Large-scale demonstration trials: Silvery thread moss on greens.

We continued with the demonstration experiment that started in summer 2011. The objective is still for the demonstration plots to be treated every 14 days during the time there is growth on the surface. In 2013 the treatment started in the middle of May, when growth was well underway, and the plots were treated eight times. Treatment stopped in the middle of November, when the surface growth at the surface had stopped completely due to low temperature.

Just as after the previous season, the plot treated with 24 kg iron sulphate showed the best visual overall impression. The plots treated with Manganese sulphate (32%): 15 kg+16 kg iron sulphate also showed some good overall impressions. Plots treated with 32 kg iron sulphate were still heavily stressed, and the grass suffered very badly. The area treated with 3 kg N was almost 100% eliminated by snow mould after the previous winter. We reseeded the area twice in 2013, but it was extremely difficult to get that plot in good shape during the season.

We observed a 0.5-1.5°C increase in soil temperature in the plots treated with iron sulphate. This affected the surface so that was less likely to retain dew, which is probably a contributing factor to the significantly lower incidence of fungus in this plots. During this season there was a severe snow mould attack in the middle of November. Every plot was attacked except the two plots treated with 15 kg manganese sulphate (32%) + 16 kg ion sulphate and 15 kg manganese sulphate (32%).

Just after the post-season report, the surface treated with 32 kg iron sulphate was best against moss and the ranking was (visual effect and effect against moss to worst):

1. Iron sulphate: 32 kg.
2. Iron sulphate: 24 kg.
3. Manganese sulphate (32%): 15 kg + 16 kg iron sulphate. 4. Manganese sulphate (32%): 15 kg.
5. Iron sulphate: 16 kg.
6. Ammonium chloride Pronto (8% solution).
7. 3 kg pure N per 100 m2 and year.
8. Bensaltensid.
9. Wetting agent Ekovett 10 L.

There is no doubt that good greenkeeping with a lot of needs-orientated actions (topdressing, spiking, hollowing, coring etc.) is the best option.