This calendar of suggested management practices is designed to assist you in the seasonal care of your athletic field. Location, terrain, soil type and condition, age of field, and previous management practices at a particular location are among the major factors that affect turfgrass performance. For these reasons, the following management practices and dates should be adjusted to suit your specific field conditions.

April–June

Mowing

Set mower to 1-inch cutting height and remove debris before the grass turns green in the spring. The best mowing height during the growing season is 1 inch for common bermudagrass and ¾ to 1 inch for hybrid bermudagrass. Do not allow bermudagrass to grow taller than 1 ½ inches between mowings. Two or three weekly mowings may be necessary. Remove only those clippings that windrow.

If the grass gets excessively high during a wet period, raise the mower and cut off one-quarter to one-half of the present growth; then in a day or two, lower the mower and mow the field at the preferred height. Reel mowers are preferred for a clean cut. Rotary mowers are the second preference, provided the blades are sharp and can be lowered to the appropriate height (if cutting heights are too low, scalping frequently occurs).

Fertilization

Apply 1 pound of nitrogen per thousand square feet two or three weeks after the grass turns green or three weeks after the last projected frost date. A complete (3-1-2 or 4-1-2 ratio) fertilizer may be necessary only once or twice annually, with remaining applications composed of nitrogen sources such as urea (46-0-0) and ammonium sulfate (21-0-0) (Table 1). If growth appears to be slow and the grass is yellowish green, apply a nitrogen source every four to six weeks at a rate of 1 pound of nitrogen per thousand square feet, as needed.

¹ Amount of product needed to apply 1 pound of nitrogen per thousand square feet. ↲

² Amount of product needed to apply 43.5 pounds of nitrogen per acre. To determine the amount of product needed to deliver 1 pound of nitrogen per thousand square feet, divide 100 by the first number in the fertilizer ratio. For example, for 16-4-8 fertilizer, divide 100 by 16; the resulting amount is 6.25 pounds of product per thousand square feet. ↲

Test the soil to determine requirements for lime, phosphorus, potassium, and other macronutrients and micronutrients. Soil test boxes can be obtained from your local Extension center.

Apply lime as needed, but do not exceed 50 pounds per thousand square feet per application. If the suggested amount exceeds 50 pounds per thousand square feet, make staggered applications six months apart. If possible, apply lime just before coring the soil or in the winter months. Table 2 gives examples of field sizes in acres.

¹ Field area may vary depending on the size and number of fields; orientation and layout of fields; quality and type of support facilities; and internal and external buffer zones. ↲

² Because Little League, Pinto, Babe Ruth, Bronco Baseball, high school, college, and professional baseball fields may have different dimensions, check with league officials for specific measurements. ↲

³ Because 4v4, 7v7, 9v9, high school, college, and professional soccer fields may have different dimensions, check with league officials for specific measurements. ↲

Irrigation

Bermudagrass usually requires a weekly application of about 1 inch of water in the absence of rainfall. In sandy soils, apply about ½ inch of water every three to four days. It takes 620 gallons of water to supply 1 inch per thousand square feet. It is best to water early in the morning (between 2 a.m. and 6 a.m.). Do not irrigate again until symptoms of wilt appear, such as folded or curled leaves, footprinting, or a bluish green color. Probe the soil to detect dryness. Avoid light, frequent irrigations, as they can promote shallow rooting and encourage growth of weeds, algae, and moss.

Minimize field use when wet to reduce the chance of wear and compaction. Postpone play or use alternate sites for band and team practices. Ideally, game fields should be used only for team play and not for team practice, physical education, or band practice.

Soil Cultivation

Vertical mowing is useful in removing thatch (dead plant residue) in bermudagrass. To remove thatch, verticut the field with a power rake about two to three weeks after the grass turns green. Run the verticutter over the field twice, with the second pass at right angles to the first, and remove the debris.

Aerification (coring) relieves compaction on heavily trafficked athletic fields. Aerate two to four times during the growing season using ½- to 1-inch-diameter tines that remove soil cores. Aerate the field twice lengthwise and once crosswise to penetrate heavy clay soils; these soils must be moist when aerated, so fields should be watered several days in advance of aerification. Allow the plugs to dry, then pulverize them with a mower or power rake, redistribute debris with a drag mat, and remove any excess debris. More frequent coring may be necessary in heavily trafficked and compacted areas such as around player benches, between hash marks, along sidelines, and in front of goals.

Soil cultivation practices are necessary for an acceptable field; however, do not perform these practices if the turfgrass is under stress. It may take up to three weeks of good growing conditions for the turfgrass to recover after aerification. After coring and debris cleanup, fertilize fields with 1 pound of nitrogen per thousand square feet to improve recovery.

If you do not have the appropriate equipment, it is recommended that you rent or borrow equipment or contract for soil cultivation services.

Establishment and Renovation

Common bermudagrass can be seeded and hybrid bermudagrass sprigged anytime when soil temperatures reach 50°F, usually in April but sometimes as early as March. The other option is to sod the field. Although sodding is very expensive, the fields can be ready for play within six weeks.

Early June is the latest preferred window for renovating a bermudagrass field by sprigging. It takes about two to three months of good growing weather before a sprigged field is ready to withstand light traffic (that is, fewer than 10 football games per year). Looks can be deceiving. Good coverage can be achieved within nine weeks after sprigging; however, the plants will not be mature enough to withstand much traffic.

Weed Management and Control

Successful weed management in athletic fields involves aggressive aerification to relieve compaction as well as proper use of herbicides that do not inhibit root growth or reduce the ability of bermudagrass to recover from traffic. Heavy traffic on athletic fields causes bermudagrass wear, divoting, and soil compaction, which reduces bermudagrass competition and increases weed encroachment. Goosegrass is a major weed problem in high-traffic areas on athletic fields and is an indicator weed for compaction. Goosegrass begins to germinate when soil temperatures reach 60°F to 65°F and adequate soil moisture is present.

Preemergence (PRE) herbicides will be necessary to control goosegrass and crabgrass on athletic fields in North Carolina. Oxadiazon (for example, Ronstar) is the preferred PRE product for bermudagrass athletic fields because it provides good control of crabgrass and excellent control of goosegrass. Most important, oxadiazon does not inhibit bermudagrass root growth, which allows bermudagrass to recover from traffic damage. However, oxadiazon is relatively expensive. If budgets do not allow for its use, dinitroaniline (DNA) herbicides can be substituted, but these products must be applied carefully, as they may inhibit root growth and result in clubbed or swollen root tips. Rather than applying the full herbicide rate in a single late-winter application, DNA herbicides should be split into two lower-rate applications; this approach helps mitigate the root inhibition caused by these herbicides. DNA herbicides include prodiamine (for example, Barricade 4FL), pendimethalin (for example, Pendulum AquaCap), and oryzalin (for example, Oryzalin 4). Dithiopyr may also be used; it is not a DNA herbicide but has the same mode of action, thus all of the rules for DNA herbicides apply to dithiopyr. Apply ¼ inch to ½ inch of irrigation after herbicide application to incorporate the product into the soil profile.

In the case of aerification, one aerification after PRE herbicide application will not have a negative effect on herbicide efficacy. However, if multiple aerifications are conducted, it is recommended to split the PRE herbicide applications and apply some of the amount immediately after aerification.

Postemergence (POST) herbicides can be used for remedial control of crabgrass and goosegrass during the summer. Quinclorac can be used for crabgrass control, but it is ineffective on goosegrass. Addition of methylated seed oil at a rate of 1 ½ pints per acre is critical for good quinclorac activity on crabgrass. POST goosegrass control can be obtained by applying metribuzin (Sencor 75%) immediately followed by ½ inch of irrigation. Foramsulfuron (Revolver), sulfentrazone (Dismiss Turf), or thiencarbazone + foramsulfuron + halosulfuron (Tribute Total) are effective on young goosegrass (prior to tillering stage). Tank mixtures of 2,4-D + dicamba + MCPP + carfentrazone (Speedzone) and topramezone (Pylex) or metribuzin + topramezone are also highly effective.

Sedges are also problematic in athletic fields. Because sedges prefer wet soils, proper irrigation management and good drainage are important to minimize their presence. Problematic sedges in North Carolina include both yellow and purple nutsedge and both green and false green kyllinga. Several highly effective POST herbicides include pyrimisulfan (Arkon), imazosulfuron (Celero), halosulfuron (several trade names), trifloxysulfuron (Monument), sulfosulfuron (Certainty), flazasulfuron (Katana), and sulfentrazone (several trade names). Nonionic surfactant must be added to the spray mixtures for optimum control. Apply these herbicides to actively growing sedges after spring green-up to limit tuber and rhizome expansion.

Broadleaf weeds can also be a problem. These include spurges, clover, dandelions, and Virginia buttonweed. Many POST herbicides are effective on broadleaf weeds, including herbicide mixtures or premixes of 2,4-D, dicamba, fluroxypyr, triclopyr, and clopyralid. Care should be taken when applying during summer months. Do not mow or water bermudagrass for at least 24 hours after application. Treat when air temperature is between 60°F and 90°F. Do not apply herbicides to turfgrass or weeds under temperature or drought stress or during spring transition.

Annual bluegrass is another troublesome weed in athletic fields, and it thrives in wet soils. Like goosegrass, annual bluegrass can be an indicator weed for compaction. Annual bluegrass should be controlled from late fall through early spring to prevent seed production and additional contributions to the soil seedbank. Spring applications during green-up are also safe and usually needed. Glyphosate (several trade names), simazine, glufosinate (Finale XL T&O), metribuzin (Sencor 75%), diquat (several trade names), or flumioxazin (SureGuard) may also be applied on dormant bermudagrass for control of annual bluegrass and many other winter weeds. Glyphosate should be applied on dormant bermudagrass on warm days (above 60°F) and should never exceed 1 pint per acre to avoid delay in turfgrass green-up. To optimize annual bluegrass control and minimize risk of herbicide resistance, it is critical to tank-mix or rotate herbicides with different modes of action.

July–August

Mowing

Follow the April–June mowing guidelines.

Fertilization

Follow the April–June fertilization guidelines.

Irrigation

Follow the April–June irrigation guidelines.

Soil Cultivation

Follow the April–June soil cultivation guidelines.

Establishment and Renovation

Make arrangements now to begin renovation and establishment early next spring. Ensure that the necessary labor, equipment, and supplies are available. (See instructions under April–June timeline.)

Weed Control

Make POST applications on sedges, broadleaf weeds, goosegrass, and crabgrass, as described in April–June maintenance section. Remember that POST herbicides work much better when weeds are small and actively growing. Avoid applications during times of plant stress. It is very important to not apply POST herbicides when temperatures exceed about 90°F. Late summer is also a favorable time for herbicide applications targeting perennial weeds such as sedges and kyllingas, as enhanced translocation to belowground plant parts improves weed control.

September–December

Mowing

Follow the April–June mowing guidelines until several weeks before the first expected frost. Raise the mowing height ¼ to ½ inch as winter approaches if fields are not scheduled to be overseeded. Mowing height is usually raised in mid-to-late September in the piedmont. Mowing height of athletic fields in the western and northwestern areas of the piedmont may be raised one to two weeks earlier, whereas in the southern-central and southeastern regions, height may be raised one to two weeks later. Do not allow turfgrass height to exceed 2 inches.

Fertilization

Do not apply more than ½ pound of nitrogen per thousand square feet (22 pounds per acre) per application after September 15. Use a low-nitrogen, high-potassium fertilizer, such as 200 pounds of 5-10-30 per acre, or supplement straight nitrogen sources with potash (K₂O) using 70 pounds of muriate of potash (0-0-60), 86 pounds of potassium sulfate (0-0-50), or 220 pounds of sul-po-mag (0-0-22) per acre. Repeat in three weeks. Bermudagrass must be green and growing actively to benefit from this application. Irrigate immediately after application to prevent turfgrass discoloration. Potassium lessens the chance of bermudagrass winterkill. Discontinue any fertilizer application before the first frost.

To determine the amount of product required to apply 1 pound of potash per thousand square feet, divide 100 by the third number in the fertilizer ratio. For example, for 6-6-12 fertilizer, divide 100 by 12; the resulting amount is 8.3 pounds of product per thousand square feet.

Irrigation

In September and October, follow the April–June irrigation guidelines. Irrigate fields in November and December if wilting occurs or if they have been overseeded with ryegrass.

Reduce compaction and wear by avoiding irrigation before heavy use. Minimize field use under wet conditions. Postpone play or use alternate sites for band and athletic practice sessions. Ideally, game fields should be used only for team play and not for team practice, physical education, or band practice.

Soil Cultivation

Do not verticut, dethatch (power rake), or aerate (core) bermudagrass fields unless you plan to overseed in the fall. Otherwise, these practices can injure bermudagrass plants because they will have insufficient time to recover before winter.

Renovation

Bermudagrass fields should not be renovated at this time of year.

Weed Control

Annual bluegrass and many winter annual broadleaf weeds typically invade sports fields from fall to early winter. Annual bluegrass germination typically begins when soil temperatures fall below 70°F under adequate moisture conditions. If left untreated and at high densities, these weeds will outcompete bermudagrass for sunlight the following spring, thus delaying bermudagrass green-up. Successful winter weed management will help ensure early green-up of bermudagrass in spring. Multiple herbicides are effective for control of annual bluegrass and many broadleaf weeds, including PRE and POST herbicides such as simazine, atrazine, and pronamide (Kerb). POST herbicides also include several ALS-inhibiting herbicides such as foramsulfuron (Revolver), trifloxysulfuron (Monument), sulfosulfuron (Certainty), and flazasulfuron (Katana). Applying mixtures of these herbicides in the fall (usually November), when temperatures are warm and annual bluegrass is small, yields best control.

Applications of sulfonylurea (SU) herbicides such as foramsulfuron (Revolver), trifloxysulfuron (Monument), sulfosulfuron (Certainty), flazasulfuron (Katana), and rimsulfuron (for example, Negate) are recommended in late October to mid-November. Nonselective herbicides like glyphosate or glufosinate can be used for broad-spectrum weed control when bermudagrass is dormant.

Winter Overseeding

Fields used in late fall, winter, or early spring may be overseeded with cool-season grasses (typically perennial ryegrass) to provide color and protection. Baseball fields are frequently overseeded, although spring recovery and growth of bermudagrass will be delayed due to the overseeded grass. See "Overseeding Bermudagrass" section for timing and other instructions.

January–March

Mowing

Baseball infields overseeded with ryegrass should be mowed at ½ to 1 inch, and outfields, sidelines, football fields, and soccer fields at ¾ to 1 ½ inches. Reduce mowing height two weeks before the bermudagrass is expected to turn green in the spring; this will weaken the ryegrass and decrease its competition with the bermudagrass.

Fertilization

Do not fertilize athletic fields that have not been overseeded. Apply no more than ½ pound of nitrogen per thousand square feet to winter-overseeded fields every three to four weeks.

Irrigation

Dormant turfgrass may need to be irrigated when warm, windy weather prevails. Winter-overseeded fields lose greater amounts of water than fields that have not been overseeded. Probe the soil to determine dryness.

Soil Cultivation

Do not power-rake or aerate dormant fields until the soil temperature reaches 50°F at a depth of 4 inches.

Renovation and Establishment

If soil temperatures are warm enough, these practices may begin as early as March. For instructions, see April–June timeline.

Weed Control

Glyphosate applied at 1 pint per acre can be effectively used on dormant bermudagrass for weed control. If applied on a warm winter day (temperature greater than 60°F), excellent control of annual bluegrass and many winter annual broadleaf weeds can be achieved.

PRE herbicide applications for control of crabgrass and goosegrass can be made any time after the first of the year. Crabgrass starts germinating when soil temperatures exceed 55°F. Sprayable formulations of oxadiazon can be applied on dormant bermudagrass and mixed with glyphosate; once green-up starts on bermudagrass, however, oxadiazon must be applied as a granular formulation to prevent bermudagrass injury. DNA herbicides offer excellent control of crabgrass and good control of goosegrass.

Bermudagrass is preferred for most athletic fields where it can be grown successfully. This includes the coastal plain, piedmont, and parts of western North Carolina. Bermudagrass cultivars should not be planted in mixtures with other warm-season turfgrasses or in shaded sites.

Common bermudagrass does not have the density, disease resistance, and cold tolerance of hybrids. However, if budgets are limited, it offers acceptable performance and can also be seeded. Several improved seeded bermudagrasses have been developed over the past decade and are currently available for purchase from local and online vendors. Bermudagrass seed typically germinates in 7 to 21 days with adequate soil moisture. Full coverage is usually achieved about three months after germination.

Compared to common types, hybrid bermudagrasses are generally more aggressive, are darker green with finer texture, and have excellent density, cold tolerance, and disease resistance. Hybrid bermudagrasses are established vegetatively (by sod or sprigs) and grow rapidly. If planted from sprigs, expect full coverage in about three months. Coverage from sod is immediate, but the roots usually need to grow for about a month before the field is used. Cultivars that are currently popular for North Carolina athletic fields include Celebration, Latitude 36, NorthBridge, PremierPRO, Tahoma 31, Iron Cutter, TifTuf, and Tifway.

Determine Extent of Winterkill Damage

Determine the extent of injury before the growing season by removing several plugs of turfgrass as soon as the soil is thawed. Place them in a greenhouse or south-facing window that receives a lot of light. Healthy plants should turn green in two to three weeks. Lack of green growth in that time frame suggests the need for renovation.

If large areas are dead, sprigging is the most reasonable method of reestablishment. For smaller dead areas, plugging is the best method. Sodding may be the only option if time is critical.

April and May are preferred for planting bermudagrass if play is scheduled for the fall. Plant as early as possible to ensure that the reestablished field can withstand traffic.

Method of Reestablishment

Plugging. Place 3- to 4-inch-diameter plugs on 12-inch centers for reestablishment. Plugs on 12-inch centers will provide 90% coverage in 6 to 10 weeks. Use a plugging device to remove plugs of soil from bare areas, then insert bermudagrass plugs collected from sideline areas. Put bare-area plugs back in the holes from which the bermudagrass plugs were removed. Fertilize the area with starter-type (high phosphorus) fertilizer, such as 10 pounds of 5-10-10 per thousand square feet.

Sprigging large areas (15,000 square feet or larger). Apply the amount of fertilizer and lime recommended by soil test results. If test results are not available and the field has not been limed in the past three years, apply 50 pounds of lime and 20 pounds of 10-10-10 fertilizer to the area to be sprigged. Lightly disk or rotovate the lime and fertilizer into the soil surface; be careful not to destroy the existing surface drainage or crown of the field. Alternatively, the area can be aggressively hollow-tine-aerated in multiple directions, and the cores can be reincorporated with a drag mat before sprigging. Spread sprigs at a rate of 7 to 10 bushels per thousand square feet. To ensure good sprig-to-soil contact, lightly disk sprigs into the soil with the disk set relatively straight. Some sprigs should be buried, and some should protrude. Roll the sprigged area to firm the soil and ensure sprig-to-soil contact. Keep the area moist for 30 days or until the sprigs are rooted. Do not let them dry out.

Fertilize with a complete (N-P-K) fertilizer such as 10 pounds of 5-10-10 per thousand square feet every four weeks until coverage is complete. This regime can be supplemented with a weekly application of ½ pound of a nitrogen-only fertilizer (for example, ammonium sulfate or urea) per thousand square feet until establishment is complete. Begin mowing (ideally with a reel mower) when the foliage reaches 1 inch tall.

Sprigging smaller areas. Use a core aerator with ¾-inch-diameter tines to disrupt the soil surface. Make a minimum of six to eight passes over the area, allow the plugs to dry, and pulverize them with a drag mat. Cut out any germinating weeds such as knotweed or crabgrass with a hoe, and then scatter sprigs (7 to 10 bushels per thousand square feet) on the surface. Broadcast ¼ to ½ inch of soil over the sprigged area to partially cover the sprigs. To prevent layering, make sure the broadcast soil is similar to the existing soil. Apply 10 pounds of 5-10-10 per thousand square feet over the sprigged area. Roll the sprigged area to firm the soil and to ensure sprig-to-soil contact. Keep the area moist for 30 days or until the sprigs are rooted. Do not let them dry out.

Fertilize with a complete (N-P-K) fertilizer such as 10 pounds of 5-10-10 per thousand square feet every four weeks until coverage is complete. Weekly supplemental applications of a nitrogen-only fertilizer (½ pound of nitrogen per thousand square feet) will enhance the filling-in process. Begin mowing when the foliage reaches 1 inch.

Sodding. Sodding is the only option if play is expected within 8 to 10 weeks of the date of renovation. Purchase planting material that is free of objectionable broadleaf and grassy weeds. Planting certified sod is a good way to ensure that the material is true to type and free of objectionable weeds and crop species. If play is expected within three to four weeks, sod must be cut thicker than normal (1 ½ to 2 inches rather than ½ to ¾ inch) because there will be insufficient time for the sod to root. Generally, thin sod roots quicker than thick sod.

Remove the existing vegetation and soil to the depth of the new sod with a sod cutter. Apply the amount of fertilizer and lime recommended by the soil test results. If test results are not available and the field has not been limed in the past three years, apply 50 pounds of lime and 20 pounds of 10-10-10 fertilizer per thousand square feet. Lightly disk or rotovate the lime and fertilizer into the soil surface, being careful not to destroy the existing surface drainage or the crown of the field. Rake or harrow the site to establish a smooth, level final grade. Lay the sod and roll the area for good soil-to-sod contact.

Thoroughly irrigate the sod immediately after rolling, making sure the soil underneath is wet. Keep the soil continuously moist by watering daily until the sod starts to root. Gently tug on the sod; resistance indicates rooting. Rooting usually requires two to three weeks. Irrigation can be reduced gradually to once a week after the sod is fully anchored. Applying a high-phosphorus starter fertilizer three weeks after installation may expedite rooting.

Bermudagrass usually stops growing and turns brown after the first hard frost. It remains dormant until nighttime temperatures reach the mid-50s (degrees Fahrenheit) for several days. Dormant bermudagrass maintains good strength, resistance, and wear tolerance with moderate use. Each fall, many athletic fields are overseeded with either annual or perennial ryegrass to provide color, uniform surface conditions, and to increase wear tolerance. This practice is particularly common in fields used extensively in the spring; hence, baseball and soccer fields are prime candidates for overseeding.

The overseeding process should be conducted in early September to mid-November, depending on the region and the playing schedule for the field. Preparing bermudagrass for overseeding, however, is a yearlong process. Bermudagrass must be healthy to withstand the harsh cultural practices and turfgrass competition associated with overseeding.

Seeding Dates

Successful overseeding can be done two to three weeks before the expected first frost date or when the soil temperatures decrease to 75°F. Overseeding in the Raleigh area is usually done between September 15 and October 31. Areas west and northwest of the piedmont may be seeded one to two weeks earlier, whereas the southern-central and southeastern areas of North Carolina may be seeded one to two weeks later.

Overseeding Preparations

A close mowing just before overseeding is essential. Hybrid bermudagrasses should be thinned using a dethatching mower, and clippings and thatch should be removed with a sweeper. With common bermudagrass, it may be possible to skip the dethatching process. The field should be cored several weeks in advance of overseeding and the cores dragged with a steel drag mat. Allowing the coring holes to recover before overseeding will prevent patchy germination.

Seed Selection

Annual and perennial ryegrasses are the major grass species for overseeding. Both are quick to establish, relatively inexpensive (especially annual ryegrass), and fairly wear-tolerant. The new perennial ryegrass cultivars have a finer texture; are more tolerant of heat, disease, and cold; and transition later in the spring than annual ryegrass. Another type of ryegrass, referred to as intermediate ryegrass, is also available. Cultivars of intermediate ryegrass are moderate in performance compared to annual and perennial ryegrass but may have the advantage of being less persistent than some of the perennial ryegrass cultivars.

Cultivars that perform well in the fall but do not persist in the spring are the logical choice for football fields, whereas late-transition cultivars are the logical choice for soccer and baseball fields with extensive spring play. Color contrast between the sidelines, outfield, and infield can be obtained by using different cultivars.

The sidelines and outfields can be seeded at 5 to 10 pounds per thousand square feet, whereas heavily trafficked areas, such as the infield and around player benches, should be seeded at 15 to 20 pounds per thousand square feet. Soccer and football fields can be seeded at 8 to 15 pounds per thousand square feet. Additional ryegrass seed (1 to 2 pounds per thousand square feet) can be broadcast on heavily worn areas during the fall and early winter.

A drop-type spreader should be used to define the margins of overseeded areas. Areas inside the borders should be seeded with a rotary spreader, applying half the seed in one direction and the other half by moving at right angles to the first pass. Intensively managed areas, such as infields, goal areas, and player benches, can be top-dressed with soil to help hold the seed in place, and the area can be dragged with a mat or carpet to smooth the playing surface. Less intensively managed areas, such as outfields, do not need to be top-dressed but should be dragged with a chain-link fence or steel drag mat. Areas not to be overseeded (sidelines) can be treated with PRE herbicides to prevent any stray seed from germinating and to improve the aesthetics.

Post-Seeding Care

Irrigate two to three times daily until the seedlings begin to emerge. Irrigate just enough to moisten the surface while preventing lateral seed movement. As seedlings emerge, reduce irrigation frequency to daily, and eventually irrigate only as needed.

Begin mowing the grass at a height of 1 inch on the infield and 1 ½ inches on the sideline and outfield areas and on football and soccer fields. Weekly mowing is often sufficient in late fall and winter, but mowing twice a week is customary in the spring.

Do not fertilize while overseeding because this may encourage the bermudagrass to compete with the young plants. Begin to fertilize shortly after shoot emergence and continue until cold weather halts the ryegrass growth. This typically requires the application of ½ pound of nitrogen per thousand square feet every two or three weeks, or 1 pound of controlled-release nitrogen per thousand square feet every four to six weeks.

Spring Transition

Lower the mowing heights by ¼ to ½ inch when nighttime temperatures approach 60°F to decrease overseeding competition, increase soil temperatures, and hasten bermudagrass recovery. Avoid applying fertilizer while the bermudagrass turns green in spring to avoid bermudagrass injury and to discourage the ryegrass.

Perennial ryegrass should be totally removed by the time bermudagrass is actively growing in late spring or early summer; this will ensure that perennial ryegrass does not compete with bermudagrass in the summer, which can result in bermudagrass death. The most consistent way to remove perennial ryegrass from bermudagrass is to use a herbicide. Cultural methods such as scalping, verticutting, aerification, and fertilization in late spring will not consistently remove perennial ryegrass.

For chemical removal, several products are effective in removing ryegrass from bermudagrass. Metsulfuron (MSM Turf) is an effective, inexpensive herbicide option. MSM Turf should be used at a rate of 0.5 ounces per acre mixed with an adjuvant, nonionic surfactant in late spring or early summer. Perennial ryegrass will gradually die over a two- to three-week period and may result in some browning of the turf. Other herbicides suitable for perennial ryegrass removal are flazasulfuron (Katana), trifloxysulfuron (Monument), and foramsulfuron (Revolver).

The slowest chemical removal of ryegrass occurs with pronamide (Kerb) applied at 1 pound of active ingredient per acre; this will completely remove ryegrass over a four- to six-week period. This slow transition from perennial ryegrass to bermudagrass will result in the least amount of unattractive turfgrass.

Weed Control

Annual bluegrass can be a challenge to manage in sports fields overseeded with perennial ryegrass. Foramsulfuron (Revolver) or metsulfuron + rimsulfuron (Negate 37 WG) can be applied one week prior to overseeding for POST control of newly emerged annual bluegrass. Ethofumesate (PoaConstrictor) and bispyribac-sodium (Velocity PM) can control annual bluegrass, chickweed, and white clover throughout the season, but must be applied sequentially. PoaConstrictor and Velocity PM can be applied 30 days after emergence of perennial ryegrass.

Overuse and compaction are the main reasons for turfgrass failure in athletic fields. Extreme soil compaction limits soil oxygen that is essential for good root growth. Turfgrass managers can reduce compaction through aerification (coring), which uses a machine to insert a hollow, metal tine or spoon into the soil. Aerification is the only way to alleviate soil compaction without seriously disturbing the turfgrass. The holes created by this process allow more oxygen to reach the root system and harmful gases to escape. These holes also allow better movement of water, nutrients, and pesticides in the soil.

The following best practices can also reduce the effects of compaction:

• Avoid irrigation two days before heavy use. Keep use of the field to a minimum when it is wet.

• Postpone play or use alternative sites, if feasible, for band and athletic practice sessions.

• Set aside one field for team or tournament play if possible.

• Change field orientation and move nonstationary goals (Figure 1) so that play is not concentrated in the same area week after week. Consider widening existing fields to accomplish this; it will enhance recovery.

• Stay off partially thawed areas.

• Do not play on new areas until they are fully established.

Figure 1. Movement of nonstationary goals (a) or reorientation of fields (b) can change the wear pattern and lengthen the life of an athletic field.

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Figure 1. Movement of nonstationary goals (a) or reorientation of fields (b) can change the wear pattern and lengthen the life of an athletic field.

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Spring dead spot, nematodes, white grubs, and mole crickets can be nuisance pests of bermudagrass athletic fields. However, diseases and insects are seldom a problem on properly maintained fields. If you suspect a pest problem, make sure you correctly identify the pest before applying pesticide. If you need assistance with identification and nonchemical control measures, consult the NC State Extension TurfFiles portal, contact your local Extension agent, or refer to Turfgrass Pest Management Manual: A Guide to Major Turfgrass Pests and Turfgrasses. If pesticides are needed, select the most appropriate product, and always read and follow label directions. The NC State Extension publication Pest Control for Professional Turfgrass Managers provides the latest pesticide recommendations. A pest problem often indicates that changes in turfgrass management methods are necessary.

Integrated Pest Management

Many pests—including diseases, weeds, insects, and animals—can cause your turfgrass to look bad. So how do you address problems? Use a pesticide or make changes in cultural practices? Both methods, as well as others, may be needed. The balanced use of all available methods is called integrated pest management (IPM).

IPM involves using all available prevention and control methods to keep pest damage from reaching significant levels. The goal is to produce a healthy turfgrass stand and minimize the influence of pesticides not only on the turfgrass but also on people and the environment.

IPM methods include:

• Use of best-adapted cultivars.

• Proper use of cultural practices such as watering, mowing, and fertilization.

• Proper selection, rotation, and use of pesticides when necessary.

Early detection and prevention will minimize pest damage, ultimately saving time, effort, and money. Should a problem occur, determine the cause or causes, then choose the safest, most effective controls available.

When chemical control is necessary, select the proper pesticide, follow label directions, and apply when the pest is most susceptible. Treat only the affected areas. Regard pesticides as only one of many tools available for athletic field care.

To learn more about IPM, pest identification, turfgrass care, or the selection and proper use of pesticides, contact your local Extension center.