Green World AN INDUSTRYWIDE PUBLICATION OF THE NEW JERSEY TURFGRASS ASSOCIATION Volume 8, Number 2 Spring 1978 A New Preemerge After 10 Years Of Testing Chemical weed control has given the greatest single improvement in turf during the past 30 years. The phase known as preemerge crabgrass (Digi- taria) control is second in importance only to 2,4-D and the phenoxy family. DCPA, the first of our modern pre­ emerge herbicides that are in use cur­ rently, appeared about 20 years ago, and this chemical along with several others have reduced crabgrass from a number one weed to just one of our weeds. These chemicals have been very helpful, but they have brought disap­ pointments. Too little study has been given to the best methods of using these herbicides. Possibly, we have not always used techniques that give the best control of crabgrass and the greatest safety to the turfgrasses. We know several of these herbicides work best when they are applied in granular form rather than spray form. They can be applied too early and too late with respect to crabgrass germination. Apparently thatch interferes with the action of several of the herbicides. They differ in phytotoxicity to the grasses. DCPA is the oldest of the current market group, and it has been used widely. Bensulide has been one of the better long-term performers. Benefin requires the lowest rate/acre of active ingredient which makes it very compe­ titive. Siduron is one of the safest on the red-fescues and it can be applied over new seedings. Consistent Control This year a new chemical is available to some growers. It has been tested on crabgrass for the past 10 years at the New Jersey Agricultural Experiment Station as RP17623. (Page 4, please) May Overlook Importance of Anthracnose on 'Poa' J.M. Vargas Jr. and R. Detweiler, Department of Botany and Plant Pathology, Michigan State University A new disease problem attacking “Poa” (Poa annua — annual bluegrass) has been identified on many golf courses over the past three years. That is not to say anthracnose (Collectotri- chum graminicola) is a previously uni­ dentified problem for it is reported in the literature. But while the disease has been reported before, its importance has been overlooked, or more correctly stated, the damage done to “Poa” by anthracnose has been blamed on other factors: Pythium, Helminthosporium, and high temperature. It was not uncommon to go onto a golf course in the summer and hear a superintendent say, “Pythium has wiped out my fairways” or “Helminth- osporium has wiped out my fairways” and “I treated it with this or that and it didn’t help.” Nor was it uncommon to walk on a golf course and hear someone say, “Look, I can’t apply more water, the fairways are saturated and they’re still wilting” or “I have even syringed in the middle of the day and they are still wilting.” Attacks Grass Under Stress The reason the Pythium and Hel- minthosporium fungicides didn’t work was because neither was the problem. Excess water and syringing didn’t work because the grass was not wilting. If anything, the excess water contributed to the anthracnose problem. The one characteristic symptom of “Poa” infected with anthracnose is its yellow appearance. When Poa or any grass wilts, it turns dark blue to purple, and yet superintendents were talking about their “Poa” turning yellow and wilting. (Page 3, please) Anthracnose (Collectrichum graminicola) as it appears through hand lens. BENTAZON NEW FOR NUTSEDGE A chemical, bentazon, produced by BASF-Wyandotte Corporation, has been introduced to the market for nutsedge control. The commercial package is known as “Basagran.” Researcher Johnny Jagschitz, who has collected considerable data, reports that two applications of 1 lb./A. each at 10-day intervals in July will give good results. Of course, follow the instructions on the label. Comments and Opinions Sound Advice Out of The Past EARL Y APPLICATION OF DACONIL CONTROLS RED LEAFSPOT DISEASE ALL YOURS This page is open to you for your comments and opinions. Let’s hear from you. “As a general rule, turf (sod) for greens should be cut as thin as 1 1/2 inches. This is especially important if the turf contains many tap-rooted weeds. The roots of the weeds and many of the coarser grasses are then left behind in the cutting. In the exper­ ience of the writer, it is frequently not a difficult matter to get excellent turf in the immediate neighborhood of a golf course.” This is one of the many still-useful observations by Dr. A. Mackenzie, author of “Golf Course Architecture,” published in 1920 and now regarded as a classic. Dr. Mackenzie has better known statements in his book. And we might react to the above as interesting writing and something of historical interest. Yet, there is hidden wisdom for us. When we try growing something that does not have well-defined cultural proce­ dures, we might begin with the natural varieties, natural soil and the natural habitat where the species occurs. Man is sel­ dom wise enough to develop new procedures without study and mistakes. In the introduction to his book Dr. Mackenzie wrote: “No doubt many mistakes were made in our early attempts, and I never visit a course which I have designed without seeing where im­ provements could be made in the con­ structional work, and as long as this is so, I feel that we shall all continue to learn and to make progress, our inst­ ructor being nature herself.” “Strangely” mistakes in con­ struction of golf courses are still occurring. The statement sug­ gesting that we “continue to learn and to make progress, our instructor being nature herself ” should be a guidepost to all in turf and the landscape. -R.E.E. (Does this headline look familiar? It should, as it appeared over the fol­ lowing information and request a year ago. The idea seems worth trying but we received no response. If you use this method in 1978, please let others know your results. A few small unsprayed check strips will make any results of lack of results more convincing. — Editor) Research at the University of Illinois on red leafspot (Helminthosporium erythrospilum), which causes serious turf decline of bentgrass turf in late spring and summer, is especially inter­ esting. They found that application of the full rate of Daconil in late April or early May gave good control while later applications made near or at the time of the disease occurrence were much less effective. This situation suggests what might be a parallel. Snow-mold control has been improved on some occasions when fungicides are applied in late October rather than at the end of the growing season only. These observations suggest that we need more study on timing of fungicide applications. If you try the early Daconil treatment and find it conven­ ient to leave a check, pass along your results. Every job is important when done with pride. Because pride gives us more than title of power. It gives us fulfillment. And fulfillment casts out disappointment like demons from the temple of our temperament. — 5. W. Martin, “Better Corps” Green World is published three times a year by the New Jersey Turfgrass Associa­ tion, P.O. Box 231, New Brunswick, N.J. 08903. Ralph Engel, consulting editor; Russell Stanton, managing editor. Please address inquiries concerning advertising to Jack Wittpenn, advertising director, Box 809, W. Caldwell, N.J. 07006 (575- 1322) EPA Adds More RPAR’s to List Hot off the press is a new list of pesticides which are called “candidates for intensive scientific review” to deter­ mine whether they should be put on the RPAR list. The April 20 Federal Register lists 31 pesticides among which are such well known products as Captan, 2, 4-D, Dacthal, Folpet, and Thiram. Where will it end? EPA will be reviewing the risk/benefit assessment of each of the 22 candidates presently on RPAR as well as those mentioned above. Your dependency on these new ones and all the other products on RPAR should be voiced. You could write directly to EPA; but, if you prefer, write to the manu­ facturer and let him forward your letter to EPA at the appropriate time. — Paul Sartoretto (“What You Can Do About EPA's List of RPAR's ” in Fall 1977 Green World.) OFFICERS OF THE N.J.T.A. Chuck Wilson President Jack Wittpenn Vice President Ralph Engel Secretary and Consulting Editor William Ritchie Treasurer EXECUTIVE BOARD Dave Buchholz Fred Eden Edgar Krause Samuel Leon Paul Sartoretto Ken Kubik Paul Boizelle Past President ANTHRACNOSE (Page l) Preventive Applications What is anthracnose? It is a weak pathogen that can attack “Poa,” Ken­ tucky bluegrass, and red fescue under stress. It appears to attack during cool as well as warm weather. The yellow­ ing is present under cool or warm weather but death of the grass plant occurs in hot, humid weather condi­ tions. Most of the stress on “Poa” came from the high temperatures last sum­ mer. The disease in “Poa” was worse in heavy soil, compacted areas, and heavy traffic areas or hillsides. In one case excess nitrogen fertility was also attri­ buted to symptom development. In Kentucky bluegrass, shade and short root systems contributed to the severity of the disease. How can the disease be properly identified in the field? By the black fruiting bodies, acervulus, (acervuli, pl.) of the fungus, with spines (setae) protruding from them, which are present in the infected tissue. The black bodies can be found in the green or chlorotic tissue (yellow) when the disease is moving rapidly during warm weather but they are more commonly found in the dead tissue. Effective Control The benzimidazole systemic fungi­ cides (Tersan 1991, Fungo 50, Cleary’s 3336, Scotts DSB & Fertilizer) at the 2-oz. rate give the best control when applied as eradicants. Rates of 1 oz./1000 sq. ft., while effective, did not give as good control as the 2 oz. rate. Four and 8-oz./1000 sq. ft. rates also gave excellent control but the cost is prohibitive. The quickest recovery oc­ curred where the systemic fungicides were drenched in after application. Weekly applications of the contact fun­ gicides Tersan 75, Tersan LSR, Fore and Daconil 2787 were effective. Many fairways which lost 50 to 75 percent of their turf prior to treatment recovered ten days to two weeks after treatment indicating that the crowns of the plants had not been killed by the anthracnose fungus. Often the roots of the treated annual bluegrass plants are up to 2 inches in length following treatment in spite of the fact the day­ time temperatures were in the high 80’s and low 90’s. In the untreated controls the annual bluegrass roots remained shallow to the point where the turf could be easily tom out. The evidence indicates that much of what has been previously called high temperature killing of “Poa,” Helminthosporium and Pythium, is in fact due to anthrac­ nose. If this summer is hot and humid, or if you are in an area that always has hot humid summers, you may wish to apply 1 oz./lOOO sq. ft. of a systemic fungicide when the daytime tempera­ tures start to go above 85°F. and the nighttime temperatures stay above 70° F. This should last for 4 weeks. Then you could apply Tersan 75, Ter­ san LSR, Fore or Daconil 2787 fol­ lowed a week later by an additional ounce of a systemic fungicide. Applied as a preventative, one ounce has been effective. Why the contact fungicide if the systemics are so effective? Because resi­ stance to the systemic fungicides has developed for every major pathogen on which it was used. This includes Colleetrotrichum spp. on other crops. There is no reason to believe it won’t happen here and if it does happen on your course, you will have to spray every 3 to 7 days with a contact fungicide from July through August to prevent anthracnose. Using a contact between systemic fungicides applica­ tion and during the rest of the year will hopefully delay the development of this resistance. Write or call for further information and current prices LOFTS Lofts Pedigreed Seed, Inc. Bound Brook. N.J. 05505 / (201) 350-1700 ’US Plum Paten; * 3186. Dwait Variety ’ ‘Protection applied loi umlei me U S Plant Variety Pmtection Act Anthracnose fruiting bodies (acervuli and setae) on “Poa” blades as seen through hand lens. (As of April) SUSTAINING MEMBERS Mercer Sod, Inc. Seacoast Laboratories Harvest Publishing Co. Limestone Products Corp. Techniturf Green Hill Turf Supply Lofts Pedigreed Seed, Inc. Lewis W. Barton Co. Wide Sky Farm, Inc. Rockland Chemical Co. Leon’s Sod Farm Garfield Williamson, Inc. A-L Services The Country Greenery The Terre Company Metro Miloganite, Inc.. Playboy Resort and Country Club Kelly DeFreitas & Assoc. PREEMERGE (from Page 1) The common name of this chemical is oxadiazon, and its commerical name is Ronstar. This herbicide has given more consistent crabgrass control and has a better 10-year crabgrass control rating than the several market types (see table). Application in late April appeared better than the third week of May. A preparation for spray application gave good crabgrass control, but a product for this method of application is not available. Unfortunately, the herbicide tends to be severe on red fescue types, Festu- ca rubra types and bentgrass Agrostis spp. and is not recommended where these grasses are important. Its safety to Kentucky bluegrass, Poa pratensis, has been very good. Observe results with this grass to determine how it might fit into your program. PREEMERGE CONTROL OF CRABGRASS WITH RP17623 GR FROM 1968 TO 1977. YEAR ai/A (LBS.) CRABGRASS CONTROL (%) 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 4 3 3 3 3 3 3 3 3 3 93 72 81 92 93 96 93 87 93 99 CRABGRASS LATE TOO? Many are asking if it is too late for preemerge herbicides. It seems ever­ yone is on a late schedule this spring and we might hope crabgrass is also. Very little crabgrass has germinated to date and if you see no seedlings, this could be the best time of the season. While preemerge (benefin, bensu- lide, DCPA) is less successful on goo- segrass (Elensine), mid-May should be a prime date for 1978 application. If you do apply preemerge, do not forget the old admonishments: 1) Read the label, 2) calibrate equipment cor­ rectly, 3) apply the herbicide in a uniform pattern. Keep records on the date of applying preemerge and your results for a future guide. -R.E.E LUSH, GREEN LAWN POSES A PROBLEM “Man blames fate for other accidents, but feels personally responsible when he makes a hole in one. ” Question — Last summer I had a lawn problem. My lawn continued to be lush and green long after the neigh­ boring lawn had turned a fashionable tan. What did I do wrong? Answer — This sounds like the result of fertilizing the lawn in spring, water­ ing it deeply in dry spells and setting the lawn mower height too high to assure proper burning of the grass. This summer, remember to lower the wheel height to its lowest position, and hope that your grass roots will go dormant. We hope you haven’t done any fertilizing or sprinkling thus far, for this would prolong your lush, green lawn condition. — Gerald Kloss, in “Slightly Kloss-Eyed” Milwaukee Journal WE’VE GOT WHAT YOU NEED FERTILIZERS: I.B.D.U. Ureaform GRASS SEEDS: Bulk or Custom Mixes INSECTICIDES: Diazinon, Dursban, Etc. FUNGICIDES: Cleary’s, Daconil WEED KILLERS: Balan, Betasan, Dacthal The TERRE Co Saddle Brook, N.J. (201) 843-6655 Garfield Williamson WHOLESALERS & DISTRIBUTORS Products for the Professional BULK SIZES/SPECIAL MIXES NEWEST VARIETIES Grass Seed Fertilizers Chemicals Featuring- FINE LEAF PERENNIAL RYE GRASS Garfield Williamson, Inc. 1072 West Side Avenue, Jersey City, N.J. 07306 201-435-3500 ABSTRACT Impact of Thatch on Preemergence Activity in Kentucky Bluegrass Turf. K.A Hurto and A.J. Turgeon. 1977 Agronomy Abstracts p. 111. Field and laboratory experiments were conducted to assess the impact of thatch on herbicide efficacy, mobility, and persistence. Preemergence herbi­ cides were applied to a Kentucky bluegrass (Poa pratensis L.) turf at two sites; one with thatch 3 cm. thick; and one with no thatch. Results showed good to excellent crabgrass control without injury to thatch-free turf treat­ ed with benefin at 4.5 kg./ha. and with all treatments of DCPA bensulide, and oxadiazon. Crabgrass control in thatchy plots was excellent with all herbicide treatments; however, turfg­ rass injury was moderate to severe in plots treated with benefin, prosulfalin, and oxadiazon. Laboratory studies showed differences in herbicide ad­ sorption and mobility in thatch and soil. Persistence of benefin and DCPA was evaluated in vitro using C-14 labeled materials incubated under aer­ obic conditions in soil and thatch. After 28 days, 68 and 56 percent of DCPA and benefin, respectively, were detected in thatch; in soil, greater than 90 percent of both herbicides was reco­ vered. One reason high achievers accom­ plish so much is that, when it comes to their jobs, they have a one-track mind. They concentrate on getting the job done! USS Vertagreen 17-0-8 with Balan... We’ll help you weed and feed! Your local USS Vertagreen distributor has a proven fertilizer for professional turf that performs two jobs at once. USS Vertagreen 17-0-8 with Balan gives your fair­ ways a healthy shot of quick­ acting nitrogen —and the supply continues because 25% of the nitrogen is derived from urea- formaldehyde. It also controls Poa Annua, crabgrass, goose grass, water grass and foxtail — thanks to Balan, the highly effec- tive pre-emergence herbicide. This versatile and economical product contains sulfate of potash for lush, green color and is rounded out with vital secondary and micro-nutrients including chelated iron. USS Vertagreen with Balan is another reason we say, "see the best, for the best" — and that's your local Vertagreen distributor. He can help you weed and feed. A product for all reasons. Agri-Chemicals Division of United States Steel PO Box 1685. Atlanta. Ga 30301 The whole in one. Now with new preemergent Chipco® Ronstar G, Rhodia can give your golf course a complete, all-season weed control program. RHODIA INC. AGRICULTURAL DIVISION Monmouth Junction, New Jersey 08852 A SUBSIDIARY OF RHONE POULENC ABSTRACT Midsummer Occurrence of Helmintho­ sporium Sorokinianum Leaf Spot on Selected Cultivars of Poa Pratensis. Clinton F. Hodges and William M. Blaine. Plant Disease Reporter 58:448- 450. Several cultivars of Poa pratensis were evaluated for midsummer Hel­ minthosporium sorokinianum (H. sati­ vum) leaf spot. Field plot evaluations of natural infections revealed that all cultivars were susceptible. Severity of midsummer H. sorokinianum leaf spot was minimal on Fylking, Glade P-29, and Pennstar; Nugget, Park, South Dakota Certified, Sydsport, and Delta were severely infected. It was conclud­ ed that the environmental conditions under which evaluations were made may have encouraged the near maxi­ mum expression of susceptibility among the cultivars. The general in­ crease in the incidence of midsummer H. sorokinianum leaf spot on P. praten­ sis in Iowa is believed to be closely associated with irrigation practices and possible changes in virulence of the pathogen. More N for G.W.? Sorry about the sick green of our last issue. Let’s blame it on the harsh winter. Betty Murdock, my secretary, said more nitrogen would bring the good green back, and our printer took her advice when he mixed his new batch of ink. - R.E.E. New Jersey Turfgrass Association P.O. Box 231 New Brunswick. NJ. 08903 Control 9 fungus diseases in greens, tees and faivways with broad-spectrum Daconil 2787 Daconil 2787 fungicide controls most fungus diseases in turf... more than any other fungicide available. Does it quickly, effectively, dependably. So you can use just one fungicide instead of two or three. Most leading country clubs in America use Daconil 2787. Start early and go right on through the summer... even in hot, humid weather. Has been used on over 25 species and varieties of grass without injury. For granular Daconil application, use ROCKLAND LAWN FUNGICIDE 2787. Contact your ROCKLAND supplier or write ROCKLAND CHEMICAL CO., INC., West Caldwell, N.J. 07006.