Microdochium nivale is a serious pathogen on Nordic golf courses. Resistance to M.nivale can be present in all environmental conditions, or may require induction by defence activators. Canadian results suggest that Civitas One™, a mixture of isoparaffin and a coppercontaining pigment, induces resistance to M.nivale. In WP1 of this project, we screened 36 bentgrass cultivars, with and without Civitas One™, for resistance to M.nivale in glass vials. The trial was replicated three times in growth chambers. Differential response to Civitas One™ was not found in colonial or velvet bentgrass, but creeping bentgrass showed a significant interaction as Civitas One™ induced resistance in ‘Penn A4’, ‘Penn G2’, ‘Penn G6’, ‘Focus’, ‘SR 1150’, ‘Bengal’ and ‘MacKenzie’, but had phytotoxic effects and reduced overall turf quality in ‘Independence’, ‘CY2’, ‘Alpha’, ‘Runner’ and ‘Cato’. In WP2, the genetic component was investigated in field trials at Landvik and Apelsvoll, Norway. Bentgrass cultivars were compared on unsprayed control plots, plots receiving Civitas One™ (54 ha-1 ) and plots receiving traditional fungicides. Civitas One™ was equally or more efficient than fungicides in controlling M.nivale at both sites.
At Landvik there was also a carry-over effect as Civitas One™ applied in autumn 2015 and 2016 resulted in less abiotic damage in spring 2018 (Photo 1). On the negative side, the waxy layer after repeated applications of Civitas One™ in autumn impaired natural green-up at Apelsvoll in spring 2017. In WP3, the effect of Civitas One™ (27 and 54 L ha-1 ) was tested in five trials on golf courses in Denmark, Sweden and Finland, 2014-2017.
In the Danish trials, with practically no snow, Civitas One™ controlled M.nivale to the same level as traditional fungicides and significantly better than potassium phosphite.
One of the Finnish trials confirmed that high rates of Civitas One™ in autumn could thin out the turf in spring, but the problem was overcome within weeks. Besides controlling M.nivale, an interesting feature of Civitas One™ in these trials was its ability to act as a sunshield, reducing the need from grass to produce antocyan pigments after snow melt. Thus Civitas One™ can become a viable alternative to traditional fungicides for control of M.nivale on Nordic golf courses. The legal rights to Civitas One™ in Europe belongs to Intelligo (http://www.intelligro.com) and work is underway on getting the product to market.
