Sand Size Affects Topdressing Removed by Mowing and Anthracnose on Annual Bluegrass Putting Green Turf

Abstract

<jats:p>Sand size can affect the ability to incorporate topdressing into the turf canopy and thatch on golf course putting greens; unincorporated sand interferes with mowing and play. This 3-year field trial was initiated to determine the effects of sand size on sand incorporation, surface wetness, and anthracnose (caused by <jats:italic>Colletotrichum cereale</jats:italic> Manns sensu lato Crouch, Clarke, and Hillman) of annual bluegrass [<jats:italic>Poa annua</jats:italic> L. f. <jats:italic>reptans</jats:italic> (Hausskn) T. Koyama] maintained as a putting green. The experimental design was a randomized complete block with four replications; treatments included a non-topdressed control and three topdressing sands (medium-coarse, medium, or medium-fine) applied every 2 weeks at 0.15 L·m<jats:sup>−2</jats:sup> during the summer. Topdressing with medium-coarse sand was more difficult to incorporate than the medium and medium-fine sands, resulting in a greater quantity of sand collected with mower clippings. Analyzing the particle distribution of sand removed by mowing confirmed that coarser sand particles were more likely to be removed in mower clippings. Surface wetness measured as volumetric water content (VWC) at the 0- to 38-mm depth zone was greater in non-topdressed plots than topdressed plots on 35% of observations. Few differences in VWC were found among sand size treatments. Turf responses to topdressing were not immediate; however, as sand accumulated in the turf canopy, topdressed plots typically had lower anthracnose severity than non-topdressed turf after the first year. Additionally, topdressing with medium and medium-fine sands produced similar or occasionally lower disease severity than topdressing with medium-coarse sand. The lack of negative effects of medium and medium-fine sands combined with better incorporation after topdressing and less disruption to the putting surface should allow golf course superintendents to apply topdressing at frequencies and/or quantities needed during the summer to maintain high-quality turf and playing conditions.</jats:p>

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

“…Although, fairways topdressed with a finer sand sometimes retained more moisture compared to medium-coarse or coarse sand, VWC of the fine sand treatment was similar or lower than the non-topdressed control (Henderson & Miller, 2009). Plots topdressed with medium-fine sand did not retain more water than the non-topdressed plots in the current study, similar to the findings of others (Henderson & Miller, 2009;Wang et al, 2020).…”

“…We found that a greater rate (0.3 L m −2 ) of medium‐fine sand can be applied without a substantial increase in the quantity of sand removed by mowing. Coarse (0.5–1.0 mm) and very coarse (1.0–2.0 mm) sand particles are more likely to be removed by mowing than particles <0.5 mm in diameter (Stier & Hollman, 2003; Taylor, 1986; Wang et al., 2020). In our study, medium‐fine sand did not contain particles above 0.5 mm (Table 1); therefore, substantially less sand would be expected to be removed by mowing.…”

“…Sand is often found in the mower clippings due to frequent topdressing (Kauffman et al, 2011; Kreuser et al, 2011; Wang et al, 2020). The interruption to play and excessive wear on mowers can discourage golf course superintendents from implementing a routine topdressing program during the summer months.…”

“…Henderson and Miller (2009) reported that finer sand tended to retain more water in the top 5 cm of the root zone of creeping bentgrass fairway turf than medium and coarse sands. More recently, topdressing annual bluegrass [ Poa annua L. f. reptans (Hausskn) T. Koyama] putting green turf with sand lacking very coarse and coarse grains reduced anthracnose disease, potentially due to greater water retention, compared to a coarser sand (Wang et al., 2020).…”

Advances in managing organic matter in turfgrass ecosystems

“…The diameter of soil cores used for OM analysis and the number of samples collected per plot vary greatly in the turfgrass literature. Most of these studies collected between two and five soil samples per plot (Barton et al, 2009;Carrow et al, 1987;Dunn et al, 1995;Espevig et al, 2012;Fu et al, 2009;McCarty et al, 2005;Murphy et al, 1993;Schmid et al, 2014;Stier and Hollman, 2003;Wang, 2015). Kauffman et al (2013) conducted a field trial in which they investigated the effect of sample size (number per plot) on thatch/mat depth and OM content of four warmseason grasses.…”