the higher rate of application. The authors indicate that tolerance to rates of PMA application will vary with the particular turfgrass spe- cies involved. This factor should be recognized and proper adjustments made to avoid potential phytotox- icity. The authors stress that this is a progress report and that fur- ther studies are needed on optimum concentrations, application meth- ods and potential detrimental af- fects to the turfgrass plant.

Comments: An antitranspirant is a compound which is utilized to re- by Dr. James B. Beard duce the transpiration rate of plant foliage. Approximately 80 per cent now. TURFGRASS of the water loss from transpira- RESEARCH tion occurs through the stomata, which are small pores or openings armchairl REVIEW in the surface of turfgrass leaves. Phenyl mercuric acetate (PMA) is irrigation Affects of antitranspirants an antitranspirant which stimu- lates the closing of stomata. Sto- on plant growth mata closure caused by PMA has for golf courses Antitranspirants—uses and af- been observed in a wide range of fects on plant life. plant species including grasses, as Complete visual control of the D.C. Davenport, R.M. Hagan, has been reported in the above entire watering system from a and P.E. Martin. 1969. California study. A 15 to 20 per cent reduc- central master control unit. Each Turfgrass Culture. 19(4):25-27. tion in the rate of water loss from Febco master controller has 2 com- (from the University of Califor- creeping red fescue leaves is cer- plete and separate control groups. nia at Davis, Davis, Calif. 95616). tainly significant, particularly Each can operate up to 25 10- when the water stress potential is station satellite controllers. This paper is a preliminary re- high. Data such as is reported in Programmed to water on a pre- port of research conducted by the the above paper suggests that the set schedule, the master controller authors concerning the affects of onset of turfgrass wilting can be can be interrupted to syringe tees delayed or even prevented by an ap- 1 antitranspirants on water conser- and greens on a 2 /2-minute cycle. vation and plant growth. The stud- plication of PMA at the proper rate Regular schedule resumed when ies were conducted on creeping and time. syringing cycle is completed. red fescue (Festuca rubra). Phenyl The stomata, through which mercuric acetate (PMA) was water is lost by transpiration, are Sprinklers — Valves sprayed on the foliage at concen- also the main pathways for carbon Controllers — Vacuum Breakers trations ranging from 10_4M to dioxide diffusion into the leaf where 10"3 M. it is used as one of the essential raw Results showed that the quanti- materials in the vital photosynthet- ty of water transpired was reduced ic process. If the stomatal-closing by 18 per cent when a moderate antitranspirant was completely ef- PMA concentration of 10~3,5M fective in restricting carbon dioxide was used. There was no significant movement into the leaves, it could The Full Line Irrigation Company reduction in shoot growth at this also reduce the photosynthetic pro- concentration. A high PMA con- cess below minimal levels. How- centration of 10'3-3M resulted in ever, data from this paper indicate a 30 per cent reduction in the that concentrations of PMA can be amount of water lost by transpira- used which will significantly reduce INCORPORATED tion and also caused a 35 per cent the rate of transpirational water P. O. Box 368 - 9121 Glenoaks Blvd. reduction in the amount of shoot loss but will not close a sufficient Sun Valley, California 91352 growth. Toxicity was evident at (Continued on page 22) A/C 213 767-8413 For more information circle number 136 on card

GOLFDOM/1970 JUNE • 19 U.S. PAT. ¿¿2989247

BEARD TURFTOP (Continuedfrom page 19) LARCHMONT'S "TURFTOP" A PLAYERS DREAM number of stomata to seriously re- strict the photosynthetic process. A NEW INNOVATION IN SPRINKLERS A significant reduction in shoot growth was evident at the higher Jehna-Manvlll* PMA concentration used in the Call or write on your letterhead for details and specifications TRANSITE X^x IRRIGATION PIPE study. The authors indicate that LARCHMONT this is a direct phytotoxicity to the ENGINEERING /.S I We use & IRRIGATION INC. swihui IMIMIIM umchtim vv c leaf tissue rather than the indirect affect of growth reduction caused LEXINGTON. MASS. 02173 Johns-Manville Transite Pipe by a restriction in the photosyn- (6i7) 862-2550 far all permanent installations thetic process. A small reduction in For more information circle number 226 on card photosynthesis caused by a restric- tion in carbon dioxide movement into the leaf would not be critical in high quality turfs as long as suffi- cient carbohydrates are being syn- thesized to maintain the existing tissues and to provide an adequate recuperative potential. Thus, a cer- tain amount of shoot growth reduc- tion is not objectionable since it will reduce the mowing require- ment and frequency of irrigation. A potentially more serious prob- lem associated with the use of a stomatalclosing antitranspirant is the possible loss of the vital cooling process of the leaf which will result from a reduction in transpiration. The transpirational process is a vital cooling mechanism in turf- grass leaves during periods of heat stress. If PMA should close suffi- cient stomata to seriously impair If Powerscreened the leaf cooling process associated important maintenance item. with transpiration, leaf tempera- topdressing Simple arithmetic tells you that tures can increase to potentially in- a Royer Powerscreen, making jurious levels quite rapidly. Studies payments on itself at five is better, dollars (or more) a yard, can concerning this potential disadvan- bring almost immediate relief tage associated with the use of sto- why does it to the maintenance budget bind. matal-closing antitranspirants are Let a Royer distributor show lacking. Thus just how important you that what goes up can cost less? come down ... meaning, such a factor is is not known at this Speed is the answer. If you're of course, the high cost of top- time. It is likely that a sufficiently topdressing with tediously dressing. And he'll show you low concentration of PMA could hand-screened material, you're how a Royer Powerscreen probably paying an extra five can be put to work on short be used which would provide a dollars a yard for a dressing that notice, and work efficiently for an significant reduction in the rate of still brings complaints from hour or a day at a speed you water loss and yet not seriously re- golfers. Sticks and stones may wouldn't have believed. hurt your reputation, and clog strict the transpirational cooling up your spreader, besides. mechanism. However, the specific Golf course Superintendents rates of PMA application at which who've gone over to Royer is achieved cannot be determined Powerscreening are reporting ROYER FOUNDRY & MACHINE CO. a real drop in cost of this 171 Pringle St., Kingston, Pa. 18704 by the available data. The duration of effectiveness of an antitranspirant and the resultant For more information circle number 167 on card (Continued on page 24) BEARD National (Continued from page 22) frequency of application is deter- Used Golf Car mined by the (a) frequency of mow- Clearing House ing, (b) amount of shoot growth produced, (c) environmental condi- Through our nation-wide network tions and (d) efficiency of the chem- of Distributors, we keep track of ical used. Further study is also literally thousands of used golf needed in this area. The effective- cars everywhere in the country. ness of antitranspirants could vary Rebuilt, as-is, gas or electric, from as little as a few days to sev- models from 1962 through 1969 eral weeks, depending on the spe- -almost anything you want, and cific conditions. at almost any price. Many are In summary, the use of stoma- bargains which certain tal-closing antitranspirants is a Distributors want to clear out, promising new idea for modifying now. certain detrimental physiological processes in the turfgrass plant. Let us know your needs and we'll However, before it can be utilized put you in touch with the right with maximum effectiveness fur- party. Write direct to: ther research must be conducted on a number of aspects related to its CUSHMAN use, rate of application, method of NOW Warren application and frequency of ap- MOTORS plication, particularly as related to 1020 N. 21 st St. brings you potentially detrimental affects. Lincoln, Nebraska 68501 Possibly, the use of antitranspir- A Division of Outboard Marine Corporation ants on turfgrasses will become For more information circle number 208 on card Warren'sJ-20 another valuable cultural practice available for use in maintaining Light Weight-One Hand Bluegrass high quality turfgrasses. The ideal grass for tees, approaches Growth and carbohydrate stor- and collars. Takes short cut. Grows age oj three Poa pratensis L. ^^SfySÄND upright, gives better support to ball. Short Resistant to leaf spot, mildew, rust strains as influenced by tem- handle, v and stripe smut. Develops less perature. light weight thatch. Greens up earlier, stays V. B. Youngner and F. J. Nudge. Golfer can green later. 1968. Crop Science. 8:455-457. rake trap Golf courses from coast to coast while (from the Department of Agron- holding club for years have planted Warren's omy, University of California at in other hand Creeping Bent stolons for the finest greens in America. Clean, pure strain Riverside, Riverside, Calif.) Warren's stolons provide perfect, even texture and color. Greens The objective of this study was planted with seed do not hold their to investigate the effect of temper- uniformity of color and texture as ature on the shoot density and HIGH DENSITY well as greens planted yvith stolons. total available carbohydrate con- PLASTICJ/VEATHER- PROOFED And Warren research has now tent of shoot bases of three varie- The bright, yellow- handled RAKE-Ezee made available the new grass, A-20, ties of Kentucky bluegrass: (a) with the same high quality, for tees Rake flags attention, Merion, (b) 0217 Fylking and (c) reminds golfers to rake and aprons of greens. A-20 has ... trap. Stands erect on been tested and rated excellent or Newport. The data was collected ^ blunt metal point. superior by leading universities. after growing eight weeks at a Sturdy, attractive, won't Write for specific information given temperature regime and rust, yet low in cost. Rake-Ezee about A-20 Bluegrass and Warren's maintained at a cutting height of stands erect on point, reminds golfer to rake trap. Fully guaranteed with tough stolons. 1.6 inches. plastic head. See your distributor, or write: Distinct differences were evi- dent among the three Kentucky MFD. BY ARREN'S bluegrass varieties in terms of NORTH CENTRA! TURF NURSERIES temperature effects. Merion and PALOS PARK, ILLINOIS (Continued on page 26) Phone (312) 974-3000 For more information circle number 172 on card For more information circle number 232 on card 24 • GOLFDOM/197C) JUNE BEARD The total available carbohy- Comments: The results of this drate content found in the base of study indicate that Newport is (Continuedfrom page 24) turfgrass shoots was significantly better adapted to cooler temper- 0217 had significantly higher lower for Newport at any given atures, whereas Merion and 0217 shoot densities than Newport at temperature than for either Mer- Fylking are better adapted to high temperatures. Newport pro- ion or 0217. This investigation warmer conditions as measured duced a higher shoot density at also showed that the lowest level by the shoot density and level of lower temperatures. At any one of total available carbohydrates reserve carbohydrates. The re- temperature treatment, the 0217 occurred at the temperature sults of this paper suggest one had a significantly higher shoot which resulted in the greatest factor which may contribute to density than Merion or Newport. amount of shoot growth. the better adaptation of Merion to warmer climates in comparison to other Kentucky bluegrass vari- eties. It also suggests that 0217 Fylking may produce a similar re- sponse. The measurement of total available carbohydrates in turf- grass tissues is an important in- dicator of the overall vigor, root- ing depth and recuperative poten- tial of the plant. Turfmen should attempt to develop cultural prac- tices which will maintain a medi- um to high level of carbohydrate reserves at all times. In this paper the lowest carbohydrate level oc- curred at the highest rate of shoot growth. Other factors which tend to deplete the carbohydrate re- serve are (a) an excessively high nitrogen fertility level or (b) se- vere defoliation of the shoots, due to either an excessively close cutting height or an excessively long interval between mowings. More studies of this type are badly needed in order to obtain a more detailed understanding of the proper adaptation and use of the turfgrass varieties currently available. In the past most studies have been devoted to comparisons between species such as bentgrass and bluegrass. With the increased number of researchers working in the turfgrass area more effort will go into the responses of varieties within a species. •

Other papers of interest: 1. Measuring rooting of sodded turfs. J.W. King and J.B. Beard. 1969. Agronomy Journal. 61(4): 497-498. (from the Department of Crop and Soil Sciences Michigan State University, East Lansing, Mich. 48823.) For more information circle number 171 on card

26 • GOLFDOM/1970 JUNE