The STRI believes that average masks some parkland courses with more than 25 per cent organic matter in the top 20mm, according to data collated from the institute's advisers.
Scottish STRI agronomist Richard Windows said the latest figures included clubs that have been following the STRI Programme. These clubs have been working to reduce levels of organic matter and benefitted from surface firmness improvements.
Golf courses following the STRI Programme of targeted aeration and amelioration for the past three years have seen a reduction in organic matter in the top 20mm of more than 13 per cent and nearly 17 per cent reduction on links course greens, which were found to have up to 12 per cent organic matter extending down to 40mm from the surface, with an average seven per cent in the top 20mm that is still 40 per cent above the target level.
Rod Burke of Syngenta suggested using Medallion TL to minimise disease pressure on golf greens.