green World AN INDUSTRYWIDE PUBLICATION OF THE NEW JERSEY TURFGRASS ASSOCIATION Vol. 11 No. 2 Summer ’81 How to Better Control Broadleaf Weeds Safely Research Professor of Turfgrass Ralph E. Engel Management Department of Soils and Crops New Jersey Agricultural Experiment Station Cook College, Rutgers University Amine and ester formulations of 2,4-D are commonly available and are registered for a variety of uses. Both types work well on dandelion, buckhorn, and broadleaved plantain and they control various other broadleaf weeds that are found in turf. Low volatility formulations are available. While they cost considerably more than amines and high volatility esters, they should be used when other sensitive plants or crops are nearby. This is especially true when large areas are treated in the spring when other plants have sensitive new growth. Mecoprop (MCPP) is a propionic form of phenoxy that has come into more common use since the suspension of silvex, a closely related phenoxy. It assists 2,4-D in killing approximately the same variety of weeds as was true for the combination of 2,4-D plus silvex. Compared with 2,4-D it gives poor dandelion control. The most important deficiencies of mecoprop FIGURE 1 Left—Drawing and photomicrograph counterpart sections of a normal Colonial bentgrass root that received no phenoxy treatment. Right—Drawing and photomicrograph counterpart sections of a Colonial bentgrass root that received silvex treatment. Note the abnormal growth habit. (Photo from Lloyd Callahan and Ralph Engel) R O C K L A N D Comments and Opinions Choose Ryegrass Seed Carefully The turf-type ryegrasses, which have been one of the major turfgrass advances of our generation, have encountered considerable abuse in certain segments of the seed trade. Occasionally, growers complain about the coarseness of these grasses. If you were not present on the June 3, 1981 Turf Research Day, you missed a convincing demonstraton of the reason for choosing turfgrass seed carefully. Seed control officials of New Jersey, Maryland, and Pennsylvania had sampled various lots of perennial ryegrass that have been offered for sale and had them planted in replicated turf trials. A number of these seed lots showed either varietal substitution or con­ tamination with annual ryegrass. Great contrasts in texture, density, and leaf extension rate occurred in some of our most attractive turf ryegrasses. While all ryegrasses tend to be tough to cut at times, the common-type ryegrasses, sub­ stituted for improved turf types, are much more difficult to mow. Violation of seed labeling appears to occur frequently with Manhattan ryegrass. Seed of this grass is more expensive to grow and it is still in great demand. This leads to the contamination or substitution that occurs with this grass variety. Manhattan has a nonfluorescing ryegrass seed. If the fluorescence test were used, this would do a lot to correct the problem of impure Manhattan ryegrass sources. This technique can also be used on most other turf-type ryegrasses. Whenever possible, the plant breeder or releasing agency should provide high purity that can be protected in new turf-type ryegrass varieties. Some think the annual ryegrass genes or off-type ryegrasses offer no problem — that they will go away. This may happen on some occasions, but in our Northeast climate, annual ryegrasses can persist for years in some mowed turf areas. Occasional annual plants germinate and develop seedstalks that escape the mower (especially where voids occur or in border areas). This can provide seed for more off-type plants in another year. If you want the best in quality of turf- type ryegrasses, avoid the genes for coarseness that can occur in various lots of ryegrass seed. A demand for pure types of ryegrass will cause a hardship for some seed growers who have contaminated fields. Yet, this is no excuse for introducing off- type ryegrasses on many individual sites in the Northeast. It seems the grower who is willing to pay has the right to all the worthwhile information available on grass seed. If you need the best in quality ryegrass seed or just want assurance of the real thing, purchase certified seed of the desired ryegrass variety from your reputable seed dealer. While these comments focus on ryegrasses, remember the same thing can happen with other turfgrasses. R.E.E. FERTILIZERS COMBINATIONS OF NITROFORM I.B.D.U. S.C.U. And And WITH INSECTICIDES PRE-EMERGENCE CRABGRASS KILLERS HERBICIDES GRANULAR LIQUID SELECTIVE AND TOTAL FUNGICIDES GRANULAR FLOWABLE WETTABLE POWDERS INSECTICIDES GRANULAR LIQUID WETTABLE POWDERS DOES IT ALL Ask your supplier or write: ROCKLAND CHEMICAL CO., INC. Passaic Ave., West Caldwell, N.J. CAREER OPPORTUNITIES Garfield Williamson, Inc. has openings for two sales representatives; one for Wonderlawn Products to retailers, the other for proprietary turfgrasses, etc. to professionals/institutions. Salary commensurate with experience. Reply in con­ fidence to John Zajac, V.P. 1072 West Side Avenue, Jersey City, New Jersey 07302, or 201-435-3500. use compared with silvex are: (1) the need to use twice the amount of mecoprop than silvex, (2) the failure of mecoprop to control certain weeds that were controlled by silvex, and (3) the need to repeat the 2,4-D + mecoprop treatment for a number of broadleaf weeds. The 2,4-D plus mecoprop treatment is safer for trees and shrubs than the 2,4-D plus dicamba treatment. For this reason it is more widely used on home lawns. The phenoxy, dichlorprop (2,4-DP) is used in combination with 2,4-D for purposes similar to the use of mecoprop with 2,4-D. Dichlorprop combined with 2,4-D is considered by some to be more effective for several hard-to-kill weeds than the com­ bination of mecoprop + 2,4-D. The Use of Dicamba — Dicamba (3,6-dichloro-o-anisic acid) is a nonphenoxy herbicide, of the growth regulator type, that is valuable for control of broadleaf weeds. This chemical, which is sold as Banvel-D, is our best herbicide for such weeds as chickweed, knotweed, red sorrel, white clover, and others. It is especially useful for wild onion. Required rates of application are considerably lower than for other turf herbicides. A treatment of 1/4 lb per acre is adequate for many weeds. When combined with 2,4-D at rates of 1/32 to 1/8 lb per acre, the efficiency of the treatment is enhanced. Dicamba may cause serious injury to trees and shrubs unless applied at low rates. Part of the reason is its quick penetration into the soil. There is evidence that 1/2 lb per acre is safe around trees. This is twice or more of the rate normally used on turf. However, if differences in trees and shrubs, the tendency for some plants to root near the surface, and the chance of overdosing are considered, it is best to avoid use of dicamba in such areas. If it is included with 2,4-D on such sites, the rates of application should be minimal. Comments on Control of Broadleaf Turf Weeds — Dandelions are the most common weed of turf. They, along with such weeds as buckhorn and broadleaved plantain, are easily controlled with 2,4-D, as mentioned earlier. When one or more of these weeds are being treated, 2,4-D should be the choice. For most turf areas, 1 1/2 lb per acre of 2,4-D in a spray ap­ plication is sufficient. Where some hard-to-kill weeds are present or the season is unfavorable, and the tur­ fgrasses are tolerant, it is best to use the full rate. Rates of 2,4-D should be somewhat higher when used on a dry carrier than with spray application. One of the keys to efficient control of these weeds is persistent control. Total control of dandelion is difficult because a prolific amount of wind- borne seed is produced. When only a few dandelions are present in a small area, spot treatment of individual Garfield Williamson WHOLESALERS & DISTRIBUTORS Products for the Professional BULK SIZES/SPECIAL MIXES NEWEST VARIETIES Grass Seed Fertilizers Chemicals FINE LEAF PERENNIAL RYE GRASS 1072 West Side Avenue, Jersey City. N.J. 07306 201-435-3500 dandelion plants may be best. This is often quicker and safer than total treatment of a site. Control of Other Weeds with Dandelions Present Frequently other weeds such as chickweed, clover, and knotweed occur with dandelions. These require the addition of mecoprop, dichloroprop, or dicamba. This combination will control additional hard-to-kill broadleaf weeds. Dandelion, Chickweed, Clover, and Knotweed — If trees and shrubs are not present, dicamba plus 2,4-D is the best choice. This combination has the highest efficiency for these weeds. Also, less phenoxy is used and the treatment is safer for the grass than a combination of several phenoxys. With Kentucky bluegrass-type lawns, apply 1 to 1 1/2 lb/A of 2,4-D and 1/4 lb discamba per acre. With bentgrass- annual bluegrass turf, apply 1/2 lb 2,4- D and 1/8 - 1/4 lb dicamba per acre. With these weeds mid-April through early May is the best treatment time. Applications for chickweed, clover, and knotweed control in late spring or summer are not desirable. Dandelions, Buckhorn, Broadleaved Plantain, and Red Sorrel — Lawns with this assortment of weeds usually are sunny and lack vigor as indicated by the presence of red sorrel and buckhorn. An application of 1 to 1 1/2 lb of 2,4-D plus 1/4 lb of dicamba per acre is suggested. Also, proper liming and an increase in fertilization is needed. 2,4-D — Susceptible Weeds and Wild Onion — This combination of weeds may occur in full sun and where trees are present. The 2,4-D plus dicamba combination described above is appropriate for the tree-free areas, but in the shade a combination of 2,4- D + mecoprop with a low rate of dicamba can be used to spot treat rather than a general spray. If spraying the herbicide over the lawn is desirable in shade or tree areas, use the com­ bination of 2,4-D plus mecoprop. This combination will require more retreatment. Clover Control — While clover is tolerated or welcomed in some turf areas, it is frequently unwanted by some because it attracts bees, it provides poor cushion for most sports, it offers a slippery footing, and it yields poor soil cover in winter. It is seldom treated purposely in home lawns, but it is often controlled with herbicides in such areas as athletic fields and golf course fairways. Clover is more abundant where nitrogen use is low. If there is the need to fertilize, the added nitrogen should increase the vigor of the grasses and give adequate clover control for most lawns. In turf areas where good control of clover is desired and no other weeds require attention, an application of 1/4 lb of dicamba per acre usually gives excellent control. In Kentucky bluegrass type turf, late summer or early fall is the best time for clover treatment. Fall treatment produces good clover control on bentgrass-annual bluegrass turf, but spring is a better time for treatment because it causes less encroachment of annual bluegrass. When only clover is present in bentgrass-annual bluegrass (continued on page 5) 1981 Officers of the N.J.T.A. Paul DesChamps President Ralph E. Engel Secretary William Ritchie Treasurer Henry Indyk Expo Chairman Fred M. Eden Past President Executive Board Dennis DeSanctis Joseph DeSantis Sheldon DuBrow Edgar Krause Samuel Leon David McGhee John VanBrunt John Zajac Joseph W. Manning, Jr. One Man’s Experience with Wetting Agents Bruce Williams Bob O’Link Golf Course Wetting agents have been around fine turf a long time and enjoyed some good reception, but a hesitancy about their use remains. When one of the men associated with the packaging and sale of wetting agents came to my office years ago, I was asked for my opinion. Without benefit of research support or literature review, I told him that I believed there were situations where wetting agents would serve a practical purpose in watering “hard to wet areas." I suggested a concentrated research effort to determine turf conditions that would be worthy of this type of treatment. This has been told to other dealers or would-be dealers. Unfortunately, we still lack adequate treated and untreated comparisons. I have always believed, and I have said many times, that wetting agents would help get water through hard-to-wet turf surfaces. We do have a number of experienced golf club course superintendents who are convinced of their value. William Smart is one of the known believers in our region. The following is a review of wetting agents by Bruce Williams of Bob O'Link Golf Course. I believe you will find this first-hand account of interest. We do not know for sure, but we expect that his experience applies to Ralph Engel lawn turf also. During the past two summers, I have attempted to take my successful results with wetting agents on greens and tees another step further and incorporate preventive applications on 35 acres of fairways. Through trial and error, the following have provided optimum results. Choice of Wetting Agents. Three wetting agents gave good results. I happened to prefer one type for results and ease of handling. Similar products are available under different labels. The experts seem to agree on the nonionic forms. You might wish to experiment with various wetting agents for your conditions. Application Techniques. The primary fairway application is made in early to mid-June and a second application should follow in 14 days. A third application in late July or in August may be desirable. With generous rainfall, two applications may prove sufficient. 1. I used the recommended rate of two gallons of a wetting agent in 200 gallons of water over one acre. 2. Wetting agents not watered in are potentially phytotoxic. I prefer early evening application with prompt watering in. 3. All wetting agents were applied alone and not in combination with any other pesticide. 4. We used the boom behind the tractor, which reduces the chance of wheel tracks showing. Effects on the Turf. Comparing wetting agent treated fairways and untreated check plots, I found that the difference was like night and day. Treated fairways had the following qualitites: 1. Dew is eliminated for a six to seven day period following the ap­ plication. 2. Localized dry spots in the wedge- shaped area adjacent to our single row irrigation system required hand watering only once during the 1979 season. Prior years have shown that 80-100 man-hours are needed to ac­ complish this task. Less hand watering means a lower labor cost and freedom to use your staff on other projects. Less hand watering means minimizing or eliminating interference to golfers. Less hand watering also means con­ servation of water and power. 3. Fairways had fewer dry spots and also fewer wet spots. 4. Overall, soil moisture continuity was increased. 5. Soils were able to absorb moisture more rapidly during the month of August when heavy precipitation was recorded. 6. Less stress was evident on treated fairways and wilting was not severe. 7. Prior to fairway applications, it was often difficult for irrigation water to penetrate a one-inch thatch layer unless fairways had been sliced or aerated in the spring. The fairway applications have proven as successful as the wetting agent program on my greens and tees. The approximate cost of materials for one application for 18 greens is $150. Thirty-five acres of fairways would be covered with $700 worth of wetting agent. Given the aforementioned results, I feel that this is a cost which is offset by a savings in water and manpower, providing a better playing surface. SUSTAINING MEMBERS 1981 A-L Serivces Inc. Chemlawn Corp. Chevron Chemical Co. Double Eagle Golf Products Fairway Landscaping Garfield-Williamson, Inc. Green Hill Turf Supply Heritage Maintenance International Seeds, Inc. JEP Sales, Inc. Leon’s Sod Farm A. Lombardi Landscaping Wilfred MacDonald, Inc. Metro Milorganite, Inc. Montco Products/Surf Side James H. Pelrine Rockland Chemical Co. Seacoast Laboratories Storr Tractor Co. Techniturf, Inc. The Terre Co. Vaughan-Jacklin Corp. Andrew Wilson, Inc. Fertilizer Controls Dollar Spot on Ryegrasses Where rye grass tees are mowed at 1/2” and the clippings removed, dollar spot may ocurr. A shot of balanced fertilizer overcomes that problem. The disease may still be there, almost unnoticable, but the new growth seems to overcome it. This is also true around greens where the sprinkle pattern seems to leach away the nutrients. Especially — Bill Lyons nitrogen. Broadleaf Weeds (continued from page 3) turf, the end of April or early May is preferred. With normal spring rains and four to six weeks of good growing weather, the grasses will fill the voids nicely. Treatment in June or later creates bare patches that remain until good growing weather occurs in late summer. As indicated previously, inclusion of dicamba, dicholoroprop, or mecoprop with 2,4-D gives good clover control. In bentgrass turf the rate of dicamba can be as low as 1/8 lb per acre when applied with 2,4-D. Combining mecoprop or dichloroprop with 2,4-D for clover control or other broadleaf weeds gives a high total amount of phenoxys. This is not advised as it causes a serious reduction in the safety margin for bentgrass and annual bluegrass. Some Thoughts on Broadleaf Weed Control with Herbicides — A discovery such as the herbicide 2,4-D, with its selectivity and safety, is a rarity. While it is not perfect, it is likely to be the mainstay of our broadleaf weed control programs for many years. We should learn more about its use and WILD FLOWER MIX The low-maintenance Perennials and annuals beauty treatment for any landscape Pinto - beautiful to look at and easy to maintain. Ideal for parks, roadsides, golf course roughs, industrial sites. that reseed themselves and give you a painted picture of reds, blues, pinks, yellows - year after year. Available either as 100% wild flowers or as a Meadow Mix combined with a fescue to aid soil stabilization. Pinto Wild Flower Mix. .. the natural way to a perma­ nent, beautiful landscape. LOFTS Lofts Pedigreed Seed, Inc. Bound Brook, NJ 08805 (201) 356-8700 For more information call John Morrissey or Marie Pompei at (800) 526-3890 develop more highly sophisticated procedures. One important and complex factor is time of treatment. With dandelions, different opinions exist as to the best time of treatment. Mid- to late April has distinct advantages. More specifically, applications should be made as soon as the dandelion plant has developed good leaf growth. Delay until the plant starts flowering permits seed to develop and enough seed can be scattered to start a new population later in the year or the next season. In contrast, some prefer September and early October treatments. Good kill occurs if cool and moist weather gives vigorous growth. However, dandelions may still germinate in late fall and early spring which may necessitate spring application. The same applies to chickweed. Knotweed is not controlled with fall treatments. While this season gives good clover control, annual bluegrass can be a problem. Another concern with fall treatment is the frequent need for fall over- seedng. Use of 2,4-D complicates seed programs. Where overseeding is an­ ticipated, 2,4-D applications should be made in late August, which will allow time and several rains to reduce 2,4-D injury. In spite of these concerns, it is often advisable to go ahead with fall treatment of dandelions that are causing an ugly problem. Since phenoxys are less effective when plants are growing very slowly or are dor­ mant, time treatments with good growth of the weeds. The knowledge that the phenoxys can hinder root development (see figure) leads to the question of which horse season causes the least injury to the development of the root system. Fall and early winter are the major periods for initiation of root growth of the cool-season grasses. Application of herbicides during these times can cause increased turf failure during en­ vironmental stresses of the following summer. Since most of these grasses appear to attain maximum root development at or just before the peak growth period in spring, it would seem that spring application of phenoxy herbicides might be somewhat less damaging than fall. However, there is no research data that support this view. Until more is known, apply phenoxys when the weeds are growing well and with all other precautions. Plan ahead for broadleaf weed control programs. Check the equip­ ment carefully before starting. Follow label instructions. As turf growers, we have some very useful broadleaf herbicides which can work for you. Groundsmaster 72 The Professional for the big jobs. The Groundsmaster 72* has power to spare from its water cooled, 4 cylinder engine. The 72“ floating cutting deck is offset to handle the bulk of the trimming jobs around trees, along fences, walls and other obsta- cles. One pedal hydrostatic drive for responsive speed selection in forward and reverse. Optional accessories like the rear discharge cutter deck, leaf mulcher, rotary broom and ROPS make this machine a versatile work- TORO Storr Tractor Co. 3191 U.S. Highway 22 Somerville, N.J. 08876 201-722-9830 The Professionals Introducing OFTANOL 5% Granular Insecticide The TERRE Co. OF NEW JERSEY, INC. 206 DELAWANNA AVE. The newest and the longest lasting insecticide available for white grub control. BOX 1014 CLIFTON, N.J. 07014 PHONE (201) 473-3393 ABSTRACT Mowing Height, Irrigation Frequency, and Soil Moisture Effects On Water Consumption and Growth Rate of 11 Turfgrasses I. Biran, B. Bravado, Bushkin-Haray, and E. Rawitz Agron. J. 73:85-90. 1981. Water use yield of clippings were determined for 11 turfgrasses. Two were cool-season and nine warm- season types. The former turfgrasses belong to the C-3 and the latter to the C-4 group. The plants were grown in containers under summer conditions of the warm, semi-arid zone. The growth rate of plants in the C-3 groups was similar to that of those in the C-4 group, but their water consumption was higher. Amongst the C-4 group, those plants with a sparse, vertical growth habit, typical of forage crops, had a higher growth rate and water consumption than the dense, low- growing ones. Delaying irrigation until the onset of temporary wilting caused a significant decrease in water consumption and growth (up to 35 percent) in most grasses. Raising the clipping height from 3 cm (1.2 inches) to 6 cm for a period of six weeks led to increased vigor in all grasses as evidenced by growth rate, chlorophyll content, and water consumption. This effect was continuous throughout the measurement period for the C-3 types, but was temporary for the C-4 types, which declined after six weeks. With constant 34.5°C temperature, net photosynthesis of tall fescue (Festuca arundinacea Schreb. ‘Alta’) (C-3) was only about one-third that of C-4 grasses, although the evapotranspiration rate was equally high. The water uptake of the C-4 type Zoysia matrella (L.) Merr. ceased at a much higher soil water potential than that observed for the C-3 tall fescue and other C-4 types. The decline of the rate of photosynthesis preceded the drop in transpiration rate caused by the decreasing soil water potential. Editor’s Comment: Since the beginning of turfgrass science several generations ago, warnings against close or severe cut have been given when drought stress is of concern. The benefits of higher cut were often associated with lower soil temperatures. This appears to be untrue or an oversimplification according to this study from Israel. Both higher cut and taller grass types gave increases in water use along with better growth rate and chlorophyll content. This suggests that higher cutting improves summer survival more through better growth of the grass than a saving in water consumption. The decrease in water use by permitting tem­ porary wilt should be considered. Of course, we must remember that some types of turf do not tolerate much wilt. While irrigation studies on turf seem a remote possibility for our climate, it seems they should help us attain better efficiency with the water we use. New Insecticide, Oftanol, Approved for Use Louis M. Vasvary Extension Specialist in Entomology Cook College, Rutgers University On May 14, 1981, the New Jersey State Department of Environmental Protection issued a Section 24-(c) registration for Oftanol 5 percent Granular insecticide. Oftanol (com­ mon name: Isofenphos) is for com­ mercial applicator use only on com­ mercial and residential turfgrass in­ cluding golf courses, cemeteries, sod farms, industrial grounds, parkways, residential lawns, and other similar areas. Oftanol 5 percent Granular in­ secticide is now available from your supplier. The approximate cost of material to treat an acre is $65.00 ($1.50 per 1,000 sq ft). During the past four years Oftanol has given excellent control of white grubs (including Japanese beetle grubs) in experimental trials. In addition to white grubs, Oftanol 5 percent Granular is labeled for Hyperodes weevil, bill bugs, chinch bugs, and sod webworms. For white grub control, use 20 to 40 pounds of Oftanol 5 percent Granular per acre (0.45 to 0.9 pounds per 1,000 sq ft). Use the higher rate for high grub population densities. Applications can be made in mid- to late July through August. For Hyperodes weevil, bill bugs, chinch bugs, and sod webworms, use the 40 pound per acre rate. Oftanol 5 percent Granular should be applied with either a drop-type or rotary-type spreader. Avoid the use of spreaders which would apply the material in narrow concentrated bands. The signal word on 5 percent granular Oftanol is “CAUTION”. Do not contaminate water when you are cleaning the application equipment or during disposal of waste materials. Do not graze treated areas or use clippings from treated areas for feed or forage. Oftanol is toxic to fish and wildlife. Do not collect clippings from first mowing after application. Do not reuse the container. Completely empty the contents and bury the unused chemical at least 18 inches deep in an approved landfill or noncrop land away from water supplies. Burn the empty con­ tainer completely and stay well away from the smoke. Fortunately, Oftanol has arrived on the scene in time to solve many of our insect problems in turfgrass. Green World is published three times a year by the New Jersey Turfgrass Association, P.O. Box 231, New Brunswick, N.J. 08903. Ralph Engel, consulting editor; Judy Chi, managing editor. Please address inquiries con­ cerning advertising to John Zajac, Garfield Williamson Co., 1072 West Side Ave., Jersey City, N.J. 07306. Phone 201-435-3500.