SeaIsle 1 - Seashore Paspalum Technical Information

     Seashore Paspalum (Paspalum vaginatum) is a warm season, sod-forming perennial grass that spreads by stolons and rhizomes. The primary center of origin for fine-leafed ecotypes is South Africa. A secondary center of origin is Argentina/Brazil. The generalized zone of adaptation is between 30-35 degrees N<>S latitude, primarily in coastal ecosystems and moist habitats.

     Morphological characteristics are quite variable, ranging from coarse forage types to intermediate types, (resembling common bermudagrass), to the finer types used in turf. It has been used over a wide range of turfgrass environments including golf courses, athletic fields, land reclamation, sand dune stabilization and bioremediation.

     Seashore Paspalum is the most salt tolerant turfgrass currently available. Ecotypes range in salinity adaptability from 10,000 ppm (ocean level salt, with mandatory management protocols). Seashore Paspalum can be irrigated with a wide range of non-potable water sources, including recycled/effluent gray water, brackish water or various blends of these sources. The species is a true halophyte (salt loving plant) and needs sodium and chloride as micronutrients in nonsalt-affected environments.

     Inflorescence is a twin primary raceme with twin rowed spikelets. In genetically pure stands, seed production is absent or rare due to pollen self-incompatibility. Genetically diverse plantings have potential to produce seed, although in most climates, hybrid seedlings are rare. Propagation of current varieties is by stolons and rhizomes.

Origin

     Sea Isle 1 (tested as Fwy-1) is a selection from a seeded introduction originating in Argentina that was collected in the 1970's.

Morphology

     Compared to "Adalayd", Sea Isle 1 has a higher tolerance to salinity (table 1.), a darker green color and finer textured leaves. Turf density and overall quality of Sea Isle 1 was rated as 8.0 while Adalayd was rated as 5.0 in tests at Griffin, GA.

     Compared to Tifway at fairway mowing heights, Sea Isle 1 's texture is similar or slightly coarser than Tifway. The appearance and texture of Seashore paspalum changes remarkably with close mowing. The leaf texture with mowed (1/2 - 3/4) juvenile growth is finer and sod significantly denser compared to unmowed turf or turf mowed at a taller height.

     Seed head production is less than Salam and Excalibur and occurs mainly after severe stress or during early spring and late fall. The inflorescence is approximately 1 - 1-1/4 inch in height with yellow anthers and bronze midrib. Viable seed are normally not produced in a monostand of Sea Isle 1.

Table 1. Comparative Salt Tolerances of Paspalum Ecotypes Relative Growth Rates

Pest Resistance/Tolerance

     Sea Isle 1 has good resistance to dollar spot, susceptibility to anthracnose when temperatures are below 77°F and moderate resistance to mole crickets. The reaction to nematodes is unknown.

Winterhardiness

     Sea Isle 1 has greater tolerance to cool temperatures (near freezing) than bermudagrass cultivars. It can tolerate moderate frosts without losing color and usually requires 28° F to go dormant and turn brown. Greenup in the spring is similar to bermudagrass with less potential injury from late spring frosts. The general zone of adaptation in the continental U .S. will be south of a line from Raleigh, NC to Chattanooga, TN to Little Rock, AR to Dallas, TX to Albuquerque, NM to San Francisco, CA.

Shade Tolerance

     Sea Isle 1 is superior to hybrid bermudagrass cultivars under prolonged cloudy, foggy, rainy conditions (light intensity). It responds to tree shade (light quality) similar to bermudagrass and should not be used in heavily shaded areas.

Management

     The keys to good management include:

(1.)	Grow-in fertility similar to bermudagrass,
(2.)	Long term N fertility should not exceed 5 Ibs. actual N/1000 sq.ft./yr.,
(3.)	N:K ratios of 1:3 to 1:5,
(4.)	Maintain high levels Mg,
(5.)	Add Na and Cl in nonsalt-affected environments to maintain adequate levels,
(6.)	Irrigation scheduling after establishment should be long duration, but infrequent. Application amounts should be adjusted according to rainfall and evapotranspiration rates,
(7.)	Mowing height should be between 0.25-0.75 inches for maximum density, reduced weed pressure and best performance,
(8.)	Sprigging rates are similar to Tifway. Grow-in time is also similar and will range from 2-3 months depending on water quality, and
(9.)	Use the lowest salt-laden irrigation water available for grow-in (<2000 ppm, if possible). Mature turf can withstand salt loads >25,000 with good management.

Seashore Paspalum