Integrated management of important turfgrass diseases and insect pests on European golf courses

Summary

This project is a joint effort by researchers and greenkeepers from the Nordic countries, Germany, Portugal, UK, Finland and Russia, suppliers (ICL, Syngenta, Suståne and Aqua-Yield), Golf Federations in Germany and Netherlands and The Danish Environmental Protection Agency to investigate cultural practices, alternative products and new technologies for managing important diseases: microdochium patch (MP) and dollar spot (DS) with no or strongly reduced pesticide inputs. Seven field trials were conducted: in Denmark (1), Norway (2), UK (2) and Germany (2).

Due to no MP outbreak at Copenhagen Golf Club in Denmark by December 2021, the effect of rolling was recorded in the 2020-21 season only. Rolling both 2 and 4 times per week reduced MP from 5% (no rolling) to 2% and improved overall impression from 4 (no rolling) to 6 (scale 1-9). No differences in coverage of annual bluegrass were found between the rolling treatments (1.5%) vs. no rolling (1.1%). At NIBIO Landvik, on annual bluegrass/creeping bentgrass putting green in March 2022 the reduction in MP by rolling twice per week from the last week in August through September 2021 ranged from 47% (control) to 32%. In addition, the following treatments reduced MP compared with control (no fung., weekly nutrition, 313 kg N/ha/yr): non-frequent (bi-weekly) nutrition, organic slow release nutrition 5-2-4+Fe Suståne (275 kg N/ha/yr) and 28% reduced N-nutrition. Late autumn fertilisation (LAF) increased MP. At STRI Bingley, on bentgrass/poa golf green the following treatments increased MP compared with control (no fung., weekly nutrition, 122 kg N/ha/yr): non-frequent (bi-weekly) nutrition and 28% reduced nutrition, but not LAF.

In spite of the low disease pressure in 2022 as in 2021, the results from the UV-C radiation trial at Osnabrueck GC showed that the highest dosage (80 mJ/cm²) compared with control (no treatment) and lower dosages (10-40 mJ/cm²) reduced MP from 1.8% (untreated control) to 0.78% (in the highest UV-C dosage) and DS from 0.87% to 0.16%.

Dollar spot fungus was not found in the seeds of 10 cultivars of turfgrass analysed in the project. Clarireedia spp. were found in turfgrass samples from golf courses in Sweden, Denmark, Germany and UK and they belonged to either C. homoeocarpa or C. jacksonii.

During immunoassay for identification of MP and DS in plant tissue, the data showed recognition of MP with ELISA prototype, but not of DS. Validation of the MP ELISA prototype is ongoing.

The review on chafer grabs and leatherjackets was completed and published.

Fundings (kSEK)