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Elionurus muticus is a native grass from Brazil that has been shown to have large variability in the chemical constituents of its essential oil. However, few studies have evaluated this species. The aims of this study were to chemically characterize four wild populations of E. muticus that were collected in southern Brazil as well as to evaluate the allelopathic effect of the essential oil, which is rich in citral. Chemical analyses were performed using gas chromatography and mass spectrometry. The phytotoxic activity was evaluated with onion and lettuce seeds. The results showed that the studied populations have chemical variability based on their geographic origin, which indicates the possibility of chemotypes. The results obtained with E. muticus essential oil, reveals phytotoxic activity on the germination and growth of lettuce and onion. [ABSTRACT FROM AUTHOR]

Turfgrass cover is an inevitable component in the urban landscapes of the United Arab Emirates. Tolerance to abiotic stress like salt, drought, and high temperature is a potential factor to be considered in the selection of turfgrass for the landscapes in the arid regions. Three Seashore paspalum genotypes, four Bermudagrass cultivars along with tall fescue as a control were screened for enzymatic changes under four different saline irrigation levels of 5,000, 10,000, 15,000, and 20,000 mg L−1of salinity. Irrigation with potable water served as the control. Turfgrasses were maintained in a field experiment under factorial randomized block design for a period of two years under sustained saline conditions by working out the leaching fraction to maintain the precise level of salinity in each treatment throughout the experimental period. The activities of antioxidant enzymes such as superoxide dismutase (SOD), ascorbate peroxidase (APX), peroxidase (POD), polyphenol oxidase (PPO), and catalase (CAT) were assayed in each of the saline water treated turfgrass types. The SOD activity was found to be high in Yukon (bermudagrass) and Sea Dwarf paspalum. In the paspalum group, Salam and Sea Dwarf showed the highest SOD activity under saline condition. In Bermuda types, Yukon and SR 9554 showed the highest SOD activity compared to other bermuda types. Compared to other cultivars, Sea Isle 2000 (Paspalum type), SR 9554, and Yukon (Bermuda types) exhibited more APX activity without any significant differences among themselves. There was an elevated activity of POD initially, followed by gradual reduction upon increasing the salinity level. Salam cultivar maintained stable POD activity even at the elevated salinity levels. The paspalum types showed relatively high level of PPO activity compared to other types under salinity. Yukon cultivar showed a significantly higher activity of PPO when the salinity level was raised from 15,000 to 20,000 mg L−1. A significant increase with respect to CAT activity was exhibited in Sea Dwarf under elevated level of salinity. Saline water irrigation brought about a significant effect on the antioxidant enzyme systems to impart oxidative stress tolerance in turfgrass species. [ABSTRACT FROM PUBLISHER]

The objectives of this research were to investigateLolium perenneL. responses to water deficit, compare drought tolerance of two cultivars derived from different germplasm and the role of endophyte in drought tolerance of the host cultivar. Plants of cultivars Ceres One50 and Grasslands Commando with and without AR37 endophyte were kept irrigated or unirrigated for two weeks and then rehydrated for one month in a glasshouse. A positive correlation between the extent of osmotic adjustment (OA) and leaf dry matter regrowth indicated that OA was correlated with the plant regrowth during recovery. For One50, the reduction in leaf elongation rate was less and the increase in proline was greater in response to drought, compared to Commando. From this observation, it was inferred One50 has enhanced capacity to continue growth, and had greater intra-cellular protection than Commando. Endophyte status did not affect plant responses to drought in this experiment. [ABSTRACT FROM AUTHOR]

Arundo donaxL. has a high biomass production and a tendency toward community dominance in many habitats and thereby a tolerance to a wide range of environmental conditions. Therefore, the present study investigated the potentiality ofA. donaxto accumulate nutrients and trace metals in its biomass. Six main habitats (Nile Bank, Drain Bank, Canal Bank, Field Edges, Railways and Roadsides) were recognized. At each habitat, six quadrats (each 1 m2), distributed equally in two sites, were selected for growth measurements (e.g., density, shoot height, diameter, leaf area and biomass), plant and soil analyses. Plants from Nile, Canal and Drain Banks had the highest values of most growth measurements, while those from Railways and Roadsides had the lowest. Canal Bank plants accumulated the highest concentrations of P, Cu and Pb in their leaves; Zn in the stem; and Mg, Cd and Fe in the rhizome. The bioaccumulation factor (BF) ofA. donax, for Cd, Fe, Mn and Zn, was greater than 1, while the translocation factor (TF) of most trace metals was less than unity in most habitats. In conclusion,A. donaxshowed morphological plasticity in response to habitat heterogeneity, and its growth was most vigorous in the riparian habitats. The high BF, as well as the significant positive correlations between trace metals, especially Cd, in soil and plant, rendersA. donaxa powerful phytoremediator. [ABSTRACT FROM PUBLISHER]

Palmarosa (Cymbopogon martinii(Roxb.) Wats.) is an essential oil bearing perennial crop having geraniol and geranyl acetate in its oil, widely used in cosmetic and perfumery industries. An experiment was conducted to determine germination percentage and seedling vigor index in PRC-1, Trishna and Tripta varieties of Palmarosa at KCl salt concentrations of 0 mM, 50 mM, 100 mM and 150 mM in Petri-dishes coupled with 16 hrs light and 8 hrs dark photoperiod placed at 25°C temperature. The highest percentage of germination and seedling vigor index I and II was observed in control followed by 50 mM, 100 mM and 150 mM. Germination percentage, seedling vigor index I and II decreased as KCl concentration increased. Highest KCl salt tolerance potential was showed by variety Trishna followed by PRC-1 and Tripta. Varieties PRC-1 and Tripta have salt tolerance potential up to 50 mM while Trishna have up to 150 mM KCl concentration. The result of our study suggests that farmers can raise Palmarosa nursery in normal soil condition and transplant it in soil salinity upto 50 mM KCl concentration. Hence, we suggest that in the nursery more than 50 mM salinity soils should be avoided except variety Trishna which can be grown up to 100 mM KCl concentration at 25°C. [ABSTRACT FROM AUTHOR]

Many C3 grasses establish mutualistic associations with endophytic fungiNeotyphodiumspp.Lolium multiflorumLam. natural diploid populations of the Pampa region present high levels of infection whereas commercial cultivars, mainly tetraploid, exhibit low or no infection. In the genusBromus, no information is available about this association in polyploid populations. The incidence ofNeotyphodiumspp. endophytes in diploid and tetraploid commercial cultivars ofL. multiflorum, as well as in natural hexaploid populations of genusBromus, was analysed. Observed infection was higher in diploid populations ofL. multiflorumthan in tetraploid populations. No infection was detected inBromusspp. Various factors such as the production and handling of commercial seeds, the interaction of endophytes with ploidy level, and the genetic manipulation of seeds are discussed as the possible causes for the differences observed between natural and improved annual ryegrass and brome populations, and between diploid and tetraploid annual ryegrass. [ABSTRACT FROM AUTHOR]

Bermudagrass (Cynodon dactylon(L.) Pers.) is a widely used turfgrass in tropical, subtropical and warm-temperate regions in the world. It is a salinity-tolerant plant, but much genetic variation exists among its genotypes. Genetic diversity has been shown to exist from a morphologic level to a molecular level among Chinese natural bermudagrass germplasm resources; however, the extent of variation in their salinity tolerance has remained unclear. We conducted greenhouse hydroponic and sand culture experiments to evaluate the variation in salinity tolerance of natural bermudagrass germplasm resources obtained from their main areas of distribution in China and treated at a 33 dS m−1salinity level for three weeks. Compared with non-saline controls, salinity stress significantly decreased shoot clipping weight (46.5% and 44.2%) and increased leaf firing (41.1% and 37.6%) in hydroponic and sand culture experiments, respectively, across all genotypes. However, significant genetic variations in relative leaf firing percentage (RLF) and relative shoot weight (RSW) were found among genotypes in both experiments, and their coefficients of variation ranged from 25.5% to 41.6%, indicating that considerable variation exists in the salinity tolerance of Chinese natural bermudagrass germplasm resources. Shoot Na+concentrations increased under salinity stress for all genotypes in both experiments. However, significant genetic variations were also found in shoot Na+concentrations. Salinity tolerance in bermudagrass genotypes was found to be significantly negatively correlated with shoot Na+concentrations in both experiments. Using a cluster analysis of RLF and RSW data, all genotypes were classified into four groups with different salinity tolerances. The results of our evaluation indicate that there is much potential for improving salinity tolerance among Chinese natural bermudagrass cultivars. [ABSTRACT FROM AUTHOR]

Understanding responses of turf grasses to drought stress is important for water resource management to maintain an acceptable level of quality for turfs under prolonged drought conditions. Four cultivars of St. Augustine grass (SA) (Stenotaphrum secundatum [Walt.] Kuntze) were evaluated for morphological and physiological responses to four watering treatments in greenhouse studies. Soil moisture treatments had greater impact on stolon number, photosynthetic rate, and dry matter production than on leaf sheath length and chlorophyll fluorescence. Full irrigation and the 75% field capacity (FC) did not result in significant differences in most of the characteristics, whereas the 25% FC significantly reduced morphological growth, physiological activities, and dry matter production of cultivars. The time when the morphological characteristics started showing differences among the watering treatments varied, with stolon numbers beginning to show response to watering treatments at week 2 (two weeks after watering treatment) and leaf sheath length not differing significantly until week 5 (five weeks after watering treatments). Cultivars differed in response to soil watering treatments among the characteristics. Floratam had the longest stolons, largest leaves, and greatest dry matter accumulation among cultivars across the environments. Raleigh had the lowest dry matter production at all levels of soil moisture but the least reduction of dry matter at 25% FC. [ABSTRACT FROM PUBLISHER]

Elemental sulfur (S) impregnated with Fe (S-Fe) fertilizer was evaluated on Kentucky bluegrass (KBG; Poa pratensis L.) in three glasshouse studies: (1) with/without Fe as S-Fe, ferrous sulfate (FS), or iron-ethylenediamine-N,N’-bis(2-hydroxyphenylacetic acid) (Fe-EDDHA) to soil (49 kg Fe ha−1), or foliar Fe-EDDHA (5 kg Fe ha−1) on two cultivars; (2) 0, 49, 197, or 592 kg Fe ha−1 of S-Fe deep mixed or surface mixed on two soils; (3) 0 or 49 kg Fe ha−1 applied as S-Fe on four cultivars. A field study comparing 0 and 49 kg Fe ha−1 applied as S-Fe to KBG was also conducted. Soil applied S-Fe was assimilated in shoots as efficiently as Fe-EDDHA applied to soil or foliage. Shoot Fe increased significantly with increasing S-Fe in a curvilinear response when deep mixed with soil and in a linear response when surface applied. However, no Fe source tested impacted yield or verdure in these studies. [ABSTRACT FROM PUBLISHER]

Warm season turfgrasses are increasingly used throughout the transitional areas of Mediterranean countries due to their low water requirements. A two-year field study was carried out in north-eastern Italy to evaluate the turf canopy quality and root system architecture of three seeded bermudagrass cultivars (La Paloma, Princess-77 and Yukon), and a zoysiagrass (Companion) under non-irrigated conditions. Plots (1.6×4.5 m) were established in July 2005 and arranged in a randomized complete block with three replicates. Visual quality ratings were assessed weekly from April to November in 2006 and 2007. Soil cores were collected at depths of 0–3, 3–8, 8–15, 15–25 and 25–40 cm in August 2006, January 2007, May 2007 and September 2007 to measure main rooting characteristics: root length density (RLD), root mass density (RMD) and root diameter. Companion zoysiagrass had higher canopy quality than bermudagrass cultivars in early spring and in the late growing season, while it displayed poorest quality from June to October. Among the bermudagrass cultivars, Yukon showed the highest quality in both years. Differences in RLD among grasses appeared to be related to seasonal changes in air temperature and precipitation. In August 2006 Companion zoysiagrass averaged 3.5–4.4 cm cm−3 less RLD than bermudagrass cultivars La Paloma and Princess-77. Visual turf quality was positively correlated to the RLD and RMD in the 25–40 cm soil layer, whereas no correlations were found with root diameters nor any parameter collected in the upper soil layers. Deep-rooting cultivars may have an advantage in deficit soil moisture periods resulting in higher quality turf throughout the year. [ABSTRACT FROM PUBLISHER]

EU requirements for Integrated Pest Management (IPM), perhaps even pesticide-free management, have implications for choice of turfgrass species and varieties for golf courses. This paper reports results from variety testing for putting greens in the southern Nordic zone comprising Denmark and coastal areas in south Sweden and south Norway, and the northern zone comprising Finland, Iceland and remaining regions of Sweden and Norway. Forty-one varieties of seven species/subspecies were compared from 2007 to 2010 at Apelsvoll (Norway, 61° 42′ N, 250 m asl) and Korpa (Iceland, 64° 09′ N, 30 m asl) (northern zone), and at Landvik, (Norway, 58° 11′ N, 12 m asl) (southern zone). Once established, the trials were mowed at 3 mm for Agrostis and 5 mm for Festuca, Poa and Lolium. Mean fertilizer rates were 1.7 kg N 100 m−2 yr−1 to A. stolonifera and 1.0 kg N 100 m−2 yr−1 to other species. No pesticides were used. On average for varieties within species, F. rubra, especially ssp. commutata, had significantly less winter damage (biotic and abiotic) than L. perenne and Agrostis sp. F. rubra also had significantly less in-season diseases (mainly Microdochium patch) than A. capillaris and A. canina in the southern zone and in comparison with all Agrostis sp. in the northern zone. On average for varieties, the ranking based on overall visual merit was F. rubra ssp. commutata>F. rubra ssp. litoralis>A. canina>A. stolonifera>A. capillaris>P. trivialis>L. perenne in the northern zone, and A. canina>A. stolonifera>F. rubra ssp. commutata>F. rubra ssp. litoralis>A. capillaris>L. perenne>P. trivialis in the southern zone. For pesticide-free management of putting greens, we recommend pure seed blends or F. rubra in both zones. Seed blends of A. stolonifera or A. canina, and seed mixtures of F. rubra and A. capillaris are compatible with IPM including limited fungicide use. Ranking lists of varieties are presented. [ABSTRACT FROM PUBLISHER]

Because of different climatic and political conditions, turfgrass variety testing in the UK or North America is not directly applicable to Scandinavian golf courses. A species- and variety-testing project was carried out from 2003 to 2006 on United States Golf Association (USGA)-specification greens at the Norwegian research stations Apelsvoll [60°42' N, 10°52'E, 250 m above sea level (a.s.l.)] and Landvik [58°20' N, 8°31'E, 10 m a.s.l.]. The two sites were considered representative for the northern/continental and southern/coastal part of Scandinavia, respectively. Forty-three varieties of six different species/subspecies were evaluated in the sowing year and subsequent three years for visual merit (turfgrass quality), plant coverage, tiller density, color, leaf fineness, winter damage, date of spring green-up, height growth, and thatch accumulation. The trials were managed as putting greens including mowing three times per week to 4.5-5.0 mm for Festuca rubra and 3 mm for Agrostis sp. and Poa annua. No pesticides were used. Agrostis canina had the highest scores for visual merit, tiller density, and leaf fineness, but also accumulated more thatch than did other species. At the northern test site Agrostis canina had better winter survival than had any other species except Agrostis capillaris. Poa annua and all varieties of Agrostis stolonifera except 'Nordlys' had significantly more winter damage than did varieties of Festuca rubra. Plant height growth increased in the order Agrostis canina

Phosphorus (P) is often reported as a nutrient whose availability increases by lime application, although some research suggests a decline in the short-term P availability upon liming. This study addresses the effects of applying different sized limestone (2-4, 0.5-2, 0.25-0.5, and <0.25 mm) on the forms and availability of soil P, P concentrations and extraction by pasture, and yields of plant species. Soil P was partitioned into organic and inorganic forms, using an ignition method. Available P was determined by the Olsen and Mehlich 3 methods. Phosphorus in plants was determined after acid digestion. Most P was present in organic form. One year after sowing, inorganic P increased and organic P decreased. Liming had no significant influences on soil P. Phosphorus extracted by Mehlich 3 explained 40% of the total dry-matter yield in the first harvest. No significant effect of liming on P concentration in plants was observed. [ABSTRACT FROM AUTHOR]

Grass-infecting Epichloё fungi depend on flies of the genus Botanophila (Diptera: Anthomyiidae) for the transfer of spermatia (gametes) and fertilization. Flies lay eggs on fungal structures and their larvae use this as a source of food, hence, this interaction is generally considered to be obligatory and mutualistic. In the present study, we monitored the occurrence of Botanophila flies in a population of Epichloë-infected wild orchardgrass (Dactylis glomerata) in central Poland. The number of eggs per stroma ranged from 0 to 14. Overall, 24.83% of all examined stromata had no eggs or brood chambers, whereas the incidence of fertilized stromata ranged from 89.66% to 100% depending on the year. Nearly all stromata that exhibited no signs of fly visitation were fertilized. These results suggest that in the Polish population of D. glomerata, sexual reproduction of Epichloё fungi depends on spermatia-carrying vectors other than Botanophila. [ABSTRACT FROM AUTHOR]

The Italian populations of Koeleria splendens C. Presl, critical group of the Mediterranean flora, are examined from the taxonomic and nomenclatural viewpoints. On the basis of literature data, herbarium investigations and field surveys, many morphologically well-differentiated taxa have been recognized. This group is widespread in the Italian peninsula and Sicily, where it is represented by the following units: K. splendens C. Presl, with four subspecies [subsp. splendens, subsp. grandiflora (Bertol. ex Schultes) Domin, subsp. brutia Brullo, Gangale & Uzunov, and subsp. ophiolitica subsp. nova], K. lucana sp. nova, K. subcaudata (Ascherson & Graebner) Ujhelyi, K. australis Kerner, K. callieri (Domin) Ujhelyi, and K. insubrica sp. nova. As concerns their distribution, both K. splendens and K. lucana are endemic to the Italian territory, while the other species occur also in some eastern Mediterranean countries. The taxonomic position of K. lobata, recently treated by some authors as a synonym of K. splendens, is also examined. A phylogenetic analysis was performed using morphological characters. Finally, a detailed iconography of the main morphological features and an analytical key of the Italian taxa (K. lobata included) are given. [ABSTRACT FROM AUTHOR]

A two-year field trial was carried out in the seasons of 1997/98 and 1998/99 at Sennar Sugar Company (latitude 13° 33′N and longitude 33° 37′E), to investigate the effect of different levels of potassium (0, 72, and 144 kg K/ha) as K2O and phosphorus (0, 29 and 58 kg P/ha) as P2O5 on the performance of two sugarcane (Saccharum officinarum) varieties (Co 6806, Co 527) and their first ratoon grown on three soil series (Hagu, Nasr, and Dinder). The layout was a randomized complete block design arrangement using three replications. The results indicated that potassium application affected plant density and stalk diameter significantly. The stalk height of the plant cane and its first ratoon was positively affected only late in the season. In the ratoon, the effect was significant early in the season on all growth parameters. The yields of cane and sugar on Dinder series were raised significantly in response to potassium addition in plant cane and ratoon. Potassium increased yield of cane and sugar on Nasr soil and yield of sugar on Hagu soil significantly. Phosphorus addition, on the other hand, reflected a significant effect on stalk height, number of internodes and plant density of plant cane and ratoon early in the season. However, the increase in stalk height and plant density of ratoon continued as the season proceeded. In plant cane, phosphorus application significantly affected sugar yield on Hagu soil. Application of phosphorus to ratoon grown on Dinder and Hagu series resulted in significant increase of cane and sugar yields. Variety Co 6806 gave the best growth and yield compared with Co 527. Soil analysis revealed a depletion of extractable potassium after plant cane harvest. The reverse was true after ratoon harvest from Nasr and Hagu soil series. Soil available phosphorus decreased after cane cropping and increased after ratoon harvest, but both were mostly less than the initial amount before cane planting. [ABSTRACT FROM AUTHOR]

Plants commonly encounter deficient and/or toxic levels of mineral elements when grown in acidic soil, and arbuscular mycorrhizal fungi (AMF) have potential to overcome many of these effects. Switchgrass (Panicum virgatum L.) was grown in acidic Lily soil (Typic Hapludult) at pHCa 4 and 5 (soil:10 mM CaCl2, 1 :emsp14;1) and inoculated with Glomus (G.) clarum, G. diaphanum, G. etunicatum, G. intraradices, Gigaspora (Gi.) albida, Gi. margarita, Gi. rosea, and Acaulospora (A.) morrowiae to determine differences among mycorrhizal (AM) plants for mineral uptake per root length (RL). Shoots of AM plants grown in pHCa 4 and 5 soil had extensive mineral nutrient content (per plant) differences, and AM plants grown in pHCa 4 soil generally had higher and wider ranges of mineral contents than plants grown in pHCa 5 soil. Mineral uptake per RL varied extensively among AM plants. The AM plants generally enhanced uptake of phosphorus (P), nitrogen (N), sulfur (S), potassium (K), calcium (Ca), magnesium (Mg), zinc (Zn), and copper (Cu) and reduced uptake of manganese (Mn), iron (Fe), boron (B), and aluminum (Al). The G. etunicatum plants particularly had higher P, N, S, K, Mg, Zn, and Cu uptake compared to the other AM plants. Most AMF isolates used were effective in enhancing mineral uptake and reducing excess amounts of toxic elements in shoots. [ABSTRACT FROM AUTHOR]