Tolerance of Creeping Bentgrass Cultivars and Selections to Anthracnose in New Jersey

S. A. Bonos, E. N. Weibel, T. J. Lawson, and B. B. Clarke, Plant Biology and Pathology, Rutgers University, New Brunswick, NJ 08901

Corresponding author: S. A. Bonos. bonos@aesop.rutgers.edu

Anthracnose, caused by the fungus Colletotrichum cereale Manns sensu lato Crouch, Clarke, and Hillman (1), is a destructive disease of bentgrass (Agrostis spp.) and annual bluegrass (Poa annua L.) turf maintained as putting greens. Anthracnose can occur as a foliar blight or a basal rot of stem and leaf sheath tissues (3). It is particularly severe on annual bluegrass, but in some areas of the country (specifically in the Southeast and Midwest) can also cause significant damage on creeping bentgrass (Agrostis stolonifera L.). Golf course superintendents struggling to control anthracnose often rely primarily on fungicides for disease suppression. However, depending solely on fungicides to control anthracnose is costly and may not be completely effective, particularly when plants are under cultural and/or environmental stress (2). Genetic resistance provides a promising approach to limiting the incidence and severity of anthracnose, thus potentially reducing fungicide inputs on golf course turf. The use of tolerant cultivars also has the potential to enhance fungicide efficacy and is an important component of an integrated pest management program.

In the autumn of 2004, 67 bentgrass cultivars and selections [including eight velvet bentgrasses (Agrostis canina L.)] were established in a putting green trial in a randomized complete block design with three replications on a Nixon sandy loam (fine-loamy, mixed, mesic Typic Hapludaults) maintained at a pH of 6.1 in North Brunswick, NJ, with agricultural limestone. Plots were seeded at a rate of 0.9 lb/1000 ft². The trial was mowed daily with a triplex putting green mower (Toro Co., Bloomington, MN) bench set at 0.125 inches. In 2007, turf received N at 1.7 lb/1000 ft² as IBDU (0.5 lb N per 1000 ft²) on 18 April followed by six foliar applications of 34-0-0 (0.2 lb N per 1000 ft²) (ammonium nitrate) from April to September. In 2008, turf received N at 0.6 lb/1000 ft² as three foliar applications of 34-0-0 (0.2 lb N per 1000 ft²) from June to August. The trial was not topdressed. Supplemental irrigation was only applied to avoid severe drought stress. Dollar spot (caused by Sclerotinia homoeocarpa F.T. Bennett) and brown patch (Rhizoctonia solani Kühn) were controlled with fungicides (vinclozolin and flutolanil) previously determined not to be efficacious against anthracnose. A natural, uniform epidemic of anthracnose basal rot occurred in both 2007 and 2008 (Fig. 1). Anthracnose severity was periodically assessed from July through August each year using a 1 to 9 (9 = least disease) visual rating scale. Data were subjected to analysis of variance (P ≤ 0.05) using the General Linear Model procedure for a randomized complete block design in the Statistical Analysis System software v. 9.1.3 (SAS Institute Inc., Cary, NC). Means were separated by Fisher’s protected least significant difference test at the 0.05 probability value.

Fig. 1. Response of tolerant (left) and intolerant (right) bentgrass cultivars and selections to anthracnose disease observed in New Jersey in 2007.

The anthracnose response among cultivars and selections was consistent between years and there was no significant cultivar by year interaction (data not shown). Therefore, data is presented as an average of both years, as well as individual years, to document the variability observed in disease resistance throughout the study. Significant differences in anthracnose resistance were observed between bentgrass cultivars and selections. The velvet bentgrass cultivars and experimental selections ranged from very good disease tolerance (VE3 comp, ‘Greenwich’) to intolerance (SRX 7EW 88-34). The commercial creeping bentgrass cultivars, ‘Shark,’ ‘Penneagle II,’ ‘Runner,’ ‘Penn A-1,’ ‘Tyee’ and ‘Authority,’ and the experimental selections SRX 1WM3, SRX 1G32, SRX 1WM213, and SRX 1WM231, exhibited very good tolerance to anthracnose, all rating a 7.2 or higher. The cultivars, ‘Penneagle,’ ‘Penn G-6,’ ‘Century,’ ‘L-93,’ ‘Penn G-2,’ ‘SR 1119,’ ‘Benchmark DSR,’ ‘Southshore’ and ‘Putter’ exhibited moderate tolerance, while the cultivars, ‘Viper,’ ‘Providence,’ ‘Penncross,’ ‘Brighton,’ ‘Seaside II’ and ‘Pennlinks II,’ and the experimental selections, PST-ORF, and PST-SYN-OHTY, were quite susceptible to this disease with ratings below 3.8. This data should be useful to golf course superintendents interested in selecting bentgrass cultivars with enhanced tolerance to anthracnose.

Table 1. Anthracnose tolerance of bentgrass cultivars and selections in a putting green trial seeded September 2004 at North Brunswick, NJ.

	Cultivar or selection	Species	Anthracnose tolerance
	Cultivar or selection	Species	2007-2008	2007	2008
1	VE3 Comp	Velvet	8.7	9.0	8.3
2	Shark	Creeping	8.3	8.3	8.3
3	SRX 1WM3	Creeping	7.5	8.3	6.7
4	Penneagle II	Creeping	7.3	9.0	5.7
5	Runner	Creeping	7.3	8.0	6.7
6	SRX 1G32	Creeping	7.3	8.7	6.0
7	Greenwich	Velvet	7.3	8.0	6.7
8	Penn A-1	Creeping	7.2	8.7	5.7
9	Tyee	Creeping	7.2	7.7	6.7
10	SRX 1WM213	Creeping	7.2	7.3	7.0
11	SRX 1WM231	Creeping	7.2	8.3	6.0
12	Authority	Creeping	7.2	8.0	6.3
13	EPC Comp	Creeping	7.0	8.3	5.7
14	Penn A-2	Creeping	6.8	7.3	6.3
15	SRX 146-12	Creeping	6.8	7.3	6.3
16	DMC Comp	Creeping	6.8	7.0	6.7
17	FDS2 Comp	Creeping	6.8	8.3	5.3
18	MacKenzie	Creeping	6.7	7.3	6.0
19	SRX 1WM COMP	Creeping	6.7	7.3	6.0
20	Villa	Velvet	6.7	6.3	7.0
21	PST-SYN-ONCE	Creeping	6.5	7.7	5.3
22	SRX 1TR3E	Creeping	6.5	7.3	5.7
23	SRX 1WM385	Creeping	6.5	6.3	6.7
24	Penn G-1	Creeping	6.3	8.0	4.7
25	Independence	Creeping	6.3	6.3	6.3
26	Kingpin	Creeping	6.3	6.7	6.0
27	T-1	Creeping	6.3	6.3	6.3
28	SR 1150	Creeping	6.3	7.0	5.7
29	SRX 1BL1E	Creeping	6.3	6.0	6.7
30	03-RSM-Comp	Creeping	6.3	6.7	6.0
31	SRX 1WM3102	Creeping	6.2	6.7	5.7
32	PST-EVX Bulk	Velvet	6.2	6.7	5.7
33	EVA Comp	Velvet	6.2	7.3	5.0
34	Declaration	Creeping	6.0	7.0	5.0
35	FDS1 Comp	Creeping	6.0	7.7	4.3
36	MVA Comp	Velvet	6.0	7.0	5.0
37	PST-SYN-OSF	Creeping	5.8	7.3	4.3
38	Crenshaw	Creeping	5.8	7.3	4.3
39	Penneagle	Creeping	5.5	6.0	5.0
40	Penn G-6	Creeping	5.5	6.3	4.7
41	Century	Creeping	5.5	6.3	4.7
42	L-93	Creeping	5.5	5.7	5.3
43	SRX 1WM232	Creeping	5.5	5.7	5.3
44	Penn G-2	Creeping	5.3	6.0	4.7
45	SRX 1WM236	Creeping	5.3	6.3	4.3
46	SR 1119	Creeping	5.2	5.3	5.0
47	SRX 1BL2G	Creeping	5.2	5.0	5.3
48	SR 7200	Velvet	5.2	7.0	3.3
49	Benchmark DSR	Creeping	5.0	6.0	4.0
50	Southshore	Creeping	5.0	6.0	4.0
51	Putter	Creeping	5.0	6.0	4.0
52	Pennlinks	Creeping	4.8	5.0	4.7
53	Penn A-4	Creeping	4.8	5.3	4.3
54	Alpha	Creeping	4.8	5.0	4.7
55	03-TTP- Comp	Creeping	4.8	6.3	3.3
56	SRX 7EW 88-34	Velvet	4.8	6.3	3.3
57	Crystal BlueLinks	Creeping	4.5	5.0	4.0
58	Sandhill	Creeping	4.0	5.7	2.3
59	SRX 1WM39	Creeping	4.0	3.7	4.3
60	PST-ORF	Creeping	3.8	4.7	3.0
61	Pennlinks II	Creeping	3.7	4.3	3.0
62	PST-SYN-OHTY	Creeping	3.5	2.3	4.7
63	Seaside II	Creeping	3.0	4.0	2.0
64	Brighton	Creeping	3.0	2.7	3.3
65	Penncross	Creeping	2.2	2.0	2.3
66	Providence	Creeping	2.2	2.7	1.7
67	Viper	Creeping	1.8	2.0	1.7
LSD at 5% =			2.1	2.6	2.3

* Anthracnose ratings were based on a 1 to 9 scale, with 9 = least/no disease and 1 = most disease.

Literature Cited

1. Crouch, J., Clarke, B. B., and Hillman, B. I. 2006. Unraveling the evolutionary relationships among the divergent lineages of Colletotrichum causing anthracnose disease in turfgrass and maize. Phytopathology 96:46-60.

2. Inguagiato, J. C., Murphy, J. A., and Clarke, B. B. 2008. Anthracnose severity on annual bluegrass influenced by nitrogen fertilization, growth regulators, and verticutting. Crop Sci. 48:1595-1607.

3. Smiley, R. W., Dernoeden, P. H., and Clarke, B. B. 2005. Compendium of Turfgrass Diseases, 3rd Edn. American Phytopathological Society, St. Paul, MN.