Previous research has shown that maple (Acer spp.) leaf litter resulted in fewer common dandelions (Taraxacum officinale) when mulched into established turfgrass. However, the leaves used in that research may have contained herbicide residues and were separated by genus, not species. Our research compared the effects of pesticide-free mulched maple and oak (Quercus spp.) leaves on dandelion populations in an established kentucky bluegrass (Poa pratensis) stand maintained as a residential lawn on sandy loam soil. The objectives of this study were to quantify the effectiveness of maple or oak leaf mulches as an organic common dandelion control method and to identify which maple species and rates (particle size and rate per unit area) provided the most effective control. The experimental design was a randomized complete block with treatments arranged as a 5 × 2 × 2 + 1 factorial, with tree leaf species, leaf particle size, leaf application rate, and control as main factors. Leaf species were red maple (Acer rubrum), silver maple (A. saccharinum), sugar maple (A. saccharum), high sugar content sugar maple, and red oak (Quercus rubra). Particle sizes were coarse (0.4–1.0 inch2) and fine (≤0.2 inch2), and application rates were low (0.5 kg·m−2) and high (1.5 kg·m−2). Mulch applications were made in Fall 2003 and 2004 and data were collected beginning in Spring 2004 on kentucky bluegrass spring green-up, and common dandelion plant counts. The high application rate, regardless of tree genus or species, resulted in the highest green-up ratings. Common dandelion plant counts after one (2003) and two (2003 and 2004) mulch applications at the high rate showed that up to 80% and 53% reduction was achieved, respectively. Results indicate that mulching leaves regardless of genus (oak or maple) or maple species into established turfgrass as a leaf litter disposal method will increase spring green-up and contribute to a reduction in common dandelion population.
Alexander R. Kowalewski, Douglas D. Buhler, N. Suzanne Lang, Muraleedharan G. Nair and John N. Rogers III
Alexander R. Kowalewski, John N. Rogers III, James R. Crum and Jeffrey C. Dunne
Drain tile installation into a native-soil athletic field and subsequent sand topdressing applications are cost-effective alternatives to complete field renovation. However, if cumulative topdressing rates exceed root system development, surface stability may be compromised. The objective of this research was to evaluate the effects of cumulative topdressing, over a compacted sandy loam soil, on the fall wear tolerance and surface shear strength of a kentucky bluegrass (Poa pratensis)–perennial ryegrass (Lolium perenne) stand. Research was initiated in East Lansing, MI, on 10 Apr. 2007. A well-graded, high-sand-content root zone (90.0% sand, 7.0% silt, and 3.0% clay) was topdressed at a 0.25-inch depth [2.0 lb/ft2 (dry weight)] per application, providing cumulative topdressing depths of 0.0, 0.5, 1.0, 1.5, or 2.0 inches applied from 11 July to 15 Aug. 2007. Fall traffic was applied twice weekly to all treatments from 10 Oct. to 3 Nov. 2007. In 2008, topdressing applications and traffic, as described earlier, were repeated on the same experimental plots. Results obtained from this research suggest that the 0.5-inch topdressing depth applied over a 5-week period in the summer will provide improved shoot density and surface shear strength in the subsequent fall. Results also suggest that topdressing rates as thick as 4.0 inches accumulated over a 2-year period will provide increased shoot density, but diminished surface shear strength.
Jacob S. Bravo, Thomas Okada Green, James R. Crum, John N. Rogers III, Sasha Kravchenko and Charles A. Silcox
The soil sterilant, dazomet, is the primary product in the turfgrass industry set to take the position of methyl bromide, which is no longer available for use on turfgrass. With turf surface renovations taking place throughout the country, the need for an effective soil sterilant is critical. This study focused on the ability of dazomet to inhibit germination of annual bluegrass (Poa annua) seeds when it is used as per the current, turf focused, label which decreased legal application rates across all surfaces. This study was a four-way factorial in a split-split plot design with whole plots in a randomized complete block design arrangement with three replications. The first factor, soil type, included two levels. Soil-type plots (60 × 95 ft) were either sand capped from topdressing over the native Capac loam or they were the native Capac loam. Sand topdressing was applied biweekly at a rate of 0.14 yard3/1000 ft2, April to September since 2011; accumulating a total of 1.5 inches of sand. Each of three replicated blocks consisted of two soil-type plots. The second factor was time trials, with two levels of starting times, June and August. Each soil-type plot was split into two subplots and the trials were assigned at random to subplots within each plot. The third factor, soil preparation, involved either removing the upper 1.5 inches of the sod/soil layer or spraying plots with glyphosate and then heavily cultivating them. This cultivation included a vertical-cut and a core cultivation with an aerator using 0.5-inch hollow tines at 2 × 2-inch spacing. The fourth factor, treatment regime, comprised 11 parameters that encompassed dazomet application rate, incorporation method, and the technique used to seal the soil surface. Dazomet treatments were applied with a shaker bottle, at rates that included 262, 421, 525, and 262 lb/acre applied twice at a 5-day interval. The treatments were incorporated into the soil either through 1 inch of irrigation, through four consecutive days of irrigation following this schedule: 1, 0.5, 0.25, 0.125 inch each day after application, respectively, or physically (P) with a rotary tiller set to 1.5 inches, the depth of the topdressing layer. All P incorporated plots were hand rolled following application, regardless of the tarping procedure. Water-incorporated plots were either sealed with a clear plastic 4-mil tarp or they were left unsealed. Researchers evaluated the level of germination control by counting individual annual bluegrass seedlings using a 1 × 1-ft grid. A significant interaction occurred between soil type and soil preparation as well as between soil type and treatment. A three-way interaction also occurred between trial, treatment and soil preparation. In general, tarped treatments showed better annual bluegrass control compared with nontarped treatments. Furthermore, sand topdressed soils showed lower numbers of annual bluegrass as compared with native soils. Finally, reduced annual bluegrass germination was found in plots that had the top 1.5 inches of material removed.
Thomas O. Green, John N. Rogers III, James R. Crum, Joseph M. Vargas Jr. and Thomas A. Nikolai
Results suggest that sand topdressing was more consistent at reducing dollar spot (Clarireedia jacksonii) in fairway turfgrass more so than rolling. This practice could be an effective cost-saving alternative to reduce frequent fungicide applications. Research was conducted from 2011 to 2014 on a simulated golf fairway and examined dollar spot severity responses in a mixed-stand of creeping bentgrass (Agrostis stolonifera) and annual bluegrass (Poa annua ssp. reptans) to sand topdressing and rolling. Treatments consisted of biweekly sand topdressing, rolling at three frequencies (one, three, or five times weekly), a control, and three replications. Infection was visually estimated. Sand topdressing significantly (P < 0.05) reduced disease up to 50% at the peak of the dollar spot activity in 2011, 2013, and 2014. Results on the effects of rolling on dollar spot were inconsistent.