Brown Patch Fungicide Trial: N.C. State Research Results

Control of brown patch in tall fescue with monthly fungicide applications in Raleigh, NC.

L.P. Tredway and E.L. Butler
Department of Plant Pathology
North Carolina State University
Raleigh, NC 27695

Trial Details

• Established 18 Mar 2003 with 'Coronado' tall fescue (6 lbs/1,000 sq ft)
• Fertilizer: 18-24-12 on 18 Mar (1 lb P/1,000 sq ft)
• Mowing: 2×/week at 3.5 in., clippings returned
• Irrigated to prevent drought stress
• Plots: 5×6 ft, randomized complete block, 4 replications
• Fungicides applied in 3 gal/1,000 sq ft, CO2 sprayer, 40 psi, TeeJet 8004 nozzles
• Applications: 1 Jul and 28 Jul (28-day interval)
• Inoculated 2 Jul with rye grain infested with R. solani AG 1-1A
• Disease assessed 14 Jul, 27 Jul, 30 Aug

Results

No symptoms at trial start. Disease increased through July after inoculation.

• 14 Jul (13 days after 1st app): All fungicides excellent except Compass (0.15 oz), Eagle (0.6 oz), 3336 (4.0 oz), ConSyst (8.0 oz).
• 27 Jul (26 days after 1st app): Heritage (0.2 oz), Insignia (0.9 oz), Banner Maxx (2.0 fl oz), Bayleton (1.0 oz), ProStar (3.0 oz), SysStar (3.0 oz) provided superior control.
• 20 Aug: Most treatments not different from untreated control, except ProStar 70WP (significantly reduced disease). 3336 50WP (4.0 oz) and ConSyst (8.0 oz) had significantly more disease than untreated.

Conclusion: When applied on 28-day intervals, Heritage (0.2 oz), Insignia (0.9 oz), Banner Maxx (2.0 fl oz), Bayleton (1.0 oz), ProStar (3.0 oz), and SysStar (3.0 oz) provided excellent brown patch control.

Lower rates of Heritage (0.1 oz) and Insignia (0.5 oz) inadequate here (though effective in other trials). More research needed on lower ProStar/SysStar rates.

See Homeowner Pesticide Products for chemical details.