Finding the best grass

From Queensland to Melbourne via Sydney and Canberra there isn’t really a perfect grass variety, but HAL (Horticulture Australia Limited) with the help from some research carried out in WA, set out to find which variety was the best for the area.

From Queensland to Melbourne via Sydney and Canberra there is no perfect grass, but HAL (Horticulture Australia Limited) set out to find a good one, including research carried out in WA.

According to recent research done by the Queensland Primary Industries and Fisheries Department of Employment, Economic Development and Innovation (HAL project TU04013), available at * they found Sir Walter was a good one.

13 buffalo (Stenotaphrum secundatum) cultivars were tested at 7 locations for their colour, turf quality and thatch development. The tables below is a summary of the results for 4 of those cultivars. (0=worst, 9=best)

Cultivar Total of colour scores Average colour % diff from control
Palmetto 64 5.8 4
Sapphire 62.9 5.7 2
Sir Walter 66.7 6.1 9
Shademaster 61.1 5.6 control
Cultivar Total of quality scores Average quality % diff from control
Palmetto 61.8 6.2 -2
Sapphire 60.7 6.1 -3
Sir Walter 64.8 6.5 +3
Shademaster 63.1 6.3 control

((0=bare ground (no thatch) 9=heaviest thatch))

Cultivar Total of thatch scores Average Thatch % diff from control
Palmetto 36.3 4 -13
Sapphire 39.3 4.4 -5
Sir Walter 40.1 4.5 -2
Shademaster 41.6 4.6 Control

* When we combine these scores with the thatch score as a negative to give a true overall figure, we get:

Cultivar Colour+quality-thatch % difference from control
Palmetto 89.5 8
Sapphire 84.3 2
Sir Walter 91.4 10
Shademaster 82.6 control

* Sir Walter, according to this research is a good one, that’s why it is the most popular and biggest buffalo in Oz (data available from TPA research).
Following are some other interesting statistics from the same recent research highlighting Sir Walter’s characteristics.

Sward height
Turf sward height (mm) on irrigated swards of 4 buffalos grown under shade at Redlands Research Station Qld. Oct 07-May 09

Cultivar Total height Av. Over 9 measurements % difference from control
Palmetto 525.1 58.3 +1
Sapphire 546.8 60.7 +5
Sir Walter 536.6 59.6 +3
Shademaster 518.8 57.6 Control

* All varieties grew to about the same height with Sapphire needing slightly more mowing to look acceptable.
NB, These results differ greatly from other non-independent research posted elsewhere on the web.

Percentages of bare ground determined visually for 4 buffalos that have undergone wear treatments in Aug 08 at Redlands Research Station Qld

Cultivar % bare over 14 wks,10 readings Acceptable level achieved at wk % difference from control
Palmetto 26.2 13 +209
Sapphire 51.9 13 +415
Sir Walter 16.3 9 +130
Shademaster 12.5 9 control

*Sir Walter & Shademaster had about half the wear of Palmetto whereas Sapphire wore twice as much. Palmetto & Sapphire took 4 weeks longer to reach an acceptable level after being worn than Sir Walter.

Drought tolerance
Total clippings produced (g/m2) by 4 buffalo grass genotypes irrigated at 80%, 50% or 33% replacement of net evaporation, for 98 days in plots at Shenton Park WA (summer of 07/08). Plots were mown weekly at 25mm.

Cultivar Clippings @ 80% replacement (control) g/dry mass/m2 Clippings @ 50% replacement
(% of control)
Clippings @ 33% replacement
(% of control)
Palmetto 148 82 17
Sapphire 149 82 47
Sir Walter 203 91 54
Shademaster 145 104 45

*Sir Walter produced more clippings under extreme drought than Palmetto or Sapphire meaning it is more drought tolerant.

Root mass
Total root mass (kg dry mass /m3) of 4 buffalo grass genotypes. Samples taken at – 12mths (Nov 06) and -24mths (Dec 07) after planting from irrigated plots irrigated at 80% replacement of net evaporation at Shenton Park WA

cultivar Increase kg/m3 % increase % increase over control
Palmetto 5.51 177 -21
Saphire 5.78 193 -13
Sir Walter 8.3 230 +24
Shademaster 6.68 225 Control

*In the 2nd year of your lawns life, Sir Walter will increase its root structure 51% more than Palmetto and 44% more than Sapphire.

Root depth
Root distribution 12mths after planting (21/11/06)

cultivar Root depth
Palmetto <50cm
Sapphire <50cm
Sir Walter 50-100cm
Shademaster 50-100cm

*After only 12 months, Sir Walters roots exceed 50cm in depth

Leaf water content
Leaf water content of 4 buffalo grass genotypes irrigated at 50% or 33% replacement of net evaporation for 56 days during summer of 06/07.Shenton Park WA.

cultivar @50% replacement of net evaporation. ml/g dry mass @33% replacement of net evaporation. ml/g dry mass
Palmetto <2.5 <2
Sapphire <2.5 <2
Sir Walter >2.5 >2
Shademaster <2.5 <2

* Sir Walter loses the least amount of moisture from the leaf in extreme dry conditions.

Subjective turf quality rating (0=dead, 6=acceptable and 10=excellent) at end of 10wk trial (11/5/09) Qld

Cultivar 0% 30% 50% 70% 90%
Palmetto 5.3 4.7 3.7 3.7 1.0
Sapphire 7.7 6.3 5.0 4.0 1.7
Sir Walter 6 5.0 4.3 4.0 1.7
Shademaster 7.3 5.3 5.0 3.7 0.7

* Sapphire & Sir Walter have similar shade tolerances at high levels of shade. Palmetto & Sir Walter may have scored better if the initial (0%) turf quality was better.

Winter growth
Comparison of winter growth of 4 buffalo grass genotypes, samples taken winter July 07 at Wembley Golf Course WA

Cultivar Winter Clippings g/m2/wk % Difference from control
Palmetto .22 -21
Sapphire .35 25
Sir Walter .76 271
Shademaster .28 control

*Sir Walter grew right through winter, producing 3.5 times the growth of Palmetto & over twice that of Sapphire, making it a true winter active lawn being more capable to handle the wear and tear of the average Aussie back yard.

Winter colour
Comparison of summer vs. winter colour of 4 buffalo grass genotypes. Measurements taken Feb 07 & Jul 07 at Wembley Golf Course WA

Cultivar Summer Hue angle Winter Hue angle Change indicating Winter decline
Palmetto 114 101 -13.2
Sapphire 118 111 -7
Sir Walter 114 106 -8.5
Shademaster 112 98 -14.8

*Sir Walter & Sapphire had the least loss of colour in winter, whereas Palmetto nearly lost as much colour as Shademaster.
NB, These results differ greatly from other non-independent research posted elsewhere on the web.

* Denotes editor’s comments.

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