Welcome to the  U.C. Cooperative Extension Research

UC Riverside 

UC Davis

Cal Poly SLO

Cal State Fresno

Cal Poly Pomona

U.C Cooperative Extension 

List of other Universities

Turfgrass Information Center at Michigan State University

Center for Irrigation Technology (CIT)
 

Allied Organizations
Research Web Sites

Northern California Golf Association - Turfgrass Services

USGA Turf Research

USGA Turfgrass & Environmental Research Online

Turfgrass Research Project

Bentgrasses for Golf Course Greens

Creeping bentgrass (Agrostis Palustris Huds.), a native of Eurasia, is the primary grass used on golf, 
as well as bowling, croquet and lawn tennis courts in the northern half of the United States.  In California, 
with the exception of the southernmost and desert areas, it is the only grass used for fine putting greens 
at golf courses.  In the past 10 years, many new and improved bentgrasses have entered the market. 
Increased national demand by golf course superintendents for information related to comparative 
performance in varying climates and under intensively managed putting conditions, led in 1997 to a 
joint research project on 13 golf courses across the United States.  A set of evaluation trials were 
sponsored by: the United States Golf association (USGA), the Golf Course Superintendents Association 
of America (GCSAA) and the National Turfgrass Evaluation Program (NTEP).  Trial sites were all
located on golf courses near Land Grant Universities with  turfgrass research programs, or in major 
metropolitan areas readily accessible to a University turfgrass scientist.  At each site eighteen (18) 
creeping bentgrass cultivars were planted on a new putting green, built according to the USGA specifications. 
This project differed from evaluations traditionally conducted at University Research Stations because 
each green is maintained in the same manner as other greens at its golf course and is used by golfers 
for practice putting and/or chipping.

The site chosen for the Northern California evaluation was at the Crystal Springs Golf Course (CSGC) 
in Burlingame on the San Mateo peninsula.  In addition to CoursCo Inc., the CSGC operating group, the 
Golf Course Superintendents Association of Northern California, the Northern California Turf and Landscape 
Council and the University of California Cooperative Extension joined as the co-sponsors of this local project.

The 18 creeping bentgrasses were seeded in September 1997 on a newly built practice green at CSGC. 
The USGA green, and its surround, were designed and donated to the project by the Robert Trent Jones Jr. 
Group of Palo alto, California.  All varieties, supplied by NTEP, were planted at the rate of 1.1lb/1000 ft2 
in a randomized complete block design, on 10 ft x 5 ft plots with 3 replications.  Seeds were planted carefully
by hand to prevent contamination of adjacent plots, and then were lightly raked in.  A complete fertilizer, 
providing 2 lbs phosphorus, 2 lbs potassium and 1 lb nitrogen per 1000 ft2 was also applied at this time.  The 
area of the green outside the research plots was seeded with “Cobra” creeping bentgrass, and then irrigation 
was turned on.  The green was maintained for 6 months until the grasses were well established, and in spring 
1998 it was opened to use by golfers.  Since then the green has been open all year for putting.  The use of 
soft-spike shoes has been encouraged.  The maintenance regime for the green since it’s opening in 1998 is 
as follows:

Mowing:  Three times weekly at 5/32 inch, with a walk-behind mower.  No rollers or groomers were used.

Cultivation/Topdressing:  Spiking and ¼” hollow-tie aeration was done several times during the year. 
No verticutting was practiced, but the green was occasionally topdressed with sand.

Fertilization:  Both inorganic and organic fertilizers (Milogamite) provided an average of 6 pounds of nitrogen 
per 1000 ft2/year.

Pesticide use:  Fungicides were occasionally used as curative applications.  Broadleaf herlicides was also 
occasionally used.  No insecticides or other pesticides were ever applied.

Data collection began in January 1998.  Each plot was rated monthly for overall quality on a scale of 1-9 (9=best). 
Color was rated on a scale of 1-9 (9=darkest green) once a year in October, when environmental stress on 
lowest and the full genetic color of any cultivars should be expressed.  Two to three times per year, stimpmeter 
readings were recorded for each plot using a stimpmeter modified for use on small research plots  (This stimpmeter 
has its ball release notch located 15 inches, rather than 30 inches, from the beveled end).  The accompanying
Table summarizes the combined data collected for 4 years, 1998-2001.  As the final, combined multi-year data,
the information provided in this table could be consulted to select the most appropriate bentgrass cultivars.

In reviewing the Table, please note values for LSD (Least Significant Difference).  This term is used to determine 
statistically significant differences among cultivars for each evaluated parameter.  To determine statistical differences 
among cultivars, subtract one cultivar’s mean rating from another cultivar’s mean rating.  Statistically significant 
differences occur when the resulting value is larger than the corresponding LSD value.  If the difference between 
the mean values for two cultivars within the same column is not greater than the corresponding LSD, then the two 
cultivars are statistically the same for that specific quality component.

For example, considering the LSD value of 0.4 given for mean turf quality ratings, there is no significant difference 
among the 8 top performing cultivars (“L-93” down to “SR1119”), since their mean differences are all smaller than 0.4.

Author’s Note:  No part of this article, or accompanying Table, may be reprinted without the written permission 
of the author.

Acknowledgements:  The authors wish to thank Mr. Ray Davies and all other Crystal Springs Golf Course 
Superintendents during the course of this study, all of CoursCo Inc., for the maintenance of the experimental 
green and assistance in collecting data.
 

TURFGRASS QUALITY AND OTHER RATINGS OF BENTGRASS CULTIVARS
AT BURLINGAME, CA(CRYSTAL SPRINGS G.C.)
1998 - 2001 DATA
TURFGRASS QUALITY AND OTHER RATINGS 1-9;9=BEST
TURFGRASS TIMPMETER READINGS MEASURED IN INCHES
CULTIVAR	COLOR	LEAF TEXTURE	%POA 2001	STIMPMETER  MAY	STIMPMETER  OCTOBER
L-93	7.8	7.8	3.5	92.3	105.3
PENN A-4	6.9	7.8	3.5	100.9	112.8
PENN G-6	7.2	7.8	3.8	95.8	113.4
PENN A-1	6.8	7.6	3.8	94.7	112.7
GRAND PRIX	6.9	7.9	3.3	96.2	114.0
IMPERIAL	7.2	7.8	5.8	89.3	110.1
PENN G-1	7.2	7.5	4.4	91.7	108.8
SR 1119	7.2	7.7	5.8	90.2	114.0
BACKSPIN	6.9	8.0	4.7	93.7	109.2
CRENSHAW	7.1	7.5	3.8	95.1	116.3
CENTURY	6.6	8.0	3.8	94.4	110.5
SR 1020	6.7	7.5	6.2	95.8	111.3
VIPER	6.7	7.4	4.8	92.7	114.2
PROVIDENCE	7.2	7.5	5.0	96.7	114.6
PUTTER	6.5	7.3	5.8	94.2	113.3
TRUELINE	6.8	7.8	6.7	95.9	114.3
CATO	6.8	7.5	7.3	96.9	113.3
PENNCROSS	5.8	6.3	5.8	101.9	116.2
LSD VALUE**	1.4	0.6	11.2	33.5	27.0
*No part of this table may be reproduced in any form without the author's permission.
** If the difference between the mean for two cultivars within the same column is not greater than the corresponding LSD,  then the two cultivars are statistically the same for the specific quality component.

Contact Information

Telephone: 866-643-8707 

FAX: 559-643-8707 

Postal address: 221 W. Palm Ave. Reedley, CA 93654

Electronic mail: rtillema@comcast.net  Webmaster: rtillema@comcast.net