Green World AN INDUSTRYWIDE PUBLICATION OF THE NEW JERSEY TURFGRASS ASSOCIATION Volume 2, Number 3 Stripe Smut In Turfgrasses Philip M. Halisky and C. Reed Funk Stripe smut is caused by a fungus that infects both annual and perennial grasses. Among the turfgrasses, stripe smut is most commonly found in Ken­ tucky bluegrass and creeping bent- grass. Only rarely is stripe smut found in red fescue or perennial ryegrass. The disease has not been observed in either zoysia or bermudagrass. Symptoms Early in April infected bluegrass plants appear as yellowish tufts of stunted, sick-looking grass. Closer ex­ amination will reveal the presence of grayish stripes in the leaves which later turn black and rupture releasing mil­ lions of smut spores into the soil. Smutted leaves subsequently curl and tear along these stripes resulting in plants that appear tattered or shredded (Figure 1). Such infected plants are readily destroyed by summer heat and drought resulting in visible thinning of the turf in late spring. Furthermore, smut-infected plants are more suscep­ tible to other fungus diseases such as leaf spot and crown rot caused by Helminthosporium vagans. Underground Fungus Although stripe smut is most com­ monly seen in the leaves of infected grasses, all infection takes place under­ neath the soil. Leaves of Merion Kentucky bluegrass shredded into ribbons by the stripe smut fungus. (Photo by Steve Bachelder) No infection takes place through the leaf surfaces. Spores of stripe smut are soil-borne and infection from these spores takes place through axillary buds on the crowns and rhizomes or through the coleoptile, all beneath the soil surface. Once the smut penetrates a grass seedling, the mycelium or fun­ gus threads become established in­ ternally throughout the plant. in newly-planted turf areas stripe smut is usually not conspicuous for several years. However, as the turf matures the incidence of smut builds up precipitously during the third to sixth years, especially in susceptible varieties TABLE 1 Age of turf and no. smutted tillers/sq. ft. 5 yrs. 1957 27 12 157 335 4 yrs. 1966 4 10 14 188 Bluegrass Variety Pennstar Fylking Newport Merion 6 yrs. 1968 33 39 181 582 Bluegrass and Bent grass Hosts Among the bluegrasses those culti- vars that tiller profusely appear to be infected with stripe smut more fre­ quently. These include Merion, New­ port, Windsor, Prato, and Cougar. In contrast, varieties with a rhizomatous habit of growth appear resistant to stripe smut. These include Pennstar, Fylking, Bonnieblue, Adelphi, Park, Sydsport, Sodco, Warrens A-20, War­ rens A-34, NJE P-57, and NJE P-29. The relative resistance and susceptibili­ ty of selected varieties of Kentucky bluegrass to stripe smut are shown in Table 2. Comparison of stripe smut incidence in Kentucky bluegrass varie­ ties at Rutgers University. TABLE 2 Smutted Tillers/sq. ft. Bluegrass Variety Pennstar FyIking Anheuser Dwarf Bonnieblue Belturf Delta Bellevue 11 Windsor 41 Merion 0 0 0 1 2 228 11 September 1972 Among the creeping bentgrasses stripe smut has been reported in Sea­ side, Washington, Evansville, Penn- cross, Pennlu, Arlington C-l, Cohan- sey C-7, Toronto C-15, Congressional C-19, and Old Orchard C-52. Table 1. Reaction of four bluegrass varieties to stripe smut infection show­ ing progressive build-up of disease during three successive years. In bentgrasses stripe smut is important on golf greens in the mid-West and southward to Missouri. Pathogenic Races Although stripe smut occurs in both bluegrasses and bentgrasses, there is no danger of the smut cross-infecting from bluegrass to bentgrass or vice- versa. The reason for this is that the smut races on Poa and those on Agro- stis are different pathogenically and each group is specific for its respective host genus. This pathogenic speciali­ zation prevents the indiscriminate spreading of stripe smut among dif­ ferent genera of turfgrasses as com­ monly found on golf courses. Further­ more, the blending of turfgrass seed to include red fescue or perennial rye­ grass with Kentucky bluegrass also is highly desirable from a standpoint of stripe smut control. Chemical Control Before the advent of systemic fungi­ cides it was virtually impossible to con­ trol stripe smut in turfgrasses. Because the mycelium of stripe smut is estab­ lished internally as systemic infection throughout the grass plant, attempts to control the disease with protectant fun­ gicides generally failed. The control of stripe smut with the systemic fungicide “benomyl” has been well documented in recent years. Subsequent research further indicated that late fall applica­ tions of benomyl were more effective and required less chemical than corre­ sponding spring treatments. The data in Table 3 verify the effectiveness of fall applications of benomyl and indi­ cate the dosages required for various levels of stripe smut control. Not all the systemic fungicides are effective against stripe smut. Many of the systemics that were reported to show some activity against the fungus in preliminary trials failed to control the disease under turf-maintenance conditions. Recent studies have re­ vealed that two experimental pyrimi­ dine compounds (EL-273 and EL- 279) are even superior to benomyl in controlling stripe smut. However, these are not available commercially at the present time. TABLE 3 Effect of a single application (October 30, 1969) of benomyl fun­ gicide on stripe smut incidence in Me- rion Kentucky bluegrass during the following spring (May 18, 1970). Dosages of benomyl1 50-WP 0 3 6 9 12 24 A.I. 0 1.5 3 4.5 6 12 233 78 7 3 1 0 Smutted tillers/sq. ft. 1 Dosages are given as ounces of formulated product (50% wettable powder) and as active ingredient, re­ spectively, per 1,000 sq. ft. of turf. Benomyl is registered for turf usage as Tersan 1991. Why the Fluctuations In Grass Seed Prices Peter S. Loft One of the questions most frequently asked by people in the turfgrass in­ dustry is why are there constant price fluctuations in the cost of grass seed. Basically, there are four influencing factors that cause these fluctuations. 1. Weather at time of harvest which influences yield. 2. Demand caused by economic conditions in the country or by inclement weather conditions, which may adversely affect ex­ isting stands of turfgrasses. 3. The demand in Europe, which causes us to either import or ex­ port large quantities of grass seed. 4. The size of the crop which al­ lows, in some cases, large users to artificially run the prices up by buying a large percentage of a particular seed. Such an example of a small crop that possibly could be influenced would be Red Top which has a rather in­ elastic demand, and is usually in short supply. In late June or early July when most grass seed crops are being harvested, a heavy rain can cause sharp price fluc­ tuations. It is virtually impossible by looking at stands of grass seed, to de­ termine whether or not they will have good or poor yields. Thus the seed market is subject to many rumors all of which may cause fluctuations. An example of economic conditions which influence usage whould be hous­ ing starts. Hot and humid weather such as we have had this year will cause many varieties to succumb to various turf diseases thus necessitating replacement which increases demand. Since establishment of the Common Market no one can ever be sure how much seed will be exported to Europe, because the laws are constantly chang­ ing. A large export order for Germany, say 10 to 15 million pounds of Ken­ tucky bluegrass, can certainly influence the market in this country, where ap­ proximately 50 million pounds are pro­ duced annually. The export market is an uncontrollable factor, thus it is im­ possible to anticipate. When dealing with some of the smaller turfgrass seed crops such as Merion Bluegrass, Poa Trivialis, Sea­ side Bentgrass or Penncross Bentgrass, it makes it tempting for some of the larger users to take very large positions and attempt to manipulate the market, either up or down. Sometimes they are successful, and here again this causes fluctuations in the price of seed that no one can foresee. All in all, buying seed in large quan­ tities is a full-time job and should be left to the professional seedsman. I would advise against anyone, who is not prepared to spend a considerable amount of time considering these fac­ tors, attempting to outguess the seed market. Timely Reminders Dr. Henry W. Indyk Algae in Turf Interest in controlling algae in lawns and other turfgrass areas seems to be greater than ever. Requests for control commonly refer to algae as “a disease covering the soil surface after it de­ stroys the turfgrasses.” Contrary to such opinions, algae is not pathogenic on turfgrasses. Therefore, its control, generally is not effective in better growth of turfgrasses in areas in which it is growing. Algae — characterized by a thin dark green to almost black film grow­ ing on the soil surface, slippery when wet and somewhat leathery when dry — is symptomatic of excessive soil moisture. The wet soil conditions rath­ er than the algael growth account for the poor performance of the turf­ grasses. Therefore, improvement of the growth of the turfgrasses in areas showing an abundance of algae, neces­ sitates correction of the soil moisture problem. The abundant and frequent rainfall experienced this year, has been con­ ducive to the prevalence of algae, par­ ticularly on poorly drained soils. Un­ der such conditions, the only good control is improvement in surface and internal drainage of the soil. Growth of algae should be a prob­ lem only when nature is generous with the rainfall. Man-made soil moisture conditions should not be overlooked as a major contributor. Frequent and ex­ cessive use of the sprinkling system provides ideal soil moisture conditions for growth of algae. Control of algae in such situations can be effectively achieved with proper water manage­ ment. Crabgrass in Late Summer If your turfgrass area is one that is suffering from the “crabgrass explo­ sion” that took place during the hot and moist conditions of early July, it would be wise to schedule it for pre­ emergence treatment next April. Ger­ mination of crabgrass began during the first week of May. An abundance of seedlings remained in a rather anemic and stunted condition during the rela­ tively cool period that extended into late spring and early summer. Growth of these seedlings seemed to explode in early July when soil moisture was plentiful and temperatures in the 90’s. Postemergence control of crabgrass can be effectively achieved with one of the methanearsonates. Best results are obtained when the crabgrass is very actively growing and in an early stage of maturity. In its present stage of maturity, crabgrass control becomes in­ creasingly difficult. Two or more re­ peat treatments will be required at an interval of 7 to 10 days between treat­ ments. In formulating a decision on treatment now, consideration should be given to the stage of maturity of the crabgrass and the time that will be re­ quired for completion of the repeat treatments. Turf Repair Turfgrasses have gone through a difficult summer season and may have suffered in varying degrees. The re­ covery season is now beginning and should be a reminder to “get busy” on the performance of various turfgrass management practices. In order to stimulate a more rapid and complete recovery for a better turf not only this fall but also next year, now is the time to give consideration to: 1. Reseeding of severely thinned or bare areas. 2. Fertilizing. 3. Liming. 4. Dethatching. 5. Selective control of broadleaf weeds. Performance of these practices dur­ ing the late summer-early fall season generally will provide greater results for effort expended than at any other time of the year. Why not take ad­ vantage of the opportunity? Growth Retardants—What Role? R. E. Engel Chemicals that retard plant growth have been arriving on the research scene in increasing numbers. Maleic hydrazide (MH), the first of our mod­ ern collection of growth retardants, was used by this writer in 1949.1 These treatments showed the chem­ ical: (1) had ability to retard growth; increased susceptibility of the (2) grasses to injury in dry weather; and (3) retarded various grass species (but not equally). Also, a few years later, the ability of this chemical to prevent annual bluegrass seedheads was ob­ served.2 In this latter study, MH was considered too injurious for use on bentgrass turf. This chemical has had varied use for restricting growth along roadsides or some hard-to-mow areas and on turf edges as a “chemical trim­ mer.” If conjecture is allowed as to why its use has not become more com­ mon, assorted reasons exist. More recently chlorflurenol (CF 125) has been sold with MH. The latter is used at a lower rate than when it has been used alone. This combina­ tion of MH + CF 125 has been sold for both growth retardation and con­ trol of annual bluegrass seedheads. Its effectiveness for annual bluegrass con­ trol is not clear. When this MH + CF 125 treatment was sprayed across ranges of the Northeast Regional Ken­ tucky bluegrass strain test in the spring of 1970, serious injury occurred on a significant number of these Kentucky bluegrasses. Thus, safety to the turf is a question with this chemical treatment. Also, in the past several years we have experienced an assortment of dis­ tinctly different chemicals that are used experimentally for retardation or con­ trol of turf growth. This is of interest to turf research and anyone who starts theorizing on the subject. One of the most advanced of these is MBR 6033 (Surtan) from 3M Research, which Dr. Duell and I have tested since 1970. While it is my opinion that we are not close to general use of chemicals for growth control, some specialized uses may develop. With new chemi­ cals and the intrinsic interest in the subject, an assortment of new experi­ ences lie ahead. The turf grower should watch these, not with the thought that he will use one of these chemicals next year, but for interest and learning about turf. Knowledge of improved safety to the turf, residue effects, op­ timum growth stage for treatment, weather effects, and reduced costs is needed. All treatments to date have not maintained the neat uniformity created by mowing. Also, we must re­ member that the physiological growth of the grass cannot be stopped totally. A plant that survives must make some measure of growth and continue cer­ tain life functions. 1 Engel, R. E. and G. H. Ahlgren. 1950. Some effects of maleic hydra­ zide on turfgrasses. Agron. J. 42:461- 462. 2 Engel, R. E. and R. J. Aldrich. 1960. Reduction of annual bluegrass in bentgrass turf with chemical. Weeds 8:26-28. Adelphi Kentucky Bluegrass C. R. Funk “Adelphi” Kentucky bluegrass was developed cooperatively by the New Jersey Agricultural Experiment Station of Rutgers University and Robert A. Russell of J. and L. Adikes, Inc., Ja­ maica, New York. NJE P-69 was the experimental designation of this vari­ ety. Adelphi is a moderately low-grow­ ing, leafy, turf-type bluegrass variety with good density and vigor and a me­ dium texture. One of the most distinc­ tive features of the variety is an attrac­ tive, bright, dark green color. Its green color is especially noticeable in early spring before many other bluegrasses become green and again in late fall after most other varieties start to lose color. A pleasing, moderately dark green color is also apparent at only moderate fertility levels. Adelphi has demonstrated good or moderately good resistance to the leaf spot and crown rot disease incited by Helminthosporium vagans, leaf rust caused by Puccinia poae-nemoralis, stripe smut caused by Ustilago strii- formis and Typhula snow mold. It is moderately susceptible to powdery mil­ dew. Turf performance trials at Rutgers and a number of other locations throughout the country indicate that Adelphi should be well suited for qual­ ity lawns, parks and sports turf in regions where Kentucky bluegrass is well adapted. It would appear to be compatible in blends with other darker colored bluegrass varieties and in mix­ tures with fine fescues and the im­ proved, fine-textured, turf-type varie­ ties of perennial ryegrass. Adelphi is an apomictic, first gen­ eration hybrid obtained by crossing “Bellevue” Kentucky bluegrass with “Belturf” Kentucky bluegrass. Cytol­ ogical studies by Dr. Jerry Pepin indi­ cate that Adelphi has approximately 80 chromosomes. It possesses all 56 chromosomes of the Bellevue plant which was used as the mother and ap­ proximately one-half of the 49 chrom­ osomes of the Belturf parent. The Bellevue parent of Adelphi was selected from the second fairway of the Bellevue Country Club near Syra­ cuse, New York by Thomas E. Topp, Superintendent, and Alexander M. Radko, USGA Green Section Agrono­ mist in the summer of 1958. This Bellevue selection had demonstrated good performance and persistance un­ der close-cut fairway conditions. Tests at Rutgers conducted by Ralph Engel and Elwyn Deal had shown the Belle­ vue selection to be essentially equal to Merion in density, texture and leaf spot resistance. In addition, it had excellent resistance to leaf rust and moderate resistance to stripe smut. Perhaps the most outstanding attribute of the Belle­ vue selection is its very attractive color in late winter and early spring. The Bellevue selection has not been re­ leased as a commercial variety because it is only about 60 per cent apomictic and therefore not sufficiently true breeding for commercial use. The Belturf parent of Adelphi was selected from an old management ex­ periment at Beltsville, Maryland by Dr. Felix Juska and Dr. A. A. Hansen of the United States Department of Agriculture. Belturf is a highly apo­ mictic turf-type bluegrass with excel­ lent density and vigor producing an at­ tractive, moderately fine-textured turf with a dark green color. It has excel­ lent resistance to stem rust and mod­ erately good resistance to stripe smut but is moderately susceptible to Hel­ minthosporium leaf spot. Adelphi recombines most of the fa­ vorable characteristics of its two elite parents. From the Bellevue parent, Adelphi inherited its exceptional early spring and late fall color, its good re­ sistance to leaf spot, its moderately good seed production potential and its good resistance to leaf rust. From the Belturf parent, Adelphi obtained its dark green color and leafiness, its re­ sistance to stripe smut and stem rust and its higher degree of apomictic re­ production. From both parents, Adel­ phi received its turf-type growth habit and its moderate tolerance to drought and close mowing. A moderate quantity of seed of Adelphi was harvested in July of 1972 and is being marketed by J. & L. Adikes, Inc., Jonathan Green and Sons, Inc., Northrup, King and Co., Inc., and Vaughan’s Seed Company. Plant patent 3150 has been granted on this variety. Sincere appreciation is expressed to the U.S.G.A. Green Section Research and Education Fund, Inc. for its gen­ erous support of the turfgrass breeding program at Rutgers University. Spring Dead Spot Down Under 1. Spring Dead Spot of Couch Grass (Bermudagrass) Turf in New South Wales. (1971) Jour. Sports Turf Res. Inst. 47:54-59. Single ascospore iso­ lates of Leptosphaeria narmari from couch grass were used on greenhouse cultures and a field planting of the grass species. This produced discolor­ ation of stems, crowns, and roots and essentially a complete kill. Nearby healthy plants were free of the organ­ ism. 2. Control of Spring Dead Spot of Couch Grass Turf in New South Wales. (1971) Jour. Sports Turf Res. Inst. 47: Spring dead spot of couch grass (Cynodon dactylon) turf caused by the fungus Leptosphaeria narmari is controlled by regular applications of either thiram or nabam. To be suc­ cessful, thiram (80% w/w) at 4.3 oz or nabam (30% w/v) at 17 fl oz/ 1,000 sq ft should be applied to turf every 4 weeks from the beginning of the last month of summer until early spring. The fungicides are applied in 30 gal water/1,000 sq ft and then washed in with the same quantity of water. These fungicide treatments have given control in the field for four years. A comparison of temperatures that favor the growth of couch grass and L. narmari showed that spring dead spot will most likely occur when tem­ peratures are between 10 and 20 C. Comments on Abstracts Leptosphaeria is the ascospore stage of a Helminthosporium fungus. The fungal agent of spring dead spot in the U.S.A. has not been determined, al­ though Helminthosporium spiciferum (= Cochliobolus spiciferus) is one fungus commonly isolated. Therefore, at this time it is not certain that the two diseases are identical. Your Editors have not forgotten where we are and who comprise most of our readers. We do find these ab­ stracts on spring dead spot of special interest because they offer some ex­ planation to the mystery of this disease. The degree of application this may have for our turfgrass friends to the South, who grow bermudagrass, will be of interest. Also, these research re­ ports should give support to probing more of our northern disease prob­ lems. For those who ask, “Where is New South Wales?”, the answer is “Australia.” R. E. Engel P. M. Halisky GREEN WORLD EDITORIAL STAFF ROY BOSSOLT .................. Co-Editor EUGENE FIELD ................ Co-Editor DON MARSHALL.... Advertising Mgr. RALPH ENGEL...... Consulting Editor Contributions or inquiries for GREEN WORLD should be addressed to: N. J. Turfgrass Association, P.O. Box 356, Springfield, N. J. 07081 or call (201) 379-1100 A First in Turf! TOP QUALITY SOD UNLIMITED QUANTITIES PALLETIZED DELIVERY Merion - Merion Mixture Fylking - Penncross Bent Kentucky/Fescue MERCER SOD INC. 53 FLOCK ROAD TRENTON, N. J. 08619 (609) 587-3500 MAN-MADE Adelphi KENTUCKY BLUEGRASS U.S. Plant Patent No. 3150 • ADELPHI GROWS NATURALLY to a DEEPER, RICH GREEN COLOR which it maintains throughout the entire growing season! • ADELPHI YIELDS TURF OF EXCELLENT DENSITY due to good rhizome and tiller devel­ opment! . ADELPHI IS LOW GROWING indicating tolerance to close mowing! . ADELPHI EXHIBITS GOOD RE­ SISTANCE TO COMMON DIS­ EASES such as Stripe Smut, Leaf Spot, Typhula Snow Mold, Crown Rot and Leaf Rust! For details contact: J & L ADIKES, Inc. Jamaica, N. Y. 11423 JONATHAN GREEN & SONS Kearny, N. J. 07032 NORTHRUP, KING & CO. Minneapolis, Minn. 55413 VAUGHAN’S SEED CO. Bound Brook, N. J. 08805 Downers Grove, III. 60515 ARBOR ASSOCIATES Tree Movers Telephone 201/263-5220 P.O. Box 182 Caldwell, New Jersey