International Turfgrass Society Research Journal最新文献

Annual bluegrass weevil (Listronotus maculicollis, Kirby) is a formidable turf pest that causes damage to shortcut turfgrass in parts of northeastern North America. The study presented in this paper investigates the efficacy of PLINAZOLIN^® technology (isocycloseram), a gamma-aminobutyric acid (GABA) gated chloride channel antagonistic modulator (IRAC group 30) insecticide, for managing L. maculicollis (Kirby) populations at an early larval stage (first through third instars). As part of this project, we demonstrate that isocycloseram controls and prevents annual bluegrass weevil damage at a rate of 100–150 g a.i. ha⁻¹.

Soccer is one of the most popular sports in South America. Chile has over 5000 soccer fields serving over 1 million athletes. However, there are no data on essential parameters affecting sports fields' playability and safety. This work aimed to measure, record, and analyze data in three sports fields in different areas of Chile to learn about trends and understand their status to improve their agronomic management. Data on volumetric water content, temperature, salinity, and Normalized Difference Vegetation Index were taken and related to soil properties in three different football fields in central Chile. Differences in moisture content between seasons on the same football field (Nacional Stadium) and trends in temperature, humidity, and the presence or absence of weeds and diseases were observed. Data suggest more differences in volumetric water content and temperatures through seasons, mainly due to differences in soil properties.

The common water retention parameters of materials used for rootzones of turfgrass are field capacity, air capacity, wilting point, and available water capacity. More measurement points are necessary to describe the entire water retention curve (WRC) correctly, for example, for model applications. Standard laboratory methods include sand suction tables and pressure plates, or technically more advanced methods using tensiometers and evaporation. All these methods require special equipment and are time-consuming (at least 1 week); using the centrifuge method as a quick test to determine the whole WRC takes not more than 1 day. We compared water retention parameters and complete WRC of seven different root zone construction materials with various textures and organic matter contents determined by standard and centrifuge methods. Nearly all centrifuge results were within the reproducibility range of the standard method, thus demonstrating the application potential of this quick method.

Take-all root rot (TARR) is a problematic disease of ultradwarf bermudagrass (Cynodon dactylon × Cynodon transvaalensis) putting greens. The etiology and chemical management of TARR are well characterized, yet little is known about how fertilization management, including nitrogen (N) rates and sources, affects TARR severity on ultradwarf putting greens. To address the lack of knowledge, two separate greenhouse experiments were conducted. In the first of this two-part greenhouse study, ultradwarf bermudagrass cores were inoculated with Gaeumannomyces graminis and fertilized with ammonium sulfate at rates of 0, 6.1, 18.3, 24.4, 30.5, 42.7, and 48.8 kg N ha⁻¹ week⁻¹ for 8 weeks to investigate inoculated turfgrass performance at different N rates. In the second part of the experiment, four distinct N sources—ammonium sulfate, potassium nitrate, calcium nitrate, and urea—were applied at a rate of 24.4 kg ha⁻¹ week⁻¹ for 8 weeks to investigate inoculated turfgrass performance to different N sources. The turfgrass was evaluated for percent root necrosis and dry root weights. This greenhouse study indicated that N rates at or greater than 18.3 kg ha⁻¹ week⁻¹ would reduce TARR severity on ultradwarf bermudagrass compared to turfgrass that received the lowest N rate at 6.1 kg ha⁻¹ week⁻¹ and the non-fertilized control. Additionally, turfgrass that received ammonium sulfate as an N source had significantly less necrosis than all other N sources, and urea and the non-fertilized control had the highest, similar necrosis rates.

Red fescue (RF, Festuca rubra L.) is one of the most widely used turfgrass species in Europe. The subspecies Chewings fescue (CF) and slender creeping red fescue (SlCRF) are used on putting greens because they tolerate a mowing height of 4–5 mm. Previous research has shown CF to be more winter-hardy than SlCRF, however, SlCRF has a greener winter color. Our objective was to find the optimal weight ratio of the two subspecies in seed blends for greens in contrasting climatic regions of the Nordic countries. Musica and Cezanne (reference varieties in SCANGREEN variety testing since 2012) were selected as representatives for CF and SlCRF, respectively. Seed blends including CF/SlCRF in weight ratios of 75/25, 50/50, and 25/75 were compared to pure CF and SlCRF at Sydsjælland GC, Denmark, NIBIO Landvik, Norway, NIBIO Apelsvoll, Norway, and Reykjavik GC, Iceland as an add-on to SCANGREEN variety testing 2015–2018. Results showed the optimal blends to produce higher turfgrass quality and tiller density than monocultures of either subspecies at all sites except Apelsvoll where plots were killed during the first winter. The best-performing CF/SlCRF blend was 50/50 at Sydsjælland and Landvik and 75/25 at Reykjavik. While this shows seed blends to have advantages compared with the pure subspecies, the study should be repeated with a focus on dollar spot (Clarireedia spp.), which has become a major turfgrass disease in Southern Scandinavia since these trials were conducted.

Nutrient deficiencies may be common due to over irrigation, especially with sand-based sports fields and golf greens. Recent innovations in sensor technology enable precise, simultaneous measurements of soluble salts via electrical conductivity (EC), which may be related to short-term availability of soluble nutrients. The objectives of this study are to correlate pore water EC with soil and grass nutrient concentrations, comparing distinct types of fertilizer application rates. Preliminary results suggest a correlation between in situ and laboratory EC. Ongoing work with the nutrients will be reported.

Centipedegrass [Eremochloa ophiuroides (Munro) Hack], a warm-season turfgrass, is widely cultivated in the southern United States due to its minimal input requirements and natural resistance to pests. However, the availability of high-aesthetic-value cultivars remains limited. As the correlation between seed yield and turfgrass quality is generally low in centipedegrass, the development of cultivars that are exclusively vegetatively propagated could potentially increase the marketability of the species. In 2022, a study was conducted to compare sprigging as an alternative establishment method to seeding for centipedegrass production and to identify advanced breeding lines that have potential for sprigging. The study included 15 breeding lines and four controls (TifBlair, Santee, Covington, and Common) in four replications. Field trials were conducted in 1.37-m × 1.37-m plots at two North Carolina locations: the McKilwean Turf Farms (New Bern, NC) and the Lake Wheeler Turfgrass Field Laboratory (Raleigh, NC). Data on percent green cover were collected weekly through visual assessments during the growing season. Results indicated that while seeding tends to achieve higher initial green cover, sprigging can match it over time when provided with proper management practices. Additionally, several breeding lines demonstrated superior establishment speed compared to the controls across locations and methods. Overall, CEN15827 showed promise as a versatile cultivar capable of successfully establishing through seeding and sprigging methods.

A professional diagnosis of the physiological status based on careful spatial observation is essential to maintain the healthy and sustainable conditions and desired quality of turfgrass areas. The objectives of this study were to demonstrate the capability of drone-based physiological remote sensing and to analyze the spatial heterogeneity of putting greens using drone-based maps. Multispectral and thermal imagery were acquired concurrently with in situ measurements of soil water content (θ) in an experimental turfgrass field and putting greens at a commercial golf course in Ibaraki, Japan, during 2020–2022. High-resolution maps of the two physiological indicators, that is, canopy chlorophyll index (CCI) as a proxy for chlorophyll content and plant stress index (PSI) as an indicator of transpiration depression, were generated from the multispectral and thermal imagery, respectively. The CCI was closely regressed to the ground-based dark green color index (DGCI) (r² = 0.80, p < 0.01), suggesting that the CCI could be an alternative to the DGCI. The PSI (0–1) had a close relationship with θ expressed by an exponential equation (r² = 0.92, p < 0.01), suggesting an intrinsic response pattern of transpiration depression to soil water deficit in creeping bentgrass (Agrostis stolonifera L.) turfgrass areas. A strong correlation was found between PSI and θ (r = −0.85, p < 0.01) in putting greens. The spatial pattern of θ was so consistent in both the horizontal and vertical axes (r = 0.8–0.9, p < 0.01) that the site-specific variability would be persistent. The physiological maps before and after an adverse weather event suggested that these maps will be useful in identifying the vulnerable areas. The drone-based physiological maps and their synergistic use with in situ θ would provide useful information for turfgrass diagnostics. Further experimental studies are needed to extend the applicability of the methods to different species and environmental conditions.

Knowledge about nematodes prevailing in thatch and soil layers of golf courses in South Africa is limited, with previous studies only focusing on plant-parasitic nematode (PPN) abundance and diversity. Therefore, the present study was conducted to generate data about the complete soil nematode community, including both PPN and beneficial, non-parasitic nematodes associated with various golf courses situated across South Africa. Nematode samples were collected from 115 greens, fairways, and tees of 13 golf courses and from fairways and roughs of two courses. Nematodes were extracted from each composite sample obtained from the greens and/or fairways and roughs of each golf course and identified to genus level for plant parasitic nematodes and to subfamily level for the beneficial nematodes. The PPN community was dominated by Helicotylenchus, Meloidogyne, and Hemicycliophora. Maturity, enrichment, structure, channel and basal indices calculated for the beneficial nematode community showed poor soil health and disturbed soil ecosystems. Faunal analysis, determined to give an indication of the turf and soil health status of each golf course, showed that most golf courses have a low structure index (<50%), while enrichment varied between 25% and 98% indicating that soil health must improve in most of the golf courses. Results from this study represent novel data about turf and soil health of golf courses and are pivotal for sustainable upkeeping of golf courses.

Spring beauty (Claytonia virginica L.) is a perennial wildflower native to the southeastern United States. Besides providing pollinator habitat, C. virginica flowers make for attractive floral displays in urban lawns. The objective of the current study is to determine the effects of common preemergence herbicides on C. virginica growth and flowering. Field research consists of two replications in 2022 and 2023 conducted in 2 × 2 m experimental units at Mississippi State University. Treatments included an untreated check, atrazine, dicamba + penoxsulam + indaziflam, pendimethalin, prodiamine, indaziflam, and 2,4-D + dicamba + MCPP as a treated check. Percentage plant density reduction and number of flowers present were assessed visually throughout the blooming period. Preliminary results suggest that 2,4-D + dicamba + MCPP and prodiamine might negatively affect C. virginica emergence compared to untreated check, whereas no other treatment affected C. virginica plant density or flower count.