1998 Iowa Turfgrass Research Report

1998 Iowa Turfgrass Research Report

Evaluation of Fungicides for Control of Brown Patch in Creeping Bentgrass - 1997

Mark L. Gleason

Trials were conducted at Veenker Memorial Golf Course on the campus of Iowa State University. Fungicides were applied to creeping bentgrass maintained at 5/32-inch cutting height, using a modified bicycle sprayer at 30 psi and a dilution rate of 5 gal/1000 ft². The experimental design was a randomized complete block with three replications. All plots measured 4 ft x 5 ft. All plots were surrounded by 1-ft-wide strips of untreated turf in order to help create uniform disease pressure.

Fungicide applications began on June 11. Subsequent applications were made at specified intervals on June 18 and 25 and July 2, 9, 16, 23, and 30.

Brown patch symptoms were first observed on July 1. Disease development on untreated check plots, expressed on a 0-5 scale (0=no disease, 1=1-5%. 2=5-10%, 3=10-25%, 4=25-50%, 5=>50% diseased area per plot), was moderately severe on July 4, 10, and 24, and severe on July 18. Many, but not all, fungicide treatments exhibited significantly (LSD, P< 0.05) less disease than the untreated check.

Severe dollar spot developed during the brown patch trial. Dollar spot was rated as the number of infection centers per plot. NOTE: The trial was organized with brown patch as the target disease.

No phytotoxicity symptoms were observed during the trial.

Table 1. 1997 Brown Patch Trial. WOI Greens - ISU Campus. Plot Size=20 ft², 3 plots/trt; 60 ft² per treatment

			Interval	July 4		July 10		July 18		July 24
Trt.	Product	Rate/1000 ft2	(days)	bp1	ds2	bp	ds	bp	ds	bp	ds
1	Check	----	----	3.3	138	3.3	150.3	4.0	175.3	3.3	187.3
2	Banner MAXX 1.24 MC	1.0 fl oz	21	0.7	13.7	2.0	26.7	2.0	36.3	3.0	13.3
3	Banner MAXX 1.24 MC	1.0 fl oz	21	0.0	38.0	0.0	0.3	0.0	1.0	0.0	0.0
	+ Heritage 50 WG	0.2 fl oz
4	Banner MAXX 1.24 MC	1.0 fl oz	21	1.0	10.7	0.7	0.3	0.3	0.0	1.7	0.0
	+Daconil Ultrex 82.5 WDG	3.8 oz
5	Sentinel 40 WG	0.167 oz	21	1.0	54.0	1.0	3.7	0.0	0.0	0.3	0.0
6	Sentinel 40 WG	0.167 oz	21	0.0	0.0	0.3	0.0	0.3	3.0	0.0	0.0
	+ Heritage 50 WG	0.2 oz
7	Sentinel 40 WG	0.167 oz	21	0.0	0.0	0.0	0.0	0.0	0.3	0.0	0.0
	Daconil Ultrex 82.5 WDG	3.8 oz	21
8	Heritage 50 WG	0.2 oz	21	0.0	74.7	0.3	111.0	0.3	146.0	1.00	118.0
9	Daconil Ultrex 82.5 WDG	3.8 oz	21	0.3	18.7	0.0	2.0	1.7	21.0	1.3	4.0
10	CGA-BMP	0.5 oz	7	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
11	CGA-BMP	0.5 oz	14	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
12	CGA-BMP	1.0 oz	14	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
13	CGA-BMP	0.5 oz	14	0.0	0.0	0.0	0.0	0.0	0.0	0.3	0.0
	+ Primo L	0.10 fl oz
14	Heritage 50 WG	0.2 oz	14	0.0	23.3	0.3	17.3	1.0	78.0	0.7	20.0
15	Heritage 50 WG	0.2 oz	28	0.3	180.3	0.3	112.0	0.3	135.0	1.0	108.7
16	Heritage 50 WG	0.3 oz	21	0.0	94.0	0.3	135.0	0.3	171.7	1.0	105.7
17	Heritage 50 WG	0.4 oz	28	0.0	168.3	0.0	160.7	1.0	250.7	1.7	175.0
18	Thalonil 4 L	4.0 fl oz	14	0.0	1.0	0.0	0.0	0.0	6.7	0.0	0.0
	+ Heritage 50 WG	0.2 oz
19	Thalonil 4L	6.0 fl oz	14	0.0	0.0	0.0	0.0	0.0	1.3	0.0	0.0
	+ Heritage 50 WG	0.2 oz
20	Thalonil 4 L	4.0 fl oz	14	0.3	0.7	0.3	0.0	1.0	16.7	0.7	0.0
21	Thalonil 4 L	6.0 fl oz	14	0.0	9.0	0.0	0.0	0.3	21.0	1.0	0.0
22	CONFIDENTIAL	----	----	1.3	73.0	1.0	92.7	2.0	119.0	4.0	89.7
23	CONFIDENTIAL	----	----	0.7	109.7	0.3	90.7	2.7	39.7	3.3	117.3
24	CONFIDENTIAL	----	----	0.3	11.0	0.7	16.0	1.0	23.7	1.0	6.0
25	CONFIDENTIAL	----	----	0.1	8.5	0.3	0.0	0.3	0.3	0.0	0.0
26	CONFIDENTIAL	----	----	0.0	0.0	0.0	0.0	0.0	0.0	0.3	0.0
27	CONFIDENTIAL	----	----	0.0	0.0	0.0	0.0	0.0	0.0	0.7	0.0
28	CONFIDENTIAL	----	----	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
29	Daconil Ultrex 82.5 WDG	3.8 oz	14	0.0	0.0	0.0	0.0	0.0	2.3	0.3	0.0
30	IB 11522	4.1 oz	14	0.0	0.0	0.0	0.0	0.3	0.0	1.0	0.0
31	Daconil Ultrex 82.5 WDG	3.0 oz	14	0.0	1.0	0.0	0.0	0.3	6.0	0.0	0.0
	+ Heritage 50 WG	0.2 oz
32	Chipco Aliette Signature 80 WG	4.0 oz	14	0.0	0.0	0.3	0.0	0.0	0.0	0.3	0.3
	+Chipco 26019 FLO 2 SC	4 fl oz.
33	Chipco Aliette Signature 80 WG	4 oz	14	0.0	0.0	0.0	0.0	0.0	0.0	1.0	2.0
	+ EXP 10790A (26 GT) 2 SC	4 fl oz
34	Chipco Aliette Signature 80 WG	4 oz	14	0.0	2.3	0.0	0.0	0.0	0.0	0.7	0.0
	+ EXP 10702B (EXP 26 GT) 2 SC	4 fl oz
35	Chipco Aliette Signature 80 WG	4 oz	14	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
	+ Daconil Ultrex 82.5 WDG	3.8 oz
36	EXP 10790A (26 GT) 2 SC	2.0 fl oz	14	0.0	0.7	0.0	0.0	0.0	0.0	1.7	5.7
	+ Cleary’s 3336 F	2.0 fl oz
37	Chipco Aliette Signature 80 WG	4.0 oz	14	0.7	86.7	2.0	24.7	2.7	102.7	2.0	99.3
38	Chipco Aliette 80 WG	4.0 oz	14	1.7	38.7	1.0	36.0	4.0	54.0	2.7	27.3
39	Chipco 26019 FLO 2 SC	4.0 fl oz	14	0.0	0.3	0.0	0.0	1.0	0.0	1.3	0.0
40	3336 F	2.0 fl oz	14	0.0	0.0	0.0	0.0	1.3	0.0	0.7	0.0
	+ Chipco 6019 FLO	2.0 fl oz
41	3336 50 WP	4.0 oz	14	0.0	0.0	0.0	0.0	0.3	0.0	0.0	0.3
42	3336 50 WP	8.0 oz	14	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
43	Spotrete 75 WDG	5.0 oz	7	0.0	0.0	0.0	0.3	0.0	0.0	0.0	0.0
44	CTM 90 WDG	4.0 oz	14	0.0	0.0	0.0	0.0	0.0	0.3	0.0	0.0
45	CTM 90 WDG	8.0 oz	14	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
46	CONFIDENTIAL	-----	---	2.0	6.3	3.0	3.3	2.7	6.3	2.3	0.0
47	CONFIDENTIAL	-----	---	1.7	3.3	2.0	1.3	1.7	2.0	2.0	0.0
48	CONFIDENTIAL	-----	---	1.0	0.0	0.7	0.0	2.3	0.0	3.3	0.0
49	CONFIDENTIAL	-----	---	0.7	1.7	0.0	0.0	0.3	0.0	1.0	0.0
50	CONFIDENTIAL	-----	---	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
51	Heritage 50 WG	400 g ai/ha	21	0.0	97.7	1.0	99.0	3.0	133.7	2.7	109.3
52	Sentinel 40 WG	300 g ai/ha	21	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
53	Eagle 40 W	1.2 oz	21	0.0	0.0	0.7	0.0	0.3	0.0	0.0	0.0
54	Eagle 40 W	1.2 oz	21	0.7	25.0	0.3	25.0	0.0	44.0	0.0	0.7
	ALTERNATED WITH
	Heritage 50 WG	0.2 oz	21
55	S-7247	2 fl oz	14	0.0	0.0	0.3	0.0	0.3	0.0	0.0	0.0
56	S-7247	4 fl oz	14	0.0	0.3	0.0	0.0	0.0	0.0	0.0	0.0
57	S-7221	0.6 oz	14	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
	+ S-7222	3.7 oz
58	S-7221	1.2 oz	14	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
	+ S-7222	7.35 oz
	LSD3			1.12	76	1.11	78	1.40	82	2.03	97.3

¹0 = no disease, 1 = 1-5%, 2 = 5-10%, 3 = 10-25%, 4 = 25-50%, 5 = >50% of plot symptomatic.

²Number of infection centers per plot.

³Least significant difference (P = 0.05).  

ISU Horticulture:Publications:1998 Turfgrass Report

College of Agriculture