The following pages show the statistical significance in the difference in the mowing rates, and have been derived from a market research program.

The purpose of the research was to test the theory that there were differences in the mowing rates for Kikuyu & Couch compared to Empire Turf.

The following tests prove that there is a significant difference in mowing rates for the three different varieties.

TEST 1 - Kikuyu compared to Empire Turf - fertilised twice per year
The purpose of a means test is to compare the size of the difference between two means in relation to the amount of inherent variability (the random error) in the data. If the random error is large then we are unlikely to find a significant difference between means unless this difference is also very large. The paired T tests use standard deviation and the mean (or average) for the mowing rates to compare the difference in mowing.

 

TEST 1 - Kikuyu compared to Empire Turf - fertilised twice per year

To test whether there was a difference in the mowing rate of Empire and Kikuyu when fertilised twice per year, the following paired samples test was conducted.

Ho: µ diff = 0 or in other words no difference
H1: µ diff > 0 or < 0 or is there a significant difference

Reject Ho if sig value < 0.05

Since 0.03 < 0.05 we reject Ho and conclude there is a significant difference in the mean mowing rates for Empire and Kikuyu, at the 95% confidence level.

Paired Samples Statistics
Mean
No
Std. Deviation
Std. Error Mean
Pair 1
EMPIRE2
21.2333
30
6.5637
1.1984
 
KIKUYU2
48.9333
30
7.5014
1.3696

Paired Samples Correlations


No
Correlation
Sig
Pair 1
EMPIRE2 & KIKUYU2
30
0.528
0.003

 

Paired Samples Test

 
Paired Differences
         
Sig. (2-tailed)

Mean
Std. Deviation
Std. Error Mean
95% Confidence Interval of the Difference
  
t
d
  
 
 
Lower
Upper
 

 

  
Pair 1
EMPIRE2 - KIKUYU2
-27.7000
6.8840
1.2568
-30.2705
-25.1295
-22.039
29
0.000


Conclusion: There is a significant difference between the mowing rates, thus with Empire Turf you can save yourself a lot of money and time by not having to mow your lawn as regularly.

TEST 2 - Couch compared to Empire Turf - fertilised twice per year

To test whether there was a significant difference in the mean mowing rates for Empire and Couch grass when fertilised twice per year, the following paired samples test was conducted.

Ho: µ diff= 0 or in other words no difference
H1: µ diff > 0 or < 0 or is there a significant difference

Reject Ho if sig value < 0.05
Since 0.256 < 0.05 we accept Ho and conclude there is no significant difference in the mean mowing rates for Empire and Couch.

Paired Samples Statistics
Mean
No
Std. Deviation
Std. Error Mean
Pair 1
EMPIRE2
21.2333
30
6.5637
1.1984
 
COUCH2
37.8667
30
7.9989
1.4604

 

Paired Samples Correlations


No
Correlation
Sig
Pair 1
EMPIRE2 & COUCH2
30
0.214
0.256

 

Paired Samples Test

 
Paired Differences
         
Sig. (2-tailed)

Mean
Std. Deviation
Std. Error Mean
95% Confidence Interval of the Difference
  
t
d
  
 
 
Lower
Upper
 

 

  
Pair 1
EMPIRE2 - COUCH2
-16.6333
9.1970
1.6791
-20.0676
-13.1991
-9.908
29
0.000

Conclusion: There is no significant difference in the mowing rates of Couch and Empire at the 95% confidence level
TEST 3 - Kikuyu compared to Empire - fertilised once per year

One of our aims was to research the difference in mowing rates for Empire compared to other grasses when only fertilised once per year. The reason for this is that Empire Turf has a distinct advantage as it will still look great even if it is only fertilised once per year, whilst other grasses may thin out. The mowing rates of turf when fertilised only once per year was also of interest.


To test whether there was a difference in the mowing rate of Empire and Kikuyu when fertilised once per year, the following paired samples test was conducted.

Ho: µ diff= 0 or in other words no difference
H1: µ diff > 0 or < 0 or is there a significant difference

Reject Ho if sig value < 0.05

Since 0.04 < 0.05 we reject Ho and conclude there is a significant difference in the mean mowing rates for Empire and Kikuyu, when fertilised once per year.

Paired Samples Statistics
Mean
No
Std. Deviation
Std. Error Mean
Pair 1
EMPIRE2
16.7000
30
5.7304
1.0462
 
KIKUYU2
39.5000
30
7.8466
1.4326

 

Paired Samples Correlations


No
Correlation
Sig
Pair 1
EMPIRE2 & KIKUYU2
30
0.507
0.004

 

Paired Samples Test

 
Paired Differences
         
Sig. (2-tailed)

Mean
Std. Deviation
Std. Error Mean
95% Confidence Interval of the Difference
  
t
d
  
 
 
Lower
Upper
 

 

  
Pair 1
EMPIRE2 - KIKUYU2
-22.8000
6.9847
1.2752
-25.4081
-20.1919
-17.879
29
0.000

 

Since 0.04 < 0.05 we reject Ho and conclude there is a significant difference in the mean mowing rates for Empire and Kikuyu, when fertilised once per year.

 

 

TEST 4 -Couch compared to Empire Turf - fertilised once per year

To test whether there was a significant difference in the mean mowing rates for Empire Turf and Couch when fertilised once per year, the following paired samples test was conducted.

Ho: µ diff= 0 or in other words no difference
H1: µ diff > 0 or < 0 or is there a significant difference


Reject Ho if sig value < 0.05
Since 0.381 < 0.05 we accept Ho and conclude there is no significant difference in the mean mowing rates for Empire and Couch.

 

Paired Samples Statistics
Mean
No
Std. Deviation
Std. Error Mean
Pair 1
EMPIRE2
16.7000
30
5.7304
1.0462
 
COUCH2
31.9000
30
8.4582
1.5443

 

Paired Samples Correlations


No
Correlation
Sig
Pair 1
EMPIRE2 & COUCH2
30
0.166
0.381

 

Paired Samples Test

 
Paired Differences
         
Sig. (2-tailed)

Mean
Std. Deviation
Std. Error Mean
95% Confidence Interval of the Difference
  
t
d
  
 
 
Lower
Upper
 

 

  
Pair 1
EMPIRE2 - COUCH2
-15.2000
9.3970
1.7156
-18.7089
-11.6911
-8.860
29
0.000

Conclusion: There is no significant difference at the 95% confidence interval for Empire Turf and Couch.

TEST 5 - Kikuyu compared to Empire Turf - under moderate wearing conditions

The final test that we wanted was to compare Empire Turf to Kikuyu under moderate wearing conditions. It is recommended that Kikuyu needs fertilizing twice per year, whilst Empire only requires fertilising once per year. Part of this included comparing the mowing rates in moderate wearing areas.

Ho: µ diff= 0 or in other words no difference
H1: µ diff > 0 or < 0 or is there a significant difference

Reject Ho if sig value < 0.05

Since 0.000 < 0.05 we reject Ho and conclude that there is a significant deifference in the mowing rates of Empire Turf and Kikuyu.

Paired Samples Statistics
Mean
No
Std. Deviation
Std. Error Mean
Pair 1
EMPIRE2
16.7000
30
5.7304
1.0462
 
KIKUYU2
48.9333
30
7.5014
1.3696

 

Paired Samples Correlations


No
Correlation
Sig
Pair 1
EMPIRE2 & KIKUYU2
30
0.767
0.000

 

Paired Samples Test

 
Paired Differences
         
Sig. (2-tailed)

Mean
Std. Deviation
Std. Error Mean
95% Confidence Interval of the Difference
  
t
d
  
 
 
Lower
Upper
 

 

  
Pair 1
EMPIRE2 - KIKUYU2
-32.2333
4.8115
0.8785
-30.4367
-34.0300
36.693
29
0.000

Conclusion: There is a significant difference in the mowing rates of Empire Turf compared to Kikuyu under moderate wearing conditions. Thus if you want to save yourself time and money purchase some Empire turf and enjoy the difference.

 

“EMPIRE™ ZOYSIA – It just keeps looking good.”

 
     
 

© 2005 Sod Solutions, Inc.