Sea Isle 1

This fine-bladed seashore paspalum cultivar, developed by Dr. R. R. Duncan at the University of Georgia’s Griffin Experiment Station, is ideal for golf course fairways, tees, and roughs. It makes a fine choice for sports turf, home lawns and commercial landscaping, too. It’s a grass that thrives on salt water. You can irrigate Sea Isle 1 using a seawater blend, or even straight ocean water with the right management practices. It also grows quite well when watered from recycled or effluent sources.

Sea Isle 1 can only be sold as certified sod or sprigs, and only by licensed members of the Sea Isle Growers Association. This group of quality-conscious sod producers has agreed to the stringent production practices set up by the Georgia Seed Development Commission. You can be assured of Sea Isle 1’s genetic purity. As a certified turfgrass, it’s grown, inspected and sold under a rigorous set of guidelines designed to ensure ongoing purity and uniformity.

Uses

Sea Isle 1 can be used on fairways and tees. It adapts well to most all soils and does exceptionally well in areas where it is difficult to grow bermudagrass.

Characteristics

Sea Isle 1 has a very fine leaf blade with excellent green color hat can be closely mowed to height of 1/4 inch.

Water Quality Tolerance

The most outstanding feature of Sea Isle 1 is its exceptional salt tolerance. It will proliferate in soils irrigated with water containing 2,500 ppm dissolved salts, and will show only a 50 percent reduction in growth at 5,000 ppm. It is considerably more salt tolerant than bermudagrasses and zoysiagrass.

Weed Tolerance

Sea Isle 1 spreads quickly during establishment and forms a dense turf which will compete with the presence of weeds when properly maintained. However, all paspalum selections are sensitive to many pre- and post-emergent selective herbicides. Use only pesticides labeled for paspalum.

Soil Fertility Range

Sea Isle 1 grows best in soils with a pH above 6.0. It performs best on a low level of applied Nitrogen, approximately 3 pounds N/1000 square feet per year. Given a balanced N:P:K program according to soil tests, Sea Isle 1 performs well in a fertility program of about 50 to 70 percent of the amount required for Hybrid Bermudagrasses.

Establishment

All paspalum selections are sterile and must be propagated by sod or sprigs.

Salinity Resistance

Two major injuries can occur at high soil or water salinity levels: drought stress brought on by the plant’s inability to uptake water, and injury to root and shoot tissues due to high salt levels. Based on tests of shoot and root growth responses to increasing salinity levels, Sea Isle 1 showed a minimum decline in rooting and maintained a high level of growth when compared to Adalayd and Tifway 419. Sea Isle 1 is the most tolerant of the warm season grasses.

Drought Tolerance

Drought resistance involves the ability to produce extensive, deep root systems. A 1997 study of seven warm season turfgrasses comparing responses to surface soil drought stress and rewatering demonstrated that Sea Isle 1 and TifBlair centipede had superior drought resistance. Both exhibeited enhanced root growth, rapid root-water uptake at deep soil levels, excellent soil surface root viability, and excellent root regeneration after rewatering.

Cold Tolerance

Sea Isle 1 does quite wels in the southern transition zone (between 30-35 degrees N-S latitudes) and has a cold tolerance similar to the hybrid bermudas. Fine textured paspalums like Sea Isle 1 are generally the last warm season grasses to go off color in the fall by two to three weeks, and it normally takes temperatures of at least 28 degrees Fahrenheight (-2.2*C) for them to go into full winter dormancy. They are also less responsive to mild midwinter and early spring temperature swings.

Wear / Traffic Tolerance

On golf courses, wear injuries usually result from physical abrasions and torn plant tissue caused by maintenance vehicles, golf carts, and incoming balls. On athletic fields, compaction, as well as cleat and spike injuries, are the most common problems. A 1998 wear simulation study involving seven paspalums and three bermudas revealed that, in general, the fine-textured paspalums had less or similar injury from wear than bermudas of similar texture.

Shade / Low Light Tolerance

Sea Isle 1, like most other warm season grasses, does not tolerate tree shade very well and should not be planted in areas with thick tree canopies or heavy shade. However, in rainy, low light environments or cloudy, foggy or smoggy conditions, Sea Isle 1 performs exceptionally well and maintains a dark green color and good turf quality versus the elongated, spindly leaves that are typical of bermudagrass response to the same to the same reduced light conditions.

Soil pH Adaptation

Paspalums in general will tolerate pH ranges from very acidic pH 3.5 to a highly alkaline pH 10.2, and they root equaly well in sands, heavy clays, silts and mucks. In acid soil field trials, Sea Isle 1 placed in the “high tolerance” group, while Sea Isle 2000, the fine-bladed greens-type paspalum cultivar, scored in the “very high tolerance” group. In extremely alkaline soils, paspalums are usually the only turf-type grass species that can survive.

Low oxygen / Hypoxia Tolerance

Paspalums have a history of tolerating complete ocean water inundations and the low oxygen problems associated with waterlogged or wet and boggy environments. That’s why Sea Isle 1 is so ideally suited for low-lying or poorly drained areas that tend to stay wet for a long time. In fact, Sea Isle 1 may actually help firm up such problem areas through water extraction, so that sports and other recreational activities can take place.

Mowing Height Tolerance

Sea Isle 1 should be maintained at 1/2″ for fairways and 1/4″ for tees. At these lower heights, Sea Isle 1 develops higher shoot densities, is more competitive against broadleaf and annual grassy-weed invasions, and maintains better turf quality. Maintaining Sea Isle 1’s cutting heights at or below 1/2″ is more important than N fertility levels in terms of low temperature color retention in the fall as well as grass color during spring greenup.

Disease Resistance

Sea Isle 1 does not have a wide variety of disease problems that tend to plague other warm season grasses. More than likely this is due to the fact that the grass evolved in a wet, humid ecosystem where it developed resistance. When irrigating with brackish or straight sea water, disease problems are negligible, since most diseases do not function well at high salt levels. Sea Isle 1 was developed to resist dollar spot and ranked “most resistant” to it in three 1995 studies.

Low FertilityRequirement

The paspalums developed and thrived in stressful ocean-exposed ecosystems. This helps explain how Sea Isle 1 developed such efficient nutrient uptake and utilization mechanisms. Sea Isle 1 will grow when the availability of nutrients is quite low, as well as in situations with severe nutrient imbalances. Because Sea Isle 1 is so efficient in its uptake of nitrogen, less than 5 pounds of N per 1000 square feet is recommended via spoon-feeding on an annual basis.

Weed Control

Most weeds lack the necessary level of salt tolerance to compete with Sea Isle 1 in a salt-affected turfgrass environment. A close mowing height of less than 12 mm (1/2″) will also provide a tight, dense canopy that deters weed growth. The exceptions include those grassy weeds like kikuyugrass, torpedograss and kyllinga, which are extremely aggressive in warm coastal venues, we soil conditions and aquatic waste sites.