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/1,000 ft². The experimental design was a randomized complete block with four replications. All plots measured 4 ft x 5 ft. Fungicide treatments were all applied on 9 Jun, then re-applied at recommended intervals on 23 Jun, 7 and 21 Jul, and 4 Aug.

Brown patch symptoms were first observed on 30 Jun. Disease development on untreated check plots was light on 1 Jul and moderate or severe on 19 and 30 Jul and 20 Aug. Most, but not all, fungicide treatments exhibited significantly less disease than the untreated check. No phytotoxicity symptoms were observed during the trial.

Disease Severity Rating*

Untreated check ----- 1.75 5.00 3.50 3.50

Heritage 50WG, 0.2 oz 14 0.25 0.00 0.00 1.00

Heritage 50WG, 0.4 oz 28 0.00 0.00 0.75 0.25

Spectro 90WDG, 2 oz 14 0.00 1.25 0.00 1.50

Spectro 90WDG, 4 oz 14 0.00 0.75 0.25 1.00

Spectro 90WDG, 8 oz 14 0.00 0.00 0.00 2.75

Compass 50WG, 0.1 oz 14 0.00 0.00 0.00 0.25

+Banner MAXX 0.5 fl oz

Compass 50 WG, 0.15 oz 14 0.00 0.00 0.00 0.00

+Banner MAXX 0.5 fl oz

*Rating scale: 0 = no disease; 1 = 1-5%; 2 = 5-10%; 3 = 10-25%; 4 = 25-50%; 5 = >50% of plot area diseased

**P = 0.05. n = 4.