Since the new fungicide Civitas was unveiled at the GIS Show in New Orleans, we've had a number of questions from golf course superintendents and product distributors about its effectiveness against turfgrass diseases. This year, we evaluated a mixture of Civitas + Civitas Harmonizer for control of brown patch and dollar spot on creeping bentgrass putting greens. So far, the results are promising.
The mixture of Civitas + Harmonizer was applied every 14 days beginning prior to the onset of disease symptoms. Industry standard fungicide treatments were included in each study: Heritage 50WG (0.2 oz every 14 days) in the brown patch study and Banner Maxx + Daconil Ultrex (2 fl oz + 3 oz every 14 days) in the dollar spot trial. The incidence of each disease was assessed periodically during periods of activity.
Civitas + Harmonizer provided good suppression of both diseases. Brown patch incidence was maintained at or below 5% of the turf surface area throughout the study, even under intense disease pressure in late July. Dollar spot incidence was significantly reduced throughout the season, reaching a maximum of 36 spots per plot in plots treated with Civitas + Harmonizer as compared to 160 spots in untreated plots.
The bottom line - Civitas showed good activity against brown patch and dollar spot in North Carolina in 2009. While it did not always provide acceptable levels of control alone, it should prove to be a useful tool for disease management as part of an integrated program.
A few words about the active ingredient in Civitas, which is a type of mineral oil, also commonly referred to as 'horticultural oil'. Horticultural oils have been used for disease and insect control in a number of crops for many years. These products have direct fungicidal and insecticidal activity, and are highly desirable in organic farming due to their safety and short residual in the environment.
Suncor, formerly known as Petro Canada, also claims that Civitas works by inducing systemic resistance in the plant. However, the research supporting this claim has not yet been published.