Agronomy

Dr. Clint Waltz
Professor and Turfgrass Extension Specialist
The University of Georgia

Seashore paspalum has critical and distinct irrigation requirements, unique herbicide tolerances and requirements, a higher salinity tolerance, and varied disease and insect pressures than bermudagrass. While seashore paspalum is not necessarily difficult to manage, its management requirements are different than that of bermudagrass — even though both grasses are warm-season species, fine-textured turfgrassess used on golf courses, sports fields and lawns. For best results, forget what you know about managing bermudagrass. When it comes to seashore paspalum management, treat paspalum like paspalum. The following section offers a comprehensive library of best practices for seashore paspalum management.

fertility

In general, seashore paspalum requires less nitrogen for fertilization than bermudagrass. Seashore paspalum can thrive on as little as 2lbs. of N per 1,000 sq.ft. per year in many situations. But N requirements are site specific and can vary by use.

Greens Fertility

  • Annual N applications of 3 – 6 lbs./1000 sq. ft. (1.47 – 2.94 kg/100 sq. m) in areas with winter dormancy.
  • Annual N rates of 5 – 8 lbs./1000 sq. ft. (2.45 – 3.92 kg/100 sq. m) in humid tropical regions with high rainfall and year round growing seasons.
  • When rates exceed 4 lbs./100 sq. ft. (1.96 kg N/100 sq. m) per year, careful application scheduling in a spoon-feeding approach or via fertigation is essential to minimize puffiness, thatch buildup, and potential scalping problems in some
    environments.

Tees Fertility

  • Annual N applications of 3 – 6 lbs./1000 sq. ft. (1.47 – 2.94 kg/100 sq. m) in areas with winter dormancy.
  • Annual N rates of 5 – 8 lbs./1000 sq. ft. (2.45 – 3.92 kg/100 sq. m) in humid tropical regions with high rainfall and year round growing seasons.
  • When rates exceed 4 lbs./100 sq. ft. (1.96 kg N/100 sq. m) per year, careful application scheduling in a spoon-feeding approach or via fertigation is essential to minimize puffiness, thatch buildup, and potential scalping problems in some
    environments.
irrigation

The Basics on Irrigating Seashore Paspalum

  • Use as low salt-laden water source as possible during the first 3-4 weeks after sprigging and up to 2-3 weeks after sodding. Any salt level over 5000 ppm TDS could be detrimental to rapid establishment. Remember that salts are site specific and in certain environments and sites, lower salinity levels can cause problems.
  • YOU MUST HAVE ACCESS TO FRESH WATER OR LOW SALINITY WATER DURING ESTABLISHMENT.
  • Salt is a great growth regulator and the higher the salt level, the slower the growth rate (reductions >50% will occur, depending on level of salinity tolerance).
  • Salinity transitioning shock: Shifting from low salt (ie. 500 ppm ) or fresh water during early establishment to high salt (>5000+ ppm) may cause a temporary leaf tip brown discoloration. This is a transitioning shock to the turf plant as it adjusts to higher salinity levels. Add Fe to maintain color and supplement with extra K.

If only highly saline water is available for establishment:

  • Sodding is better than sprigging
  • Aerate with solid tines (the deeper the better)
  • Apply gypsum (2-3 lbs/1000 sq/ft.) prior to sodding
  • Apply a wetting agent when flushing to uniformly move salts downward
  • Apply a cytokinin product to enhance rooting
  • Maintain irrigation scheduling about 5% above evapotranspiration
  • Wastewater treatment is designed to remove solids, decrease organic matter, and disinfect. The process does not deal with inorganic salt levels or extraction of nutrients or heavy metals. The fertility program must be adjusted accordingly.
  • Total salinity of municipal wastewater can increase threefold from the potable initial source to the final effluent discharge. The SAR may increase 5 – 10X.
  • Savings from reclaimed water use may be offset by increases in soil amendments, water treatment, cultivation events, and retrofitting of irrigation equipment.
  • Negotiations on the price for effluent water should be tied to the quality of that water and its future impact on soil type, plant species, irrigation system efficiency, and climate.
  • Seasonal water quality fluctuations are possible. The salinity effect is site specific.
  • Avoid salt – based amendments in salinity – affected sites.
  • Good surface/subsurface drainage is essential.
  • Monitor Ca, Mg, Mn, P, and K soil and water concentrations regularly, since these nutrients may be leached out before the turf roots can absorb them.
  • Irrigation rates might vary from 0.5 – 1.0 inch daily (very poor quality, high total salts/bicarbonates) to 1 inch weekly (good quality water).

Irrigation During Establishment

  • Keep sprigs/sod moist for 2-3 weeks after establishment.
  • Apply irrigation water each time fertilizer treatments are made.
  • Gradually transition the irrigation schedule from short duration, frequent events to longer intervals between applications
    and a longer duration during each application in order to force the roots deeper into the soil profile.

General Irrigation Maintenance

  • Rates can vary from 1 inch weekly to 1 inch biweekly, depending on soil conditions and climate.
  • Scale back an irrigation frequency during the fall months to force roots (rhizomes) deeper and to improve winterhardiness.
  • In arid regions, maintain field capacity (-3 bars) during the winter months to minimize cold temperature injury.
Seashore Paspalum Mowing Recommendations

For Golf Courses
Maintain mowing heights for Sea Isle 2000 in the 3 – 5 mm range (0.12 – 0.20 inches). Precision reel mowers with sharpened blades will be needed for uniform cuts. Stimps of 9 – 12 feet can be achieved 365 days a year with proper management (regular light verticutting, light topdressing, periodic rolling). Paspalum properly mowed at this height normally does not develop a “grain”.

For Golf Tees
Optimum mowing heights should range from 13 – 20 mm (0.50 – 0.75 inch).

Thatch Management & Verticutting
  • Excess water combined with N rates >5 lbs./1000 sq. ft./year can cause puffiness, thatch buildup, and increased potential for scalping. Heavily trafficked greens or high use sports fields may require verticutting once per month during peak use times. Less-trafficked greens may require verticutting two to four times per year. Landing zones in fairways may need 2 – 4 verticutting events annually to escalate recovery.
  • Tees could require weekly verticuts after line markers are moved to enhance recovery. Verticutting stimulates each node to root and initiate new stolons and rhizomes. Verticutting or slicing depths can range from 13 – 25 mm deep (0.5 – 1.0). Single cuts should be sufficient for grow-in enhancement and for damage repair. Direction of verticut should be altered with each application.
  • In heavily thatched areas and during Spring greenup, a double verticut could prove beneficial in tightening up (increasing the density) of the canopy. Light frequent topdressing applications will promote a firm, uniform surface and minimize thatch accumulation with proper fertilization and irrigation scheduling.