Selection and management of bentgrass cultivars for genetic and induced resistance to microdochium patch and pink snow mold caused by Microdochium Nivale

Summary

the absence of fungicides, the most efficient approach to control this disease is to use resistant plant material. Genetic resistance to M. nivale can be present irrespective of environmental conditions, or it may require induction by defence activators. Canadian results suggest that Civitas One, a mixture of food-grade isoparaffins and emulsifiers, induces resistance to M. nivale.

In Subproject 1 (SP1), the third replicate over time of a screening experiment with 36 varieties of creeping bentgrass (Agrostis stolonifera), colonial bentgrass (A. capillaris) and velvet bentgrass (A. canina) was completed in 2016. Seedlings were grown in glass vials, inoculated with M. nivale and damage to the plants (%) and development of mycelium (%) were assessed. The final statistical analyses remain to be completed, but mean values suggest a stronger reduction in M. nivale due to Civitas One in velvet bent than in the two other bentgrass species. The interaction Civitas One x Variety was not significant in any species.

SP2 was sown in 2015 as an extension of the SCANGREEN trials at Landvik and Apelsvoll, Norway. Selected bentgrass varieties are compared on three main plots, one receiving Civitas One (54 L/ha every 3 wks from late Aug.), one treated with prothioconazole + trifloxystrobin in mid-October plus fludioxonil in early November, and one unsprayed control. At Landvik, winter 2015-16 had on/off snow cover, with the longest period being 3 wks. Here, Civitas One was equally effective as the fungicides in controlling M. nivale. In contrast, control by Civitas One was inferior to that of fungicides after more than 100 days of snow cover at Apelsvoll.

SP3 is funded by Petro Canada and includes registration trials. In 2015-16, trials were conducted at Sydsjælland GC, Denmark, and Lepaa GC, Finland. The Danish trial had no snow cover and showed 100% control of M. nivale after four applications of Civitas One at 54 L/ha from late August to late November. At 27 L/ha, the efficacy of Civitas One was slightly less and similar to that of two applications of prothioconazole at 0.2 kg a.i/ha. In the Finnish trial, Civitas One provided good control of M. nivale up to snow melt in March, but the natural green-up in spring was impeded after four applications of Civitas One at 54 L/ha from September to early December. In order to avoid this effect, lower rates and earlier termination of the Civitas regime in autumn are now being investigated in a new trial at Hillside GC, Finland.

FACTS
Category: Disease control
Status: Ongoing
Project period: June 2014 - December 2017

Fundings (kSEK)

 

2014

2015

2016

2017

2018

Total

STERF

323

492

441

4081

 

1663

Other sources

110

183

183

110

 

586

Total

433

675

623

518

 

2249

1Reserved, not granted [total funding from Canadian sources:  $148,000/yr for three years from January 2015 to December 2017)

Project objectives

Overall objective:

To reduce the dependence on fungicides for the control of diseases caused by Microdochium nivale on golf courses in Scandinavia and Canada.

Subgoals: 

1. To screen in vitro top selling cultivars of Agrostis sp. for resistance to M.nivale, with and without cold hardening and with and without the application of Civitas One mineral oil, and to identify genotypes that are either resistant or show increased responsiveness to the defence activator.
2. To validate level of resistance and responsiveness to Civitas One of the most promising cultivars (from subgoal 1) in field trials in contrasting climates in Canada and at NIBIO Landvik and Apelsvoll, Norway.
3. To determine the effect of Civitas One on microdochium patch occurring during the growing season or under snow cover in registration trials on golf courses in the Nordic countries.

Project participants

Trygve S. Aamlid

Head of Research

Norwegian Institute for Bioeconomy (NIBIO), Department for Urban Greening and Environmental Technology, Turfgrass Research Group, Landvik, Reddalsveien 215, 4886 Grimstad, Norway.

+47 90 52 83 78

+47 90528378

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