' TURF CULTURE V A Bulletin from UNITED STATES GOLF ASSOCIATION EXECUTIVE OFFICES •• 73 East 57tH Street •• NEW YORK CITY vot !,«<>. 4 TURF CULTURE July, 1936 Issued by the UNITED STATES GOLF ASSOCIATION GREEN SECTION P. O. Box 73, Benjamin Franklin Station, Washington, D. C. Frank M. Hardt, Chairman of Green Section Committee Dr. John Monteith, Jr., in Charge of Washington Office United States Golf Association Executive Office, 73 East 57th St., New York, N. Y. APPLYING CORROSIVE SUBLIMATE AND CALOMEL TO TURF In the interval of ten years since the Green Section first developed the method of controlling turf diseases with corrosive sublimate and calomel, these chemicals have become the most used fungicides on tuif. In that interval various methods of application have been tested and a tew of the better have been recommended. To be rated satisfactory, a method for applying chem­ icals to turf must provide for even distribution, rapid and economical use, as little interference as possible with play, and, above all, minimum danger to those who handle them. The fungicides commonly used against turf diseases all contain mercury and are therefore dangerous. Gor- rosive sublimate is one of them with well-known deadly possibilities if carelessly handled. Certain methods of application, particularly the dusting method, which seemed to present unnecessary hazards to workmen were from the first discouraged by the Green Section. In spite of the fact that hundreds of thousands of applications of these extremely poisonous chemicals have been made on turf during the past ten years, we have yet to learn of a serious injury by them to any member of a greenkeeping staff. However, there have been some recent reports of poisoning cases which, although fortunately not serious, have nevertheless served to focus attention on the possibility of serious consequences of careless or improper methods of using these chemicals. The recent reports of poisoning have resulted from a modified dusting method. The breathing of fine dust of these poisons is to be avoided and any method that unnecessarily exposes workmen to mercury dust must be strongly condemned. Mercury poisoning is accum­ ulative in the human system and therefore may be slow in its action. With ordinary care these mercury compounds may be used without danger. The best methods for applying corrosive sublimate and other fungicides were described in detail in The Bulletin’ of the United States Golf Association Green Section, Vol. 12, pp. 125-132. One of the methods there described is that of applying the chemical mixed in small quantities of sand or compost. This method has been gaining in popularity in recent years. One of the principal objections to the latter method is that the chemicals tend to form lumps in the pack­ ages and considerable care is required in breaking them. Unless all lumps are reduced to powder there cannot be an even distribution of the chemical. A method used at Arlington to remove these lumps ef­ fectively was described in the Bulletin referred to above. During the past two years an improvement has been made in this method. It provides for a much more nearly uniform distribution of the compound through the sand or compost carrier, saves time in preparation and greatly reduces the poison dust hazard. This improved method consists of putting the cor­ rosive sublimate into solution instead of breaking the lumps. The concentrated solution is then mixed through the sand or compost carrier, thereby coating each particle with a film of poisoned solution. This eliminates the dust of the old mixing method and prevents the escape of poisoned dust during application. The pro­ cedure is as follows: Preparing stock solution: Put two pounds of cor­ rosive sublimate and one pound of table salt in a gallon bottle and fill with water. This may be shaken until the chemicals are dissolved or it can simply be allowed to stand for an hour or more until the corrosive sub­ limate is in solution. The salt is included as an aid to dissolving the corrosive sublimate. Spread 64 quarts of dry, finely-sifted sand (finishing sand) in a thin layer on a cement floor or in a mortar box. Put the above gallon of solution in a watering can and sprinkle over the sand. Then with a circular motion stir the mixture with a rake until it is well mixed, which' will be clearly indicated by the darkening due to the added water. Larger quantities can be mixed in the same propor­ tions, using earthenware or wooden containers for pre­ paring the solution and for storing the poisoned sand. This mixture may be prepared on a rainy day or on other occasions when work is slack, and set aside to use as needed. It will not deteriorate noticeably even when left standing for several months. Each quart of the above sand contains i/2 ounce of corrosive sublimate. If one wishes to treat a green of 5,000 square feet at a rate of 1 ounce to 1,000 square feet, he simply takes from the reserve stock a 10-quart bucket of the poisoned material and broadcasts it over the green. If the 10 quarts are considered insufficient for even coverage by the man who is assigned to the task, it is a simple matter to mix it with sufficient additional sand or fine compost to assure good coverage; or if preferred, the original quantity of sand in the stock mixture can be increased to meet the particular re­ quirements of the distributor. Mixtures of calomel with corrosive sublimate mav be prepared in the same manner. The calomel will not go into solution but will remain in suspension. The mixture should be well shaken or stirred to make a milky- fluid before adding it to the sand. Much larger quantities of calomel than of corrosive sublimate may be added to the water, thereby providing a means for increasing the strength of the sand mixture if desired. The amount of corrosive sublimate should not greatly exceed 2 pounds to a gallon of water, especially if there arc lumps or large crystals which will not dissolve in more concentrated solutions. Any excess of corrosive sublimate which fails to dissolve but which remains in the bottom of the bottle as a fine sediment will mix through the sand and be just as effective as when in solution, provided it is well shaken or stirred before pouring on the sand. The advantages claimed for the sand or compost method of application are that no expensive equipment is required for applying it, less time is used than with some methods of liquid application, there is no need of spraying or other equipment and hose to interfere with play, distribution may be made by the simple process of hand broadcasting or by means of various seed and fertilizer distributors. One of the principal disadvantages of the method has been the time required to break up lumpy material and get even distribution through the sand or other material used as carrier. The preparation of the stock solutions as above described completely eliminates the difficulty experienced in mixing lumpy corrosive sublimate. It also practically eliminates the breathing of dust of this poison during the process of mixing and spreading. During the short time required in handling the dry powder for weighing and placing it in the containers for solution, the workman can be further guarded by using a suitable mask or simply by tying a moist towel across the nose and the mouth. This precaution should be taken in handling any of the mercury fungicides and arsenate of lead as well. In using the above method it is important to have on hand a good supply of dry, fine sand to be used in mixing. If the mixture proves to be too moist to distribute well, a larger quantity of dry sand may be used or the mixture may be permitted to dry out until the right consistency is reached. The effectiveness of the chemical will not be changed by such drying. The mixture may be kept moist in storage by covering the container tightly or by the occasional covering with wet burlap. The preparation of stock solutions as above described will be found to offer many advantages in applying these fungicides with the liquid method also. CONTROLLIN WEB WORMS This is the season of the year when webworms usual­ ly injure turf most seriously. Because of the drought conditions in the Central West, it may be expected that these pests will congregate in putting greens due to the parched condition of the grasses in fairways and rough. The webworms prefer succulent grass, which they eat off very close to the soil level. In dense velvet bent turf it is not unusual to find the grass blades eaten off at the bottom and still standing to shrivel and form the characteristic brown lines over the silk- lined tunnels. The webworms’ work in such turf closely resembles that of the clothes moth in plush, and in both cases the caterpillars (larvae) do the damage rather than the moths. The turf is usually injured by birds searching for the worms. A rather complete description of the life of the web­ worms has been published in The Bulletin of the United States Golf Association Green Section, Vol. 10, p. 115, Vol. 12, p. 14, and in the latter volume is sum­ marized the efficiency of various control treatments. The life cycle of the webworm begins with the eggs dropped promiscuously on turf by the moths at night. These soon hatch into naked caterpillars. They grow rapidly and construct tunnels of silk covered with bits of grass or soil in which they feed. As they reach mature size, about one inch, they burrow into the soil and go into the chrysalid or pupa stage, from which they emerge as grayish white moths. The moths rest with the head down and with wings folded close to the body. In one important species there are three more or less distinct broods during the year. The webworms prefer to feed in turf which is dense or tall enough to offer a hiding place, and are most active at night or when the sky is overcast during the day. If conditions are suitable, the larvae reach maturity in two or three weeks, which means that if injury is to be prevented the measures for control should be applied as soon as their presence is noticed. The control measures fall into two groups: contact poisons and stomach poisons. Among contact poisons are kerosene emulsion and extracts of pyrethrum, derris and rotenone, applied with a sprinkling can or barrel cart. The most effective stomach poison seems to be arsenate of lead, either in a spray or a dust. The kerosene emulsion method is not recommended for putting greens because of the likelihood of injuring the grass. The pyrethrum, derris and rotenone materials are not injurious to the grass when applied at a dilution of 1 - 400, which has been found effective. The rate of application should be approximately 100 gallons to 1,000 square feet. The larvae are brought to the surface by these materials in much the same way as earth­ worms treated with corrosive sublimate. The disad­ vantage of the contact method is the cost of the extracts, which may amount to $4.00 for 1,000 square feet. The stomach poison, arsenate of lead, has been found to give good control applied as a spray at the rate of 1J/2 or 2 pounds in approximately 5 gallons of water to 1,000 square feet. It is important that the spray be directed downward in order to coat the base of the leaves and stems with the poison. One of the dusting methods consists of applying a mixture of 2 pounds of the arsenate of lead with 4 to 6 quarts of dry, finely-screened sand to each 1,000 square feet. The application is made either by hand or with a wheelbarrow spreader. The poison is carried down by the weight of the sand particles and dusts off enough to coat the leaves lightly. The turf is dis­ colored less when the poison is applied in this way and no expensive equipment is needed. The arsenate of lead treatments should be applied when clear weather is predicted. Greens should be well watered before the poison is applied and further watering should be suspended so that the poison may remain on the leaves where the grubs are feeding during one or two nights. From the economy point of view the arsenate of lead spray or sand methods are the most practical since the applications for webworms probably carry sufficient poison to control earthworms and grubs as well. It must be remembered that arsenate of lead is a dangerous poison which is slowly eliminated from the body. The greenkeeper’s staff should be protected from the dust or spray as much as possible by covering the nose and the mouth with a towel or a mask during any work involving this compound. COPPER FU NGICIDES During the last two or three years there has been some renewed interest in the use of copper fungicides for the control of turf diseases. It therefore seems well to again warn against the use on turf of chemicals containing copper. It is well known that the copper fun­ gicides will effectively control brownpatch. As a matter of fact, the first chemical control of brownpatch was with copper compounds. We quote from The Bulletin of the United States Golf Association Green Section, Vol. 12, pp. 119, 120, as follows: “Experiments with Bordeaux mixture and other copper compounds led to injuries which were far worse than the disease they were intended to cure. This injury was copper poisoning, resulting from the accumulation of copper in the soil; it is likely to develop more rapidly in some soils than in others. Some of the golf courses which had used Bordeaux mixture for several years were forced to rebuild some of their putting greens to eliminate the soil containing copper.” On page 120 of that number of The Bulletin is pub­ lished a picture of turf injury due to copper poisoning. There is no test which can be made of soil to in­ dicate where copper is likely to be poisonous and where it may prove harmless to grass. Therefore, the only way to determine this point is by trial. This trial method is on a par with the method of testing whether a mushroom is a poisonous or an edible species. One simply eats the mushroom, and if it kills him it is a poisonous variety and if it causes no harm it is an edible variety. Those who insist on using this method on their putting greens may in a few years have to pay dearly for the experiment. Some of the copper compounds now offered for sale to golf clubs are not Bordeaux mixture. However, the Green Section experimental tests at Arlington in­ cluded forms of copper other than Bordeaux mixture. The results clearly indicated that the question of toxicity was one of how much copper was used and not one of chemical combination. Therefore, we warn clubs against any extensive use of copper compounds on turf, regardless of the lure of a somewhat reduced cost in controlling disease. It is far better to let attacks of the disease go untreated than to risk per­ manent injury from copper poisoning. A MODERATE CROP OF KENTUCKY BLUEGRASS SEED IS REPORTED Dry weather this season through the Middle West has affected the growth of Kentucky bluegrass not only in fairways but also on farms from which Ken­ tucky bluegrass seed is obtained. According to the estimates of the Bureau of Agricultural Economics of the U. S. Department of Agriculture, the crop of Ken­ tucky bluegrass seed this year is expected to be about half of that produced in 1935. This summer’s drought will undoubtedly result in the killing of large amounts of Kentucky bluegrass on farms as well in lawns, parks and on golf courses. Therefore, there is likely to be an increased demand for Kentucky bluegrass seed for reseeding purposes during the late summer and early fall of this year. The increased demands coupled with a smaller crop have already materially affected the price of Kentucky blue­ grass seed and are likely to result in even higher prices before the season is over. Therefore, golf clubs where, the drought has resulted in any considerable loss of turf should anticipate their needs as far as possible and get their supplies of seed early. The reseeding should be done in late August or early September to take advantage of favorable fall-growing conditions. According to the Department of Agriculture figures, the average annual production of rough cured seed in bushels during the past few years is as follows: Bushels 2,700,000 1,200,000 1,400,000 Year 1935 1936 to average annual product ion is 1,046,000 Bushels 1,400,000 1,300,000 400,000 Year 1932 1933 1934 Ten years’ bushels. The factor mentioned as probably the most important cause for lower yield was the unusually dry weather in May and earl}- June. The stripping of the seed was uninterrupted by rain anywhere this year and the seed was cured quickly under almost ideal conditions, and therefore should be brighter than usual. Unless there is too much light­ weight seed, the germination of the seed in the Western District is expected to average better than last year, which was reported below average for that year. New crop 21-pound seed was being quoted on June 27 by a few dealers at about $18 per 100 pounds, com­ pared with $12 last year, $22.50 in 1934 and $12.50 in 1933 on corresponding dates. A number of the wholesale seedsmen reported that the spring demands, both domestic and export, for Kentucky bluegrass were unusually good, but doubt­ less some of this seed was bought for speculation be­ cause of the relatively low prices. In Kentucky the production of rough cured seed was much below average, one-fifth of the yield in 1935, while in the Western District including Missouri, Iowa, Nebraska, Kansas, Minnesota, Wisconsin and a few other States the yield may be about twice the ten-year ‘average and two-thirds of that in 1935. Some of the data on rough cured seed reported is shown for the two sections as follows: Production in Bushels Western District Year 1921-30 1931 1932 1933 1934 1935 1936 Kentucky 435,000 2,300,000 400,000 600,000 175,000 900,000 175,000 611,000 1,200,000 1,000,000 700,000 225,000 1,800,000 1,200,000 SEASONAL REMINDERS Extra Jobs: July and August are, as a rule, the busiest months for the greenkeeping staffs of northern golf courses. Weather conditions are usually unfavor­ able for growth of turf grasses. Extra work is re­ quired for watering, controlling insects and diseases, and for many other jobs incident to nursing grass through these trying months. Chib officials can greatly help tlie cause of better turf maintenance during these months if they will withhold orders for extra jobs which are not absolutely necessary. Individually these odd jobs may appear insignificant but collectively they may divert altogether too much labor and attention from the main task of greenkeeping. It is far better to simply make record of these additional jobs and let them wait, if possible until the fall months when grass naturally gets along with little coaxing. Reduce Fungicide Rate: During hot, sultry periods it is important to reduce the amount of chemicais used on turf in order to avoid burning. In such periods brownpatch is often active and fungicides are required at frequent intervals to preserve the turf. Rates of application of these fungicides should be reduced, however, to 1/3 or 1/6 the normal rates. Reduced quantities applied frequently are more effective, in controlling disease and are much less likely to injure the grass than arc the infrequent heavier rates. Water Shortage: Drought in certain sections of the country has greatly curtailed the use of water on many golf courses. Even though there has been rain in the affected areas there has not been an appreciable in­ crease in the reserve supplies of water. Therefore it is likely that watering operations will have to be curtailed on some courses during the remainder of the summer. When the water supply is threatened it is well to raise the mowers higher to provide for additional shading of the ground and prevention of excessive evaporation. It is also better to gradually reduce the amount of water that is used than to stop watering op­ erations suddently. Grass that has been watered in ex- cess, as is so often the case on putting greens, will have a shallow root system and is likely to suffer severely if the watering is suddenly stopped. A gradual re­ duction in the amount of water will give an opportunity to the plant to adjust itself slowly to changing condi­ tions and it will be able to recover more rapidly in the fall when rains arc adequate. Poison Ivy: During recent years poison ivy has been neglected along with other weeds on many golf courses. It now has become too generally distributed and troublesome. A comparatively cheap but effective wav of killing this pest is with the use of sodium chlo­ rate. The best time to use this chemical is in August. A method found to be effective is to spray the foliage of poison ivy with a solution of sodium chlorate in the proportion of 1J// pounds of the chemical to 1 gallon of water. The best results arc obtained when the spray is used during a period of hot, sultry weather following a few cloudy days and occasional showers, as occur often in August. Enough of the liquid should be used to thoroughly wet the foliage without causing dripping from the leaves. This spray can be used for killing poison ivy around the trunks of trees provided the material is not applied so heavily that there is a large amount of dripping from the leaves. If there is any excess dripping there may be some injury to the trees. In using sodium chlorate care .should be taken to avoid getting the material on clothing or any other material that will burn. Peat or Muck: On some golf courses there are de­ posits of peat or muck which form excellent material for mixing in topdressing. This material can be more easily and quickly moved during periods of drought than at other seasons. Summer Fertilizing: Turf that is not forced too vigorously with fertilizer during the summer months will present less maintenance difficulties than turf that is over-fertilized. Even though the greens look slightly yellow and starved at this time it is well to withhold much fertilizing for at least another month. Where unusual damage has occurred from disease attacks and other causes, a light application of fertilizer will prove to be a great aid in hastening recovery, if the greens have previously been kept rather undernourished. Algae on Greens: During the summer months, par­ ticularly in moist periods, areas of turf where the grass is rather thin are likely to be covered with a green scum. This scum is produced by a growth of minute plants known as algae. Excessive watering also en­ courages their growth. The growth of algae can be checked by applications of corrosive sublimate at the rate of 1 ounce to 1,000 square feet. In cases where heavy layers of scum have dried out and formed a paper-like crust, it is advisable to go over the affected areas with a hand rake to break up the crust and to then apply a light topdressing. Controlling Algae in Ponds: During July and Au­ gust ponds and other water hazards are often covered with a green scum of algae. This growth is likely to accumulate near the edge of water and as it decays it gives off a strong, unpleasant odor. The growth of algae can be checked in ponds by the use of copper sulphate. The rate of application is 1 pound of copper sulphate to a million gallons of water. In calculating the number of gallons to be treated, take the cubic capacity of the pond and multiply it by 6.25. The copper sulphate is placed in a burlap bag which is dragged through the water until the chemical is all dissolved. Watering greens: Late in summer greens are in­ clined to become thin and somewhat discolored and there is always a tendency to attribute the injury to lack of water. The recovery of many greens is delayed rather than speeded by the use of excessive amounts of water, especially during July and August. Pythium disease: A common cause of injuries to putting greens during extremely hot weather is a fun­ gus known as Pythium. As yet there is no satisfactory fungicide to control this disease. The hot weather of this summer has been favorable for the development of the pythium disease but the damage has been much less than would have been the case had there been an abundance of rainfall along with the excessive heat. Where greens have been watered in great ex­ cess, however, there has been much damage from this fungus. A more judicious use of water is the oniy remedy now known for this disease and under most conditions this remedy proves adequate. Spiking greens: During dry periods such as have prevailed this summer there is likely to be much injury to turf through the drying out of the surface soil in irregular patches. These areas usually occur on the higher portions of the green or on slopes that are more wind-swept than the rest of the green. Ordinary sprinkling will not prove sufficient to help the grass recover from this injury. Spiking with a spike roller or with a fork to enable water to penetrate more rapidly will aid in the recovery of these dry areas. Special hand watering, however, is essential to assure a tho­ rough moistening of the soil to a depth of several inches. After spiking and rolling, these dry areas should be tested by cutting into them with a knife or with some soil sampling device to make sure that there has been sufficient water added to wet the soil to a depth of several inches. Remove Crabgrass Early: The most effective way to reduce next year’s crop of crabgrass is by prevent­ ing the production of seed this season. Crabgrass is an annual plant which produces seed during late sum­ mer and fall. This seed remains in the ground and germinates the next spring. Often the removal of crabgrass from greens is delayed until after it has matured much seed. The weeding operation can be done more rapidly when the plants are small than when they are old enough to produce seed. The scars where the weeds are removed will be smaller if they are taken out while they are young. It is well also to remove crabgrass before it goes to seed at the edges of the green, especially from the mounds from which seed may be easily washed to the putting green. Compost Piles And Soil Beds: Large quantities of weed seed are planted on putting greens through the medium of topdressing. At this season when weeds are producing seed freely it is important to give special attention to compost piles and soil beds to prevent the production of weed seed on or near the source of top­ dressing material.