Fungicide strategies for the control of turfgrass winter diseases

Abstract

It is a goal of the turf industry to reduce fungicide use, maximize fungicide efficacy, and minimize the risk of fungicide resistance. Based on these integrated pest management principles and current fungicide labels, our objective was to elucidate the optimal use of propiconazole (Banner Maxx, 156 g a.i. L -1 ), azoxystrobin + propiconazole (Headway, 62.5 + 104 g a.i. L -1 ), and fludioxonil (Medallion TL, 104 g a.i. L -1 ) for the control of the winter-active pathogens Micordochium nivale and Typhula incarnata. Five experiments were conducted on greens and fairways at four sites in Norway and Sweden during the winter seasons of 2011-2012 and 2012-2013. Iprodione (Chipco Green, 250 g a.i. L -1 ), which was used in Scandinavia until 2009 and is still a widely used fungicide internationally, was included in two experiments. One application of propiconazole (468 g a.i. ha -1 ) or azoxystrobin + propiconazole (187.5 + 312 g a.i. ha -1 ) in October controlled 80% of the microdochium patch, and the control of both microdochium patch and typhula blight usually exceeded 90% if the first application of one of these fungicides was followed by at least one application of fludioxonil (375 g a.i. ha -1 ) before snow cover. After an initial application of propiconazole or azoxystrobin + propiconazole in October, two applications of fludioxonil in late autumn were more efficient in improving visual turf quality in spring than one application of fludioxonil in autumn plus one application of propiconazole just after snow melt in spring. Fludioxonil gave the same level of control of microdochium patch as iprodione despite a much lower use of the active fungicide ingredient. In conclusion, one application of propiconazole or azoxystrobin + propiconazole while the turf is still growing, followed by one applications of fludioxonil after growth cessation, will usually provide adequate control of the winter diseases in turfgrass.

Combinations of rolling, mineral oil, sulfur, and phosphorous acid affect Microdochium patch severity

“…This disease occurs in cool, humid regions such as in northern Europe and the U.S. Pacific Northwest, where it is considered to be the most important turfgrass pathogen (Vargas, 2005). Traditional fungicide applications are successful at mitigating this disease (Aamlid, Waalen, & Espevig, 2015; Vincelli, Clarke, & Munshaw, 2017), although there have been reports of M. nivale resistance to dicarboximide fungicides (Chastagner & Vassey, 1982; Gourlie & Hsiang, 2017). Recent regulations limiting the use of pesticides have generated concerns about the availability of synthetic chemicals to manage turfgrass pests such as Microdochium patch (Christie, 2010).…”

The Effect of Ice Encasement and Protective Covers on the Winter Survival of Six Turfgrass Species on Putting Greens

“…Both covers, when used with A. capillaris, caused a 25% increase in microdochium patch compared with natural winter conditions in the spring of 2013. Most likely, the single application of fungicide in September was not sufficient to keep A. capillaris under the covers free from disease throughout the entire winter and should have been followed by a new application, preferably of a contact fungicide in November (Aamlid et al, 2014). Moreover, the temperature under the protective covers was never lower than −6°C, which was earlier reported to be a minimal temperature for M. nivale growth (Årsvoll, 1975), and air conditions were aerobic, as also required for growth of the fungus (Tronsmo et al, 2013).…”

Microbiological Products for Control of Microdochium nivale on Golf Greens

“…One possibility that still remains open is whether increased populations of G. catenulatum or Streptomyces in the rhizosphere may contribute to a reduction in the number of fungicide applications on Scandinavian golf greens or from two applications, or three to two applications, to only one application yr −1 (Aamlid et al, 2014). Practical experience from Finland suggest that this might be the case (K. Laukkanen, Finnish Golf Union, personal communication, 2014), and the question warrants further investigation.…”

“…This fungus causes Microdochium patch both during the growing season and after snow melt. To control the disease, a common strategy in Nordic countries is to treat the greens preventatively with fungicides one to three times before winter (Aamlid et al, 2014). However, the Directive 2009/128 EC of the European Union calls for a reduction in pesticide use through the introduction of Integrated Pest Management (IPM), including replacement of chemical pesticides with low‐risk biological or physical alternatives (EU, 2009a).…”