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The use of bermudagrass in the Mediterranean area is increasing for its outstanding tolerance to heat and drought, and its aggressive growth and high recuperative potential make it particularly suited to heavily worn areas and appreciated for sports turfs. However, the overall performance of a given genetic type can be affected by the adaptation to a specific environment. The objective of this research was to determine the variability of a number of phenotypic traits that can affect bermudagrass turf performance on a wide range of bermudagrass accessions grown in two locations in Italy. In May 2010, 44 accessions of bermudagrasses, grouped in “wild”, “improved” “hybrid” and “dwarf” types were transplanted in the center of field plots in Pisa and Palermo. In 2011, when the turf was completely established, the following traits were determined: shoot density, horizontal stem density, node density, leaf width, colour, quality, spring green-up, and fall colour retention. Dwarf and hybrid types yielded the best aesthetic characteristics. With respect to colour retention and spring green-up, great variability was recorded within the groups. Dwarf types presented the earliest dormancy, while the hybrid types were in general the ones to green-up first in spring.

Turfgrass is a major vegetation type in urban and peri-urban areas. Being high maintenance ecosystems, turfs can contribute substantially to urban climate change. The object of this study was to evaluate the contribution to GHG emissions by urban turfgrasses in Mediterranean conditions (Tuscany, central Italy). CO2 and CH4 emission fluxes from a mature stand of tall fescue and bermudagrass were evaluated, by static chambers method, for the assessment of C emission under different nitrogen fertilization rates (0 - 50 - 150 kg N ha-1 ). Both species showed a correlation between N fertilization rate and CO2 emissions, whilst, no correlation was observed for CH4. In the case of tall fescue, cumulative CO2 emissions were significantly higher with 150 kg N ha-1 and no differences were observed between 0 and 50 kg N ha-1 . As for bermudagrass differences were found between control and other treatments but no differences were observed on cumulative CO2 emissions between 50 and 150 kg N ha-1 . In both species, N fertilization did not affect CH4 emissions. Results indicate that both N rate and turfgrass species influence C emissions, for this reason they should be considered in the management of green areas in the climatic transition zone. [ABSTRACT FROM AUTHOR]

In the south-central Italy, during summer rainfall does not supply a sufficient amount of water. Therefore, irrigation management during dry periods is important for maintaining turf quality. The hybrid bermudagrass (Cynodon dactylon (L.) Pers. × Cynodon transvaalensis Burtt-Davy) is known to represent the dominant warm-season turfgrass in warm to temperate climatic regions and its drought tolerance make bermudagrass a competitive turfgrass. A greenhouse experiment was conducted using uniform cores of hybrid bermudagrass, which were secured in a polyvinyl chloride cylinders and watered by constant sub-irrigation. The objectives of the present research were to measure the spectral reflectance with a new generation handheld spectroradiometer on hybrid bermudagrass and to explore various vegetation indices to be used as future detecting tool to study water stress in bermudagrass. Moreover, the potential uses of multivariate processing techniques for discriminating different water stress conditions in turfgrass has been investigated. Besides spectral indices, multivariate methods, although performed on a data set limited in terms of sample size, have shown a great potential for water stress monitoring in turfgrass and surely deserve further investigations. There are different indices that use distinct water absorption features independent of chlorophyll concentration, such as water index (WI = R900/R970) that has been reported to be a robust index of canopy water content and is used as an active indicator of changes in Leaf Relative Water Content (LRWC). Also, the ratio of WI with NDVI (WI/NDVI = (R 900 /R 970 )/((R 800  - R 680 )/(R 800  + R 680 )]) was found to be an effective indicator of water stress. Another vegetation index to detect water features is normalized difference water index (NDWI), designed to maximize reflectance of water by using green wavelengths. In our trial in bermudagrass the relationships studied, suggest that WI (900/970) and WI/NDVI, among the indices studied, are the more effective indicators of water stress. In fact, lower values of WI indicate higher water stress, while higher values of WI/NDVI indicate higher water stress levels.

Leaves act as a primary organ for the interception of solar radiation and their spatial arrangement determines how the plant canopy interacts with light. Many studies have been carried out on the penetration of radiation into crops however to date, few results are available on turfgrasses, mainly due to the difficulties of introducing sensors into the turf without disturbing the natural position of the leaves. In the present research two warm season turfgrasses, hybrid bermudagrass (Cynodon dactylon × transvaalensis) 'Patriot' and manilagrass (Zoysia matrella) 'Zeon', were studied. The aim was to describe their canopy architecture grown with minimal disturbance to the natural arrangement of the leaves and stems, and to determine the potential effects of canopy architecture on light penetration and reflectance. Radiometric measurements were carried out at eight different profile levels of turfgrasses that were up to 12 cm tall. A LI-COR 1800 spectroradiometer with an optical fiber cable and a 7 mm diameter sensor was used. Measurements were carried out in the 390-1100 nm region at 5 nm intervals. The LAI value was higher for the manilagrass (9.0) than for the hybrid bermudagrass (5.6). The transmitted radiation was found to be closely dependent on downward cumulative LAI. Despite a more upright habit (mean insertion angle of 22.4° ±3.4), Zoysia matrella showed a higher NIR reflectance compared to Cdxt, which has a horizontal leaf arrangement (mean insertion angle 62.1° ± 9.6). The species studied showed substantial differences both in terms of phytometric characteristics and in the capacity to attenuate solar radiation.

Spectral reflectance data originating from Unmanned Aerial Vehicle (UAV) imagery is a valuable tool to monitor plant nutrition, reduce nitrogen (N) application to real needs, thus producing both economic and environmental benefits. The objectives of the trial were i) to compare the spectral reflectance of 3 turfgrasses acquired via UAV and by a ground-based instrument; ii) to test the sensitivity of the 2 data acquisition sources in detecting induced variation in N levels. N application gradients from 0 to 250 kg ha-1 were created on 3 different turfgrass species: Cynodon dactylon x transvaalensis (Cdxt) 'Patriot', Zoysia matrella (Zm) 'Zeon' and Paspalum vaginatum (Pv) 'Salam'. Proximity and remote-sensed reflectance measurements were acquired using a GreenSeeker handheld crop sensor and a UAV with onboard a multispectral sensor, to determine Normalized Difference Vegetation Index (NDVI). Proximity-sensed NDVI is highly correlated with data acquired from UAV with r values ranging from 0.83 (Zm) to 0.97 (Cdxt). Relating NDVI-UAV with clippings N, the highest r is for Cdxt (0.95). The most reactive species to N fertilization is Cdxt with a clippings N% ranging from 1.2% to 4.1%. UAV imagery can adequately assess the N status of turfgrasses and its spatial variability within a species, so for large areas, such as golf courses, sod farms or race courses, UAV acquired data can optimize turf management. For relatively small green areas, a hand-held crop sensor can be a less expensive and more practical option.