Velvet bentgrass putting green quality, water retention, and infiltration as affected by topdressing sand size and rate

Abstract

Velvet bentgrass (Agrostis canina L.) putting greens require intensive sand topdressing programs for thatch management; however, their high shoot density combined with the low mowing heights make it challenging to maintain smooth, sand-free putting surface when topdressing is applied at high rates. A field trial was initiated to determine the effects of sand size and topdressing rate on a 'Greenwich' velvet bentgrass putting green. Treatments were arranged in a 2 × 2 factorial and included a non-topdressed control arranged in a randomized complete block design. The two factors were topdressing sand (medium-coarse sand and medium-fine sand) and topdressing rate (0.15 and 0.3 L m -2 ). Topdressing improved turf quality compared to the non-topdressed control. Additionally, velvet bentgrass had better quality when topdressed at the rate of 0.3 L m -2 compared to 0.15 L m -2 . Increasing topdressing rate from 0.15 to 0.3 L m -2 notably increased the quantity of unincorporated mediumcoarse sand remaining on the putting surface, whereas it often did not increase or only slightly increased the quantity of unincorporated sand with medium-fine sand.Independent of sand size and rate, topdressing treatments maintained the top 0-to-3.8-cm soil profile relatively dry and increased infiltration rate measured with mini disk infiltrometers. The lack of negative effects of medium-fine sand on measured parameters and the minimum disruption to putting surface may encourage superintendents to apply greater quantities of topdressing for improving the performance of velvet bentgrass putting greens.

Comparing methods to quantify cover in turfgrass research

“…To decrease variability in this work, Williams et al (2011) filled divots with pink sand and used the digital image analysis software to select the pink color, rather than the green, when quantifying divot recovery. In another study, Wang et al (2021) successfully modified the digital image analysis procedures developed by Richardson et al (2001) to detect white sand remaining on a velvet bentgrass (Agrostis canina L.) putting green after topdressing. Green pigments have been found to mask differences that would otherwise be detectible with digital image analysis .…”

“…In another study, Wang et al. (2021) successfully modified the digital image analysis procedures developed by Richardson et al. (2001) to detect white sand remaining on a velvet bentgrass ( Agrostis canina L.) putting green after topdressing.…”