?XOCe o^Vxe obiuEcnoN Proceedings Of The 38th Northwest Turfgrass Conference Sept. 17 - Sept. 20, 1984 Sheraton Hotel Spokane, Washington PRESIDENT'S MESSAGE Ray McElhoe As my term as president of the Northwest Turfgrass Association comes to a close, I would like to thank all the members of the NTA for carrying on the tradition of a great conference. The split sessions worked out well this year and the program was one of the best we have had. Many good comments were heard concerning the suppliers exhibition night. All in all, the conference was very well attended. These kinds of conferences, however, don't just happen. A lot of planning and hard work goes into the making of a conference. But, that's not enough! We need the input from the membership. You can make the difference between a fair or good conference. You must give your time and input if you want a good conference. You need to speak up and let the board know what speakers you would like to hear and the subjects or problems you want to learn about. Make it a personal challenge to get involved! In closing, I would like to thank everyone who helped make the Spokane Conference a success—from you the membership, and also the board of directors. I hope that everyone will support Gary Sayre and his board in the same manner they supported me in 1984. 3 NORTHWEST TURFGRASS ASSOCIATION 1984 Officers Richard Malpass Past President Ray McElhoe President Gary Sayre Vice President William Campbell Treasurer Roy L. Goss Executive Secretary BOARD OF DIRECTORS William Campbell Sahalee Country Club 21200 NE 28th Place Redmond, WA 98052 Jim Connolly Turfgo Northwest P. O. Box 18873 Spokane, WA 99208 John C. Eby Turfgo Northwest 23129 - 131st SE Snohomish, WA 98270 Roy L. Goss Western Washington Research and Extension Center Puyallup, WA 98371 Richard Malpass Riverside Golf & Country Club 8105 NE 33rd Drive Portland, OR 97221 Ray McElhoe Everett Golf & Country Club Box 1105 Everett, WA 98201 Mike Nauroth Veterans Golf Club 1235 Belle Walla Walla, WA 99362 Dennis Pagni 13222 Rosebery Avenue Oregon City, OR 97045 Gary Sayre Oakbrook Golf & Country Club 2411 Worthington Steilacoom, WA 98388 Mark Snyder Salishan Golf Links Salishan Lodge Gleneden Beach, OR 97388 TABLE OF CONTENTS The Politics of Pesticides David Dietz 8 Physiological Aspects of Mowing Turfgrasses Tom Cook 14 Chemical Control of Moss in Turf Russell Vandehey and Tom Cook 18 Nitrogen Source, Rate, and Time of Application on Bluegrass/Ryegrass Performance William J. Johnston 23 Turfgrass Response to New Slow Release N Sources S. E. Brauen, R. L. Goss and J. Nus 30 Soil Drainage Systems That Function Carl H. Kuhn 35 Minimizing Winter Desiccation with Synthetic Covers Dr. John M. Roberts 40 Carts and Cart Paths:The Best or Worst Invention for Golf? Larry W. Gilhuly 42 Aerification: A Comparison of Shattercore vs. Hollow-Tined Dr. Roy L. Goss 46 Some New Approaches to Annual Bluegrass Control S. E. Brauen, R. L. Goss and J. Nus 49 Influence of Amendments in Sand on Bentgrass Establishment.... 53 Dr. Jeff Nus Tee and Bunker Design and Construction: Factors to Consider.... 57 Ronald W. Fream The Effects of Endothal, Ethofumesate, and Fenarimol (Rubigan) on Annual Bluegrass Seedlings J. L. Gullikson and W. J. Johnston Involvements of a City Parks Foreman Bob Teufel 65 70 Understanding and Using Nitrogen Dr. Roy L. Goss 74 Reel Versus Rotary Mowers Roger J. Thomas 77 TLC for a High-Use Athletic Field Sonya K. Watts 80 Irrigation Installation: Do It Right the First Time Donald A. Hogan 82 Soils and Planting Landscape Plants Dr. Ray Maleike 85 Performance of Fine Leaved Tall Fescues Dr. Jerry Pepin 92 Necrotic Ring Spot: Research on a New Disease of Bluegrass Turf and Its Control in the Pacific Northwest Gary Chastagner Drought Resistance Dr. Jeff Nus 94 96 Successful Weed Control with Preemergence Herbicides Robert Parker 101 Exciting Developments with Tall Fescue R. D. Ensign and M. J. Dial 104 THE POLITICS OF PESTICIDES1 David Dietz2 1 Presented at the 38th Northwest Turfgrass Conference, Sheraton Hotel, Spokane, WA, September 18-20, 1984. 2 State Director, Oregonians for Food and Shelter, Salem, OR. The politics of pesticides is a rather humorless topic, as I am sure most of you know. I have always been told that when you start an address or make a speech you should have some kind of humor, if for no other reason than you at least get your audience to listen to you for two minutes during any presentation. For those of you who may be members of the Audubon Society of members of the Sierra Club, I will, in advance, make my apologies for the joke I am about to tell. It is not really meant as a put down if you happen to be a member of one of those esteemed groups, but I think it is indicative of what we face today. The only endangered species on the face of the earth today are those of you who happen to use synthetic chemicals to try to benefit mankind. Now, the joke goes something like this. It seems that two Martians landed outside a small U.S. desert town (not too awfully far from here, if you want to know the truth), and the Martians descended from their spacecraft and walked into this town and the first thing they ran into was a deserted gas station. Here are the gas pumps all sitting in a row, and one of the Martians mistook one of the gas pumps to be a human being and, interestingly enough, one of the Martian's name was Sierra Club and the other was named Audubon Society. Sierra walked up to the gas pump and he said, " I am here from Mars and I am here to make sure we do not have an inter-galactic space war. It is imperative that we have peace throughout the galaxy. Take me to your leader . . and he went on for about five minutes. Of course, he got no answer from the gas pump whatsoever. He turned around to Audubon and he said, "You know, Audubon, that is the most uncommunicative human being I have ever met in my life. I am going to blast that turkey." Audubon looked at Sierra and he said, "You know, Sierra, I just don't think I would do that. That guy looks kind of mean. I would hold off on that if I were you and I would try talking to him again." Sierra shurgged his shoulders, walked back to the gas pump, went through his speech again for five more minutes and got nothing in response from the gas pump, turned back to Audubon and said, "That's it! I have had it!". So he pulled out his ray gun and shot the gas pump. The gas station erupted in an explosion and the Martians were hurdled for 100 yards into the air. They came to rest in a vacant lot. Sierra shook his head and said, "You know, Audubon, you said there was something about that guy that made you nervous, you told me to be cautious. What on earth gave you that hint." Audubon shook himself off and said, "You know, Sierra, any guy with arms that long and hands that big that goes by the name Ethyl has got to be one tough son-of-a-bitch!" In a sense, I guess you can call us Ethyl because part of what we try to do with Oregonians for Food and Shelter and part of what I want to introduce you to (and there will be brochures on this group, the Pesticide Public Policy Foundation, at the back of the room today, and the brochure is called simply " A Pesticide Short Story") is designed to get a common sense reassertion among ourselves, in the public's mind and in the minds of the decision-makers that rule our livelihood that a new pesticide perspective is absolutely necessary. Those of you who work with pesticides probably understand what I am about to tell you as well as anyone in the world. We have lost the benefit perspective when it comes to pesticides. Today, in this country, and in other nations around the world, our perspective is entirely risk-oriented. We no longer have a balance in the mind's eye of the media, nor in the mind's eye of the public as a whole, when it comes to talking about pesticides. We talk, instead, about the risk to man, the risk to the environment and the risk to wildlife that is wrought by the very use of the modern tools that have brought us production and health protection miracles. And, until that risk perspective is reasserted in a balance, folks, we are going to lose the very tools that we depend on today to produce quality food, economical fiber and the good health of this nation. You know, it is absolutely amazing to me that we can ban the use of an EDB and restrict its contamination in ready-to-eat products to 30 ppb, when at the same time we allow aflotoxin, which is a mold in peanut butter, to be present to the tune of 15 ppb knowing full well that aflotoxin has 1,000 times the carcinogenic potential of EDB. That is the consistency and logic of our federal government. That is the consistency and logic of the states in this nation and until that consistency and logic is changed from a perception of truth to fact, we will con- tinue to lose the very tools that have brought us the finest standard of living that the world has ever known. If you listen to the chemagogues, and that is what we talk in terms of when we talk about those that are radically anti-pesticide, (if you look up the definition of demagogue and substitute "chem" for "dem", you will understand what I mean) you would be led to believe that people are dropping left and right, dying from pesticide exposure, of cancers, dying because of birth defects, dying because our population's health is immediately threatened. We are told that pesticide uses are creating more spontaneous abortions and dooming our future generations from mutations. That is what you would be led to believe if you were a member of the public reading the newspaper articles or seeing the TV shows that you or I are exposed to. The truth is something else. The truth is that life expectancy in these United States continues to increase. The truth is there is no cancer epidemic (all cancer rates, except for lung cancer, are in decline or stable in the United States of America) and that is based on 50 years of data. But the fact is that we have to deal with public perception, because perception is truth. It is what the public perceives that we must come to grips with. And, what the public perceives is that you and I are out poisoning America today. We know that is not true, we know that is not fact. But God bless the poor public, they don't have a chance to know otherwise. Two and a half years ago, I made a presentation before the Second Annual Symposium on Dioxin. It was a symposium composed of the world's foremost experts with that particular chemical. It was held in Washington, DC. I got up and I gave a speech and I said, "Folks, if you don't get off your rear ends and start telling people the truth, you are going to condemn the public to an emotional, fear-wrought paranoia and hysteria about their exposure to various chemicals in the United States of America and around the world." I nearly got skewered by some in the audience because those scientists said, "That is not our task." So now we watch moon-suited EPA'ers in Times Beach, Missouri and the impression left with the public is not what's justified: That what we deal with is so very dangerous that you have to be dressed up like you are going into outer space if, in fact, you want to expose yourself to the chemicals we use. And, dioxins get linked to pesticides. It is that simple. Folks, the public doesn't remember anymore what you people do for us. They have forgotten the diseases you control, they have forgotten that you bring us food that is safe to eat, they have forgotten that you are the people that allow restaurants to meet sanitary codes, they have forgotten that we can walk into a doctor's office or a hospital and not be fearful of walking out with a secondary infection because hospitals and doctors have learned to use pesticides wisely to prevent disease. Those are the things we need to talk to people about. We need to remind the homeowner that the headlice breakout in their school is prevented by pesticides. We need to remind the regular folks that the reason they enjoy their environment, in their home and in their yard, is because they have pesticides available to control the very things that we rebel against. And, until we do that, our tools are going to be taken away. Now, if you don't think that's happening, please give it another thought. Congress is considering Harpers Ferry. If you have never heard of it, John Brown knows about it, but our Harpers Ferry Bill, HB 3818, will so radically change the registration and re-registration of pesticides that no manufacturer, none, would be able to meet the new registration requirements. Not one! The language of that bill says that to register a pesticide, we have to do behavioral testing. I debated the author of that bill down in Texas a few months ago. I looked at Tom and I said, "Tom, what in the world is behavioral testing? Does that mean if we have got mental impairments or education impairments or a mental slowness or a speaking disability, that these are the behavioral effects we have got to test?" He said something to the effect that, "that sounds good to me!" The point is they have written language into a bill that is so vague that no one knows what it means. But we do know it can and will be used to tieup the system forever. That will be the end of pesticides. There are 80,000 municipalities in the United States. Local government wants to get into the act of registering and controlling the use of pesticides. Name one manufacturer of our chemical tools that will try to meet 80,000 different registration dictates. But, it is happening in Montgomery, Maryland; Surfside, Florida; Wauconda, Illinois; Clatsop County, Oregon; Mendocino County, California (they are before the Supreme Court right now trying to decide the question of who has regulatory authority). The courts of this country, woe be to them, are also being faced with the question, "What can we do with pesticides?" I regard this question as my profession's Full Employment Act of 1984, because the fact of the matter is that you can sue and sue and sue on pesticides and never exhaust the legal possibilities you have. Last Thurs11 day in a federal district court in the State of Oregon, all herbicides were banned from further use by the United States Forest Service and the Bureau of Land Management in the States of Oregon and Washington. Every use was banned from roadside vegetation management to progeny sites to test sites. Every use! Noxious weed control, specifically, said the court, will be prohibited until a worst case analysis is done by the federal government under the National Environmental Policy Act. Do you know what the worst case analysis has to be? When it comes to the chemical 2,4-D, not a proven carcinogen, you must assume it is a carcinogen and then extrapolate the number of cancers that will be created in the United States by the use of 2,4-D before we can go ahead and use that chemical. That's illogical in the extreme, but that's what the courts of this country have now told us we must do. That is why you are an endangered species. The politics of pesticides is coming at us like a ton of bricks and unless we figure out how to put mortar to the bricks to build our own wall, or figure out a way to get out of the way, we are going to lose the tools that we have to have to maintain this country's liveability. Pesticides are not endangering this nation. They are the environmental promotion, health protection and food and fiber production tools that are absolutely essential to the health and well-being of this country and to the people of this country, and that is the story we have got to start telling. I am sick and tired of politicians using the pesticide issue to fearfully make their constituents react so they can buy votes through fear. It has got to end. The way to end the illogic is to turn it around and talk in terms that are as vigorous and as emotional and as vibrant as the terms that are now being used against us. Because the fact is, we will lose our ability to use pesticides unless we go forward, hard, with our message. That is part of what we try to do with Oregonians for Food and Shelter. It is what we have started to do with the Pesticide Public Policy Foundation which is an interesting creature, because 3PF (the Pesticide Public Policy Foundation) was created by the arbor, lawn care and landscape industries. The reason they wanted a national network among all of us is very simple. They are the urban environmentalists, they are the people who keep the acres of trees available to eat five to six tons of carbon dioxide a year and produce four tons of oxygen. They are the people who add 20% to the value of homes. They are the people who give us an aesthetic bal- ance that you and I demand and must have if we are to be productive and work in a healthy environment. Those folks know that they are threatened. You have just gone through the 1080 debaucle. You know what it means to have the government making decisions for you based on perception rather than fact. That is why you are threatened. That is why we have got to align perception with fact, because unless we do and until we do, the politics of pesticides are going to win, and the politics of pesticides are: Take these dangerous tools away, don't let people have access to them. Politically, it is wiser to air on the side of zero risk than it is to try to explain risk relationships. Politicians find it easier to say, "You can have a riskless society." But you can't have it. I can't walk across the street today and guarantee you I won't be hit by a car. But, a politician will sell the idea of zero risk before he will take the time to explain the risk relationships, because that is hard. Why? Well, number one, because he or she might not know any better. And, number two, it is tough to do and it takes time. That is what you folks, as professionals, are able to do. That is what people like me try to do. Because we are the ones that must do it, now! If we pull together and all work down the same path, I think we can make the difference. That difference will be having the chemical tools still there when we need them. Not only to produce the food and fiber that this society demands, but to protect the health and the environment of the American public in our country. I frankly remain convinced that if we work together and talk in concert, with strength and unit, we can succeed. But it will take all of us. I urge you today, as you go through the rest of your conference, to listen carefully to what is being told to you and relate what you hear to how you can talk to your friend or neighbor in terms of how you benefit their health, how you protect their environment, how you assure their children of a better world in which to live. Because those are the messages that are going to make sense. I think if we all do that, we will get common sense back into the question of the politics of pesticides. PHYSIOLOGICAL ASPECTS OF MOWING TURFGRASSES1 Tom Cook2 Presented at the 38th Northwest Turfgrass Conference, Sheraton Hotel, Spokane, WA, September 18-20, 1984. 2 Associate Professor, Dept. of Horticulture, Oregon State University, Corvallis, OR. 1 In recent years, due to lack of money, many park and school districts have been forced to curtail mowing frequency and, in many cases, raise mowing heights in attempts to maintain their turf with less input. At the other extreme, golf courses are under increasing pressure to lower mowing heights on tees, fairways, and putting greens to improve the playing surface for golfers. Selection of mowing height and frequency has generally been taken away from turf managers and is now dictated by budget or green committees. Since mowing is the fundamental stress we apply to turf, it is important to understand what impact our mowing practices will have on vigor, appearance, and persistence of our turf. The following sections highlight some of the important physiological and developmental changes that occur when turf is mowed. Understanding these changes will allow you to predict what effect your mowing practices will have on your turf. HOW GRASSES TOLERATE MOWING In general terms, turfgrasses tolerate mowing because initiation and development of leaves, tillers, and other secondary shoots are not disrupted by periodic clipping. Two factors in particular account for this: 1) The stem apex remains close to the ground because internode elongation does not normally occur to a great extent in turf adapted species, and 2) the pattern of leaf development via intercalary meristems allows leaves to continue growth in spite of clipping. To appreciate how turfgrasses respond to mowing, it helps to visualize the turf plant as a very simple machine. The shoots, via photosynthesis, provide carbohydrates to very young lateral shoots and the root system. The roots supply the shoots with water and minerals. Surplus fuel (carbohydrates) is stored primarily in the crown region. If something happens to the shoot system (eg., it is removed via mowing), the immediate source of carbohydrates for the roots decreases. If enough of the shoot system is removed, roots will dieback. Storage carbohydrates are preferentially used by the injured shoot system to regenerate itself via axillary buds or existing, partially defoliated shoots. Normally, we can generalize that shoots have priority for available carbohydrates over roots. Alberda (1960) showed very clearly that percent total soluble carbohydrates dropped in leaves, stubble, and roots of perennial ryegrass during the first four days after cutting. In this test, it took nearly 14 days for carbohydrates to return to precutting levels. Davidson and Milthorpe (1965) showed root extension of orchardgrass dropped dramatically following severe defoliation. While both of these tests were done under forage management conditions where infrequent severe cutting is the rule, other work indicates similar phenomena occur when turfgrasses are clipped. Crider (1955) noted that if more than 40% of the leaf surface area of Kentucky bluegrass is removed in a single mowing, the impact on root growth is severe. Removing smaller percentages of foliage resulted in continued root growth, although not as great as in undipped plants. TURF RESPONSES TO MOWING HEIGHT A N D FREQUENCY Most turfgrasses seem to perform best when mowed within a relatively narrow range of mowing heights. Optimum mowing height for a given grass will vary depending on where it is grown and under what site conditions. As mowing height is lowered within the optimum range for a grass, several developmental and physiological changes will generally occur. Invariably, leaf area index will decline. This is offset somewhat by an increase in shoot density. There is a decrease in carbohydrate synthesis and storage and as a result a decrease in total root production (Beard, 1973). Mowing frequency affects turf in much the same way as cutting height. As frequency increases, shoot density increases, carbohydrate reserves decrease, rooting decreases, and there is less dry matter production (Beard, 1973). In general, the effects of frequency are more subtle than the effects of mowing height on these factors. Optimum mowing height ranges for several common turfgrasses are list in Table 1. These heights are based on bench settings and on observations of turf performance in the Pacific Northwest. Because of our generally mild climate, we can get away with lower mowing than many other areas in the United States. Several problems may develop when grasses are mowed above their optimum height range. Colonial bentgrass will develop false crowns at mowing heights above 1 inch. This is due primarily to internode elongation which yields a tree like plant with a tuft of foliage at the top. When this condition develops, the turf tends to scalp badly and generally looks brown after mowing. This trait is one of the reasons many turf managers don't Table 1 Optimum mowing height ranges for turfgrasses in the Pacific Northwest. Creeping bentgrass Colonial bentgrass Annual bluegrass Perennial ryegrass Kentucky bluegrass Chewings fescue Hard fescue Spreading fescue (Red) Tall fescue 3/16" 1/4" 1/8" 3/4" 1" 3/4" 1" 1-1/2" 1" - 1/2" - 1" - 1-1/2" - 2" - 2" - 2" - 2" •2+ " -2 + " care for bentgrass. To avoid false crowns all you have to do is lower the mowing height. Another problem occurs when Kentucky bluegrass is mowed too high. Stripe rust, Puccinia striiformis, which is severe on bluegrass during cool weather, is worse when the turf is mowed at 2 inches or higher. At higher mowing heights there is simply more mature leaf tissue in the canopy. These older leaves are definitely more susceptible to rust than young leaves. Perennial ryegrass generally shreds worse when mowed above 2 inches than at lower mowing heights. This is probably due to greater size and degree of vascularization in developing leaf blades under high mowing conditions. Finally, all grasses prone to thatch accumulation, such as Kentucky bluegrass and the fine fescues, tend to produce more thatch at higher mowing heights than at lower heights. Mowing below the desirable lower limits for a turfgrass generally will result in reduced density and increased rate of invasion by better adapted grasses. Kentucky bluegrass, fine fescues, and even perennial ryegrass will generally be rapidly invaded by bentgrass, annual bluegrass, and/or Poa trivialis when mowed too low. SUMMARY Several generalizations can be made regarding mowing practices. Mowing under any circumstances is a stress. Low, frequent mowing generally yields attractive turf that is under a high level of stress. Higher, less frequent mowing (within the optimum range) will yield healthier turf able to tolerate greater stress in terms of temperature, drought, etc. Mowing above the optimum height range will often result in poor turf quality. Mowing below the optimum range will generally lead to increased invasion by weedy species. Optimum frequency for mowing still appears to be that which will remove no more than 40% of the total leaf surface area of the turf. Infrequent, severe defoliation results in a depletion of carbohydrate reserves and temporary stoppage or even dieback of roots. REFERENCES Alberda, Th. 1960. Proc. 8th Int. Grassld. Cong. Reading, England. 612. Beard, J. B. 1973. Turfgrass: Science and Culture. Prentice-Hall Inc. 658 pp. Crider, F. J. 1955. Root growth stoppage resulting from grass defoliation. U.S. Tech. Bull. No. 1102. Davidson, J. L. and F. L. Milthorpe. 1965. Am. Bot. (NS) 29, 407. CHEMICAL CONTROL OF MOSS IN TURF1 Russell Vandehey and Tom Cook2 Presented at the 38th Northwest Turfgrass Conference, Sheraton Hotel, Spokane, WA, September 18-20, 1984. 2 Turf Student and Associate Professor, Department of Horticulture, Oregon State University, Corvallis, OR. 1 In the spring of 1984, a moss control test was initiated at the LewisBrown Horticulture farm near Corvallis, Oregon. The test was part of an ongoing effort to evaluate various techniques for controlling moss in turf. BACKGROUND INFORMATION In spite of the fact that moss has long been a significant problem in turf culture, surprisingly little information about lawn mosses is available. Few people can accurately identify moss and references in the literature tend to be rather vague regarding which moss species are most common in turf. Worldwide there are less than a dozen mosses that repeatedly receive mention as being turf weeds (4) (Table 1). Of those mentioned Rhytidiadelphus triquetrus and related species appear to be most important in turf in British Columbia, Washington, and Oregon (3). Brachythecium albicans was identified as a frequent component of mossy lawns in Corvallis, Oregon by Chapman and Sanborn in 1941 (1). Table 1. Reported lawn moss species. Rhytidiadelphus triquetrus, squarrosus, others Brachythecium albicans Polytrichum juniperinum Hypnum sp. Rhytidium rugosum Calliergonella cuspidata Rhodobryum roseum Bryum rubens Pottia davalliana Unlike seed plants, mosses produce spores which germinate to form a threadlike structure called a protonema (Figure 1). The protonema is very tiny and closely resembles a green alga initially. Eventually buds form on the protonema and develop into the gametophyte which we typically see as moss (Figure 2). The gametophyte gives rise to the sporophyte which is composed of a stalk and capsule. The capsule contains many spores which help to further spread the moss. It appears that common species of lawn moss are not dependent on spores for propagation since small fragments of the gametophyte can spread vegetatively. In fact, vegetative propagation may be the primary source of invading moss as lawn mosses rarely produce the sporophyte stage under turf conditions. Fig. Fig. 2 1 A young moss plant. Moss gametophyte Fig. 3 Gametophyte and Sporophyte Stages The persistent and recurring nature of lawn mosses may be due to the fact that these plants can tolerate long periods of drought in a dehydrated condition. What appear to be dead brown moss will often quickly rehydrate and resume growth with the onset of fall rains. Moss invasion into lawns occurs generally when there is a lack of competition by the turf. This is commonly associated with acidic, infertile soils, shade, excess water, and turf injury due to disease or chemical damage. Moss growth normally starts in the fall and continues through the rainy period reaching a peak in spring. Moss growth declines with the onset of summer which coincides with increased growth of desirable turfgrasses. Under shady conditions when turf is irrigated, moss may persist in vigorous condition through the summer months as well. In western parts of the PNW, moss often grows vigorously during winter in lawns that are dense and well fertilized. This may happen because the moss grows better at lower temperatures than the turf although we are not aware of any studies that address this possibility. CHEMICAL CONTROL OF MOSS Our literature search indicated numerous materials suggested for moss control in turf (Table 2). Compounds containing heavy metals have been widely used to kill moss. These chemicals generally show contact activity with limited movement within the plant and no residual soil activity. The one exception appears to be mercury which is slow to act initially but does appear to prevent spore germination for a relatively long period (2). The other chemicals in Table 2 have often been listed as controlling moss but little is known about their mode of action. Table 2. Reported moss control chemicals. Ferric sulfate Ferrous sulfate Ferrous ammonium sulfate Copper sulfate Zinc sulfate Mercury compounds Ammonium sulfate Lime Hydrated lime Pentachlorophenol Chloroxuron X-77 spray adjuvant In the test reported here we used several iron compounds along with lime, ammonium sulfate, copper sulfate, and zinc sulfate. Treatments and application rates are listed in Table 3. All materials were applied in dry form except for the ferric sulfate treatments which were applied in liquid form. The test area was a perennial ryegrass turf under low fertility, maintained at a low mowing height. Summer shade from nearby trees and shrubs created a good environment for moss to grow. The test was set up as a randomized complete block design with three replicates. Individual plots were 4 x 8 feet. Treatments were applied April 5, 1984, and plots rated visually through that month. Results reported here reflect observations made during that time. Table 3. Chemical treatments and rates. Treatment Rate/1000 ft2 Ferric sulfate Ferric sulfate 20-3-5 + Fe 20-4-6 + Fe 12-3-6 + Fe Agricultural lime 21-0-0-24 MICROCOP (CuS04) ZnS04 1.25 lb Fe .60 lb Fe .63 lb Fe .60 lb Fe .83 lb Fe 50.00 lb lime 1.50 lb N .34 lb Cu 1.80 lb Zn Moss control ratings are presented in Table 4. Best overall control was observed with liquid ferric sulfate at both full and half rates, and the 12-3-6 fertilizer plus iron. Fair moss control was observed with two experimental fertilizer plus iron materials, 20—3—5 +Fe and 2 0 - 4 - 6 +Fe. The zinc sulfate material gave reasonably good moss control but caused unacceptable injury to the turf. Ammonium sulfate, copper sulfate (microcop), and agricultural lime had no significant impact on moss in this test. Table 4. Percentage of live moss remaining in plots one, two, and three weeks after treatment. Live moss, % of plot Treatment 4/5 4/12 4/19 4/26 Ferric sulfate 1X Ferric sulfate 1/2X 20-3-5 + Fe 20-4-6 + Fe 12-3-6 + Fe Agricultural lime 21-0-0-24 MICROCOP ZnS04 28 32 37 35 37 32 50 28 47 2 0 15 13 0 32 45 22 17 0 0 10 8 0 32 42 22 8 0 0 8 5 0 32 35 20 8 The key to moss control with iron products appears to be thorough coverage of moss foliage with the material being applied. The liquid materials and the dusty fertilizer plus iron material were very effective in providing thorough coverage and thus control of the moss. Further tests are warranted to determine the lowest effective rate of liquid ferric sulfate that provides acceptable moss control. ACKNOWLEDGENTS We would like to thank the students in Hort 417 who helped set up and carry out this test as part of a class project. Also, thanks to the Chas. Lilly Company in Portland, Oregon for supplying many of the products used in this test. References 1. Chapman, C. J. and E. I. Sanborn. 1941. Moss flora of the Willamette Valley Oregon. Oregon State Monographs Studies in Botany. 4:1-72. 2. Escritt, J. R. 1978. ABC of turf culture. Kay and Ward Ltd., London, pp. 147-152. 3. Schofield, W. B. Some common mosses of British Columbia. Handbook 28 of the British Columbia Provincial Museum. Victoria, B.C. 4. Smith, A. J. E. 1978. The moss flora of Britain and Ireland. Cambridge University Press, pp. 664—669. NITROGEN SOURCE, RATE, AND TIME OF APPLICATION ON BLUEGRASS/ RYEGRASS PERFORMANCE1 William J. Johnston2 1 Presented at the 38th Northwest Turfgrass Conference, Sheraton Hotel, Spokane, WA, September 18-20, 1984. 2 Assistant Professor and Assistant Agronomist, Washington State University, Pullman, WA. In the past several years, there has been a dramatic increase in the use of turftype perennial ryegrass both in monoculture and in mixed stands. The use of perennial ryegrass with Kentucky bluegrass, especially for athletic turf, or other heavily trafficked areas, has been a very successful management tool. This use of perennial ryegrass with Kentucky bluegrass has come about because many of the new improved turftype ryegrasses are very compatible in appearance to Kentucky bluegrass. The newer ryegrasses have finer leaves, greater density, somewhat better mowing qualities, persist longer, and have very good wear tolerance compared to the older perennial ryegrasses. It is their excellent wear tolerance that enhances their desirability in a bluegrass/ryegrass turf. To better learn how to manage a bluegrass/ryegrass turf, this study was undertaken. The purpose was to determine the effect of turfgrass growth and quality of nitrogen sources, rates of application, and time of application. In April 1982, a 6400 ft2 area was seeded at 3 lb per 1000 ft2 with a 60:40 mix by weight of Kentucky bluegrass (Victa and Bristol) and perennial ryegrass (Derby and Loretta). The area was fertilized with 1/2 lb N per 1000 ft2 in May and 1 lb N per 1000 ft2 in early June 1982. Fertility treatments and programs for application (Tables 1 and 2) were initiated in late June. Individual plot size was 7 x 13 feet. All plots were mowed (approximately once per week) at 1.5 inches. Plots were watered as needed to maintain acceptable turfgrass growth and appearance. The experimental design was a randomized complete block wTith three replications. Table 1. Nitrogen sources. Fertilizer Methylene urea IBDU Sulfur coated urea Ammonium sulfate Complete Formula B* Complete Formula C** Ammonium nitrate Check Analysis Program no. 40-0-0 31-0-0 38-0-0 21-0-0 34-3-7 21-3-5 33-0-0 1,2,3 1,2,3 1,2,3 1,2,3,4,5 1,2,3 1,2,3 5 * Scotts Super Fairway ** Best Turf Gold Table 2. Fertilizer programs for time and rate of application. 1 2 1.8 0.7 0.7 0.7 0.45 0.45 0.7 1.8 Program No. 3 4 5* (lb N/1000 ft2) April May June July August September October November Totals 0.9 0.5 1.0 1.4 1.0 2.0 3.65 3.65 2.3 3.0 1.5 * Program 5 initiated in 1983. The plots were evaluated for turfgrass parameters quality, color, density, species composition, and root weight. Soil tests were taken in 1983. A list of the parameters observed in the test and the number of times each observation was taken per year are given in Table 3. Table 3. Turfgrass parameter and number of times each was recorded. Data taken Quality Color Density Species composition Root weights Soil tests 1982 1983 1984* 5 5 1 9 9 4 6 6 3 1 1 - * 1984 as of September 1984 - 1 1 Before we look at the effects of nitrogen source on turfgrass quality, let's observe the importance of the programs, that is, the time of application and rate of nitrogen application when results are averaged over all nitrogen sources. These results are presented in Tables 4, 5, 6 and 7. Table 4. Turfgrass quality as affected by program. Program no. 1 2 3 4 5 1982 1983 1984 Mean 7.0 7.4 7.1 7.7 6.2 6.8 6.1 6.9 5.8 6.0 5.0 5.6 3.8 2.5 6.3 6.7 6.1 6.7 3.8 4.1 — Check 5.9 — 4.0 Quality 1-9; 9 = excellent Table 5. Turfgrass color as affected by program Program no. 1 2 3 4 5 1982 1983 1984 Mean 6.8 7.4 6.8 7.9 6.4 7.0 6.3 6.9 5.5 5.8 5.1 5.5 4.0 3.7 6.2 6.7 6.1 6.8 4.0 4.4 — Check 5.6 — 3.9 Color 1-9; = acceptable dark green color. Table 6. Turfgrass density as affected by program. Program no. 1 2 3 4 5 Check 1982 66 77 70 84 - 43 1983 1984 (grams dry weight) 76 88 84 89 69 72 92 88 33 35 23 Mean 77 83 70 88 33 34 Density is the clipping dry weight harvested between a bench setting of 1-5/8 inch and 1 inch. T Table 7. Root weight as affected by program. Program no. Check 1982 1983 1984* (grams dry weight) Mean 1.0 0.7 1.0 1.0 0.9 0.8 1.05 1.05 0.95 0.75 1.0 0.8 0.9 1 1.1** 2 3 4 5 1.1 • 1984 data not yet taken at time of this report. • * Dry weight of five, 10 x 2 cm cores per plot. When averaged over all nitrogen sources, programs 2 and 4 gave the best turf ratings for quality, color, and density. There was little effect of program on root weight. In program 2, nitrogen was applied 4 times per year (April, June, August, and October) with the bulk of the nitrogen being applied in the fall (see Table 2). In program 4, plots received a total of 3 lb N per 1000 ft2; however, all of the nitrogen was applied in the fall during September and November. It would appear that fall applications of nitrogen are very important to obtain a high quality bluegrass/ryegrass turf in eastern Washington. Tiller counts made in the late fall of 1982 (Table 8) indicated that program 2 for complete formula C, methylene urea, and possibly IBDU gave the greatest number of Kentucky bluegrass tillers (data for interactions not presented). No fertilizer or program increased the number of ryegrass tillers above that of the check; however, methylene urea in program 1 did show reduced amounts of ryegrass as compared to the check. Methylene urea in program 1 was also the only treatment that was significantly different from the check in total tiller number (bluegrass + ryegrass). It reduced tiller number. Table 8. Program number 1 2 3 4 Check Species composition as affected by program and nitrogen source. Percent Percent Nitrogen Total bluegrass bluegrass source tillers 21 17 Methylene urea 235* 22 22 IBDU 291 16 262 17 SCU 14 Ammonium sulfate 15 249 Complete formula B** 15 246 10 23 Complete formula C * * * Check 10 * Shoot counts made November 12, 1982. ** Scotts Super Fairway * * * Best Turf Gold The bluegrass:ryegrass ratio indicated that methylene urea in programs 1 and 2, IBDU in program 2, and complete formula C in program 2 all had more bluegrass in the turf than the check. All treatments except ammonium sulfate in program 2 were numerically greater in the bluegrassrryegrass ratio than the check. All programs for IBDU and complete formula C had ratios greater than 0.20 (check was 0.11). Since the initial ratio was approximately 10.0 (assuming 100. germination and emergence), the low ratios observed illustrate dramatically the potential domination of a bluegrass/ryegrass turf by perennial ryegrass. The effect of the various fertilizers and programs to alter this ratio over time needs to be studied. Shoot counts made in 1984, but not presented here, will help to answer this question. Soil test results are given in Table 9. These tests indicate that there was essentially no difference among either programs or nitrogen sources in their effect on soil pH. Soil tests also indicated adequate levels of phosphorus and potassium. This is fairly common for the soils of eastern Washington and is the reason no phosphorus or potassium response was observed in the two complete analysis products used in this test. Table 9. Soil pH as affected by program and nitrogen source. Program number Soil pH Nitrogen source Soil pH 1 6.2 6.2 6.2 5.9 Methylene urea IBDU SCU Ammonium sulfate Complete formula B * Complete formula C Check 6.3 6.3 6.2 5.9 6.2 6.1 6.1 2 3 4 5 Check 6.1 Soil test taken November 14, 1983 * Scotts Super Fairway ** Best Turf Gold As an indicator of overall turfgrass performance, the results of the individual ratings for turfgrass quality, turfgrass color, and turfgrass density were pooled. The best performing nitrogen source—program combinations are presented in Table 10. The best performing nitrogen sources were ammonium sulfate, sulfur coated urea, and complete formula C. The success of these products indicates the enhanced performance of a bluegrass/ryegrass turf when sulfur is a part of the fertility program in eastern Washington. Table 10. Nitrogen source-program combinations giving the best overall turfgrass performance at Pullman, Washington during 1982-1984. Nitrogen source Program number Ammonium sulfate Sulfur coated urea Sulfur coated urea Complete formula C* Ammonium sulfate Ammonium sulfate Ammonium sulfate 2 1 2 2 4 1 3 * Best Turf Gold Numerous applications of nitrogen, or as it is sometimes called, "spoon feeding", in general produced turf of the highest overall performance regardless of whether the nitrogen source was from ammonium sulfate, sulfur coated urea, or complete formula C (Best Turf Gold). The use of ammonium sulfate as a fall only application of nitrogen did produce excellent results. Also, very good performance was produced with a spring and fall application of ammonium sulfate (ammonium sulfate in program 3) where the bulk of the nitrogen was fall applied. These tests indicate the importance of fall applications of nitrogen and the additional need for sulfur in eastern Washington. TURFGRASS RESPONSE TO NEW SLOW RELEASE N SOURCES1 S. E. Brauen, R. L. Goss and J. Nus2 Presented at the 38th Northwest Turfgrass Conference, Sheraton Hotel, Spokane, WA, September 18-20, 1984. 2 Associate Agronomist, Extension Agronomist and Research Associate, Western Washington Research and Extension Center (WSU), Puyallup, WA. 1 The turfgrass industry is constantly concerned with identifying new nitrogen sources that promote turfgrass growth, provide efficient use of nitrogen at economic levels without undesirable pollution of the environment. Field assessment studies are commonly a part of the evaluation techniques used to assess turfgrass growth and quality. Currently a number of new nitrogen-containing materials have appeared from research and development. Some are being evaluated at Puyallup on bentgrass putting green turf and compared to standard N sources. These studies were begun in the early summer of 1983 to study the effects of oximide and melamine on growth rate, color and quality of putting turf. The experimental area consisted of Highland bentgrass putting turf established on a Puyallup fine sandy loam soil. A replicated completely randomized design with plots 5 ft x 10 ft were used. Phosphorus at 2 lb P 2 0 5 per 1000 ft2 and potassium at 6 lb K 2 0 per 1000 ft2 were applied annually in split applications in the spring and fall. Total nitrogen application was applied at 6 lb of N per 1000 ft2 annually applied at 2 lb N rates in April, July and October or 3 lb N rates in April and October. Granular applications of oximide and IBDU were hand applied to plot areas. Plots were rated monthly for color, turf quality and turfgrass phytotoxicity. Oximide contains about 31% nitrogen. Like urea formaldehyde (UF) and isobuytylidene diurea (IBDU), oximide's release is controlled primarily by low solubility in water. Oximide, a diamine of oxyalic acid, has the solubility of approximately four times that of IBDU and the release rate is strongly influenced by particle hardness and size. Cleavage of the carbon to carbon bond by microbial action results in the formation of ammonium carbonate that can result in ammonia-N volatilization losses. Melamine is a triamino-triazine product which contains 66.6% nitrogen. Soil-water content, organic matter level and previous treatment with melamine may all alter the rate of nitrogen availability. Primary nitro- gen release is by microbial degredation into plant available forms although some melamine may be taken up by the plant and metabolize the melamine in the leaf blade. The initial nitrogen treatments with melamine were carried out with a product containing 75% nitrogen from melamine source and 25% from urea (60-0-0). Beginning in April 1984, melamine alone and melamine urea combinations were applied as melamine powder suspensions and urea solutions. The color ratings graphically shown in Figures 1 and 2 closely illustrate the effect of these nitrogen carriers on general turfgrass quality. Applications of granular melamine 75%/urea 25% formulations in mid-1983 caused some depression in turf quality at the 3 lb N rate as compared to the 2 lb N rate (data not shown). Application of the same material in October 1983 improved turfgrass color as compared to untreated plots; however, turf quality was in the marginally acceptable range (5.5). Turf quality was very poor during the winter months of 1983-84 after October application. Application of melamine 75% and urea 25% as fine melamine suspensions and urea solution in mid-April increased the quality of turfgrass putting turf in May and June, but was followed by a depression in turfgrass color and turfgrass quality by early July. Repeat applications of the melamine 75%/urea 25% solution improved turf quality following applications in July and October but quality declined again in September. Melamine 50%/urea 50% solutions were begun in April 1984. The effect of this combination was to raise the average turf quality of the plots with improved turf color and turf quality following the April, July and October applications as compared to the melamine 75%/urea 25% solutions applied. Melamine applied alone without urea and applied as a fine suspension did not cause a phytotoxic reaction to the putting turf in 1984, but it did not improve the turf color and quality as compared to unfertilized plots. These data suggest melamine is very, very slowly released following application. Treatment of turf with melamine at 1.5 lb N per 1000 ft2 in the fall was insufficient to retain good turfgrass color throughout the winter months of 1983-84. Similarly, melamine degredation and N availability appeared insufficient to retain turfgrass color during extended periods during summer which is suggested by the turfgrass color and turf quality response associated with reapplications of melamine 75/urea 25% product applied in April, July and October. Fertilizer applied in coarse granular form that contained high (75%) melamine-N levels produced phytotoxic effects on bentgrass turf in 1983. However, suspended melamine applications up to 6 lb N per 1000 ft2 failed to produce bentgrass phytotoxicity in 1984. Thus, fine granular fertilizers containing less than 25% melamine and applied at less than 1 lb N per 1000 ft2 could likely be used safely even on fine quality turf. £ CO Q CO Z cc fe z o *U - J OQ cc UJ s UJ fe QC O