Evaluating biological and oil‐based fungicides for dollar spot suppression on turfgrass. (28th September 2020)

• Record Type: Journal Article
• Authors: Koch, P.L.; Hockemeyer, K.; Buczkowski, E.
• Is Part Of: Agronomy Journal. Volume 113:Number 5(2021)
• Page Start: 3808
• Page End: 3818
• Publication Date: 2020-09-28
• Subjects: Agronomy -- Periodicals; 630
• DOI: 10.1002/agj2.20407
• Languages: English
• ISSNs: 0002-1962

Abstract

Abstract: Dollar spot (caused by Clarireedia jacksonii ) receives more fungicide applications than any other turfgrass disease. Increasing restrictions on fungicide usage and expanding reports of fungicide resistant fungal populations have resulted in renewed interest in biological and plant‐based control of turfgrass diseases. Six commercially available biological fungicides (Actinovate AG, Double Nickel LC, Nortica, Rhapsody, Serende Opti, Zio) and two oil‐based fungicides (Civitas, Timorex Gold) were evaluated for dollar spot control on a creeping bentgrass putting green in Madison, WI, USA in 2017 and 2018. No biological or oil‐based fungicide provided effective full‐season dollar spot control compared to the synthetic fungicide boscalid. However, Civitas mineral oil provided levels of dollar spot control similar to boscalid on 9 of 12 rating dates over both years. The remaining treatments tested provided levels of dollar spot control and turf quality similar to boscalid ranging from 4 to 7 of a possible 12 rating dates. These results indicate that the biological fungicides tested here failed to provide commercially acceptable dollar spot control under moderate disease pressure in the midwestern U.S. The mineral oil Civitas did provide effective suppression under moderate disease pressure, while the tea tree oil Timorex Golf did not. Certain oil‐based fungicides like Civitas can provide effective dollar spot control during periods of low to moderate disease pressure, but more research is needed before biological fungicides can be successfully integrated into a dollar spot management program.