factors are uncontrollable. Low-temperature hardiness can fluctuate from season to season, and soil temperature plays an important role in determining the degree of hardiness the plant can reach. If factors are favor­ able, plants will achieve the maximum levels of cold hardiness at the start of winter. However, a plant that can tolerate temperatures of below 0° F in December may only be able to tolerate temperatures slightly below 20° F in early April. It is possible for the turf to experience improved cold hardiness, but the level never reaches the initial cold hardiness established prior to winter. Simply put, as the winter season progresses, there are fewer energy reserves within the plant to draw on to tolerate the colder weather. Golf tees can be impacted by winterkill as well. Attention to traffic stress, compaction, and proper agronomic procedures are equally critical issues. NOVEMBER-DECEMBER 2004 5 '■a®.' Black topdressing sand was used to rapidly melt snow and ice on this putting green surface. Using 75 to 100 lbs. of product per 1,000 sq. ft. removes significant ice accumulation in 24 hours. Research indicates that fall applications of black sand can increase soil temperatures.This may help turf better tolerate winter freeze-and-thaw cycles. This further emphasizes the need to fertilize in an appropriate manner and at the proper time in the fall and early winter to maximize the natural stress mechanisms of the turf. The hardening process is of great importance for grasses to sur­ vive the winter. Planning to control as many factors as possible will help improve the chances for turf survival, no matter what weather condi­ tions may be presented. While weather is a diffi­ cult factor to calculate into management regimes, the need for communication is not. Don’t stop communicating to golfers the importance of what needs to take place during a time of year when preparation is everything. REFERENCES Tompkins, Darrell K. 2004. Winter Injury Causes Problems on Annual Bluegrass Greens. Turfgrass Trends, Golfdom Magazine, January 2004. pp. 54-56. Woods, Micah. 2004. Commentary, Q&A: Water-Based Extraction Methods for Turf Soils. Turf Net Monthly. Vol. 11 No. 5., pp. 8-9. Hamilton, George. 2003. Field Research Trials Results. Tompkins, D. K., C. J. Bubar,J. B. Ross. 1996. Physiology of Low-Temperature Injury with an Emphasis on Crown Hydration in Poa annua L. and Agrostis palustris. 1996 PTRC Annual Report, pp. 40-49. Tompkins, D. K., C. Budar, E.Toews, J. Ross. 1995 Prairie Turfgrass Research Centre Annual Report, pp. 22-31. Johansson, L. 1994. Nordic Research on Limitation of Winter Damage to Golf Greens, pp. 1-49. Roberts, John. 1993. New Hampshire Turf Talk. Winter Injury Update, pp. 4-6. Located in Pittsburgh, Pennsylvania, Keith A. Happ is a senior agronomist in the Mid-Atlantic Region, visiting courses in the states of Delaware, Maryland, Pennsylvania, Virginia, and West Virginia. He is a graduate of The Ohio State University. ponsored Research Yow Can Use Turfgrass Establishment on Various Rootzones A comprehensive study at Rutgers University sheds light on the efficacy of various rootzone amendments. BY JAMES A. MURPHY, HIRANTHI SAMARANAYAKE, JOSH A. HONIG, T. J. LAWSON, AND STEPHANIE L. MURPHY Sand is commonly used to con­ struct putting green rootzones and is often amended with organic amendments, such as peat or soil con­ taining silt and clay to improve physical and nutrient properties for turf. Goals of amending sand include improving plant-soil relationships, altering the growing conditions on or beneath the playing surface, and minimizing soil and turf management problems.20 Materials other than peat that have been studied for amending sand include slag, calcined clay, expanded perlite and composted soil,19 clinoptilolite zeolite,12,14 rice hulls, sawdust, calcined clay and vermiculite,15 bark,2 perlite,210 green waste, wood chips, pulp, sewage and plant residue and fibers,9 and finer- textured soils.3’4,7,17,18 Many of these previous reports emphasized physical properties of rootzone mixtures with some information provided on turfgrass response. Amending sand may alter nutritional properties of rootzones, depending on the properties of the amendment and amount added, the properties of the material being amended, and mixing uniformity.20 It is important to have a rapid and thorough establishment of turfgrass on newly constructed rootzones, as it can affect the initial revenues and use of a golf course. The objective of this field study was to examine the effects of rootzones varying in amendment type and/or rate, and consequently physical and nutritional properties, on the estab­ lishment of creeping bentgrass turf. SETTING UP THE EXPERIMENT Three general classes of amendment materials were used (loam, organic, and inorganic) to construct the rootzones at various volume ratios. Rootzone treat­ ments are described in Table 1. A com­ mercially available medium-sized sand meeting USGA guidelines for sand size was used as the major component for rootzones except the 100% loam and 20% compost treatments. The 20% compost treatment used a sand con­ sidered too fine based on USGA guide­ lines. The 100% loam and 20% compost treatments were included for the pur­ pose of comparison (i.e., relatively extreme rootzone properties). Plots were fertilized with 10-10-10 and 12-24-14 (N-P2O5-K2O) fertilizers, each at N rate of 1 lb. per 1,000 sq. ft. (total 2 pounds per 1,000 sq. ft. of N) before seeding with L-93 creeping bentgrass at 1 lb. per 1,000 sq. ft. Four­ teen post-planting fertilizations were made to all plots except 100% loam and 20% compost during 1998, applying a total of 5.1,2.5, and 2.8 lbs. per 1,000 sq. ft. of N, P2O5, and K2O, respectively. The 100% loam and 20% compost plots received 13 post-planting fertilizations that amounted to 4.7,2.5, and 2.8 lbs. per 1,000 sq. ft. of N, P2O5, and K2O, respectively. A fertilization of 46-0-0 at 0.3 lb. per 1,000 sq. ft. of N was required on the non-amended sand plots to produce sufficient turf growth to survive mow­ ing. Five fertilizations were made to all plots between May 7 and June 1,1999, applying a total of 2.1,0.5, and 1.1 lbs. per 1,000 sq. ft. of N, P2O5, and K2O, respectively. Irrigation was applied to supplement rainfall, and mowing was maintained at 0.5 inch until the height was gradually lowered to 0.125 inch by the end of May 1999. Plots also were topdressed with their respective root­ zone mixes and core cultivated. Visual ratings of turfgrass establish­ ment and quality were taken, and turf cover for each plot was quantified via line-intersect counting. Samples from the 0- to 4-inch depth were collected in April 1999 to assess rootzone fertility. Three cores were taken from selected plots in 1999 and sectioned into 3-inch intervals to assess rooting. TURF ESTABLISHMENT RATINGS Bentgrass establishment through 60 days after seeding (DAS) was better on most of the amended rootzone mixes compared to unamended sand. An acceptable establishment rating (5 or higher) was observed at: • 13 DAS for 20% compost mixed with finer sand • 17 DAS on 10% ZeoPro and 100% loam mixes NOVEMBER-DECEMBER 2004 7 • 20 DAS for 20% sphagnum, 20% loam, and 20% Profile mixes • 24 DAS for 10% sphagnum and 10% reed sedge, 20% Irish, and 10% Profile mixes • 28 DAS for 5% reed sedge, 10% Irish, 5% Fertl-Soil, and 10% compost mixes • 31 DAS for 5% loam • 37 DAS for 2.5% loam, 5% sphag­ num, 10% Isolite mixes • 41 DAS for unamended sand, 10% Greenschoice, and 10% Kaofm mixes Note that unamended sand and Kaofm plots received an additional 0.3 lbs. per 1,000 sq. ft. of N at 37 DAS to promote sufficient growth and enable turf to survive mowing, yet these plots remained the slowest to establish. The 100% loam plots initially estab­ lished turf very well until mowing was Table 1 Description of materials and mixing rates used to amend a medium-sized sand and construct rootzones 12 inches deep over a 4-inch gravel layer, except where noted Amendment Material Description Volume Mixes Percent Amendment None Loam Medium-sized sand Loam mixed with medium sand Clay 0.7 1.0 2.8 Sand 98.2 96.8 88.9 Silt 1.0 2.2 8.3 (% by volume) Loam Over Subgrade Rootzones constructed 12 inches deep over subgrade with drainage pipe (i.e., no gravel layer) Sand Silt Clay 96.8 5.8 2.2 48.7 (% by volume) 1.0 15.5 Organic Amendments Sphagnum Peat Sphagnum peat from Sun Gro, Canada Reed Sedge Peat Reed sedge peat from Dakota Peat, North Dakota Irish Peat Kaofin Sphagnum peat from Ireland Granulated recycled paper manufacturing by-product containing cellulose and kaolin from New Jersey (also containing surfactant) Fertl-Soil Spent mushroom soil compost from Pennsylvania AIIGro Compost In-vessel composted biosolids from AIIGro in New Hampshire AIIGro Compost with Finer sand amended with in-vessel composted finer sand (AT Sales)* biosolids from AIIGro, Pennsylvania Inorganic Amendments Isolite Axis Porous ceramic - diatomaceous earth Porous ceramic - diatomite Greenschoice Porous ceramic - clay based Profile ZeoPro Porous ceramic - clay based Nutrient charged clinoptilolite zeolite ZeoPro surface 4-inch Surface 4 inches of rootzone amended with ZeoPro overlying 8 inches of medium sand ZeoPro Plus surface 4-inch Surface 4 inches of rootzone amended with ZeoPro containing micronutrients overlying 8 inches of medium sand 0 2.5 5 20 5, 10,20 5,10 10,20 10 5 10 20 10 10 10 10,20 10 10 10 *Sand used to mix with 20% compost contained a high amount of fine sand based on the USGA guidelines for rootzone composition. All other mixes contain medium sand conforming to USGA size guidelines (see Table 1). 8 GREEN SECTION RECORD started, and then the turf establishment suffered. The decline in establishment resulted from mower scalping that was caused by lack of firmness (stability) in the soil under frequent irrigation and uneven settling of the loam. TURF COVER Turf cover measurements at June 22 and July 8 (22 and 38 DAS, respectively) reflected turf establishment ratings and indicated that the lower amendment rates of loam (2.5% and 5%), sphagnum (5%), reed sedge (5%), and Irish peat (10%) were not as effective in promot­ ing establishment as were greater rates of those amendments. The 20% com­ post mixed with finer sand and 100% loam plots had the greatest turf cover compared to other mixes. While the 20% compost mix rapidly developed and maintained excellent turf cover, turf cover on 100% loam plots decreased from 92% to 82% by July 8. Again, this decline in turf performance on 100% loam plots was due to mower scalp caused by inadequate surface stability and uneven settling of the rootzone. Amending with 10% Kaofm, 10% Greenschoice, and 2.5% loam did not improve plant cover compared to unamended sand by July 8. Kaofm plots had the least turf cover compared to other plots on June 22 and July 8, which reflected the challenges of establishing turf on these plots. Improved turfgrass establishment was attributed to improved soil physical and nutritional conditions. Bentgrass estab­ lished most rapidly on the 100% loam, 20% compost, and 10% ZeoPro plots as would be expected on mixes with a high nutrient content. The positive turf response to the nutrient-charged ZeoPro amendment was expected.1 Ferguson et al.11 and Nus and Brauen15 reported improved creeping bentgrass establishment in field trials using non­ charged zeolite. Increasing amendment rates of loam, sphagnum peat, Irish peat, and reed sedge peat improved the rate of estab­ lishment. Most amendments increased CEC, although the level of CEC was less than 4 cmol kg1, which is con­ sidered low.8 The majority of fertilizer N in this trial was in the form of ammonium. Thus, it is probable that the improved turf establishment on mixes with increased CEC was attributable to better nutrient retention, particularly ammonium nitrogen. Huang and Petrovic13 and Ferguson and Pepper11 reported increased ammonium retention in sand amended with non-charged zeolite, and Bigelow et al.6 observed lower ammonium loss in leaching studies with Profile and non-charged zeohte. Greater water retention (capillary porosity at or above the USGA recom­ mended maximum of 25%) was often associated with rapid turf establishment. Murphy et al.14 reported better turf establishment on mixes with capillary porosity of 25% (0.25 m3 m3) or higher (the mixes in that study were not con­ founded by differences in nutrient retention). Greenschoice and Kaofin mixes were exceptions compared to other amended sand mixes and exhibited either similar or poorer establishment than unamended sand. These two mixes were very dry despite the light, frequent irrigation used during establishment, as evidenced by the low capillary porosity of these mixes, particularly Kaofin. TURF QUALITY Turf quality ratings indicated that many mixes performed at a level that was consistent with observations made at early establishment. However, there were some mixes with dramatic changes in performance. Profile plots, which initially had established turf better than the unamended sand, became similar in turf quality to the unamended sand by October 1998. Eventually, turf quality on the Profile plots was lower than the unamended sand. The ZeoPro plots produced very high turf quality up to October 1998. However, quality dechned to moderate and low accept­ able levels by April and May 1999. The Kaofin plots, which initially established very slowly (slower than unamended sand), achieved very high turf quality by October 1998 and maintained that level of quality into May 1999. This change in performance on Kaofin plots was attributed to the surfactant (droughtiness and phyto­ toxicity) dissipating from the Kaofin amendment, and subsequently turf growth improved. The 10% Greens­ choice plots, which initially established at a rate similar or slightly less than the unamended, declined to unacceptable levels of quality by October 1998. Turf quality on Greenschoice plots was so poor in May 1999 that the plots nearly failed. The 5% loam plots (over gravel and over subgrade) produced a moderate level (6.5 to 7.5) of turf quality. How­ ever, low acceptable quality levels were observed on 2.5% and 20% loam plots. Thus, turf responses suggested that the 20% loam mix was approaching exces­ sive amounts of the amendment (i.e., silt and clay). As noted previously, sur­ face instability on 100% loam plots continued to negatively impact turf performance from October 1998 to May 1999 to the point that quality was unacceptable by April 1999 and plots could be judged as failing. The 10% and 20% Profile and 4-inch ZeoPro plots produced relatively low NOVEMBER-DECEMBER 2004 9 turf quality ratings that were less than the unamended sand in May 1999. Irri­ gation was not re-initiated until May 13,1999. Thus, the improved nutritional characteristics of these mixes that were an asset under the frequent irrigation during seeching establishment were probably negated by the relatively low water availability (capillary porosity) in those plots when irrigation was more limited in 1999. Moreover, the greater ability to retain nutrients, particularly ammonium, probably became less important as fertilization was decreased towards a maintenance level over time and ammonium was depleted from the charged zeolite. Similarly, low water retention was attributed to the poor turf performance on the 10% Greenschoice plots. Bigelow et al.5 reported the inability of inorganic amendments to improve available water retention in sand mixes using standard laboratory techniques. In fact, some of their data indicated available water was decreased in sand mixes containing in­ organic amendments. Our field data for turf performance on mixes containing inorganic amendments was in agree­ ment with those findings? ROOTING RESPONSE ONE YEAR AFTER SEEDING Roots were observed at all depth zones for all mixes, and the relative differences in total root mass among rootzone mixes were generally evident in root mass assessed at all four 3-inch depth intervals. Greatest total root mass was found in the unamended sand, 2.5% and 5% loam, 5% loam on subgrade, 5% sphagnum, 10% and 20% Profile, and 10% ZeoPro mixes. Higher amendment rates of loam and peat in the rootzone mix decreased the total root mass to the point that the high amendment rates of sphagnum, reed sedge peat, and loam had considerably lower total root mass than unamended sand. The lowest total root mass was found in the 20% com­ post mixed with finer sand and 10% ZeoPro Plus (i.e., containing micro­ nutrients) plots. 10 GREEN SECTION RECORD Thus, there was a relationship of lower root mass with mixes having greater water storage, yet these mixes also consistently produced high turf quality. Murphy et al.14 observed that fmer-textured and, consequently, wetter sand rootzones resulted in lower root mass at depths below 3 inches and better turf quality during the first year of establishment. These findings indicate that variation in water availability of sand-based rootzones can be sufficient to impact distribution of dry matter between roots and shoots. ACKNOWLEDGEMENT This work was supported by the New Jersey Agricultural Experiment Station, State and Hatch Act funds, Rutgers Center for Turfgrass Science, and other grants and gifts. Additional support was received from the United States Golf Association, Tri-State Turf Research Foundation, Golf Course Superintendents Association of America, New Jersey Turfgrass Foundation, and Golf Course Superintendents Association of New Jersey. REFERENCES 1. Andrews, R. D., A. J. Koski,J. A. Murphy, and A. M. Petrovic. 1999. Zeoponic materials allow rapid greens grow-in. Golf Course Management 67(2):68-72. 2. Baker, S.W 1984. Long-term effects of three amendment materials on moisture retention characteristics of a sand-soil mix. J Sports Turf Res. Inst. 60:61-65. 3. Baker, S.W 1999. The effects of sand type and rootzone amendments on golf green perfor­ mance. I. Soil properties.J. Turfgrass Sci. 75:2-17. 4.Baker, S.W, and C.W Richards. 1993. Soil physical properties of soccer pitches: relation­ ships between laboratory and field measure­ ments. Int. Turfgrass Soc. Res.J. 7:489-503. 5. Bigelow, C. A., D. Bowman, and K. Cassel. 2004. Physical properties of three sand size classes amended with inorganic materials of sphagnum peat moss for putting green root­ zones. Crop Sci. 44:900-907. 6. Bigelow, C. A., D. Bowman, and K. Cassel. 2000. Sand-based rootzone modification with inorganic soil amendments and sphagnum peat moss. USGA Green Section Record 38(4):7-13. 7. Brown, K. W., and R. L. Duble. 1975. Physical characteristics of soil mixtures used for golf green construction. Agron.J. 67:647-652. 8. Carrow, R. N., D.V. Waddington, and P. E. Rieke. 2001. Turfgrass soil fertility and chemical problems: Assessment and management. Ann Arbor Press, Chelsea, Michigan. 9. Cook, A., and S.W Baker. 1998. Effects of organic amendments on selected physical and chemical properties of rootzones for golf greens. J. of Turfgrass Sci. 74:2-10. 10. Crawley, W, and D. Zabcik. 1985. Golf green construction using perlite as an amendment. Golf Course Management 53(7):44-52. 11. Ferguson, G. A., and I. L. Pepper. 1987. Ammonium retention in sand amended with clinoptilolite. Soil Sci. Soc. Amer. J. 51:231-234. 12. Ferguson, G. A., I. L. Pepper, and W R. Kneebone. 1986. Growth of creeping bentgrass on a new medium for turfgrass growth: clinoptilolite zeolite-amended sand. Agron. J. 78:1095-1098. 13. Huang, Z.T., and A. M. Petrovic. 1994. Clinoptilolite zeolite influence on nitrate leaching and nitrogen use efficiency in simulated sand based golf greens. J Environ. Qual. 23:1190- 1194. 14. Murphy,J. A.,J. A. Honig, H. Samaranayake, T. J. Lawson, and S. L. Murphy. 2001. Creeping bentgrass establishment on rootzones varying in sand sizes. Int. Turfgrass Soc. Res. J. 9:573-579. 15. Nus,J. L., and S. E. Brauen. 1991. Clinoptilo- litic zeolite as an amendment for establishment of creeping bentgrass on sandy media. HortScience 26:117-119. 16. Paul, J. L.,J. H. Madison, and L. Waldron. 1970. The effects of organic and inorganic amendments on the hydraulic conductivity of three sands used for turfgrass soils. J. Sports Turf Res. Inst. 46:22-32. 17. Swartz, W E., and L.T. Kardos. 1963. Effects of compaction on physical properties of sand- soil-peat mixtures at various moisture contents. Agron.J. 55:7-10. 18. Taylor, D. H., and G. R. Blake. 1979. Sand content of sand-soil-peat mixtures for turfgrass. Soil Sci. Soc. Amer.J. 43:394-398. 19. Waddington, D.V,T. L. Zimmerman, G. J. Shoop, L.T. Kardos, and J. M. Duich. 1974. Soil modification for turfgrass areas. I. Physical prop­ erties of physically amended soils. Pennsylvania Agric. Exp. Stn. Prog. Rep. 337. 20. Waddington, D.V 1992. Soils, soil mixtures, and soil amendments, pp. 331-383. In Wadding­ ton et al. (ed.) Turfgrass. Agron. Monogr. 32. ASA, Madison, Wisconsin. A more comprehensive paper on this project, including data on physical and nutritional prop­ erties of these rootzone mixes, can be found on the USGA’s Turfgrass and Environmental Research Online at http://usgatero.msu.edu. James A. Murphy, Ph.D., is a turfgrass extension specialist; Hiranthi Samara­ nayake, Ph.D., is a post-doc research assistant; Josh A. Honig and T. J. Lawson are research technicians; and Stephanie L. Murphy, Ph.D., is a lab support specialist; Department of Plant Biology and Pathology at Rutgers University in New Brunswick, New Jersey. Letting he Numbers Tell to™ on Cart Damage e numbers shows how golf carts damage turf in a variety of ways A well-designed cart path that is easy for golfers to follow with routing and curbs for traffic deflection will reduce turf damage significantly. Play golf and ride in a golf cart. It is almost a given these days. But the traffic jam caused by golf carts is getting out of control and is taking an increasing toll on turf. Now golfers are asking, “Why can’t I drive my own golf cart on the golf course? It seems to me that one golf cart per person will cause less damage compared to two golfers per cart.” While it is easy to count the money generated by golf cart rentals, it is not so easy to account for the damage and additional maintenance required to compensate for unrestricted cart use. There have been several good research studies in recent years documenting the impact of golf carts on turf wear, and this article will examine these effects by letting the numbers tell the story. CART DAMAGE DEFINED Several studies have analyzed the turf damage caused by golf carts and other turf vehicles. The impacts can be broken down into two broad categories: • Turf injury — The wear damage caused by vehicles is influenced by the speed of travel and BY DAVID L. WIENECKE the amount of stopping, starting, and turning. The tread design of tires also affects wear damage. Wear symptoms include leaf tissue matting and a subsequent exposure of underlying thatch. With additional traffic, leaf blades are bruised. Ruptured cells eventually give turf a dark, water-soaked appearance. Wilt sets in as water is lost from the leaves, eventually causing a loss of chlorophyll and cell death. • Soil compaction — The soil compaction caused by carts reduces the shoot growth rate and the recuperative potential of turfgrass. Compac­ tion reduces air and water porosity within the soil as well as water movement through the soil pro­ file. Soil compaction can impact turf growth for several weeks or months, resulting in the total loss of turf cover and chronic problems with poor drainage and the invasion of weeds that prefer compacted soil conditions. There are other variables, such as soil type and moisture levels, that further impact wear stress. Research by Carrow and Johnson noted that turf­ grass growing on sandy soils and some clay soils is more prone to wear injury. Soil compaction is greatest when traffic is imposed over excessively wet soils. Any factor reducing turf growth rate, such as soil compaction, high external salt levels, and frozen soils causes a further increase in wear damage compared to a vigorously growing turf. COMPACTION All forms of traffic cause some degree of com­ paction. This is typically an indirect problem Figure I 18-HoleTraffic Impact Area* Calculations of areas impacted by walking, pull carts, and riding carts show the significant area of turf potentially damaged by carts when compared to walking golfers. One golfer per cart impacts approximately the same area as two golfers per cart.Two carts with one golfer in each cart potentially will impact twice the area compared to two golfers in one cart. Transportation Mode by D. Wienecke Figure 2 Compression Pressure (PSI)* Calculations of actual compression pressure show pressure on the heel of the foot while walking is equal to pressure from a four-wheel pickup with one rider. Turf area impacted must also be considered with compression pressure to get a true picture of the cause of vehicle turf damage. Transportation Mode by D. Wienecke 12 GREEN SECTION RECORD commonly resulting in a reduction in turf vigor. The forces that contribute to compaction include the weight of the golfer or golf cart spread over the turf surface. The following example illustrates the amount of pressure exerted on the turf from various sources: • 200-pound golfer heel of foot (walking) = 25 pounds per square inch (psi) • 200-pound golfer ball of foot (walking) = 16.6 psi • 200-pound golfer full foot (standing) = 10 psi • 200-pound golfer both feet (standing) = 5 psi • Pull cart (17 pounds) 2"-wide tires = 2.1 psi (two tires) • Pull cart (17 pounds) 3"-wide tires =1.4 psi (two tires) • Pull cart (17 pounds) 4"-wide tires = 1.1 psi (two tires) • Electric golf cart (empty, 950 pounds) with four 8"-wide tires = 3.7 psi • Electric golf cart with one person and gear (1,200 pounds) = 4.7 psi • Electric golf cart with two people and gear (1,450 pounds) = 5.7 psi • Maintenance pickup truck (3,000 pounds) = 25 psi (four tires) Based on compression pressure, we would expect to see walking golfers causing the most damage. In fact, the majority of wear damage observed in the field is caused by four-wheeled motorized golf carts. Why is this true? Read on! AREA IMPACTED — WHERE THE RUBBER MEETS THE ROAD The damage caused by various modes of trans­ portation can be estimated by measuring the contact area of shoes or tires and multiplying this over the total area covered during a round of golf. The following example illustrates the average area impacted while playing a 6,200-yard golf course: • Walking golfer with golf bag = 1,283 sq. ft. • Walking golfer using a pull cart with 3"-wide wheels = 12,908 sq. ft. • Golfer riding a golf cart = 61,845 sq. ft. • Two golfers each using a golf cart = 123,690 sq. ft. Looking at the numbers, it is easy to under­ stand why four-wheel golf carts impact (and compact) the golf course so dramatically. LESSONS LEARNED The preceding examples paint a clearer picture of why golf carts cause significant damage to golf courses. By analyzing the numbers, we can learn the following lessons: • All vehicles cause turf damage. This includes motorized golf carts, pull carts, and maintenance vehicles. Some of the damage may not be visible for days or even weeks as a result of the effects of soil compaction. • Walking the golf course and carrying your clubs impacts the golf course far less than pull or motorized carts based on the total amount of area impacted. • Pull carts impact the golf course less than motorized carts, but all carts impact the golf course more than walking. This is due to the smaller area contacted by foot traffic and the wheels of the pull cart. • Vehicle traffic has the greatest impact on wear and soil compaction due to the amount of area covered and the increased damage caused by repeated traffic over a concentrated area. Damage is further increased with a greater number of turns, a higher speed of travel, and the number of traffic passes over a given area. Based on the research results, the main focus for minimizing the damage caused by golf carts should be on spreading traffic over a wider area or restricting golf carts to paths. • There is some evidence to suggest that the newer designs of golf carts can reduce the overall impact on turf injury due to wider tires and smoother tread design. IDEAS FOR SPREADING CART WEAR AND REDUCING TURF DAMAGE FROM VEHICLES To reduce the inevitable damage caused by golf carts, it is important for courses to establish policies for cart use. While each course is differ­ ent, the following suggestions can help with the development of practical policies to reduce the damaging effects of golf carts: • Encourage golfers to spread cart traffic over a wider area and avoid turning and driving over the same areas repeatedly. • Vary the entry and exit points along the cart paths each day to spread traffic and wear more evenly. • All vehicles should be kept at least 30 feet from the edges of tees and greens to avoid damaging sensitive turf areas. • Carts should never be taken across excessively wet areas. • The use of carts should be suspended or restricted following periods of heavy rainfall or under persistently wet conditions. • Golfers should always share a cart. • Encourage golfers to use the 90-Degree Rule by exiting the path and driving to the first ball, Wet turf is more susceptible to cart damage. Excluding vehicles from excessively wet areas using signs and barriers will protect the turf until the moisture is reduced via drainage or drying. NOVEMBER-DECEMBER 2004 13 Signs coupled with marshal enforcement and golfer education work well for keeping carts on paths. Install signs frequently throughout the course to remind golfers when they need to stay on paths. then to the next ball, and then returning to the path. • Restrict carts to the path on all par-3 holes. • Propose a “walkers-only day” one time per week when no golf carts are allowed on the course. • Consider closing one additional hole to cart traffic on each nine on a weekly rotation. This allows the turf to recover from damage and gives the maintenance staff time for extra aeration and other procedures to stimulate turf recovery. Most of the damage caused by golf carts can be minimized when drivers use common sense and observe proper course etiquette. Each person driving a cart must be aware of the damage that vehicles cause and take steps to reduce that damage in order to preserve the condition of the course for all golfers. REFERENCES Carrow, R. N. 1997. Tire change offers small decline in turf wear. Golf Course Management. 65(5):49-51. Carrow, R. N. 1996. Turfgrass wear stress: Effects of golf car and tire design. J. Amer. Soc. Hort. Sci. 31(6):968-971. Carrow, R. N., and B. J.Johnson. 1989.Turfgrass wear as affected by golf car tire design and traffic patterns.}. Amer. Soc. Hort. Sci. 114(2):240-246. Gross, P. 2002. “Trolley follies.” USGA Green Section Record 40(5): 19-22. Vavrek, R. 2002. “How much traffic can you bear?” USGA Green Section Record 40(4): 1-6. Dave Wienecke is an agronomist in the Southwest Region of the USGA Green Section, where he shares practical advice on reducing traffic damage and other turf management issues at courses in Arizona, California, and Nevada. 14 GREEN SECTION RECORD ponsored Research You Can Use New Tool for Biological Warfare on Cutworms? Recent discoveries by University of Kentucky scientists may make biological control of black cutworms a reality. BY CALLIE ANNE PRATER AND DANIEL A. POTTER TBhe black cutworm (BCW), Agrotis ipsilon, is a major pest of golf courses and sports fields in the U.S. and throughout the world. The BCW larvae make burrows in the thatch or soil, or occupy aerification holes or other cavities, emerging at night to chew down grass blades and stems around the burrow. The damage appears as small dead patches or sunken pockmarks that resemble ballmarks on greens. Birds probing the turf for a meal of juicy caterpillars may pull up tufts of grass with their beaks, further reducing smoothness and uniformity of the putting surface.3 Because of the low golfer tolerance for such damage, BCW warrants frequent insecticide applications. Some superin­ tendents treat every two to four weeks during the growing season as a prevent­ ive measure. Although most modern turf insecticides are intrinsically less toxic than products used a generation ago, some still have the potential to adversely affect pollinators, decomposers, and beneficial natural enemies (predators and parasitoids) that help buffer the turf against outbreaks.3 Some insecticides have the potential to run off or leach into surface or groundwater, and to impact aquatic organisms and wildlife. These issues, along with societal concerns, have led to increased restrictions and loss of some insecticide registrations. Some communities have already mandated that only so-called “organic” fertilizers and pesticides be used on turf, and the turfgrass industry itself has set forth a new initiative to seek alternative biological controls. A NEW DISCOVERY In the summer of 2003 we made a serendipitous discovery that may pro­ vide a new tactic for safe and long- lasting control of BCW on golf courses. Large numbers of BCW were being collected from six Kentucky golf courses to survey for parasitic insects, but the study was thwarted when about 75% of the field-collected larvae died from a pathogen infection. Diseased larvae showed necrotic spots covering the integument (skin), followed by a swollen, milky white appearance. Death by hquefaction occurred within a few days. With help from colleagues in our Insect Virology Unit, the mystery pathogen from BCW cadavers was isolated, purified, and sequenced using PCR analysis, providing a genetic fingerprint useful for identification. The sample matched profiles of Agrotis ipsilon multicapsid nucleopolyhedrovirus (AgipMNPV), a baculovirus originally discovered infecting BCW in Illinois cornfields.1 The Kentucky strain was amplified by feeding it to healthy cater­ pillars, allowing them to die, and then harvesting more virus from their car­ casses. Liquid and bait formulations of the virus were tested in the lab and field in autumn 2003. High mortality (80- 90%) from virus was obtained in both trials. More extensive tests were carried out in summer 2004. AgipMNPV MODE OF ACTION For infection to take place, the cater­ pillar must ingest virus particles that stick to grass blades and stems. Once ingested, the virus particles dissolve in the alkaline environment of the insects gut. This releases infective baculovirus virions that penetrate the insects gut wall. One round of replication occurs in the cells that hne the gut. These virus particles are then released into the insects blood and travel throughout the caterpillar to invade and replicate in other susceptible tissues. This second generation of virions then becomes coated by a protective protein layer called polyhedrin. The virions plus protein coat are now referred to as occlusion bodies. The insects cells are unable to contain the numerous occlusion bodies and even­ tually rupture. The insect liquefies internally and dies. The integument soon ruptures, releasing the liquefied contents that contain millions of virus particles into the environment.4 POTENTIAL OF BACULOVIRUSES FOR INSECT CONTROL Baculoviruses have the potential to be ideal biological control agents. Their protective protein coat dissolves only at a specific pH and other conditions NOVEMBER-DECEMBER 2004 15 found in the gut of host caterpillars. This specificity enables the virus to control pest populations without harm­ ing non-target organisms.3 Baculo- viruses also are known to infect only the particular insects to which they are adapted, and therefore are safe for humans and other vertebrates as well as plants. Additionally, as a result of their protein crystallized coating, they are able to persist in the population as well as in the environment for extended periods of time.1 Once established, baculoviruses may remain active in upper soil layers for many years. This persistence might allow for fewer applications compared to chemical controls, and may possibly provide season-long or even multi-year control. Baculoviruses also are highly pathogenic, allowing them to spread quickly throughout pest populations. On the downside, the specificity of action that is an advantage in one con­ text limits the potential market for a commercial product compared to con­ ventional insecticides that control a broader range of insect pests. These viruses also have the ability to be mixed with fungicides, herbicides, The black cutworm (BCW), Agrotis ipsilon, is a major pest of golf courses and sports fields in the U.S. and throughout the world.The BCW larvae make burrows in the thatch or soil, or occupy aerification holes or other cavities, emerging at night to chew down grass blades and other stems around the burrow. Damage from black cutworms appears as small dead patches or sunken pockmarks that resemble ballmarks on greens. 16 GREEN SECTION RECORD and other insecticides, and they can be used in conventional spray equipment. Unlike some chemical controls, baculo- viruses do not have broadly toxic resi­ dues that may adversely impact the environment. There have been 15 cases of successful, permanent biological con­ trol with insect viruses.2 For example, viruses were used to suppress the European spruce sawfly in Canada and the United Kingdom. In one study, researchers applied an NPV for control of soybean loopers, and when the plots were reevaluated 15 years later, the virus was still providing about 63% control.2 PROGRESS TO DATE In our USGA-funded project we are evaluating the potential for developing this insect­ specific virus as a bio­ insecticide against BCW in turf. So far we have made some interesting discoveries. For example, most larvae die within a week after becoming infected with the virus. When young larvae become infected, their growth and development are stunted, and they die while still small. In contrast, older infected larvae may continue to feed up until the day of death. Thus, the virus may be better suited as a preventive for season-long suppression than as a rescue treatment in response to damage. We continue to evaluate field efficacy of AgipMNPV under golf course con­ ditions. For example, one of the main factors limiting the use of baculoviruses as bioinsecticides is their tendency to be degraded by exposure to ultraviolet (UV) light. We currently are evaluating if AgipMNPV formulated with optical brighteners may enhance stability of the virus in sunlight and provide better suppression of BCW under field con­ ditions. Irrigation is another factor that may affect the virus. We are comparing the effectiveness of the virus with and without irrigation, and in combination with spray adjuvants (e.g., spreader/ stickers) to increase the virus’s foliar persistence. Persistence of the virus in the host population is vital for sustained control. This is dependent upon horizontal transmission from insect to insect. When larvae die from a viral infection, they release millions of occlusion trum pesticides, this type of research is necessary to ensure that professional turfgrass managers will always have adequate alternatives to chemical con­ trol. We have seen naturally occurring baculoviruses nearly wipe out localized BCW populations on golf courses in some years. Thus we are optimistic that commercial development of AgipMNPV baculovirus could offer a viable alternative to traditional insecti­ cides for this perennial pest. We envision that golf course superintendents might apply AgipMNPV early in the growing season as a preventive measure, causing high mortality in the first- generation BCW popula­ tions. Death of those larvae will in turn create a reservoir of virus in the soil and thatch that perpetuates control of BCW through the growing season. The tactic would be both cost effective and environmentally sound, resulting in need for fewer chemical applications. We hope the groundwork Once infected with the baculovirus, the black cutworm liquefies internally and dies. The integument soon ruptures, releasing the liquefied contents containing millions of virus particles into the environment. bodies into the surrounding environ­ ment that may infect other host larvae. We will determine the probability of healthy larvae contracting the virus after feeding on turf cores where infected larvae have died. This will give us an idea of how easily this virus is spread throughout the population. We also hope to determine if there might be a synergistic interaction between the virus and endophytic grasses. In other words, will feeding on endophytic grasses make BCWs even more susceptible to the virus? BREAKING NEW GROUND This is the first research to investigate use of a virus to control an insect pest in the turfgrass environment. Given the increasing restrictions on broad-spec­ provided by this project will encourage interest in developing new biological insecticides for use on turf. ltit/rwc. JRF cited 'Boughton, A.J., R. L. Harrison, L. C. Lewis, and B. C. Bonning. 1999. Characterization of a nucleopolyhedrovirus from black cutworm, Agrotis ipsilon (Lepidoptera: Noctuidae). J. Invertebr. Pathol. 74: 289-294. 2Moscardi, F. 1999. Assessment of the application of baculoviruses for control of Lepidoptera. Annu. Rev. Entomol. 44:257-289. Totter, D. A. 1998. Destructive turfgrass insects: Biology, diagnosis, and control. Wiley, New York. 4Smith, K. M. 1967. Insect virology. Academic Press, New York, N.Y. Callie Prater is a master’s degree candidate at the University of Kentucky, Lexington, Kentucky. Dr. D. A. Potter, professor of entomology, is her advisor. NOVEMBER-DECEMBER 2004 17 WALKING GREEN MOWERS: Solution or Problem? Carefully analyze several factors before determining the best plan. BY BOB RANDQUIST When triplex green mowers were introduced into the golf course equipment market in 1968, they were welcomed courses began to eliminate the use of triplex green mowers and return to the use of walking green mowers for mow­ ing greens. In response to this trend, I wrote an article published in the November/December 1983 issue of the USG/4 Green Section Record entitled “Should You Change from Triplex Green Mowers to Walking Green Mowers?” that explained why we changed back to using walking green mowers to mow the greens at Southern Hills C.C. in Tulsa, Oklahoma. Since that time, the debate has continued. with open arms by golf course super­ intendents who recognized the poten­ tial cost savings and convenience these mechanical marvels would provide for golf course maintenance operations. I remember very well my first experience mowing greens with a triplex green mower in 1971 atTrosper Park G.C. in Oklahoma City. It was very exciting to be able to mow all 18 greens and the practice greens by myself in only 3 to S/ hours time. I was usually one of the three employees who spent 214 to 3 hours each morning mowing greens with a walking green mower and racing to finish ahead of the early morning golfers. Mowing with the new triplex green mower made this task so much easier for us and allowed the superin­ tendent I worked for to assign two other employees to other important jobs. By 1975 the use of triplex green mowers became the preferred method for mowing greens at many golf courses. Unfortunately, wear pattern and stress-related problems on greens and surrounding areas began to appear as triplex green mowers were used to mow greens over an extended period of time. The simple solution for many of these problems was a return to the use of walking mowers for greens. By the early to mid-1980s, many golf 18 GREEN SECTION RECORD THE QUESTION Is walk mowing greens the best solution for problems caused by triplex mowing greens, or does walk mowing create too many problems for golf course superintendents due to budgetary and/or staffing limitations? As we attempt to correctly answer this question, let’s examine the factors that must be considered: the problems that triplex green mowers cause and some possible solutions for these prob­ lems, and the challenges associated with walk mowing greens. TRIPLEX GREEN MOWERS: PROBLEMSAND POSSIBLE SOLUTIONS • Triplex Ring. One of the first problems that appears with the use of triplex green mowers is a thinning of the turf where the cleanup cut is made around the perimeter of the putting surface. This thinning is caused by two factors: large areas of turf are double cut each day due to the space required to properly lift and lower the mower attachments, and the centrifugal force exerted on the triplex tires as the tri­ plex mower travels in a circular motion around the green. The additional abrasion caused by these factors often adds stress to or physically damages the turf in these cleanup pass areas. This stress can be reduced by slowing the triplex mowing speed, only mowing a cleanup pass every other day, or by mowing the cleanup pass with a walk­ ing green mower. In most situations, Above:With labor costs having increased dramatically over the past few years, options for increasing efficiency without compromising quality are being reviewed at all courses. Left: Turning the triplex green mower too quickly and too sharply resulted in wilted turf. Depending on weather conditions the next day, the result could be brown turf and a slow recovery process. due to bunkering, vegetation, water features, or cart path curbs.This damage to surrounding turf areas greatly in­ creases as cool-season grasses are sub­ jected to heat-related stresses in the summer, or warm-season grasses are dormant or trying to break dormancy in the spring. Matted turf, thin turf, bare ground, or increased weed popu­ lations often are the result of this daily triplex mower traffic. Additional costs associated with correcting these prob­ lems must be considered when com­ paring costs for triplex mowing versus walk mowing greens. When adequate maneuvering room is available around greens, this problem can be overcome by properly training equipment operators to make wide, slow turns with the tri­ plex mower. If this is not the case, walk mowing greens is usually the best solution to this problem. • Increased soil compaction of a green soil profile. The argument is often made that the total weight of triplex mowers (1,100 to 1,200 lbs. with operator) causes added soil compaction of a green’s soil profile. This point is debatable due to the even distribution of the weight across the three reels and the triplex mower tires. With current aerification tools and methods, this potential compaction can easily be eliminated. The only time this triplex mower weight may be a factor is when mowing is done on very wet greens and triplex tire tracks may be some­ what visible. This is not usually a valid reason for switching to walk mowing greens. • Hydraulic leaks. Unsightly hydrau­ lic leaks on greens will always be a risk when mowing greens with triplex green mowers. Good preventative maintenance, leak detection devices, or the use of readily visible dyes in the hydraulic fluid certainly lessen the potential for excessive damage on putt­ ing greens caused by these leaks. How­ ever, walk mowing greens is the only way to insure that hydraulic leaks will not be a problem. • Uniformity of mowing height. It can be difficult to keep three separate mowing units on one triplex green mower cutting at the same height and with the same quality over the course of mowing 9 or 18 greens. This is especially true when greens have been recently topdressed with sand. If quality or cutting height changes on one unit and not the other two, the difference may be visible to golfers and the green may appear to be mowed unevenly. With walk mowing, the changes that may occur are not as noticeable since the change tends to be uniform throughout the green being mowed. Proper attention to mowing quality by operators, supervisors, and mechanics NOVEMBER-DECEMBER 2004 19 walk mowing the cleanup pass is the only solution that solves the triplex ring problem. A triplex ring around the green perimeter is unacceptable to golfers for both aesthetic and playability reasons. Labor savings associated with triplex mowing are often significantly reduced by efforts to eliminate this problem. • Wear on turf areas surrounding greens. Damage to turf areas surround­ ing greens often occurs as triplex green mowers repeatedly turn on these turf areas. This is especially true when maneuvering room for the triplex green mowers around greens is limited can solve this problem with triplex mowing. • Change in the original shape of the green. When greens with irregu­ larly shaped perimeters are mowed with triplex mowers, triplex mower operators tend to soften the turning radius and round the turns in areas where severe turns are required. Over a period of time much of the original design character of this type of green becomes lost as the green becomes more rounded. In severe cases, interesting hole locations and putting challenges may be sacri­ ficed as a result of triplex mowing greens. This problem usually does not occur with walk mowing greens. CHALLENGES OF WALK MOWING GREENS • Increased cost compared to triplex mowing. Golf course super­ intendents and their employers need to carefully examine the difference in costs for triplex mowing vs. walk mowing greens. Several factors affect this cost difference: size of greens and labor hours required for mowing; hourly labor costs for equipment operators; ease of maneuverability around greens and possible resulting costs for addi­ tional aerification, traffic damage repair, and additional weed control caused by triplex mowing; initial cost, ongoing maintenance costs, and projected life span of mowing equipment. While these factors and costs vary from one golf course to another, the net savings realized by triplex mowing greens is usually in the range of $10,000 to $25,000 per year. For almost all golf course operations, this cost difference represents only a small percentage of the total golf course budget. This is a small price for any golf facility to pay for having the best possible putting and aesthetic greens conditions. The impor­ tance of providing consistent, quality playing conditions in areas immediately surrounding the greens should not be underestimated. Golfers expect good playing conditions for the numerous shots they will play from these areas during every round of golf. • Staffing limitation problems. When considering walk mowing greens as a solution to the problems associated with triplex greens mowing, the challenge for many golf course superintendents is having daily avail­ ability of the 3 or 4 employees needed to walk mow 18 greens. When golf facilities restrict or refuse to allow employee overtime, this can present a real obstacle to walk mowing greens. One excellent solution for this problem is to mow greens with walking mowers on weekdays and mow greens with triplex mowers on weekends. This compromise tends to prevent many of the problems caused by triplex mowing from ever occurring without added un­ desired overtime labor costs. This issue is primarily a matter of convenience for supervisors and their employees. With creative and flexible scheduling, this problem can usually be solved. Are walking green mowers the solu­ tion or the problem? For any golf facility, only the golf course superin­ tendent and those he works for can answer this question correctly. It is our joint responsibility to carefully analyze all the relevant factors before making the recommendation to use triplex mowers or walking mowers for mow­ ing greens at our golf facility. For most golfers, the improved quality of putting greens and the surrounding playing areas is worth the minimal investment and creative, flexible staff scheduling that walk mowing greens requires. Be open minded and objective when con­ sidering the possibility that walking green mowers may be the solution and not the problem for mowing your golf courses greens. Bob Randquist, CGCS, has been the director of grounds and maintenance at Boca Rio G. C. in Boca Raton, Florida, for six years. Prior to moving to Florida, Bob was the golf course superintendent at Southern Hills C.C. in Tulsa, Oklahoma, for 19 years. Walk mowing of putting greens is the only way to totally avoid hydraulic oil leaks and damage. 20 GREEN SECTION RECORD ponsored Research You Can Use Environment and Culture Affect Bermudagrass Growth and Decline The roles temperature and shade play in ultradwarf bermudagrass health are not totally understood. during cloudy, wet periods of late summer and early fall. Drs. Joseph Krausz, Philip Colbaugh, Roy Stanford, and Richard White were part of the turfgrass research team at Texas A&M University that explored the effects of cultural, environmental, and plant growth factors on the re­ because bermudagrass decline often becomes more severe during persistent cloudy and overcast conditions (Waltz, 2003).Texas A&M University research also focused on cultural practices to en­ hance recovery of turf exhibiting ber­ mudagrass decline symptoms. Although bermudagrass decline is not inevitable, BY RICHARD H. WHITE Bermudagrass decline is a devastat­ ing root disease of highly man­ aged bermudagrass turf, especially on golf greens in the southern United States (Elliott, 1991). It is caused by an interaction of host-predisposing abiotic stresses and the soil-borne, ectotrophic, root-infecting fungus Gaeumannomyces graminis var. graminis (G^g). Bermuda­ grass decline results in large areas of turf with weakened, short, brown-to- black root systems and an absence of feeder roots and root hairs. Symp­ toms include foliar chlorosis, a thin­ ning stand, poor response to fertilizer and irrigation, and premature plant death. The pathogen causes root, rhizome, and stolon rotting. Nutrient and irrigation manage - ment is difficult because of diminished root systems. Above-ground symptoms of infection often become evident any­ where from spring green-up through the spring and summer months, when heat and moisture stress challenge the weakened root systems of affected plants. Symptoms also are common when the disease does occur, strategies are needed to hasten turf recovery. CULTURAL STRATEGIES TO ENHANCE RECOVERY FROM BER­ MUDAGRASS DECLINE Recommendations for hastening turf recovery from ber­ mudagrass decline often include raising the mowing height and applying acidifying fertilizers and/or foliar feeding (Fermanian et al., Tifeagle bermudagrass green at the time of treatment initiation in July. covery of bermudagrass from damage caused by Ggg. A strong component of the research was to gain a better under­ standing of how temperature and light levels influence dwarf bermudagrass growth and development. The influence of light and temperature on dwarf bermudagrass growth was of interest 2003). A four-year-oldTifeagle bermuda­ grass putting green with severe symptoms of bermudagrass decline was used to explore cultural approaches for alleviat­ ing the disease symptoms. The green was maintained at 0.125 inch, had a soil pH of 9.1, and was previously fertilized with a coated urea nitrogen fertilizer. NOVEMBER-DECEMBER 2004 21 Table I Turf quality in August and October forTifeagle bermudagrass as influenced by monthly aerification with hollow or solid tines and biweekly fertilizer applications to provide 6, 12, and 24 pounds of N per 1,000 sq. ft. annually1 HollowTine Solid Tine Nitrogen August October August October 6 12 24 1.5a2 2.0a 2.2a 2.5a 2.9a 3.2a 2.8a 3.2a 3.0a 4.0c 5.3b 6.4a Plots were rated on a l-to-9 scale, with 9 as the highest quality. A 5 was considered the minimal accepted quality level for putting greens. 2Means within months followed by the same lower-case letter are statistically similar. Previous applications of several fungi­ cides in a replicated trial conducted on the green the previous year were not effective in controlling the disease. A series of treatments was established in early July, including nitrogen (N) regimes, aerification, and topdressing arranged in a split-plot design. Nitrogen regimes included bimonthly applications of ammonium sulfate at 0.25, 0.5, and 1.0 lb. N per 1,000 sq. ft. to supply total annual N of 6,12, and 24 lb. per 1,000 sq. ft. Ammonium sulfate was used in this study because of its acidifying effect on soils. Nitrogen regimes were supple­ mented with potassium, phosphorus, and micronutrients based on soil tests. Aerification treatments included monthly application of 0.5-inch solid tines and 0.5-inch hollow tines with cores removed. Topdressing treatments included none, 0.125-inch monthly, and 0.02-inch bimonthly. Treatments were initiated in early July and ended in early September. Visual evaluations of turf­ grass quality were taken every two weeks. Microscopy was used to assess presence of Ggg. Aerification is an important manage­ ment tool that is used to remove and control thatch, reduce compaction, and improve root development. In this study, hollow-tine aerification disrupted the surface more than solid-tine aerifi­ cation (Table 1). Aerification of any type had not been applied to the green for several years, resulting in heavy thatch, increased disease severity, and poor rooting. The poor rooting pre­ vented the initial hollow-tine aerifica­ tion from producing quality cores and uniform coring holes, resulting in greater surface disruption and a longer healing time than when solid tines were used. Turfgrass quality improved and evidence of bermudagrass decline Table 2 Turf quality of Tifeagle bermudagrass in October as influenced by none, biweekly dusting, and monthly heavy topdressing' Topdressing Treatments Nitrogen 6 12 24 None 3.1b2 3.5b 4.1a Dusting Heavy 3.0b 3.6b 4.4a 3.2c 5.0b 6.1a 1 Plots were rated on a 1 -to-9 scale, with 9 as the highest quality. A 5 was considered the minimal accepted quality level for putting greens. 2Means within months followed by the same lower-case letter are statistically similar. 22 GREEN SECTION RECORD symptoms decreased with increasing N, especially for the solid-tine aerification treatments. Although 24 lb. N per 1,000 sq. ft. is considered excessive, this treatment, in conjunction with solid­ tine aerification, resulted in rapid turf quality recovery and diminished ber­ mudagrass decline symptoms. Also, turf quality increased and bermudagrass decline symptoms decreased to a greater extent for increasing N in con­ junction with heavy topdressing than when compared to no and light, fre­ quent topdressing (Table 2). The most advantageous treatment combination for recovery from ber­ mudagrass decline symptoms and improvement of turfgrass quality was solid-tine aerification, heavy topdress­ ing, and 24 lb. N per 1,000 sq. ft. This improvement in quality was accom­ plished without raising the mowing height above 0.125 inch. Excessive N can cause rapid thatch accumulation, and the combination of the greatest amount of N and no topdressing be­ came excessively soft by early October. However, plots that received the greatest amount of N in conjunction with heavy or light topdressing remained firm. Surprisingly, the large amounts of N used did not contribute to an excessive vertical growth rate. The marked recovery of Tifeagle from bermudagrass decline symptoms for specific treatment combinations occurred even though Ggg was still present. Large amounts of N, as used in this study, should not be applied to bermudagrass for long periods of time due to the potential to negatively impact the environment and because of the potential to cause excessive thatch accumulation and contribute to reduced stress tolerance. Increasing N for short periods to enhance recovery followed by lower amounts of N to sustain turf density is, however, a more reasonable approach. Careful rootzone pH man­ agement combined with a sound nutrient management plan may reduce severity of bermudagrass decline (Waltz, 2003). Nitrogen nutrition influenced growth but was not as influential as the temper­ ature regime. The effects of temperature regimes were robust. Internode length was 0.23,0.51, and 0.83 inch, and leaf length was 0.29, 0.45, and 0.49 inch for the 95/80, 80/66, 66/51°F (day/mght) bermudagrass. Although Tifeagle was not a main focus of the growth cham­ ber study, Tifeagle bermudagrass was exposed to the same temperature regimes to determine if growth responses were similar in Tifdwarf and Tifeagle. Similar responses to tempera- ture regimes were observed for Tifdwarf and Tifeagle. DWARF BERMUDAGRASS GROWTH AND DEVELOPMENT IN RESPONSE TO ENVIRONMENT The optimum temperature for growth of bermudagrass is 80 to 95°F (Beard, 1973) and for Ggg the optimum growth tem­ perature in culture is 86°F (Fermanian et al., 2003). Thus, both the bermudagrass and pathogen should grow and develop well at a range of 80 to 90°F. Controlled environment chambers were used to explore the effect of temperature on bermuda­ grass and Ggg and on subsequent disease development. A single sprig of Tif­ dwarf bermudagrass was surface sterilized and then grown in a greenhouse for several months to create planting stock for use in the experiment. Sprigs were obtained from the single stock plant and established in individual containers to receive the following treatment combinations. Treatment combinations included inoculated and uninoculated plants, nitrogen treatments of 4, 8, and 12 pounds of N per 1,000 sq. ft., and temperature regimes of 95/80,80/66, and 66/51°F day/night temperatures. Artificial lighting provided about one- third of full sunlight. SUMMARY The results of this study explain why raising the mowing height is often recommended as a cultural practice to reduce bermudagrass decline symptoms. In coastal and other areas affected by long periods of overcast, rainy weather, growth habit of dwarf ber- mudagrasses may change dramatically Tifdwarf bermudagrass growth response to temperature regimes of 95/80°F (left) and 80/66°F day/night (right). Plants were grown in growth chambers with 14 hours artificial light at about one-third of full sunlight. temperature regimes, respectively. While the growth responses exhibited by Tif­ dwarf in these growth chamber studies were consistent with growth under low light (shade), temperature was a con­ trolling factor in the degree of response. Additional studies were conducted with light levels of about 10,25, and 50% of full sun within temperature regimes of 95/80 and 80/66°F (day/night). Decreasing light caused increases in leaf and internode length, but the degree of increase was regulated by temperature. The results of this study indicate that temperature as well as light levels regu­ late expression of dwarfhess in Tifdwarf in response to low light and lower temperatures. The altered growth form of Tifdwarf that may occur during overcast and rainy weather would not likely tolerate close mowing heights. Thus, mowing stress would result in increased sensitivity to pathogenic organisms such as Ggg and may result in more substantial expression of disease symptoms. Weather data from Texas A&M University indicate that the high and intermediate temperature regimes and light levels used in this study can occur in southern climates in late summer and early fall during periods of heavy rain and week-long NOVEMBER-DECEMBER 2004 23 periods of overcast skies. Evidence of the altered growth form was observed within three to four days of exposure to the moderate temperature regime and light levels used in this study. In addition to the potential implica­ tions that the changes in growth habit in response to environment may have for disease toler­ ance in dwarf bermudagrass, the effect of temperature on dwarf bermudagrass growth habit has tremen­ dous implica­ tions for dwarf bermudagrass golf green management. The effects of temperature on growth habit of dwarf bermudagrass may explain why exces­ sively large amounts of N applied during summer did not cause more robust vertical growth of Tifeagle in the field study described earlier in this text. Temperature should also be a major consideration in the timing and severity of cultivation practices such as core aerification. Healing of surface disruption caused by core aerification and vertical mowing may occur extremely slowly during July and August, periods previously perceived to support maximum bermudagrass growth. During exposure to the high temperatures of July and August, for example, the growth habit of many dwarf bermudagrasses may be extremely compact and not conducive to recovery 24 GREEN SECTION RECORD from injury caused by aerification and vertical mowing. Tolerance to pests and wear also may be less during high- temperature periods. Establishment rates of dwarf bermudagrasses may be dramatically affected by seasonal changes in temperature, with slow • Low light caused increased leaf and internode length in dwarf bermuda­ grasses, but temperature regulated expression of the dwarf growth habit. • The alterations in growth form in Tifdwarf bermudagrass caused by low light and cooler temperatures that often occur during overcast rainy periods justifies raising the mowing height to reduce mow­ ing stress that may con­ tribute to bermuda­ grass decline severity. • High temperatures cause a compact growth habit in dwarf bermuda­ grasses and may slow healing of surface damage caused by cultivation or pests. Effect of monthly solid (front three rows) and hollow-tine (back three rows) aerification, nitrogen at 6, 12,24 and 6, 12, 24 lb. N per 1,000 sq. ft. (front to back), and heavy, light, and no topdressing (left to right) on the appearance of Tifeagle bermudagrass. establishment occurring at temperatures greater than 90°E This notable dis­ covery about the effects of temperature on dwarf bermudagass growth and development provides strong rationale for additional research on numerous aspects of bermudagrass culture, estab­ lishment, and pest and abiotic stress tolerance. RESEARCH SUMMARY POINTS • Tifeagle bermudagrass recovery from bermudagrass decline symptoms was enhanced by aerification, heavy top­ dressing, and aggressive fertilization with ammonium sulfate. REFERENCES Beard, J. B. 1973. Turfgrass: Science and Culture. Prentice Hall, Inc., Englewood Cliffs, N.J. Elliott, M. L. 1991. Determination of an etiological agent of bermudagrass decline. Phytopathology 81:1380-1384. Fermanian,T. W, M. C. Shurtleff, R. Randell, H. T. Wilkinson, and P. L. Nixon. 2003. Controlling Turfgrass Pests, pp. 401-410. Prentice Hall, Upper Saddle River, N.J. Waltz, Clint. 2003. Fungus Family Provides Fodder for Several Diseases. Turfgrass Trends, http: //www. turfgrasstrends, com/ turfgrasstrends / article/articleDetail.j sp?id=51998. Richard White, Ph.D., is professor of turfgrass management and physiology in the Soil and Crop Sciences Department at Texas A&M University. Evaluating Recycled Waters for Golf Course Irrigation To avoid problems, analyze recycled water thoroughly before starting to use it to irrigate a golf course, and monitor it regularly thereafter. BY M. ALI HARIVANDI Throughout the United States and in many other parts of the world, an increasing number of golf courses use recycled municipal water for irrigation. Much of the re­ cycled water used for irrigation contains high concentrations of dissolved salts that are potentially toxic to turfgrasses and other golf course plants. Conse­ quently, chemical water analysis and periodic monitoring are key compo­ nents of sound irrigation management at such sites. Water analysis done by commercial laboratories provides data on many parameters, most of which are not of great significance for turfgrass irrigation. The most important parameters for this purpose are: total concentration of soluble salts (i.e., salinity); sodium (Na) content; relative proportion of sodium to calcium (Ca) and magnesium (Mg) (Sodium Adsorption Ratio, or SAR); chloride (Cl), boron (B), bicarbonate (HCO3), and carbonate (CO3) content; and pH. The following parameters are also often reported on a water test re­ port and should be reviewed, although none by itself plays a major role in determining the suitability of a given recycled water for irrigation: nutrient content (nitrogen, phosphorus, and potassium), chlorine content, and suspended solids. SALINITY All recycled waters contain some dis­ solved mineral salts and chemicals. Some soluble salts are nutrients and thus are beneficial to turfgrass growth; others, however, may be phytotoxic or may become so when present in high concentrations. The rate at which salts accumulate to undesirable levels in a soil depends on their concentration in the irrigation water, the amount of water applied annually, annual precipi­ tation (rain plus snow), and the soil’s physical/chemical characteristics. Water salinity is reported differently by different laboratories. It is reported quantitatively as Total Dissolved Solids (TDS) in units of parts per million (ppm), or milligrams per liter (mgL '), or reported as electrical conductivity (ECw) in terms of milimhos per centi­ meter (mmhos cm'1), micro mhos per centimeter (pmhos cm1), decisiemens per meter (dSm '), or siemens per meter (Sm-1). Some labs may also report the individual components of salinity (e.g., sodium) in milliequivalent per liter (meqL-1). The following equations may be used to convert results from one set of units to another, thus enabling com­ parisons of data from differently for­ matted reports: (1) 1 ppm = 1 mgL'1 (2) 1 mgL1 = meqL'1 X Equivalent Weight (see Table 1) (3) 1 mmhos cm1 = 1 dSm1 = lOOOpmhos cm1 = 0.1 Sm-1 The relationship between ECw and TDS is approximately: (4) ECw (in mmhos cm1 or dSm1) X 640 = TDS (in ppm or mgL1) Most waters of acceptable quality for turfgrass irrigation contain from 200 to 800 parts per million (ppm) soluble salts. Soluble salt levels above 2,000 ppm may injure turfgrass; recycled irrigation water with salt levels up to 2,000 ppm may be tolerated by some turfgrass species (Table 2), but only on soils with exceptional permeability and subsoil drainage. Good permeability and drain­ age allow a turfgrass manager to leach excessive salt from the rootzone by periodic heavy irrigations. Sand-based golf greens create the proper soil structure for this form of salinity management. Table 3 lists the parameters that should be considered in evaluating irri­ gation water quality. As indicated, re­ Table I Conversion factors: mgL1 and meqL1 To Convert mgL1 to meqL'1 To Convert meqL'1 to mgL1 Multiply by 0.043 0.050 0.083 0.016 0.033 0.029 23 20 12 61 30 35 Constituent Sodium (Na) Calcium (Ca) Magnesium (Mg) Bicarbonate (HCO3) Carbonate (CO3) Chloride (Cl) NOVEMBER-DECEMBER 2004 25 cycled water with ECw values above 0.7 dSm-1 (or 450 mgL '), present in­ creased salinity problems. Only careful management will prevent deleterious salt accumulation in the soil if water with a high ECw is used for irrigation. Recycled water with an EC above 3 dSm1 should be avoided or diluted with less saline water before use for irrigation. The salt tolerance of turfgrass and other plants is expressed in terms of the salt content of the soil rootzone [e.g., as indicated in Table 2, Kentucky bluegrass will tolerate soil salinity (ECe, Table 2 The relative tolerances of turfgrass species to soil salinity (ECe). Sensitive (<3 dSm') Moderately Sensitive (3 to 6 dSm ') Moderately Tolerant (6 to lOdSm ) Tolerant (> lOdSm') Annual Bluegrass Annual Ryegrass Perennial Ryegrass Alkaligrass Colonial Bentgrass Creeping Bentgrass Tall Fescue Kentucky Bluegrass Fine-Leaf Fescues Zoysiagrasses Rough Bluegrass Buffalograss Bermudagrasses Seashore Paspalum St. Augustinegrass From: M.A. HarivandiJ. D. Butler, and LWu. 1992. Salinity and turfgrass culture. In: Turfgrass. D.V. Waddington, R. N. Carrow, and R. C. Shearman (eds.) pp. 207-229. Series No. 32, American Society of Agronomy, Madison, Wisconsin, USA. Table 3 Guidelines for the interpretations of recycled water quality for irrigation. Potential Irrigation Problems Units Degree of Restriction on Use Salinity ECw TDS Soil Water Infiltration Evaluate using ECW (dSm ') and SAR together: if SAR = 0 to 3 and ECW = if SAR = 3 to 6 and ECW = if SAR = 6 to 12 and ECW = if SAR = 12 to 20 and ECW = if SAR = 20 to 40 and ECW = Specific Ion Toxicity Sodium (Na): Root Absorption Foliar Absorption Chloride (Cl) Root Absorption Foliar Absorption Boron (B) Miscellaneous Effects Bicarbonate (HCO3) PH Residual Chlorine None Slight to Moderate Severe dSnr' mgL' <0.7 <450 0.7 to 3.0 450 to 2,000 >3.0 >2,000 >0.7 >1.2 >1.9 >2.9 >5.0 <3 <3 <70 <2 <70 <3 <100 <1.0 <1.5 <90 0.7 to 0.2 1.2 to 0.3 1.9 to 0.5 2.9 to 1.3 5.0 to 2.9 3 to 9 >3 >70 <0.2 <0.3 <0.5 <1.3 <2.9 >9 — — 2 to 10 70 to 355 >10 >355 >3 >100 1.0 to 2.0 >2.0 1.5 to 8.5 90 to 500 >8.5 >500 normal range: 6.5 to 8.4 <1.0 1 to 5 >5 SAR meqL1 mgL1 meqL' MgL1 ueqL' mgL-1 mgL' meqL1 mgL' — mgL' Adapted by: M.A. Harivandi from: Westcot, D.W„ and R. S. Ayers. 1984. Irrigation water quality criteria. In: Pettygrove, G. S., and T. Asano (eds.). Irrigation with reclaimed municipal wastewater—A guidance manual. Report No. 841-lwr. California State Water Resources Control Board, Sacramento, California; and from: Farnham, D. S„ et al. 1985. Water Quality: Its effects on ornamental plants. University of California Cooperative Extension Leaflet 2995. Div. of Agric. Nat. Resources, Oakland, California. 26 GREEN SECTION RECORD indicating electrical conductivity of soil water extract) at levels up to 3 dSm1]. Therefore, soil physical characteristics and drainage, both important factors in determining rootzone salinity, must also be considered when deciding about the suitability of a given recycled irrigation water. For example, water with an ECw of 1.5 dSm-1 may be successfully used on grass grown on sandy soil with good drainage (and thus high natural leach­ ing), but prove injurious within a very short period of time if used to irrigate the same grass grown on a clay soil or soil with limited drainage due to salt buildup in the rootzone. Table 2 is a general guide to the salt tolerance of individual turfgrasses. As indicated, soils with an ECe below 3 dSm1 are considered satisfactory for growing most turfgrasses. Soils with an ECe between 3 and 10 dSm-1 can suc­ cessfully support only a few salt-tolerant turfgrass species. SODIUM Sodium content is another important factor in recycled irrigation water quality evaluation. Plant roots absorb sodium and transport it to leaves, where it can accumulate and cause injury. Thus, symptoms of sodium toxicity resemble those of salt burn on leaves. Recycled irrigation water with high levels of sodium salts can be particularly toxic if applied to plant leaves by over­ head sprinkler, since salts can be absorbed directly by leaves. Sodium toxicity is often of more concern on plants other than turfgrasses, primarily because accumulated sodium is removed every time grass is mown. Among grasses grown on golf courses, annual bluegrass and bentgrass are the most susceptible to sodium phytotoxicity. In their case, mowing may not provide protection, since grasses are generally cut very shot (a stress in itself), and any sodium accumulation will comprise a large proportion of the small quantity of remaining leaf tissue. Table 3 provides general guidelines for assessing the effect of sodium in Weak, thin turf is the result of salt accumulation in heavy soils due to use of recycled irrigation water. irrigation water. As indicated in the table, the level of sodium tolerated by non-turf plants varies with irrigation application method. Most landscape plants will tolerate up to 70 ppm (mgL !) sodium when irrigated by overhead sprinkler. SAR (SODIUM ADSORPTION RATIO) Although sodium can be directly toxic to plants, its most frequent deleterious effects on plant growth are indirect due to its effect on soil structure. It is this latter effect that is most often of con­ cern to golf course superintendents and other professional managers of intensively used turfgrasses. When irrigation is applied to soil, the best indicator of sodium effect is a recycled water’s Sodium Adsorption Ratio (SAR), a value that should be provided in all laboratory water analyses. Although, in general, water with an SAR below 3 is considered safe for turf and other ornamental plants (Table 3), SAR is an important enough factor in water evaluation to merit thorough understanding. The high sodium content common to recycled water can cause defloccu­ lation or breakdown of soil clay par­ ticles, reducing soil aeration and water infiltration and percolation. In other words, soil permeability is reduced by a recycled irrigation water high in sodium. The likely effect of particular irrigation water on soil permeability can be best gauged by the waters SAR in combination with the ECw (Table 3). Generally, recycled water with an SAR above 9 can cause severe permea­ bility problems when applied to fine- textured (i.e., clay) soils over a period of time. In coarse-textured (i.e., sandy) soils, permeability problems are less severe and an SAR of this magnitude can be tolerated. Golf greens constructed with high-sand-content rootzone mixes, for example, can be successfully irrigated with high-SAR water because their drainage is good. For recycled waters high in bicar­ bonate, some laboratories “adjust” the calculation of SAR (yielding a number called “adjusted SAR” or “Adj. SAR”) because soil calcium and magnesium concentrations are affected by the waters bicarbonate. In simplest terms, Adj. SAR reflects the water content of calcium, magnesium, sodium, and bi­ carbonate, as well as the water s total salinity Other labs are adjusting the SAR value using a newly introduced method and report the adjusted value as Rna. INTERACTION OF SALINITY AND SAR Salts and sodium do not act indepen­ dently in the plant environment. The effect of sodium on soil particle dis— NOVEMBER-DECEMBER 2004 27 pH 0, water is increasingly acidic; moving from pH 7 to pH 14, water is increasingly basic (or “alkaline”). pH units are on a logarithmic scale, which means that there is a tenfold change between each whole pH number. Thus, a water with pH 8 is 10 times more basic than a water with pH 7, and 100 times more basic than a water with pH 6. Water pH is easily determined and provides useful information about the waters chemical properties. Although seldom a problem in itself, a very high or low pH warns the user that the water needs evaluation for other con­ stituents. The desirable soil pH for most turfgrasses is 5.5 to 7.0; the pH of most irrigation waters, however, ranges from 6.5 to 8.4. Depending on the soil on which the grass is grown, an irrigation water pH range of 6.5-7 would be desirable. Recycled water with a pH outside the desirable range must be carefully evaluated for other chemical constituents. CHLORIDE In addition to contributing to the total soluble salt concentration of irrigation water, chloride (Cl) may be directly toxic to plants grown on a golf course. Although chloride is not particularly toxic to turfgrasses, many trees, shrubs, and ground covers are sensitive to it. Chloride is absorbed by plant roots and translocated to leaves, where it accumulates. In sensitive plants, this accumulation leads to necrosis — leaf margin scorch in minor cases, total leaf kill and abscission in severe situations. Similar symptoms may occur on sensi­ tive plants if water high in chloride is applied by overhead sprinklers, since chloride can be absorbed by leaves as well as roots. Turfgrasses tolerate all but extremely high levels of chloride as long as they are regularly mowed. Chloride salts are quite soluble and thus may be leached from well-drained soils with good subsurface drainage. As indicated in Table 3, recycled irri­ gation water with a chloride content above 355 mgL 1 is toxic when absorbed Application of salty recycled water has caused burn and necrosis of leaf margins. persion (and therefore permeability) is counteracted by high electrolyte (soluble salts) concentration; therefore, a water s sodium hazard cannot be assessed inde­ pendently of its salinity. The combined effect of water ECw and SAR on soil permeability is given in Table 3. Note that the table provides general guide­ lines only. Soil properties, irrigation management, climate, a given plants salt tolerance, and cultural practices all interact significantly with recycled water quality in the actual behavior of soils and plant growth. BICARBONATE AND CARBONATE The bicarbonate, and to a lesser degree carbonate, content of recycled irrigation water also deserves careful evaluation. Recycled waters, as well as well waters, are especially prone to containing excessive bicarbonate levels. Substantial bicarbonate levels in irrigation water can increase soil pH and may affect soil permeability. In addition, bicarbonate content may make itself obvious during hot, dry periods, when evaporation may cause white lime (CaCO3) deposits to appear on leaves of plants irrigated by overhead sprinklers. Although high levels of bicarbonate in water can raise soil pH to undesirable levels, it is bicarbonate’s negative impact 28 GREEN SECTION RECORD on soil permeability that is more often a concern. As mentioned above, the bicarbonate ion may combine with calcium and/or magnesium and precipi­ tate as calcium and/or magnesium carbonate. This precipitation increases the SAR in the soil solution because it will lower the dissolved calcium concentration. Table 3 indicates tolerable levels of bicarbonate in irrigation waters. The bicarbonate hazard of recycled water may be expressed as Residual Sodium Carbonate (RSC), calculated as follows: (5) RSC = (HCO3+CO3)-(Ca+Mg) In this equation, concentrations of ions are expressed in meqL1 [see Equa­ tion (2) and Table 1 for conversions]. Generally, recycled water with an RSC value of 1.25 meqL1 or lower is safe for irrigation, water with an RSC between 1.25 and 2.5 meqL1 is marginal, and water with an RSC of 2.5 meqL 1 and above is probably not suitable for irrigation. pH (HYDROGEN ION ACTIVITY) The pH is a measure of water s acidity and alkalinity and is measured in pH units. The scale ranges from 0 to 14, with pH 7 representing neutral (i.e., water with a pH of 7 is neither acidic nor alkaline). Moving from pH 7 to by roots, while a chloride content higher than 100 mgL1 can damage sensitive ornamental plants if applied to foliage. CHLORINE Municipal recycled water may contain excessive residual chlorine (CL), a potential plant toxin. Chlorine toxicity is almost always associated only with recycled waters that have been disin­ fected with chlorine-containing com­ pounds. Chlorine toxicity will occur only if high levels of chlorine are sprayed directly onto foliage, a situation likely to occur only where recycled water goes straight from a treatment plant to an overhead irrigation system. Free chlorine is very unstable in water; thus, it will dissipate rapidly if stored for even a short period of time between treatment and application to plants. As indicated in Table 3, residual chlorine is of concern at levels above 5 mgL1. BORON Boron (B) is a micronutrient essential for plant growth, though it is required in very small amounts. At even very low concentrations (as low as 1 to 2 mgL1 in irrigation water), it is phyto­ toxic to most ornamental plants, capable of causing leaf burn (Table 3). Injury is most obvious as a dark necrosis on the margins of older leaves. Turfgrasses are generally more tolerant of boron than any other plants grown on a golf course; however, they are more sensitive to boron toxicity than to either sodium or chloride. Most will grow in soils with boron levels as high as 10 ppm. NUTRIENTS Recycled waters always contain a range of micro (trace) elements sufficient to satisfy the need of most turfgrasses. They may also contain enough macro (major) nutrients (i.e., nitrogen, phos­ phorus, and potassium) to figure signifi­ cantly in the fertilization program of large turfed areas. Most laboratories test recycled water for nutrient content and often report nutrients in “lb./acre ft. of water applied.” The economic value of these nutrients can be substantial. Even where the quantities of nutrients are low, because they are applied on a regular basis, the nutrients can be used very efficiently by plants. If the labora­ tory report does not include the Ib./acre ft. of nutrients, the following conversion formula can be used to determine this value for any nutrient contained in irrigation water: (6) Ib./acre ft. of nutrient = nutrient content (mgL-1 or ppm) X 2.72. SUSPENDED SOLIDS Suspended solids (SS) in irrigation water refers to inorganic particles such as clay, silt, and other soil constituents, as well as organic matter such as plant material, algae, bacteria, etc. These materials do not dissolve in water and thus can be removed only by filtration, an essential step for most irrigation systems in which plugged sprinkler head openings and/or valves reduce system efficiency and life. The suspended solids in domestic municipal water sources are negligible and not a cause for concern. However, suspended solids should be monitored in wells, canals, and especially lakes or ponds storing recycled water used for irrigation. Nitrogen and phosphorus in recycled water can lead to algae growth in storage lakes during the winter. Such growth can pose a major concern when the water is introduced into an irrigation system. In addition to the mechanical problems they present for irrigation systems, suspended solids and algae can seal a soil surface, especially on sand­ based golf greens and sand bunkers. Solids can fill in air spaces between sand particles, reducing infiltration and drainage, and increasing compaction. Since these effects vary considerably with type of solid, irrigation system, and turfgrass soils, it is difficult to formulate acceptable suspended solid values for irrigation water. The com­ plexity and variability of irrigation waters and systems make effective filtra­ tion the most sensible approach to con­ trolling hazards posed by suspended solids and algae in recycled water. INTERPRETING WATER QUALITY HAZARD As the preceding indicates, recycled water quality must be analyzed on an individual basis. There are very few recycled water sources that are absolutely unsuitable for turfgrass irrigation. While the discussion presented here can be used as a general guide to help turfgrass managers determine whether a water quality problem exists, the precise natureand magnitude of a potential problem may require more than water analysis. Climate, soil chemistry and physics, use patterns, and turf quality expectations will all contribute both to any problem and to any potential remedies. M. Ali Harivandi, Ph.D., is an environ­ mental horticulturist for the University of California Cooperative Extension in the San Francisco Bay Area. He also is a member of the USGA Tufgrass and Environmental Research Committee. An extreme example of a salty crust on an area where the turf has disappeared. NOVEMBER-DECEMBER 2004 29 Considerations in Retrofitting a Golf Course for Recycled Water Irrigation Start thinking about preparing for the use of recycled water at your course. BY M. ALI HARIVANDI Within the United States as well as the rest of the world, the future of the golf industry is tied to water availability and price. Even in areas where water was once an unlimited resource, it is now viewed as limited and highly valuable, particularly in arid, semi-arid, and highly populated regions. The price of potable water rises with scarcity; both rising cost and the increased politicization of using a scarce resource for leisure and entertainment purposes put pressure on golf courses to use something other than potable water for irrigation. In many locations, using recycled water (i.e., treated municipal sewage water, which may also be known as reclaimed or effluent water) for golf course irrigation is a viable strategy for coping with water shortages and the rising cost of fresh water. Some states, in fact, have already mandated recycled water irrigation on new golf courses and landscapes. Elsewhere, interest in recycled water irrigation continues to increase as more and better-quality recycled water becomes available for re-use. Irrigating a golf course with recycled water poses unique challenges for a course superintendent. Whether a course is new and in the development phase or well established and switching to recycled water irrigation, issues arise in the areas of environmental steward­ ship, health, and agronomics. These issues are more easily addressed when a 30 GREEN SECTION RECORD course can be designed and built with recycled water irrigation in mind than when an established course decides to retrofit (or convert) to recycled water use. In both instances, however, a num­ ber of concerns are best handled during the planning phase; in fact, preparing for recycled water irrigation is almost always more efficient and effective than managing the potential negative effects of its misuse. Resolution of the following infra­ structure and management issues will ensure minimal negative impact of recycled water irrigation on the play­ ability and agronomic health of a golf course. It will also ensure that legal and financial responsibilities are carefully considered and all parties are clear on their roles and responsibilities should problems arise. Most of these issues apply equally to courses under develop­ ment and those being retrofitted for recycled water irrigation. Every site, however, will also be subject to specific health and environmental regulations which, due to the great variation between sites and communities, are not discussed here. Readers are therefore advised that the following discussion is not exhaustive with respect to such issues, complete evaluation of which should occur before contracts are signed. RECYCLED WATER TREATMENT PROCESS Recycled water used for golf course irrigation must be at least secondary, and preferably tertiary, treated waste­ water. Secondary treatment is a bio­ logical process in which complex organic matter is broken down to less complex organic material, then metab­ olized by simple organisms that are later removed from the wastewater. Secondary treatment can remove more than 90 percent of the organic matter in sewage. The secondary liquid efflu­ ent is always chlorinated or otherwise disinfected before release. Often, sewage treatment facilities associated with resi­ dential developments consist of aerated lagoons, a less sophisticated secondary treatment process. Advanced wastewater treatment con­ sists of processes similar to potable water treatment, such as chemical coagulation and flocculation, sedimentation, filtra­ tion, or adsorption of compounds by a bed of activated charcoal. Because advanced treatment usually follows high-rate secondary treatments, it is AGRONOMIC AND MANAGEMENT CONSIDERATIONS FOR RETROFIT There are unique challenges associated with using recycled water to irrigate golf courses originally designed for freshwater irrigation. Depending on the quality of the recycled water available, the costs of converting an irrigation The issue of water availability continues to grow and impacts all industries.With rising costs of potable water, the use of recycled water is a viable secondary, and can be used on strategy. Once the preferably tertiary, treatment facility, it treatment before it water arrives at the must receive at least system and adapting course maintenance to the new irrigation can be substantial. The following items all bear careful consideration in planning for conversion of a course to recycled water irrigation. Most have both cost and management consequences, although some are cost free. Some of the items may have already been addressed by local authorities — e.g., regulatory issues. Every effort is made to include all items of potential concern in this report; however, other, site-specific issues that are not apparent initially may come to light as the conversion project progresses. the golf course. IRRIGATION SYSTEM ISSUES • Cross connection. Protection of cross-connection systems may be necessary if the golf course irrigation system is connected to a potable water system or any dedicated fire line using potable water. In general, all physical connections between the recycled water irrigation system and the potable water system must be disconnected. • Lakes, wells, and creek protec­ tion. On-site lakes, wells, and creeks whose water is used for potable pur­ poses should be protected from over­ spray or runoff from recycled water irrigation. Drinking-water fountains on the property should also be protected from overspray. Local regulations may require modification or redesign of the NOVEMBER-DECEMBER 2004 31 sometimes referred to as tertiary treat­ ment. These processes can provide highly purified waters. Reverse osmosis, an advanced method of water treat­ ment, can actually produce pure water; however, very high initial and opera­ tional costs and environmental prob­ lems related to disposal of reject saline brine limits the use of this process for golf course irrigation. Generally, secondary and tertiary treated waters do not differ significantly chemically — i.e., in their dissolved salt content. However, due to the greatly reduced level of suspended (i.e., not dissolved) solids, tertiary waters are much more desirable for golf course irrigation. Suspended solids can plug irrigation heads and seal sand-based (USGA or California type) golf greens, thereby reducing drainage. Conse­ quently, installing an efficient filtration system is essential when using recycled water for golf course irrigation, espe­ cially if the recycled water is only secondary treated effluent. irrigation system to ensure these protections. • Quick couplers. It may be neces­ sary to tag or replace all quick couplers on the course with specialized couplers that prevent inadvertent drinking of recycled water by maintenance personnel or others. • Labeling, tagging, and painting. On new golf courses, purple irrigation system components generally signify (and warn unsuspecting users of) the presence of recycled water. On existing golf courses, all buried components of the existing irrigation system are often “grandfathered in.” However, a golf course may be required to label all visible irrigation system components with purple tape, tags, paints, etc. It may also be necessary to install signs warning of recycled water use in more than just English (in most cases, warnings in Spanish are also mandatory) throughout the course, at the clubhouse and pro shop, and on scorecards. The cost of this “publicity” will depend on the type and magnitude of labeling a course chooses. • Pumping costs. Depending on the pumping capacity and pressure require­ ments of the existing system, a booster pump and electricity for additional pumping may be required. The pressure provided by the treatment plant releas­ ing the recycled water is often inade­ quate for irrigating a golf course. • Water storage facilities — construction and maintenance. If recycled water cannot be stored in existing lakes on the course, additional storage facilities may be required. Covered storage tanks or “lined” ponds are options. The size and location of such storage facilities must be thoroughly evaluated in relation to environmental issues as well as for both fixed and operational costs. Note: Recycled water storage facilities require a high level of maintenance. Generally, covered (or buried) storage tanks require less main­ tenance than lakes, since the absence of light eliminates algae growth; on the other hand, settling of suspended matter 32 GREEN SECTION RECORD is a problem in tanks. With frequency depending on water quality, storage tanks must be periodically emptied and cleaned. The initial cost of constructing lined storage lakes may be less than that of installing covered tanks; however, the maintenance cost is generally higher. Due to elevated levels of nutrients such as nitrogen and phosphorus, algae and weed growth is a constant problem in storage lakes. Substantial labor and chemicals are often needed to keep pond water clean and suitable for irri- It is commonplace that purple irrigation system components generally signify and warn unsus­ pecting users of the presence of recycled water. gation. Depending on the quality of the water, the cost of maintaining a storage pond for recycled water could be several times higher than maintenance costs for a pond of potable water (due primarily to algae and weed growth, and odor problems). If any existing lake at a course is converted for storage of recycled water, it may require lining to prevent potential groundwater contamination. • Irrigation water filtration. Given the suspended matter content of recycled water, a dependable irrigation filtration system may be essential. Particularly if recycled water is stored in ponds, where algal bloom is a constant problem, filtration must be of high quality. If the existing filter system at a course is sub par, it must be replaced before beginning recycled water irri­ gation. Without effective filtration, algae and other suspended matter will plug irrigation nozzles, reducing irrigation efficiency and uniformity, and requiring additional labor for repeatedly unplug­ ging heads. In addition, without ade­ quate filtration, the fine, suspended particles delivered in recycled water may plug pore spaces in the rootzone of sand-based golf greens, impeding both drainage and leaching — costly problems! • Irrigation water blending. Re­ cycled water may need to be blended with fresh water to reduce its salt con­ tent. If blending, often done in a storage tank or lake, is not possible, a course may be alternately irrigated with re­ cycled and fresh water to leach salts (a process called “flushing”). Cost and logistics would determine which approach is used at a given golf course. • Adjacent properties. Depending on local regulations, golf courses irri­ gated with recycled water may be required to protect adjacent properties from runoff or overspray from their irrigation. Compliance with such regu­ lations may mean redesigning the irri­ gation system to allow irrigation of the perimeter with fresh water. AGRONOMIC ISSUES • Recycled water dissolved salts. In most cases, recycled water will have a higher dissolved salt content than the water already being used for irrigation. In addition to salinity, other important chemical components of the recycled water are pH, sodium, calcium, mag­ nesium, chloride, boron, bicarbonate, and residual chlorine. Depending on the levels of these chemical constituents, management practices on the course may need to change to counteract potential negative effects on soil, turf­ grasses, and other plants. Such effects may range from slight to substantial. Without an analysis of the recycled water, it is impossible to predict the extent of its effect on management; however, any or all of the following may be needed: 1. Irrigation water blending (i.e., recycled with fresh). 2. Injection into the irrigation water of acids, gypsum, or other amendments. 3. Application of gypsum, sulfur, and other amendments to the soil. 4. Additional core aerating to reduce soil impermeability caused by elevated sodium levels. 5. Installation of additional drainage lines in low-lying areas to remove leached salts. 6. Application of additional herbi­ cides and fungicides to combat weed and disease problems if existing grasses are stressed by the presence of salt. 7. Application of more water than is currently applied to leach salt below the grass rootzone (leaching requirement). 8. Regular and more frequent soil and water testing. Twice a year, soils must be lab tested to identify potential salinity problems. Soil samples should be taken from representative greens, tees, fair­ ways, roughs, and general landscaped areas. Recycled water must be lab tested at least quarterly to determine the level and fluctuation of dissolved salts. • Trees, shrubs, and other non-turf plants. Depending on the recycled water’s salt content as well as the sensi­ tivity of the course s trees, shrubs, and other plants, remedial actions may be required to prevent plant injury. The most common remedial practice is modification of the irrigation system so that water from sprinklers does not wet plant leaves. Although trees and shrubs may tolerate certain levels of salt accumulation in the soil, they can exhibit injury from saline water sprayed on their foliage. • Consultant fees. Agronomic issues relating to recycled water can be com­ plex, requiring the input of consulting specialists. Most golf course superinten­ dents work closely with a turfgrass water quality consultant. The cost of such ser­ vice, as well as lab test fees, is a consistent recurring cost associated with recycled water irrigation, and it should be added to the management budget. ENVIRONMENTAL AND MANAGEMENT ISSUES • Groundwater monitoring. If a golf course is located above a drinking water aquifer, a comprehensive ground­ water quality monitoring program may be required if the course is irrigated with recycled water. At issue is whether the golf course or the sewage treatment plant is responsible for mounting and paying for such a program. • Odor problems. Depending on the level of treatment, recycled water irri­ gation may cause an odor problem. It should be decided in advance who will be responsible for correcting the situation. This special design protects the water fountain from being struck by recycled irrigation water. • Liability issues. Although extremely rare, human health problems, adjacent property contamination, and other negative impacts may result from recycled water irrigation. It is highly advisable to determine ahead of time whether the golf course or the sewage treatment plant, or both, will take responsibility for such outcomes. • Equipment deterioration. Turf­ grass maintenance equipment rusts and deteriorates in other ways more quickly when exposed to saline irrigation water. How big a problem this may be at a given golf course will depend on the salinity of the recycled water. • Golf course superintendent compensation. Switching from fresh to recycled irrigation water will add to the responsibilities (and therefore on- the-job time) of the golf course super­ intendent. In addition to extra agro­ nomic tasks that the use of recycled water imposes, the superintendent will spend more time inspecting, keeping records, preparing reports, and filing documents with environmental and regulatory agencies. He will also have to spend more time with regulators, community representatives, consultants, laboratories, and vendors providing goods or services related to recycled water. Total labor needs on the course, including that of the superintendent, often rise 10-20% when recycled water irrigation replaces freshwater irrigation, the actual figure depending on the quality of water used. ADVANTAGES OF RECYCLED WATER • Conservation and availability. Using recycled water is an excellent means of conserving fresh water. Water availability, especially during a drought or other water shortages, is almost guaranteed when using recycled water. • Cost. Recycled water is almost always less expensive for golf course irrigation than fresh water. • Nutrient Content. All recycled waters contain nutrients required by turf plants (e.g., nitrogen, phosphorus, and potassium). The quantities of nutri­ ents available at a given site and their impact can only be evaluated after recycled water becomes available and can be tested for nutrient content. This limitation notwithstanding, most re­ cycled waters contain enough nutrients to completely eliminate fertilization of roughs and even fairways, and to sub­ stantially reduce the fertilizer required by greens and tees. AUTHOR’S NOTE Use of recycled water for irrigation is rapidly spreading worldwide. The author is interested in staying abreast of issues arising from recycled water irrigation on golf courses in regions with varying social, environmental, political, and climatic conditions. Readers are encouraged to communicate issues related to recycled water irrigation that are not covered in this article. The author will compile and periodically cover these issues in new publications. The author may be reached at: maharivandi@ucdavis. edu. M. Ali Harivandi, Ph.D, 1'5 an environ­ mental horticulturist for the University of California Cooperative Extension in the San Francisco Bay Area. He also is a member of the USGA Tufgrass and Environmental Research Committee. NOVEMBER-DECEMBER. 2004 33 On Course With Nature Good News for the Bottom Line and Environmentally Sensitive Golf Course Development Yes, you can have it both ways. BY NANCY RICHARDSON Whether there is an economic advantage to environmen­ tally sensitive golf course development is of central importance not only to investors and developers, but to environmentalists as well. If the answer is No, the added costs of build­ ing in an environmentally sustainable way will be a burden that many in the golf industry will not choose to pay. If the answer is Yes, there is a much greater likelihood that environmentally sensitive golf course development will continue to gain support. Over the past year, members of Audubon International’s Signature Programs (for properties in the design and development stages) have been reviewing their economic bottom lines and reporting their findings as part of a survey to gauge the business value of environmental stewardship. The pro­ grams’ 118 Signature golf courses — comprising 50,000 acres in 33 U.S. states, as well as in Canada, China, Portugal, Puerto Rico, and South Africa — are being designed, built, and managed according to stringent envi­ ronmental standards. Members con­ sidered operational costs, up-front investments, and the importance of the program in marketing and promotion. Their responses bode well for the future of sustainable golf course development. • 96% viewed their participation in the Signature Program as “a good business decision,” with the remaining 4% indi­ 34 GREEN SECTION RECORD cating that they “don’t know” at this time. • 90% of respondents reported that they believed annual operation and maintenance costs for their facilities were either “lower than” or the “same as” the costs of an equivalent, non­ Signature member golf course. 43% of respondents attributed lower operation and maintenance costs to their partici­ pation in the Signature Program. • 63% of respondents stated that participation in the Signature Program, including up-front monetary and staff investment in the program, has saved or will save money, as compared to a course designed, constructed, and managed without Audubon Inter­ national assistance. Another 20% of the remaining respondents stated that they “don’t know” yet. • 90% stated that they believed the Certified Audubon Signature Sanctuary status earned through following pro­ gram guidelines has or will have value in marketing and promotional efforts, with the remaining 10% indicating only that they “don’t know.” “In Austin, or anywhere in the country for that matter, environmental stewardship is a great business decision,” says Anne Hickman-Hudgins, Environ­ mental Landscape Coordinator for Barton Creek Resort and Spa in Texas. “Community outreach and education is a benefit to establishing our club as a role model for other properties.” “Combining wildlife preservation and development is not only the right thing to do, but it makes good business sense,” agrees Jim L. Awtrey, CEO of PGA of America (PGA Golf Club in St. Lucie, Florida, is a Certified Signa­ ture Sanctuary).“Long-term operating costs can be significantly reduced while providing valuable environmental bene­ fits to the community. It is a business- environmental partnership that serves everyone.” “The concepts incorporated in the Signature Program will absolutely pay for the cost of what we’re doing over five to ten years ... .We’ll have better­ managed water and irrigation systems and use less chemicals,” reports Bill Fiveash of East West Partners, developers of Old Greenwood Golf Course in California. Just as wildlife inventories and water quality data help to determine environ­ mental outcomes, data about operational costs and return-on-investment are critical in evaluating the financial value of environmentally sensitive develop­ ment and management. Taken together, these benchmarks are beginning to demonstrate clearly that embracing sustainable development benefits the quality of life, the environment, and the bottom line. Nancy Richardson is the director of the Audubon Signature Programs, based in Henderson, Kentucky. She can be reached at (270) 869-9419 or e-mail nrichardsonfifiudubonintl. org. News Notes 2005 TURF ADVISORY SERVICE To keep up with the increasing costs of providing a high-quality advisory service to member clubs and the game of golf, it is necessary for the USGA to increase the fees charged for the Green Section s Turf Advisory Service. The 2005 fee schedule continues to offer a $300 discount for fees received by May 15,2005. Payment received by Payment received after May 15,2005 May 15,2005 Half-Day Visit Full-Day Visit $ 1,400 $1,900 $ 1,700 $2,200 Despite the increase, the USGA will subsidize the Turf Advisory Service (TAS) by about 50% in 2005, reflecting a commitment to provide golf courses with the best of services from a top-quality staff of 18 full-time agronomists. A Green Section visit is a bargain for the many benefits that are realized. The TAS strengthens the golf course superintendent’s and Green Committee s position, and it provides a positive environment to discuss common problems and realistic solutions and expectations at whatever level of golf course budget is available. PHYSICAL SOIL TESTING LABORATORIES The following laboratories are accredited by the American Association for Laboratory Accreditation (A2LA), having demonstrated ongoing competency in testing materials specified in the USGA’s Recommendations for Putting Green Construction.The USGA recommends that only A2LA-accredited laboratories be used for testing and analyzing materials for building greens according to our guidelines. Brookside Laboratories, Inc. 308 Main Street, New Knoxville, OH 45871 Attn: Mark Flock Voice phone: (419) 753-2448 FAX: (419) 753-2949 E-Mail: mflock@BLINC.COM Dakota Analytical, Inc. 1503 I I th Ave. NE, E. Grand Forks, MN 56721 Attn: Diane Rindt, Laboratory Manager Voice phone: (701) 746-4300 or (800) 424-3443 FAX: (218) 773-3151 E-Mail: lab@dakotapeat.com European Turfgrass Laboratories Ltd. Unit 58, Stirling Enterprise Park Stirling FK7 7RP Scotland Attn:John Souter Voice phone: (44) 1786-449195 FAX: (44) 1786-449688 Hummel & Co. 35 King Street, PO. Box 606 Trumansburg, NY 14886 Attn: Norm Hummel Voice phone: (607) 387-5694 FAX: (607) 387-9499 E-Mail: soildr I @zoom-dsl.com ISTRC New Mix Lab LLC 1530 Kansas City Road, Suite 110 Olathe, KS 66061 Voice phone: (800) 362-8873 FAX: (913) 829-8873 E-Mail: istrcnewmixlab@worldnet.att.net Sports Turf Research Institute hyperlink to www.stri.co.uk St. Ives Estate, Bingley West Yorkshire BD16 I AU England Attn: Michael Baines Voice phone: +44 (0) 1274-565131 FAX:+44(0) 1274-561891 E-Mail: stephen.baker@stri.org.uk Thomas Turf Services, Inc. 2151 Harvey Mitchell Parkway South, Suite 302 College Station,TX 77840-5247 Attn: Bob Yzaguirre, Lab Manager Voice phone: (979) 764-2050 FAX: (979) 764-2152 E-Mail: soiltest@thomasturf.com Tifton Physical Soil Testing Laboratory, Inc. 1412 Murray Avenue,Tifton, GA 31794 Attn: Powell Gaines Voice phone: (229) 382-7292 FAX: (229) 382-7992 E-Mail: pgaines@friendlycity.net Turf Diagnostics & Design, Inc. 31OA N.Winchester St, Olathe, KS 66062 Attn: Sam Ferro Voice phone: (913) 780-6725 FAX: (913) 780-6759 E-Mail: sferro@turfdiag.com STATEMENT OF OWNERSHIP, MANAGEMENT, AND CIRCULATION 1. Tide of Publication — USGA GREEN SECTION RECORD. 3. Date of Filing — September 1, 2004. 4. Frequency of issue — Bimonthly: January/February, March/April,May/June, July/August, September/October, and November/December. 5. Number of issues published annually — 6. 6. Annual Subscription Price — $18.00. 7. Complete mailing address of known office of publica­ tion — United States Golf Association (USGA), Golf House, 77 Liberty Corner Road, P.O. Box 708, Far Hills, NJ 07931-0708.8. Complete mailing address of the head­ quarters or general business office of the publisher — USGA, Golf House, 77 Liberty Corner Road, P.O. Box 708, Far Hills, NJ 07931-0708. 9. Names and addresses of Publisher, Editor, and Managing Editor: Publisher — USGA, Golf House, 77 Liberty Corner Road, P.O. Box 708, Far Hills, NJ 07931-0708. Editor—JamesT. Snow, USGA, Golf House, 77 Liberty Corner Road, P.O. Box 708, Far Hills, NJ 07931-0708. Managing Editor —James T. Snow, USGA, Golf House, 77 Liberty Corner Road, P.O. Box 708, Far Hills, NJ 07931-0708.10. Owner (If the publication is owned by a corporation, give the name and address of the corporation immediately followed by the names and addresses of all stockholders owning or holding 1 percent or more of the total amount of stock. If not owned by a corporation, give the names and addresses of the individual owners. If owned by a partnership or other unincorporated firm, give its name and address, as well as those of each individual owner. If the publication is published by a nonprofit organization, give its name and address.) — United States Golf Association (USGA), Golf House, 77 Liberty Corner Road, P.O. Box 708, Far Hills, NJ 07931- 0708. 12. For completion by nonprofit organizations authorized to mail at nonprofit rates — The purpose, function, and nonprofit status of this organization and the exempt status for federal income tax purposes has not changed during preceding 12 months. 13. Publication title — USGA Green Section Record. 14. Issue Date for Circulation Data Below — Sept./Oct. 2004. 15. Extent and nature of circulation — Average No. Copies Each Issue During Preceding 12 Months Actual No. Copies of Single Issue Published Nearest to Filing Date a.Total Number of Copies 18,320 18,200 (Net press run) b. 1. Paid/Requested Outside- 16,845 16,820 County Mail Subscriptions Stated on Form 3541 b.2. Paid In-County Subscriptions Stated on Form 3541 b.3. Sales Through Dealers and Carriers, Street Vendors, Counter Sales, and Other Non-USPS Paid Distribution b.4. Other Classes Mailed Through the USPS c.Total Paid and/or Requested Circulation d. Free Distribution by Mail (Samples, complimentary, and other free) 0 0 0 0 0 0 16,845 16,820 d. 1. Outside-County as Stated 810 795 on Form 3541 d.2. In-County as Stated on Form 3541 d.3. Other Classes Mailed Through the USPS 0 0 0 0 e. Free Distribution Outside the Mail (Carriers or other means) 295 280 f.Total Free Distribution g.Total Distribution h. Copies Not Distributed i.Total j. Percent Paid and/or Requested Circulation 1,105 17,950 370 18,320 93.8% 1,075 17,895 305 18,200 94% I certify that the statements made by me above are correct and complete. JAMES T. SNOW, Editor NOVEMBER-DECEMBER 2004 35 All Things Considered No, It Really Is Not Just Your Golf Course! The issues at your golf course are often being experienced by other courses in your area. BY DARIN S. BEVARD How many times have you said it at your club? “Ours is the only course that is having this prob­ lem. I played at the course down the street, and they did not have any prob­ lems. Their golf course was perfect.” Please, be honest. Have you said it? I’ll bet you have. The “only course with a problem” syndrome raises a red flag, in my opinion. More importantly, we should evaluate reasons why this state­ ment is made so frequently. There are many other things that happen only at “your” golf course. Yours is the only golf course that ever closes. No one else closes. Yours is the only golf course that ever has a frost delay. No other courses ever have a frost delay. Your course is the only one that had any winter damage, disease, etc. Basically, every other golf course is perfect. Why don’t golfers recognize problems when they visit other golf courses in the same way that they do at their own? HEAD UPVS. HEAD DOWN The “head up vs. head down” syn­ drome is one explanation for the “only our course” problem. When playing a new course, or at least one that they do not play on a regular basis, golfers tend to have their head up. They look around at the scenery and analyze each golf hole. They simply enjoy their new surroundings and soak in the golf experience. A thin spot here or a weed or two (or more) there go unnoticed. The goal is just to enjoy a different golf course. Additionally, most golfers will play a round of golf in 72 to 100 36 GREEN SECTION RECORD strokes. This does not lend itself to seeing every area of a golf course and providing a critical evaluation. Playing their regular course daily provides ample opportunity to notice problems. At their own golf course, their head is down. Every blemish is noticed and criticized, regardless of the cause. They have seen everything that there is to see on their own golf course. There is no reason to look around because their golf course is not a new experience. BIG EVENT SYNDROME “Big Event Syndrome” is another com­ mon cause of “only at our golf course.” Be it member/guest or some other premier event at the “other” club, golfers often visit other golf courses for these special events. The condition of the golf course is peaked. Every detail is tended to; the greens are fast; every bunker is raked. The maintenance staff at that golf course has been preparing in one way or another for several weeks leading up to the event. If you look at your own club and think back to your big events, I believe you will find that your golf course was in top condition as well. The golf course superintendent makes a special effort to showcase the golf course for any major event, but these conditions cannot be sustained on a daily basis at most golf courses. Many different factors impact daily conditions on the golf course. Weather is the biggest factor that regularly affects turfgrass maintenance. Most mainte­ nance decisions are based on what practices can be implemented under a given set of weather conditions. When it is hot and dry at your golf course, it is hot and dry at other local courses as well. Maybe XYZ Country Club has a new irrigation system that allows them to manage water more efficiently when environmental stresses arise. Other factors influence daily condi­ tions, including construction methods, turfgrass variety, irrigation efficiency, and last but certainly not least, available resources to implement maintenance practices (budget). In our region, similar problems are widespread at different golf courses at any point during the growing season. Your golf course may have problems. Realize that you are not alone. Every golf course has problems that need to be addressed. At times, problems will occur on your golf course and not at others. The point of this rant is not to say that no problems exist on your golf course. We all know that they do. But your golf course is not perfect and neither is any other course that is main­ taining turfgrass with the same basic resources as your own. Do not make the mistake of comparing your golf course conditions to a facility that has far more resources. Every facility should strive to correct problems that exist and improve the golf course overall. But do not talk yourself into believing that yours is the only course having problems. The grass is not always greener, faster, or better at the course down the road! It is probably about the same color as yours. Darin Bevard is an agronomist in the Mid-Atlantic Region. GREEN SECTION NATIONAL OFFICES United States Golf Association, Golf House P.O. Box 708 Far Hills, NJ 07931 (908) 234-2300 Fax (908) 781-1736 James T. Snow, National Director jsnow@usga.org Kimberly S. Erusha, Ph.D., Director of Education kerusha@usga.org Green Section Research P.O. Box 2227 Stillwater, OK 74076 (405) 743-3900 Fax (405) 743-3910 Michael P. Kenna, Ph.D., Director mkenna@usga.org Construction Education Program 720 Wooded Crest Waco.TX 76712 (254) 776-0765 Fax (254) 776-0227 James F. Moore, Director j moore@usga. org 904 Highland Drive Lawrence, KS 66044 785-832-2300 JeffNus, Ph.D., Manager jnus@usga.org Northwest Mid-Continent Florida REGIONAL OFFICES ©Northeast Region David A. Oatis, Director doatis@usga.org James H. Baird, Ph.D., Agronomist jbaird@usga.org P.O. Box 4717 Easton, PA 18043 (610) 515-1660 Fax (610) 515-1663 James E. Skorulski, Senior Agronomist jskorulski@usga.org 1500 North Main Street Palmer, MA 01069 (413) 283-2237 Fax (413) 283-7741 •Mid-Continent Region Paul H. Vermeulen, Director pvermeulen@usga.org 9 River Valley Ranch White Heath, IL 61884 (217) 687-4424 Fax (217) 687-4333 Charles “Bud” White, Senior Agronomist budwhite@usga.org 2601 Green Oak Drive Carrollton,TX 75010 (972) 662-1138 Fax (972) 662-1168 •North-Central Region Robert A. Brame, Director bobbrame@usga. org P.O. Box 15249 Covington, KY 41015-0249 (859) 356-3272 Fax (859) 356-1847 Robert C.Vavrek, Jr., Senior Agronomist rvavrek@usga. org P.O. Box 5069 Elm Grove, WI 53122 (262) 797-8743 Fax (262) 797-8838 •Northwest Region Larry W. Gilhuly, Director lgilhuly@usga. o rg 5610 Old Stump Drive N.W, Gig Harbor, WA 98332 (253) 858-2266 Fax (253) 857-6698 Matthew C. Nelson, Agronomist mnelson@usga.org P.O. Box 5844 Twin Falls, ID 83303 (208) 732-0280 Fax(208) 732-0282 •Southwest Region Patrick J. Gross, Director pgross@usga.org David Wienecke, Agronomist dwienecke@usga.org 505 North Tustin Avenue, Suite 121 Santa Ana, CA 92705 (714) 542-5766 Fax (714) 542-5777 •Mid-Atlantic Region Stanley J. Zontek, Director szontek@usga. org Darin S. Bevard, Agronomist dbevard@usga. org 485 Baltimore Pike, Suite 203 Glen Mills, PA 19342 (610) 558-9066 Fax (610) 558-1135 Keith A. Happ, Senior Agronomist khapp@usga.org Manor Oak One, Suite 410, 1910 Cochran Road Pittsburgh, PA 15220 (412) 341-5922 Fax (412) 341-5954 •Southeast Region Patrick M. O’Brien, Director patobrien@usga. org P.O. Box 95 Griffin, GA 30224-0095 (770) 229-8125 Fax (770) 229-5974 Christopher E. Hartwiger, Agronomist chartwiger@usga. org 1097 Highlands Drive Birmingham, AL 35244 (205) 444-5079 Fax (205) 444-9561 •Florida Region John H. Foy, Director jfoy@usga.org P.O. Box 1087 Hobe Sound, FL 33475-1087 (772) 546-2620 Fax (772) 546-4653 Todd Lowe, Agronomist tlowe@usga. org 127 Naomi Place Rotonda West, FL 33947 (941) 828-2625 Fax (941) 828-2629 ©2004 by United States Golf Association® Subscriptions $18 a year, Canada/Mexico $21 a year, and international $33 a year (air mail). Subscriptions, articles, photographs, and correspondence relevant to published material should be addressed to: United States Golf Association, Green Section, Golf House, P.O. Box 708, Far Hills, NJ 07931. Permission to reproduce articles or material in the USGA Green Section Record is granted to newspapers, periodicals, and educational institutions (unless specifically noted otherwise). Credit must be given to the author, the article’s title, USGA Green Section Record, and the issue’s date. Copyright protection must be afforded. To reprint material in other media, written per­ mission must be obtained from the USGA. In any case, neither articles nor other material may be copied or used for any advertising, promotion, or commercial purposes. Green Section Record (ISSN 0041-5502) is published six times a year in January, March, May, July, September, and November by the United States Golf Association®, Golf House, Far Hills, NJ 07931. Postmaster: Address service requested — USGA Green Section Record, P.O. Box 708, Golf House, Far Hills, NJ 07931-0708. Periodicals postage paid at Far Hills, NJ, and other locations. Office of Publication, Golf House, Far Hills, NJ 07931. ® Printed on recycled paper Egl live about 30 feet from a golf course. At approximately 6:10 a.m. each morning the mower cuts the grass just outside my bedroom win­ dow and I hear a number of other pieces of loud equip­ ment being operated. What can golf courses do to be more neighbor-friendly? (North Carolina) How did the USGA come up with 80% sand / 20% peat for a putting green rootzone? (North Dakota) they must start as soon as it is light enough to see. There are a few options that can help: If only a few homes are H Unfortunately, the answer to your question concerning early morning disruptions is not an easy one. The mainte­ nance crew must complete their morning tasks before golfers arrive, so that means affected, sometimes the grounds crew can wait until the end of their 2-hour morning rush to work in that area; some of the noise­ producing work may be done the evening before; identify the machinery causing the majoring of the noise (e.g. blowers) and use these tools after 9:( MI a.m.; or a growing number of courses are using battery-powered, low-noise-producing machinery for early morning work. Discuss your concerns with the golf course super­ intendent and ask if one or more of these options could be implemented. O There is nothing in the USGA guidelines for building greens that calls for such a mixture. In fact, the guidelines do not mandate any amendments if the sand provides the necessary porosity and saturated hydraulic conductivity values. It must also meet the particle size distribution specifications. Most sands, however, cannot meet these requirements without some modification. The ideal percentage of sand and amendment can only be determined by a physical soil testing laboratory. As a general rule, the mixing ratio usually falls somewhere between 80/20 and 95/5, depending entirely on the materials used. E We are trying to replace a number of declining sugar maple and asii trees on the golf course. The Norway maple tree was highly recommended as a fast­ growing replacement for those trees. What are your thoughts? (Connecticut) The Norway maple (Acer platanoides) is a vigorous, non-native, and invasive tree species. It is densely canopied and has aggressive roots that compete significantly with the turf for sun and water. The dense shade created by the canopy makes it nearly impossible to provide an acceptable playing surface under the tree. The wood is softer and more brittle than the traditional sugar maple, making it more prone to storm injury. The tree’s root system also has a tendency to wrap around the base of the trunk, girdling and eventually killing the tree. The tree is undesirable in the view of many state foresters and biologists due to its invasive qualities. The best policy for long-term success is to select tree species that are endemic to your region and that have a proven track record. Contact your local Cooperative Extension agent to identify those species. www.usga.org