green world AN INDUSTRYWIDE PUBLICATION OF THE NEW JERSEY TURFGRASS ASSOCIATION VOL. 13 No. 2 Endophytic Fungi in Perennial Ryegrass and Tall Fescue, and Their Association with Insect Resistance and Animal Performance Jennifer M. Johnson-Cicalese, Cara L. Johnson, C. Reed Funk, Philip M. Halisky, and Sami Ahmad1 Endophytic fungi are fungi that live within plant tissues, but not necessari­ ly as parasites. Endophytic fungi have been known to occur within certain grasses for over one hundred years. However, the endophytes living within the tissue of tall fescue (Festuca arundinacea) and perennial ryegrass (Lolium perenne) (figure 1) received very little attention until recently, when two impor­ tant discoveries were made. These discoveries are: (1) an association of en­ dophyte presence with occasional periods of poor performance in animals graz­ ing tall fescue and ryegrass pastures, and (2) the resistance of ryegrass con­ taining the Lolium endophyte to several important insect pests. These discoveries have resulted in considerable interest in endophytes by both tur- fgrass and animal production specialists. Although there are still many ques­ tions to be answered about endophytic fungi, they may become an important tool in turfgrass pest management. Figure 1. Fungus threads (mycelium) grow in the intercellular spaces between cells of the aleurone cell layer (numerous oval cells) in the ryegrass or tall fescue seed. The endophyte grows between host plant cells in the seed, leaf sheath, and the pith of the flowering stems. The mycelium of the endophyte has not been observed to actually penetrate the host plant cells. 1/Associate Research Scientist; Assistant Research Scientist; and Professor, respectively, Soils and Crops Department; Professor Department of Plant Pathology; and Associate Professor, Depart­ ment of Entomology and Economic Zoology, New Jersey Agricultural Experiment Station, Cook College, Rutgers The State University of New Jersey, New Brunswick, New Jersey 08903 Summer 1983 Early Work Sampson (1933) working at the Welsh Plant Breeding Station, noted that the Lolium endophyte in ryegrass was similar or identical to the fungus Epichloe typhina (Fr.) Tul, which causes the choke disease of fine fescue and some other grasses. However, when the endophyte is pre­ sent in ryegrass, or tall fescue, it fails to produce choke disease symptoms, or any other readily visible symptoms. Sampson also observed that the en­ dophyte was transmitted maternally by seed, as well as by vegetative pro­ pagation of an infected grass host. Neill (1940, 1941) and Lloyd (1959) conducted additional studies on the Lolium endophyte in New Zealand. They found that the endophyte was widely distributed throughout the coun­ try and was especially common in old pastures. They showed the endophyte lost viability, or died, in seed stored more than eighteen months. Very limited feeding trials showed no adverse effects of endophyte-infected plants on animal performance. No evidence was found that the en­ dophyte had any effect upon its host plant either, leading to the conclusion that the fungus had little agronomic significance. Animal Disorders Associated With Endophyte Presence In 1977, work done by Bacon et al. in Georgia led to a reexamination of the endophyte in tall fescue. Studies were being conducted to identify the cause of “summer syndrome” or “fescue toxicity syndrome,” a disorder that frequently occurs in cattle grazing tall fescue during hot summers. This continued on page 3 Comments and Opinions When Is Dioxin A Critical Problem? We read a lot about dioxin, a chemical that has been present in many places for a long time and develops naturally as well as synthetically. Most articles are written by newswriters. One group that is seldom read or quoted is Cast. This is an association of scientists whose membership includes an impressive list of agronomists, horticulturalists, entomologists, animal scientists, veterinarians, plant pathologists, food technologists, weed scientists plus biologists and chemists associated with these fields. Information from this organization is seldom presented in the general press. The following is a sum­ mary statement from Dr. C.A. Black, Executive Vice President of Cast, who was an eminent soil scientist at Iowa State University until his retirement a few years ago. The presence of dioxin in soil does not provide acceptable evidence of the existence of significant exposure of human residents in eastern Missouri adjacent to roads treated years ago with dioxin- contaminated waste oil. Traces of dioxin are widespread in the en­ vironment. As a basis for determining whether the current exposure to dioxin is sufficient to be of concern, the first logical step would appear to be to determine the incidence of skin ailment known as chloracne in the human population. Other tests based upon easily conducted studies with animals would provide further verification of the significance of the hazard. Whether you agree with the Cast statement, think of the recent govern­ ment expenditure by EPA and the material loss of burying fifteen trainloads of turf fertilizer that possibly contained a teaspoon of dioxin as a contaminent in the silvex herbicide component. What will EPA propose for the road materials that people have been near or in contact with for years. Dioxin as a concen­ trated material must be treated with greatest respect, but when will our govern­ ment agencies develop a better perspective when the concentration is one part per billion or one-tenth part per million. REE Sustaining Members A-L Services, Inc. Blue Ridge Peat Farms Brouwer Turf Equipment The Country Greenery, Inc. Debuck’s Sod Farm Double Eagle Equipment Co. DuBrow’s Nurseries Florence Landscaping Svc. Inc. G & G Lawn Service, Inc. Garden State Goodall Garfield Williamson, Inc. Green Hill Turf Supply Hewlett-Packard Hoffmann-LaRoche, Inc. Jade Run Turf & Sod Farm JEP Sales, Inc. J & J Baby Products Co. Keystone Lawn Spray Leon’s Sod Farm Limestone Products Corporation Lofts Seed, Inc. A. Lombardi Landscaping Wilfred MacDonald, Inc. Metro Milorganite, Inc. Montco/Surf Side Newton Country Club Northeastern Associates Reid Sod Farm Rockland Chemical Co. Seacoast Laboratories, Inc. Somerville Equipment Co. Storr Tractor Co. Super Lawns, Inc. Sweeney Seed Co. The Terre Co. Vaughan-Jacklin Corp. Steven Willand Inc. Andrew Wilson A. R. Zimmer Inc. OFFICERS OF THE N.J.T.A. Dennis DeSanctis, President Dave McGhee, Vice President Ralph Engel, Secretary William Ritchie, Treasurer Edgar Krause, Past President Henry Indyk, Expo Chairman Paul DesChamps, Past President EXECUTIVE BOARD Samuel Leon Joseph DeSantis John Zajac Joseph W. Manning, Jr. William H. Peterson Robert Dobson William A. Nist John Poksay Douglas Moody The pleasure of golfing should first feast the eye. An Old Bilk Lyons Proverb. Endophytic Fungi continued summer syndrome results in poor weight gain, low milk production, an elevated body temperature, high rate of respiration, intolerance of heat, and overall poor performance. Because of the seasonal and sporadic nature of the syndrome a fungal toxin was suspected. Bacon et al. isolated the endophytic fungus, Epichole typhina (Fr.) Tul. (later renamed Acremonium coenophialum Morgan-Jones and Gams) from tall fescue pastures where cattle showing the summer syndrome were present. This study and several others have shown a definite associa­ tion between endophyte-infected tall fescue and summer syndrome. Recent studies in New Zealand by Fletcher and Harvey (1981), Mortimer et al. (1982) and others have shown that endophyte-infected ryegrasses may be responsible for another disorder, known as “Ryegrass Stag­ gers” (RGS). This disorder affects sheep, cattle, and deer feeding on some overgrazed ryegrass pastures during periods of severe heat and drought stress. It involves temporary muscular tremors, causing the animal to stagger and fall, and occasionally causing injury and production losses. The animal will recover from RGS when a new source of feed is provid­ ed or when the pasture recovers from drought stress. These investigations found the endophyte to be most highly concentrated at the base of the plant in the leaf sheath, in the pith of flower­ ing stems, and in seed. Heat and Parkmaster The Professional for large areas. The Toro Parkmaster mows swaths from 30 inches to 18l/2 feet wide -up to 80 acres a day. With a 7 or 9 unit hydraulically-controlled frame, it has a compact pattern of gangs for easy mowing, easy transporting. The Parkmaster is the mowing tractor built to take Spartan gangs. Comes with powerful gas or diesel engine with cab and roll over protection system (ROPS) optional. TORO Storr Tractor Co. 3191 U S. Highway 22 Somerville, NJ 08876 201/722-9830 the Professionals that keep you cutting drought stress appear to increase the amount of endophyte within an in­ fected plant, as shown in Table 1. This helps explain why outbreaks of RGS occur, predominantly during periods of drought stress and heat, and during periods of over grazing, when animals are consuming the base of the plant. Unless these conditions are present, the widely distributed Lolium en­ dophyte will not cause RGS. Ryegrass is also widely grown as a highly desireable pasture grass in Northwest Europe. Although the Lolium endophyte is present in this area, no reports of RGS or similar disorders have been reported, pro­ bably due to the cool, moist climate. The authors are also unaware of any reports of ryegrass staggers affecting animals in the United States, where ex­ tensive acreages of annual ryegrass (Lolium multiflorum) are grown for winter grazing in the southeastern states. Nevertheless, using ryegrass varieties and seed lot with low en­ dophyte levels would seem advisable, when the grass is to be used for forage purposes. Toxins Associated With Endophyte Presence While studies were conducted on the fungus responsible for these animal disorders, other scientists in­ vestigated the chemical nature of possible toxin(s) involved. In 1981 Gallagher et al. reported the isolation of a new group of neurotoxins, the lolitrems from ryegrass tissues and im­ plicated them as the causative agents of RGS. When these neurotoxins ex­ tracted from ryegrass tissues were in­ jected into mice, a tremor response similar to RGS symptoms, was obtain­ ed. It was later found that the toxins could only be extracted from ryegrass tissue that contained Lolium en­ dophyte, further supporting the cor­ relation betrween endophyte infection Sanity is the conquest of truth without illusion. and RGS (Gallagher et al., 1982). The neurotoxins could not be extracted from the fungus when it was grown on artificial media; this suggests that an association between an endophyte and its host plant triggers the produc­ tion of lolitrems. In tall fescue, endophyte presence is positively associated with the pro­ duction of two pyrrolizidine alkaloids, N-acetyl loline and N-formyl loline (Bush et al., 1982). The accumulation of these alkaloids may be influenced by the environment, or an interaction between the fungus and host may oc­ cur during the growing season to pro­ duce varying amounts of these toxic compounds. It is also possible that the toxins are not produced by the fungus but by the plant in response to the fungus (Bacon and Hinton, 1983). The plant may be producing compounds toxic to fungi; such compounds are called phytoalexins (Whittaker and Feeny 1971). Insect Resistance in Perennial Ryegrasses Containing the Lolium Endophyte During the recovery of the grazing trial set up by Mortimer et al. (1982, 1983) containing plots of endophyte- free grass plants and plots of endophyte-infected grass plants of the same cultivar, an unexpected dif­ ference in regrowth was observed. The trial area had been very closely graz­ ed and subjected to drought condi­ tions. The plants containing high en­ dophyte levels produced uniformly good regrowth while the endophyte- free plants exhibited uniformly poor regrowth. Investigations into why this remarkable difference occured show­ ed endophyte-free plants to contain five times more adult Argentine stem weevils (Listronotus bonariensis) than were found on endophyte-infected plants. The endophyte-free grass plants had been severly damaged by the weevil, accounting for their lack of regrowth. This insect pest can cause decreases in pasture production of more than twenty percent, and is con­ sidered a major pest of New Zealand’s droughty regions (Kain et al, 1982). continued on page 4 Endophyte Further evidence to support the resistance of endophyte-containing ryegrasses to Argentine stem weevil is given by Prestidge et al. (1982). Their study showed that over a period of in­ sect infestation, pastures not treated with insecticides had a significantly greater number of plants that contain­ ed endophyte than insecticide-treated pastures. Natural selection of endophyte-infected plants was occuring, which explains high percentages of endophyte-containing plants in older pastures and turfs. Weevil numbers and damage levels will gradually decline with aging of the pasture because of the increase in percent of endophyte-infected plants. While this work was progressing in New Zealand, an unusual response to sod webworm (Crambus spp.) feeding was noticed on perennial ryegrass turf trials conducted by Mazur et al (1981) and Funk et al (1983a) at the New Jersey Agricultural Experiment Sta­ tion, Adelphia, New Jersey. Some cultivars and selections showed high levels of resistance to the sod web­ worm, whereas other entries showed substantial damage. Resistant entries showed a lack of larval feeding and an absence of larvae from the soil beneath them. Maternal transmission of insect resistance was dramatically evident, suggesting a hypothesis of endophyte-enhanced resistance to sod webworms. When remnant seed lots from these turf trials were microscop­ ically examined for fungal presence, the ryegrass entries showing resistance to sod webworm had a high percentage of seed possessing the Lolium endophyte, whereas the sus­ ceptible entries contained an insignifi­ cant amount of this fungus. The pre­ sence or absence of the endophyte was also confirmed by ELISA analysis. In other studies, seeds of forty-eight other cultivars and selections, in­ cluding all entries entered in the 1982 National Ryegrass Turf Trials, were ex­ amined microscopically for endophyte infection. Of these forty-eight entries, twenty-one were free of endophyte whereas twenty-seven were infected. Rated on the basis of percent seed in­ fected, five entries had ninety to one hundred percent, eight had fifty to eighty-nine percent, and fourteen showed less than thirty-three percent infected seed. Ryegrasses with high endophyte levels included Repell (GT- II), Citation II, HR-1, and Pennant. Endophyte-enhanced resistance to the bluegrass bug (Sphenophorus parvulus Gyllenhal) in perennial ryegrass is also suspected (Funk et al., 1983a). In New Jersey turf trials, plots found to be resistant to this important insect pest had a lack of larval damage and a nearly complete absence of lar­ vae. Maternal transmission of billbug resistance suggested a closer look and seed lots of both insect susceptible and resistant entries are now being ex­ amined for endophyte presence. The black beetle (Heteronychus arator) (A.V. Stewart, pers. comm., 1983) may also be controlled by the Lolium en­ dophyte. Since endophyte-enhanced insect resistance is found in two dif­ Table 1. Concentration of Lolium endophyte in plants sampled from a New Zealand ryegrass pasture. Date Oct. 9 Nov. 2 Nov. 16 Nov. 30 Dec. 30 Jan. 11 Feb. 8 Feb. 22 Mar. 9 Relative Amount 6 20 44 89 206 67 28 18 26 Spring Summer Fall Adapted from Fletcher (1983). Amounts of endophyte were determined using an ELISA test. COUNTRY CLUB Professional Turf Products 18-3-12 70% 18-4-10 90% 18-5-9 50% Soluble Spray Grades SCU Blends PESTICIDES LEBANON 25% 29-3-5 13-25-12 8-4-24 30% 20-8-8 50% 20-4-10 40% Special Mixes HERBICIDES LEBANON CHEMICAL CORPORATION P.O. Box 189 Dayton, NJ 08810 P.O. Box 180 Lebanon, PA 17042 ferent orders of insects (Coleoptera and Lepidoptera), this suggests a broad-based mechanism of resistance. Disease organisims and nematode pests may also be affected. En­ dophytic fungi may well become a very useful tool for the plant breeder, not only for grasses but for other plants as well. The Next Step . . . How Can This Endophyte Be Utilized? With this newly acquired knowledge about endophytes in grasses many questions have arisin; the foremost be­ ing if and how they can be utilized. New Zealand scientists and farmers tend to feel that endophyte-infected grass is better than no grass for their animals to graze on, which might be the result if this important source of in­ sect control is eliminated. Other ways of controlling RGS include improved grazing management practices and breeding livestock for resistance to en­ dophyte. Sheep exhibit a large varia­ tion, shown to be highly inherited, in susceptibility to RGS. U.S. farmers want the endophyte out of their tall fescue pastures. Because continued Endophyte tall fescue is the major pasture grass of the upper southeast U.S., and a statewide survey in Kentucky showed ninety-seven percent of the fields sampled to be infected with the en­ dophyte (Lacefield et al., 1983), large numbers of livestock are involved. However, complete elimination of the endophyte may not be necessary as pastures with low percentage of endo­ phyte-infected plants or pastures con­ taining legumes in the mixture general­ ly result in good animal performance. Measures are now being taken to pro­ duce endophyte-free seed so that pastures with lower endophyte levels can be established. Storing infected seed for approximately eighteen months at room temperature (cold storage prolongs fungus life many more years), or treating seed with systemic fungicides will result in endophyte-free seed (Latch and Christensen, 1982; Harvey et al. 1982). The treated seed can then be used as breeder lines and can be grown and multiplied for mass production of endophyte-free seed. Treating pastures with fungicides is not very ef­ fective and is cost prohibitive. Since no cases of endophyte- enhanced pest resistance in tall fescue have been found, controlling the en­ dophyte should provide an effective, but not complete, solution to the sum­ mer syndrome problem. Moreover, it will be important to observe these endophyte-free tall fescue pastures for possible increases of damage from in­ sect pests. Turfgrass breeders see the en­ dophyte as an important source of in­ sect resistance which can be incor­ porated into new turfgrass varieties. Studies by Funk et al. (1983b) indicate that approximately ninety-five percent of the seed produced by an endophyte- infected plant will also contain the en­ dophyte. Since the endophyte- containing plants are widely distributed in nature, and are also present in many commonly used varities, artificial in­ oculation of plants is not really crucial. However, this technique could prove useful if endophytic fungi with superior characteristics are isolated. Before the turfgrass breeder can proceed, more Wilfred Mac Donald, Inc. 340 MAIN AVENUE CLIFTON, NEW JERSEY 07014 201-471-0244 TURF EQUIPMENT SPECIALISTS Jacobsen National Giant Vac Cushman Kut Kwick Olathe Gravely Broyhill Burton Howard Smithco Bob cut information is sorely needed about how the fungus affects its host plant. From the earliest studies to the pre­ sent, no evidence has been found of the endophyte having any adverse ef­ fects on yield or plant performance, but no comprehensive studies have ever really been done. With the use of en­ dophytes in turfgrass varieties impor­ tant modifications must be made in seed handling, storage, and labeling. The endophytes of ryegrass, tall fescue, and many other grasses are not a new phenomenon. They are found in high frequencies in many pastures and turfs around the world. Their presence is not always associated with livestock problems as many environmental factors are also involved. Hopefully, with the proper use of these endophytes, turfgrass and even livestock managers can look for­ ward to fewer pest problems and im­ proved performance of their turfs, pastures, and cattle. Acknowledgment New Jersey Agricultural Experiment Sta­ tion, Publication No. E-15267/11130/08130 -2/2/2-83. This work was supported by U.S. Hatch Act Funds, State Funds, a grant from U.S. Golf Association Green Section Research, and Education Fund, Inc. and other grants and gifts. Literature Cited Bacon, C.W., and Hinton, D. 1983. Biology of the endophyte of fescue: Ultrastructural analysis and physiologic­ al relationships. Forage and turfgrass Endophyte Workshop Proc. pp. 19-28. Bacon, C.W., Porter, J.K., Robbins, J.D., and Luttrell, E.S. 1977. Epichloe typhina from toxic tall fescue grasses. Appl. Environ. Microbiol. 34:576-581. Bush, P.P., Cornelius, P.L., Buckner, R.C., Varney, D.R., Chapman, R.A., Burrus II, P.B., Kennedy, C.W., Jones, T.A., and Saunders, M.J. 1982. Association of N-acetyl Loline with Epichloe typhina in tall fescue. Crop Sci. 22:941-943. Fletcher, L.R., and Harvey, R.C. 1981. An association of a Lolium endophyte with ryegrass staggers. N.Z. Vet. J. 29:185-186 Funk, C.R., Halisky, P.M., Johnson, M.C., Siegel, M.R., Stewart, A.V., Ahmad, S., Hurley, R.H., Harvey, I.C. 1983a. An en­ dophytic fungus and resistance to sod webworms: association in Lolium perenne L. Bio/technology 1:189-191. Funk, C.R., Halisky, P.M., Hurley, R.H. 1983b. Implications of endophytic fungi in breeding for insect resistance. Forage and Turf Endophyte Workshop Proc. pp. 65-75. Gallagher, R.T., White, E.P., and Mortimer, P.H. 1981. Ryegrass staggers: isolation of potent neurotoxins Lolitrem A and Lolitrem B from staggers-producing pastures. N.Z. Vet. J. 29:189-190. Gallagher, R.R., Smith, G.S., DiMenna, M.E., and Young, P.W. 1982. Some observations on neurotoxin production in perennial ryegrass. N.Z. Vet. J. 30:203-204. Harvey, I.C., FLetcher, L.R., Emms, L.M. 1982. Effects of several fungicides on the Lolium endophyte in ryegrass plants, seeds, and in culture, N.Z. J. Agric. Res. 25:601-606 Kain, W.M., Wyeth, T.K., Gaynor, D.L., Slay, M.W. 1982. Argentine stem weevil (Hyperodes bonariensis Kuschel) resistance in perennial and hybrid ryegrasses. N.Z. J. Agric. Res. 25:255-259. Lacefield, G., Evans., J.K., and Burns, J. 1983 Tools and information used in tall fescue toxicosis extension. Tall fescue Toxicosis Workshop Proc. pp. 72-79. continued page 6 Endophyte Latch, G.C.M., and Christensen, M.J. 1982 Ryegrass endophyte, incidence and control. N.Z. J. Agric. Res. 25:443-448. Lloyd, A.B., 1959. the endophytic fungus of perennial ryegrass. N.Z. J.Agric. Res. 2:1187-1194. Mazur, G., Funk, C.R., Dickson, W.K., Bara, R.F. and Johnson-Cicalese, J.M. 1981. Reactions of perennial ryegrass varieties to sod webworm larvae. Rutgers Turfgrass Proc. 12:85-88. Mortimer, P.H., Fletcher, L.R., diMenna, M.E., Harvey, I.C., Smith, G.S., Barker, G.M., Gallagher, R.T., and White, E.P. 1982. Recent advances in ryegrass staggers. Proc. Ruakura Farmers’ Conf. 34:71-74. Mortimer, P.H., and diMenna, M.E. 1983. Ryegrass staggers: further substantia­ tion of a Lolium endophyte aetiology and the discovery of weevil resistance of ryegrass pastures infected with Lolium endophyte. Proc. N.Z. J. Grassland Assoc. 44:240-243. Neill, J.C., 1940. The endophyte of rye­ grass (Lolium perenne). N.Z. J. Sci. and Tech. 21:280A-291 A. Neill, J.C. 1941. The endophytes of Lolium and Festuca. N.Z. J. Sci. and Tech. 23:185A-193A. Prestidge, R.A., Pottinger, R.P., and Barker, G.M. 1982. An association of Lolium endophyte with ryegrass resistance to Argentine stem weevil. Proc. N.Z. Weed and Pest Control Confce. 35:119-122. Sampson, K. 1933. The systemic infection of grasses by Epichloe typhina (Pers.) Tul. Trans. Brit. Mycol. Soc. 18:30-47. Whittaker, R.H., and P.P. Feeny. 1971. Al- lelochemics: chemical interactions bet­ ween species. Science 171:757-770. Green World is published three times a year by the New Jersey Turf­ grass Association, P.O. Box 231, New Brunswick, NJ 08902. Ralph Engel, consulting editor; Mary Jane Christofferson, managing editor. Please address inquiries concerning advertising to Dennis De Sanctis, Terre Company, Box 1014, Clifton, NJ 07014. Paul Des Champs, award chairman, presents the 1982 New Jersey Hall of fame plaque to Dr. C. Reed Funk. Recognized for his outstanding contributions to the field, Dr. Funk is Professor of Turfgrass Breeding at Rutgers University. Dr. Funk’s work has included release of Manhattan ryegrass; discovery of ryegrasses that resist sod webworms; and consistent improvements in tall fescue grasses. His awards include the Queen of the Netherlands 1982 Distinguished Guest List; the New Jersey Turfgrass Association’s Achievement Award in 1976. Abstract: Compaction and Irrigation Tests on Kentucky Bluegrass by K.J. O’Neil and R.N. Carrow Agron J. 74:933-936. 1982 “Baron” was grown for two years on a Kansas soil with 19.6 percent sand, 60.7 percent silt and 19.7 percent clay. The sod was subjected to four treatments resulting from a factorial design with two levels of compaction (none and 30 passes per week with a roller) and two levels of irrigation. The set schedule was 3.8 cen­ timeters (1.5 inches) water per week plus rainfall, and 3.8 centimeters when the tensiometer at 10 cm depth read—0.70 bar. Soil compaction had no effect on the root weight or distribution. Visual quality, shoot density, verdure, and the percentage of total cover were reduced by compaction while total nonstructural carbohydrates (TNC) were unaffected. In the surface 3 centimeters of soil, compaction in­ creased bulk density and moisture retention but reduced aeration porosity at-0.1 bar from 18.1 to 12.5 percent. Irrigation treatment had no effect on any of the soil’s physical properties. Without affecting turf quality, water use with a tensiometer was reduced by 28 and 48 percent on noncompacted and compacted areas, respectively, compared to set-schedule irrigated plots. Water use over a nine-day period in August indicated that the turf grown under the tensiometer-scheduled regime was physiologically or anatomically continued Abstract continued from page 6 adapted to use less water even when it was available. The study showed this adaptation was not due to dif­ ferences in vegetative or root growth. movement by the roots? If facilities had permitted it would be of great in­ terest to continue a test of this type for a period of three to five years. This might show some good and bad long-term watering effects. REE Compaction reduced water use by 20 percent over the four-month study. During a nine-day period in August, compaction reduced water use by 3.5 to 11 percent for the tensiometer and set-scheduled treatments, respectively. This response appeared to be due primarily to altered moisture reten­ tion properties and reduced shoot growth. Thus, compacted and non- compacted sites should be irrigated on separate schedules. Editorial Comments The water saved with use of a ten­ siometer for irrigating Kansas turf as compared with a fixed quantity of water per week, shows the inef­ ficiency of watering on a schedule. Using a green thumb or agronomic know-how might supplement the tensiometer or substitute for it in guiding water programs. Conjecture on the reduced water use on com­ pacted plots is of interest. Were there differences in quantities of clippings which might have caused the difference? The author indicated the possibility of anatomical or phy­ siological factors. Did the compac­ ted soil develop a low oxygen level that reduced efficiency of water Endothal Goes Full Circle A note on the use of endothall was published recently in some golf turf publications. The writers’ conclusions were similar to mine more than twenty years ago. Compare the following (May 1983 Collaborator, New York State) with a statement from my 1960 publication. May 1983 Collaborator Controlling annual bluegrass (Poa annua L.) in bentgrass putting greens is a perennial problem. There are a number of preemergence herbicides that effectively control annual bluegrass. However, the continuing problem is to achieve control without damaging the bentgrass shoot or root system. Injury to the root system is par­ ticularly noticeable. Also, bentgrass damage can be aggravated by poorly drained soil and heat stress. Australian golf course superinten­ dents have tackled the problem dif­ ferently. In 1976 several Australian superintendents began a long-term ex­ perimental program of endothall usage Sales and Service of Goodall Turf Equipment GARDEN STATE GOODALL World’s First Direct Drive Rotary ... 4054 Quakerbridge Road Trenton, N.J. 08619 (609) 799-4101 that resulted in bentgrass putting greens free of annual bluegrass. Other superintendents using a similar control program are currently achieving the same results. Endothall has been available for many years; however, the approach in the United States has always been to use it as a short-term treatment at high application rates with the objective of quick eradication. The Australians are doing just the opposite. They are pur­ suing a program of light, repeated ap­ plications appropriately scheduled. Continual application has resulted in complete control of annual bluegrass. The endothall formulation being us­ ed is the sodium salt that contains 17.5 grams of active ingredient per liter. It is sprayed at a rate of 1/4 to 1/3 ounce to 2 1/2 gallons of water per 1,000 square feet. Typically, two applications at two to four week intervals are made in both spring and fall when temperatures are between 50° and 70°F. The result has been a gradual elimination of annual bluegrass over a two year period. There is evidence that perennial types of annual bluegrass are not as easily controlled with en­ dothall as are the annual types. It is important to avoid treatment when the turf is under heat, drought, or wear stress. Early morning or late evening treatments have been most ef­ fective. Endothall-treated bentgrass turfs possess substantially reduced wear tolerance; thus, application should be avoided five days before in­ tense traffic is expected. An error in application, such as applying when temperatures are too high or at too high a rate, can result in some foliar burn to the bentgrass. However, the turf readily recovers because endothall has no long-term soil residual that can cause toxicity problems for bentgrass, especially the root system. The specifics on how such a long­ term endothall program might be us­ ed in the United States are not established. The rates and timings may vary slightly depending on the location’s specific conditions. Those interested in experimenting with such continued on page 8 Endothall continued a program should start on a nursery green with a rate of 1/8 ounce per 1,000 square feet and slowly increase the rate until the bentgrass phytotox­ icity rate is established. Annual bent- grass control should be attempted on­ ly on greens that contain an adequate stand of bluegrass. A concluding statement by Engel and Aldrich in WEEDS, 1960 Vol. 8:26-28 Two to three applications of 1/2 pound of endothall per acre applied at approximately two week intervals beginning with the start of early spring growth gave consistently good reduc­ tion of annual bluegrass (on a golf course fairway). This treatment also gave good clover control. Obviously, we liked what we saw more than twenty years ago with en­ dothall when the common name was spelled with one “I.” Note that we sug­ gested two to three applications of 1/2 lb. per acre in early spring (before warm weather arrived). When en­ dothall reached the market, it was often used at higher rates and after the start of warmer weather, which caus­ ed appreciable turf injury. These, along with the need for repeat applications, prevented the occasional users from accepting endothall in the USA. Within the past several years, I was informed that some experts in Oregon recom­ mended endothall for annual blue­ grass control in bentgrass at one pound per acre. For those who are looking for annual bluegrass control in bentgrass fairways, endothall is one of several things that might be con­ sidered. The cost of material is small and several applications give excellent clover control. Stature comes not with height but with depth. Benjamin Lichtenberg Another statement from this earlier research is of interest and read as follows: “Maleic hydrazide reduced the number of annual bluegrass seedheads, but also seriously reduced the bentgrass content of the turf and allowed an increase of clover which forced discontinuance of this treatment (on fairways) after two years.” REE Kentucky Bluegrass has A Cure for Hot Weather Turf Depression Hot, dry weather does more than cook the grass; it builds gloom and despair with each added spell of excessive heat. I am sure many of us are suffer­ ing from a sense of futility because we have had more hot days and drought than average to date. Nature’s cure for the Kentucky blue­ grass lawn is the return of cool weather and some moisture which works like magic. Watching this recovery is one of my late summer-fall pleasures. Ap­ ply fertilizer a bit earlier and possibly use an extra application. Slice or scarify some seed into plate-size or larger voids. Even if the lawn is lean­ ing toward the turf-type ryegrasses, in­ clusion of some good Kentucky blue­ grass types keeps some of this grass on hand for good fall recovery and its other desired qualities. A balance of the two grasses is more desirable than either alone. REE No Conclusive Evidence of 2,4-D Danger A report by the American Medical Association’s Advisory Panel on Tox­ ic Substances concluded that, “There is still no conclusive evidence that the commercial herbicides 2,4-D and 2,4-5-T are mutagenic, carcinogenic or teratogenic in man, nor that they have caused reproductive difficulties in (humans).” According to the report, both herbicides break down rapidly in the soil” and are, therefore, of little en­ vironmental concern.” Pennsylvania Pesticide Report FERTILIZERS COMBINATIONS OF NITROFORM I.B.D.U. S.C.U. And And WITH INSECTICIDES PRE-EMERGENCE CRABGRASS KILLERS HERBICIDES GRANULAR LIQUID SELECTIVE AND TOTAL R O C K L A N D FUNGICIDES GRANULAR FLOWABLE WETTABLE POWDERS INSECTICIDES GRANULAR LIQUID WETTABLE POWDERS DOES IT ALL Ask your supplier or write: ROCKLAND CHEMICAL CO., INC. © Passaic Ave., West Caldwell, N.J.