Suggested Management Practices
| TifEagle was bred, evaluated,
developed and released by USDA-ARS in cooperation with
the University of Georgia at the Coastal Plain Experiment
Station in Tifton, GA. It was evaluated in over 25 golf
course environments from North Carolina to Barbados to
California from 1993 to1997. The data collected from
these sites showed that TifEagle produces a premium
quality putting surface, superior to Tifdwarf, that meets
the highest golfing standards. TifEagle putting greens
have been overseeded with Poa trivialis since 1994. High
quality, uniform overseeded putting surfaces are
characteristics give TifEagle its unique advantages:
I. General Considerations:
Research has shown that inadequate maintenance of TifEagle will result in thatchy and spongy putting surfaces. Therefore, each superintendent considering TifEagle is encouraged to review these suggested management practices to determine if their personnel and budget will support the required management inputs. TifEagle, like most other bermudagrasses, needs full sunlight to produce healthy turf.
Off types have not been a problem on TifEagle greens. However, regular roguing of all bermudagrass greens is important to maintain genetic purity and putting quality. It is especially important to rogue foreign contaminants before overseeding.
TifEagle is recommended for closely mowed areas ONLY. A suggested alternative for collars is Certified TifSport turf. Maintain a border between TifEagle and the collar area with a nonselective herbicide such as Roundup or Finale until TifEagle is established and being routinely mowed at 0.125 inch (3.2mm).
II. Establishment: (From Sprigs or Sod).
2. Sprigbed (Stolonbed) preparation: The surface should be as smooth and firm as possible. A mechanical sand rake or comparable machine combined with wetting of the surface is suggested to compact the sprigbed. The sprigbed should be fumigated at a rate of 400 to 500 lbs methyl bromide/acre (450 to 550 kgs /hectare) or otherwise treated to eliminate contaminating seeds and vegetative plant parts. Nematodes need to be controlled, especially in renovated greens where sting, root knot, lance and other nematodes can become a major problem. Controlling nematodes on the perimeter of the green is also important. Good root zone moisture should be established before planting.
3. Planting: It is best to get 100% uniform coverage of the surface with individual grass sprigs (stolons), not clumps. Due to increased traffic, sprig (stolonize) the greens perimeter at a slightly higher rate so that the entire green develops at the same rate. Sprigs should be cut into the surface, preferably in at least two directions, and the surface firmed with a roller. Thin areas should be re-sprigged between cutting-in operations. Use only freshly harvested, cool sprigs. Sprigs should arrive at the planting site at a temperature below 120ºF (50ºC) in the center of the box of sprigs. Research has shown that sprigs transported in a box with a reinforced sealed plastic liner to exclude air (anaerobic) remain viable for longer periods of time. Sprigs with temperatures between 120º and 130º (50º and 60ºC) in the center of a box showed variable amounts of vigor and ability to survive. Sprigs over 130ºF (60ºC) were dead.
4. Water requirements: Water the surface before spreading the sprigs to cool the surface. When planting on days when the temperature is greater than 90ºF (32ºC) and full sun, irrigate immediately after cutting in the sprigs. Any drying of sprigs will reduce survivability and increase grow-in-time. If topdressing is used, apply cool, moist sand. If dry sand is used, water as the sand is applied, especially during mid-day when temperatures are very hot. Be prepared to hand water immediately after planting each section of a green. Irrigate frequently during daytime until rooted, keeping soil surface moist, but not saturated. After rooting (typically in 10 to 14 days) gradually reduce irrigation frequency to twice per day, then once per day, then alternate days or less to encourage deep rooting.
5. Fertility recommendations during establishment:
Chemical soil analysis
B. Grow-in suggestions,
6. Mowing: Do not allow TifEagle to grow several weeks without mowing.
A. Begin mowing at approximately 0.180 inch (4.5mm) shortly after shoot growth is initiated. Mow frequently, at least 2 to 3 times per week, such that only small amounts of leaf tissue are removed during any one mowing.
B. At least 80% coverage should be obtained in 30 days depending on soil temperatue and time of year. Mowing height should be gradually lowered to 0.140 inch (3.5mm) within this period.
C. Coverage should be 100% within 45 days depending on temperature and time of year. During this period mowing height can be gradually lowered to 0.125 inch (3.2mm).
7. Reducing surface irregularities:
A. Topdress after 80% coverage using greens mix sand. Use heavier applications if necessary to fill in depressions. Topdress lightly at about four weeks such that the topdressing material does not completely cover grass blades.
B. Begin regular topdressing at 90-100% coverage. Regular light topdressing applications should be continued on a weekly or biweekly schedule when grass is rapidly growing. Use consistent, good quality topdressing sand that matches the greens construction media.
C. Roll the surface as needed.
D. After 80% coverage, light grooming weekly with a triplex mower equipped with vertical mowing heads can also be effective.
8. Increasing turf density: Mow daily. Hydrojet or aerify with 1/4 inch (6mm) quadra-tines or star-tines every 3 weeks to improve root growth, plant health, and turf density.
9. Weed Control: Remove broadleaf and grassy weeds by hand. Eliminate coarse-textured bermudagrass contaminants introduced or encroaching from collars and surrounding areas.
10. Sodding vs. sprigging: Sprigging (stolonizing) is preferred to sodding (turfing) to start a uniform and healthy turf. High quality, vigorous sprigs free of pathogenic nematodes have provided the most consistent and best results. Theoretically, sodding should result in a shorter interval between establishment and a high quality putting surface, but only if the turf is maintained at putting green height on the turf farm, including frequent topdressing, verticutting, aerification and other routine practices for a TifEagle green. Some sodded greens have been inconsistent, primarily because of the variability of turf production practices. If considering using sod, take several profiles of the proposed turf and determine if there is a thatch layer, soil that is incompatible with the greens mix, or some other irregularity that would be detrimental on the golf green. Washing turf to remove incompatible soil will fix the soil problems, but potentially causes the development of a severe thatch layer that will be difficult to remove or control. It will be extremely difficult, if not impossible, to reintroduce sand into a dense mat of washed turf.
11. Other planting procedures: If TifEagle is planted as sod from plastic, sand based fields or washed sod, greens should be aerified with core removal and topdressed with sand after sod is rooted to minimize root zone layering.
III. General Management Guidelines During Active
1. Fertility: Nitrogen needs are less than Tifdwarf due to increased density. Apply only enough nitrogen to maintain a quality putting surface or density (not color), usually 0.5 to 1.5 lbs/1000 (0.25-0.75 kgs./100m2)/growing month. (Note: we recommend higher levels of N during establishment). This averages about 1/2 lb.(0.25kgs) of N for every two weeks of active plant growth. Use higher rates of N during periods of active growth and after vertical mowing or aerification. Apply N immediately after vertical mowing or aerification to help turf heal and recover. Use soluble sources. Monitor potassium levels on soil reports and maintain high levels. On an annual basis apply at least one pound of K per pound of N. Fertility levels will vary depending on whether you have an 8 or 12-month growing season or somewhere in between. The longer growing season will require more fertility than a shorter one. Some have observed benefits to rotating (changing) the N source.
A. High rates of N can increase thatch buildup.
B. Granular products will be picked up by mowers due to the height of cut and density of TifEagle. Suggested alternatives are micro or mini particles or highly soluble granular materials. Use particle SGN (size guide number) 100 or less to reduce pick up by mowers.
C. Use of liquid fertilizer materials has improved consistency of TifEagle color and putting surface performance. This is probably due to the ability to better manage plant tissue nutrient levels.
D. Soil test (for P, K, Ca, Mg and lime needs) at least twice yearly on sand greens. On high CEC or push-up greens, once per year should be adequate.
E. TifEagle responds to micronutrients.
2. Irrigation: Irrigate to prevent stress. Heavy infrequent irrigation is preferable to frequent light irrigation after turf is established, to encourage deep rooting. The TifEagle rootzone can become hydrophobic because of its density. Periodic application of a good wetting agent, frequent quadratine aerification, and/or use of a hydrojet can lessen these hydrophobic conditions.
3. Mowing height: Mow your grass at the height that is best for your course, depending on several variables. Some important considerations are: the amount of play (higher cut to tolerate more traffic), environmental condition (higher cut if cloudy, cool, poor water quality, etc), greens slope and contours, health of grass (fertility, disease, nematodes, etc), A. TifEagle can tolerate much closer mowing than Tifdwarf. Mow at least once daily at 0.156 inch (4.0mm) or lower during periods of active growth. Double mowing will add speed and smoothness, but is probably not needed when grass is growing slow (e.g. spring and autumn). During extended periods of stress, height of cut should be raised (maybe as high as 0.180 inch [4.5mm] during the cloudy and rainy periods common in tropical areas). Raising the mowing height as much as possible in the autumn will improve winter survival, especially in the transition zone where there is a chance for winterkill. Remember, lowering the height of cut also reduces the amount of leaf area available to intercept sunlight and to produce energy for plant growth and maintenance. TifEagle can tolerate much closer mowing than Tifdwarf, but it also has its limit. Excessive low mowing reduces root growth and shade tolerance and increases the potential of soil borne and foliar diseases.
B.Walk-behind mowers provide an optimum surface and produce less traffic stress on the grass than triplex mowers. New flex mowers can eliminate some scalping.
C. During periods of rapid growth, do not decrease height of cut more than 0.010 inch (0.25mm) every 4 days.
4. Thatch prevention: A key concept is THATCH PREVENTION rather than thatch control. These practices are recommended to prevent excessive thatch formation and provide optimum putting speeds with true ball rolls.
Thatch is the layer of organic material including
stems and roots between the soil surface and the green
vegetation. Unhealthy thatch has very little sand mixed
within the layer, and poor
aeration, water infiltration and rooting are common. In
contrast, thatch should not be confused with mat.
Healthy mat is a layer of stolons and rhizomes mixed with
soil, sand or other topdressing materials. A healthy mat
layer is desirable, but try to keep the layer less than
1/2 inch (12mm). The specific management protocol for
managing this mat layer will depend on season, weather,
fertility and growth patterns of the grass. If thatch
develops or the mat layer becomes excessive (hydrophobic,
scalping, spongy, etc.), implement elimination procedures
slowly. Severe verticutting and/or aerifying will result
in damaged greens. Verticutting during active growth
periods will not reduce the amount of injury, but will
shorten the recovery time.
B. Brushing daily (with the brush behind the front roller or somewhere in front of the bedknife) and/or turf grooming 2 or 3 times a week are excellent ways to help prevent thatch. The type of brush is probably not that important. The purpose of the brush is to raise the stolon tips so they can be cleanly cut. Grooming should be more aggressive when the grass is rapidly growing and less aggressive in the spring and fall when growth has slowed down. Some superintendents have eliminated light verticutting by using brushing, grooming and light topdressing.
C. Light verticutting (usually during the
months of rapid growth and in more tropical climates also
during spring and autumn) alternating with topdressing is
an excellent tool for promoting a smoother ball roll.
Verticutting requirements depend to a large degree on
location, weather and fertility rates. Some greens may
benefit from vertical mowing in two directions, whereas
that may not be necessary for others. TifEagle usually
does not tolerate deep verticutting; however, some
superintendents have had good experience in removing
thatch by verticutting 1.25 inches (30mm) deep in late
spring or early summer when growing conditions are ideal.
The greens are topdressed immediately after verticutting.
5. Aerification: A good goal for aerification is to impact 10-15% of the surface area at one time in sub-tropical climates. In tropical climates, try to impact 15-25% of the surface. Aerify 2 to 5 times per year (during early and late summer months) using up to 5/8-inch (12mm to 16mm) tines on 2-inch (50mm) centers. Remove aerification cores and debris. Sufficient topdressing material (greens mix sand w/o organic matter) should be applied and worked into aerification holes. Use solid tines, star tines and/or a Hydrojet as needed to enhance infiltration. This will also improve root growth, reduce surface firmness and reduce dry spots. Consult the USGA website (www.usga.org) for details on how tine size and spacing impacts surface areas.
6. Plant growth regulators: Long-term effects of such compounds as Primo are not known, but research has shown that TifEagle plots treated with Primo, at the label rate, during months of rapid growth, maintained higher turf quality, better colour, higher shoot density and faster greens speeds than TifEagle not treated with Primo. Plots treated with Primo also recovered more quickly after thatch removal with a Graden mower. Caution: Since plant growth regulators usually lessen turf vigor, a growth regulator may also make the turf more susceptible to diseases in stress situations.
7. Scalping: The closer mowing heights on the ultra dwarfs can cause scalping on greens with sharp contours. Some of this problem can be solved by reversing the front roller on the mowers to bring the roller and bedknife closer together. Greens contours may need to be softened due to the closer mowing heights of TifEagle. Scalping can also be due to excessive thatch buildup.
8. Pest management requirements: Similar to Tifdwarf. Apply fungicides curatively for any diseases noted. Control thatch to help produce a healthy plant.
9. Improving winter hardiness: A number of small things can add up to improved winter hardiness.
A. Gradually raise the mowing height in the fall so that by the time night-time temperatures reach the low 50ºF (10ºC), the height is 0.188 inch (4mm).
B. Develop a healthy mat layer with stolons and rhizomes with sand. The recommended mat layer thickness is slightly less than 1/2 inch (12mm). If a thatch layer, that is, a layer of stolons and rhizomes without sand, is allowed to form, the primary roots and rhizomes will develop above the soil, making them more susceptible to freezing temperatures. Deep rooting should be encouraged because it will improve winter hardiness.
C. Maintain high levels of K (up to 1N:2K) throughout the year, with special emphasis during late summer and fall.
D. Greens covers may be needed in the transition zone when temperatures routinely fall below 25ºF (minus 5ºC). Use greens covers if temperatures will be lower than 20ºF (minus 8ºC). Greens with detrimental thatch layers will need to be covered when temperatures are below 25ºF.
E. In the northern part of the transition zone, paint and do not overseed.
10. Shade tolerance: Observations on golf courses indicate that TifEagle needs 8 to 10 hours of full sun each day during the growing season. Raising the height of cut can improve shade tolerance because more leaf area is available to intercept the light. TifEagle, like all bermudagrasses, needs adequate sunlight.
11. Salt tolerance: Salinity tolerance of TifEagle is similar to Tifdwarf, i.e., threshold EC of about 3.5- 4.0 DSM and 50% growth reduction EC of about 25 (one DSM = 640 ppm.).
IV. Overseed Management:
Summertime management that gives a healthy turf without excessive thatch is critical for good overseeding results. Overseeding can weaken the turf, especially in the year of establishment and in the transition area. Avoid overseeding during the year of establishment.
1. Overseed Establishment:
A. Surface preparation: Mow at 0.125 inch (3.2mm), spread sand, plant seed, and then topdress. If vertical mowing is used in preparation, leave plenty of time between a vertical mowing and overseeding. If vertical mowing grooves are obvious, the seed will fall into the grooves, creating stripes.
B. Species: Smaller seeded species are preferred. 100% Poa trivialis is preferred and has been shown to be satisfactory.
C. Seeding rate: total 6-12 lbs./1000 sq. ft (3-5kgs./100m2).
D. Topdress lightly and drag in with a carpet.
E. Irrigate as needed to keep seed bed moist throughout the day during germination and seedling establishment.
F. Raise height of cut to 0.140 inch (3.5mm) until stand is established.
G. Fungicide treated seed and preventative fungicide applications for 3 to 4 weeks after seeding are suggested for pythium control.
2. Spring transition: Practices that have led to successful Spring transition with Tifdwarf should be successful when incorporated into the TifEagle management protocol.
A. When weather and course conditions are appropriate for transition, lower cutting height to 0.125 inch (3.2mm) or less.
B. Grooming at this time may improve putting quality and thin the overseed canopy.
C. Increase fertility to encourage bermudagrass growth. Limiting water may also help limit the Poa trivialis growth.
For information on insects, diseases and weeds, visit: http://www.georgiaturf.com
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