Sapphire St. Augustine

 

Testing Period Passes One Year Mark;

Preliminary Results Positive

 

By Roberto Gurgel, Agricultural Engineering Specialist, Sod Solutions, Inc.     

 

            Sapphire^TM St. Augustine, an improved warm season St. Augustinegrass introduced by Sod Solutions, has been grown and tested in Texas for just over one year. Sapphire was introduced through an innovative pre-release program, which has allowed producers to grow it on their farms and observe Sapphire’s excellent characteristics under their own management and conditions for an initial trial period, prior to committing to a full license.

 

            During this first year in Texas, Sapphire has demonstrated a rapid growth rate and a nice deep blue green color. Some growers have already expanded their first initial acre to several acres; and they are ready to start selling Sapphire this summer.

 

            During this same period, Sapphire has also been tested under a trial called Sapphire St. Augustine Comparative Evaluations (SSCE), established at 21 sites throughout the southern United States. The main goal of the SSCE is to quantify Sapphire characteristics, and to compare it to local standards. Texas has four sites: Crosby, Boling, San Antonio and Dallas, where the standards were Raleigh and Palmetto.

 

            All sites followed the same specified protocol for installation and maintenance. This protocol was comprised of:

-         pre-plant herbicide application.

-         plot dimensions: 25’ (5 x 5’) plugs were planted 18 inches apart.

-         replications: 3 rep. for each treatment.

-         maintenance: regular fertilization and mowing height for all plots.

 

Dr. Dave Han, Assistant Professor and Extension Specialist, Auburn University, has coordinated the study, gathering all the data collected during this first year from the several SSCE sites, and making a detailed analysis of the data compiled.

 

The preliminary conclusions coming out of this first year of test and comparisons support, overall, the general perceptions and observations coming from the field: Sapphire has an increased ground coverage rate; or in other words, is a faster growing variety compared to the standards. Sapphire also has shown a deeper green color.

 

The more detailed preliminary conclusions from Dr. Han are summarized below:

 

-         Growth rate and time to fill in from plugging (% of covered area):  There were significant differences for the months of June through September of 2004, when Sapphire had significantly greater coverage than both Raleigh and Palmetto (Figure 1). There were no significant differences in coverage between Raleigh and Palmetto. Sapphire also achieved full coverage (95%) in August, two months before Palmetto and Raleigh. Sapphire consistently demonstrated much more aggressive growth under establishment conditions than either Raleigh or Palmetto.

 

-         Internode distance (cm): Another measure of Sapphire’s aggressive growth was its significantly greater internode distance, both between nodes 4 and 5 and between nodes 7 and 8. Raleigh was the next most aggressive grower with internode distances significantly greater than those of Palmetto (Table 1).

 

 

-         Overall Turfgrass Quality (1-9 scale, with 9 representing perfect turf): Data pooled over all sites and ratings dates showed Sapphire clearly had a higher quality rating than either Raleigh or Palmetto (Table 2). In order to determine how the different varieties perform at different times of the year, the quality ratings were pooled across locations but broken down by month (Table 3). Sapphire had significantly higher quality ratings than either Raleigh or Palmetto throughout the summer, from the month of June until September. In April, interestingly, Palmetto had a significantly higher quality rating than Sapphire or Raleigh (Figure 2). This could suggest that Palmetto is faster to break dormancy, and green-up, during spring. Actually, this should not be a surprise, as Palmetto is known to have excellent cold tolerance. In summary, Sapphire demonstrated superior quality to both Raleigh and Palmetto in the summer and early fall.

 

-         Diseases and Insects: Disease and insect activity was sporadic at most locations, and it is not possible to make definite conclusions about these varieties and their resistance to disease and insects at this time. (Note: Symptoms of gray leaf spot were detected on Sapphire at some fields in Texas during the late winter/early spring. However, due to its rapid growing ability, Sapphire outgrew the problem).

 

-         Future directions: The project will continue for the upcoming year. With the plots fully established, it will be time to observe how Sapphire and the other grasses perform under more “normal” maintenance conditions. If possible, a “dry-down” will be conducted at several  locations. The grasses will be deprived of water for a period up to two weeks or longer, to evaluate drought stress tolerance. Also, evaluations will include the way the grasses behave going into winter as an established stand, and the way they behave coming out of a second winter.

 

These were the main conclusions and observations from Dr. Han, for the first year of the SSCE. Again, the highlights for Sapphire during this first year of tests were superior turf quality, color and ground coverage.

 

Enhanced Turf Quality and Color augment Sapphire’s marketability, as producers and customers generally prefer turfgrass varieties that are more aesthetically pleasing. Increased ground coverage rates, present in Sapphire, reduce production and overhead costs and provide turfgrass producers with larger profit margins and quicker harvest cycles, making it possible to manage smaller areas with the same results.

 

Table 1.  Mean distance between nodes in St. Augustinegrass cultivars, 60 DAP

 

        Variety         Distance between Nodes 4 & 5          Distance between Nodes 7 & 8

• Sapphire                      4.8 cm                                                  4.9 cm

• Raleigh                         4.4 cm                                                  4.6 cm

• Palmetto                       3.8 cm                                                  4.1 cm

•  

• LSD (0.05)                     0.3                                                       0.3

 

 

Table 2.  St. Augustinegrass Quality evaluated across all rating sites and dates

 

         Variety             Mean Quality Rating 

• Sapphire                       7.0

• Raleigh                         6.2

• Palmetto                       6.1

•  

• LSD (0.05)                   0.3

 

 

Table 3.  St. Augustinegrass quality ratings by month from May 2004 to April 2005 across all locations

 

Variety                                                             Mean Quality Rating

 

                         May     Jun       Jul        Aug      Sep      Oct      Nov     Dec      Jan       Feb      Mar      Apr

Sapphire           7.1       7.4       7.5       7.1       7.0       6.7       7.3       7.1       6.5       5.3       6.3       6.0

Raleigh 6.8       6.0       6.0       6.0       5.8       6.8       6.7       6.4       6.4       5.0       6.2       5.8

Palmetto           6.5       6.1       5.8       5.8       5.3       6.3       6.3       6.8       6.6       5.9       6.7       6.5

                       

LSD (0.05)      1.0       0.8       1.0       0.8       1.0       1.3       0.7       0.9       1.0       1.4       0.6       0.5