Cultivation and Topdressing Requirements for Thatch Management in A and G Bentgrasses and Creeping Bluegrass

Abstract

<jats:p>Empirical observations suggest certain new cultivars of creeping bentgrass (<jats:italic>Agrostis stolonifera</jats:italic> L.) with high shoot density require more intensive topdressing and core aeration to control thatch compared to less dense cultivars such as `Penncross. In addition, a variety of <jats:italic>Poa annua</jats:italic> var. <jats:italic>reptans</jats:italic> Hausskn., `DW-184, has recently been released for putting green use but management requirements are undocumented. The objective of our project was to determine the core aeration and topdressing requirements for thatch management of creeping bentgrass cultivars `A-4, `G-2, and `Penncross as compared to `DW-184. Plots were established on a sand-based root zone and maintained as putting green turf for 3 years. A factorial treatment arrangement was used to assess the effects of core aeration and topdressing on thatch, topdressing removal, turf quality, and disease. Both `A-4 and `G-2 produced more organic matter as (thatch/mat) than `Penncross and `DW-184. Grass type, core aeration frequency, and topdressing regime affected the amount of topdressing removed by mowing. An interaction between grass type and topdressing regime showed biweekly topdressing with verticutting resulted in less topdressing removal from all grasses except `G-2 compared to monthly topdressing without verticutting. Since no more than 3% of the topdressing applied was removed from any single treatment, however, the overall impact of grass type, core aeration frequency, or topdressing regime are unlikely to affect turf response. Both `A-4 and `G-2 provided consistently better quality turf than `Penncross or `DW-184 at 3.2 mm mowing height, though `A-4 was more susceptible to dollar spot disease (<jats:italic>Sclerotinia homeocarpa</jats:italic> F.T. Bennett) than `Penncross or `G-2. Cultivation and topdressing methods for management of `A-4 and `G-2 bentgrasses do not differ substantially from `Penncross or `DW-184 creeping bluegrass.</jats:p>

Brushing Plus Vibratory Rolling Enhances Topdressing Incorporation on Ultradwarf Bermudagrass Putting Greens

“…Previous research found similar amounts of sand topdressing incorporation into Penn A and G series creeping bentgrass using brushing alone as this study found on ultradwarf bermudagrass when topdressing using brushing + vibratory rolling (25). Stier and Hollman (25) found that 1 to 3% of topdressing applied to Penn A and G series bentgrass was removed by mowing after being incorporated by brushing alone, which was similar to the amounts of topdressing sand removed after brushing + vibratory rolling on ultradwarf bermudagrass. This amount was hypothesized to have little effect on practitioners (25).…”

“…Stier and Hollman (25) found that 1 to 3% of topdressing applied to Penn A and G series bentgrass was removed by mowing after being incorporated by brushing alone, which was similar to the amounts of topdressing sand removed after brushing + vibratory rolling on ultradwarf bermudagrass. This amount was hypothesized to have little effect on practitioners (25). However, the amounts of topdressing sand removed by brushing alone or vibratory rolling in this study were larger than those found in the previous study (25) and could lead to mowing equipment damage and poor playing conditions.…”

“…Similarly, sand topdressing had minimal impact on SOM accumulation in the upper 2.5 cm of the rootzone on creeping bentgrass putting greens (22). Stier and Hollman (25) also reported no significant difference in SOM measurements from the presence or lack of sand topdressing.…”

“…Sand topdressing was applied biweekly from 28 July to 22 September 2008 and 6 July to 28 September 2009 using a Cushman TD 1500 topdressing unit (Cushman TD 1500, Textron, Charlotte, NC) calibrated to apply sand at 550 g/m 2 , equivalent to a 0.4‐mm depth. Although this sand application rate was twice that used by Stier and Hollman, it is often used by turf managers for ultradwarf bermudagrass (25). Particle size of the topdressing sand was as follows: 15.6% coarse sand (0.5 to 1.0 mm), 73% medium sand (0.25 to 0.50 mm), and 11.4% fine sand (0.15 to 0.25 mm), with no organic matter present.…”

“…Two days after application, clippings were collected from a single pass of a mower (52.5 cm wide) from each plot and oven‐dried at 105°C for 24 hours, similar to Stier and Hollman (25). Grass clippings were separated from the sand by adding water and decanting the water and clippings.…”