Traffic simulators are often utilized when researching turfgrass wear tolerance and recovery. However, the availability of a durable traffic simulator capable of producing dynamic force is limited. Therefore, the objectives of this research were to: (i) evaluate a novel traffic simulator with improved durability and capable of producing dynamic force and (ii) evaluate the biophysical effects of the traffic simulator on a native soil turfgrass system. The Baldree traffic simulator is a modified Ryan GA 30 (Jacobsen, A Textron Company, Charlotte, NC) riding aerification unit, equipped with fabricated, spring loaded steel plate feet studded with screw in cleats. The effects of this unit on a ‘Tifway’ bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt‐Davy] system established on a Tifton loamy sand (fine‐loamy, kaolinitic, thermic Plinthic Kandiudults) were evaluated at the Coastal Plains Experiment Station, Tifton, GA. Factors included location (1 and 2) and traffic rate (0, 12, and 24 passes applied over a 6 wk period). Field data included soil bulk density, turf density, and percent green turf cover. An in‐ground force plate at the McPhail Equine Performance Center, East Lansing, MI was used to quantify vertical and net shear ground reaction force produced by the Baldree traffic simulator when operated in the forward and backward direction. The Baldree traffic simulator produced more cleat marks per pass than the Brinkman and Cady traffic simulators. At the low traffic rate the Baldree traffic simulator increased soil bulk density, while turf density and percent green turf cover decreased; therefore, the tool can be used to simulate heavy traffic conditions with a minimum number of passes.

In recent years, turfgrass breeders have given increased attention to the development of lower maintenance turfgrass cultivars. Fine fescues (Festuca spp.) have been identified as potential candidate species for low-maintenance lawns because of their reduced need for water, mowing, and fertilizer. Unfortunately, these species have some weaknesses that must be improved to facilitate their use; perhaps, the most important of these is tolerance to wear and traffic. For this trait to be improved in new cultivars, there must be sufficient heritable variation available for plant breeders to exploit; however, little is known about the heritability of this complex trait in fine fescue species. Therefore, the objective of this study was to determine the heritability of wear and traffic tolerance in three fine fescue species. Replicated field studies were established in North Brunswick, NJ, and St. Paul, MN, and each included 157 Chewing’s fescue (Festuca rubra L. subsp. fallax), 155 hard fescue (Festuca brevipilia), and 149 strong creeping red fescue (F. rubra L. subsp. rubra) genotypes. Wear tolerance was evaluated in North Brunswick and traffic tolerance was evaluated in St. Paul during 2015 and 2016 using different simulators to determine both plant performance and broad-sense heritability estimates for wear and traffic tolerance. Broad-sense heritability estimates for the three species when calculated on a clonal basis was between 0.69 and 0.82 for wear tolerance in the North Brunswick location and between 0.49 and 0.60 for traffic tolerance in the St. Paul location. On a single-plant basis, broad-sense heritability estimates for the three species were between 0.31 and 0.45 for wear tolerance in the North Brunswick location and 0.09 and 0.12 for traffic tolerance in St. Paul. However, this research does indicate that improvement of wear and traffic tolerance in fine fescues is possible through recurrent breeding methods based on selection of replicated clonally propagated genotypes rather than selection of single individual plants of a population. This was the first study to determine the genetic effects of wear and traffic tolerance in any turfgrass species.

Summer patch is a common and destructive root disease of turfgrasses. In this study, a new Magnaporthiopsis species, M. meyeri-festucae, was identified from the roots of fine fescue (Festuca spp.) turfgrasses with summer patch-like symptoms. It is described and illustrated on the basis of phenotypic characteristics and partial sequences of rDNA 18S, internal transcribed spacer (ITS), and 28S regions, and of MCM7, RPB1, and TEF1 genes. A key for all seven described species in the genus Magnaporthiopsis is provided. Distinctions between the new species and related species are discussed. Fulfillment of Koch's postulates confirmed Magnaporthiopsis meyeri-festucae as a pathogen causing summer patch-like symptoms of fine fescue turfgrasses. This work is the basis for future studies on biogeography, host range, and impact of summer patch pathogens on a broader scale.

Hybrid bermudagrasses (Cynodon dactylon × C. transvaalensis) typically have excellent wear tolerance when compared with other turfgrass species. This trait should be evaluated during variety development to reduce the risk of failure when new grasses are planted in areas with traffic stress. The objective of this research was to evaluate the wear tolerance of four hybrid bermudagrasses with differing morphological characteristics. Traffic was applied to the hybrid bermudagrass varieties ‘Tifway’, ‘TifSport’, and ‘TifTuf’, as well as an experimental hybrids (04-76) using a traffic simulator for 6 weeks. Leaf morphology (leaf width, length, and angle) and quantitative measure of density and color [normalized difference vegetation index ratio (NDVI), dark green color index (DGCI), and percent green turf color] were characterized before traffic, and then percent green turf color after 6 weeks of traffic was measured to estimate wear tolerance. ‘TifTuf’ hybrid bermudagrass provided the greatest wear tolerance, as well as the narrowest and shortest leaf lengths, greatest NDVI values and percent green color, and lowest DGCI before traffic. Conversely, 04-76 produced the poorest wear tolerance, as well as the widest and longest leaves, lowest NDVI values and percent green color, and highest DGCI values before traffic. Regression analysis determined that DGCI, leaf length, and leaf width were inversely, or negatively, correlated to wear tolerance, whereas percent green turf color before traffic was directly correlated to wear tolerance. For these hybrids, DGCI had the strongest correlation to increased wear tolerance.

The average 18‐hole golf course is predominantly comprised of rough areas, which are often maintained at a mowing height comparable to commercial, residential, and sports turfgrass areas. If the mowing frequency of these turfgrass areas were reduced without compromising aesthetic value by using cultivars with inherently slow vertical growth combined with plant growth regulators, the labor hours, fuel, and budget allocated to turf maintenance could be vastly decreased. The objective of this research was to determine if bermudagrass (Cynodon spp.) cultivar selection and trinexapac‐ethyl (TE) use can significantly reduce the mowing events required to maintain bermudagrass at a 1.0‐inch height with mowing frequency based on the one‐third rule without compromising turfgrass aesthetics. Field research was initiated at Woodruff Farms, Abraham Baldwin Agricultural College, Tifton, GA on 11 Apr. 2011. Factors included year (2011 and 2012), month (July and August), bermudagrass cultivar [improved common types (C. dactylon) as well as hybrid crosses (C. dactylon × C. transvaalensis) and monthly applications of TE applied at a rate of 0.125 lbs of a.i. per acre compared to an untreated control. In 2011 ‘Discovery’ bermudagrass treated with TE required the lowest number of August mowing events to maintain the turf at a 1.0 inch height, followed by Discovery without TE and ‘Tifway’ treated with TE. In 2012 Discovery and ‘TifGrand’ treated with TE required the lowest number of mowing events. In 2011 and 2012 ‘Celebration’, ‘Patriot’, Tifway, and TifGrand without TE, as well as ‘DT‐1’ with or without TE required the greatest number of mowing events. In 2011 turf quality of Celebration, TifGrand and DT‐1 was reduced by TE applications, while in 2012 the quality of these cultivars as well as Tifway was reduced by TE applications. The visual quality of Discovery bermudagrass was not affected by TE application; however, this cultivar produced some of the lowest quality ratings with and without TE. If turf managers began utilizing slow growing bermudagrass cultivars coupled with TE use to decrease mowing frequency requirements, substantial reductions in labor hours and fuel consumption would be observed; however, reduced mowing frequency was associated with lower turf quality, and TE applications increased the maintenance budget of all the cultivars in this study.