Search

Supplements or conserved forage are often used to overcome forage quantity deficits for beef cattle, but stockpiled forage can be more economical. Limpograss [Hemarthria altissima (Poir.) Stapf & C.E. Hubb.] is the best available species for stockpiling in Florida because it is productive in autumn and maintains greater digestibility than other grasses at advanced stages of maturity. New limpograss hybrid breeding lines have been developed, but they have not been tested under stockpiling. Three limpograss breeding lines (1, 4F, and 10) and the most-used cultivar, Floralta, received 50 or 100 kg N ha-1 at initiation of stockpiling and herbage accumulated for 8, 12, or 16 wk. Entry 4F had greater herbage accumulation (7.3 Mg ha-1) than Entries 10, 1, and Floralta (6.1, 6.0, and 5.4 Mg ha-1, respectively). Entry 4F also had greater in vitro digestible organic matter (IVDOM) concentration (530-594 g kg-1) than Entries 1 and Floralta, but 4F was not different from Entry 10 (519-531 g kg-1) after 12 and 16 wk of accumulation. As stockpiling period increased from 8 to 16 wk, herbage accumulation increased from 5.3 to 7.4 Mg ha-1, dead material proportion increased from 1 to 10%, and herbage crude protein (CP) decreased from 44 to 32 g kg-1. Limpograss hybrids 4F and 10 are superior to Floralta for stockpiling, stockpiling period should not be longer than 12 wk, and protein supplement will be required to achieve satisfactory animal performance on stockpiled limpograss. [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]

The article presents a study which described the grass species found in the East Anatolian region of Turkey called Psedophleum anatolicum. Topics discussed include the use of field sampling techniques to acquire the plant specimens for the study, the use of the JEOL-6060 scanning electron microscope in the analysis, and the results of the comparative morphological studies of the species.

Perennial ryegrass ( Lolium perenne L.) and Italian ryegrass ( Lolium multiflorum Lam.) are important temperate forage grasses which are closely related, generating fertile interspecific hybrids. All groups are represented by multiple cultivars in the commercial pasture seeds market. Due to the close taxonomic relationship between the two species, differentiation based on morphophysiological criteria is not always readily achievable. In addition, an obligate outbreeding reproductive habit produces high levels of individual heterozygosity and intrapopulation diversity, which presents problems for discrimination between cultivars. Molecular genetic marker polymorphism provides an effective means of addressing these challenges. An iterative process of resequencing from loci distributed across the perennial ryegrass genome was used to identify single nucleotide polymorphism (SNP) markers, which were then validated and formatted in a highly multiplexed (384-plex) assay system. SNP genotyping was then performed across samples of 48-192 individuals from a total of 27 ryegrass cultivars (19 of perennial ryegrass, seven of Italian ryegrass and one hybrid cultivar). SNP markers from perennial ryegrass exhibited a high level of transfer to Italian ryegrass. Data analysis permitted quantification of intra- and inter-species diversity, as well as discrimination between cultivars within each species, including diploid and autotetraploid cultivars of perennial ryegrass. Lower levels of SNP-based diversity were detected in Italian ryegrass than in perennial ryegrass. A neighbour-joining tree based on genetic distance analysis located a hybrid cultivar to an intermediate position between the two species-specific cultivar groups. The resulting catalogue of ryegrass cultivars will provide support for the processes of cultivar accreditation and quality assurance. [ABSTRACT FROM AUTHOR]

Coastal dune vegetation distributes zonally along the environmental gradients of, e.g., soil disturbance. In the preset study, arbuscular mycorrhizal fungal communities in a coastal dune ecosystem were characterized with respect to tolerance to soil disturbance. Two grass species, Elymus mollis and Miscanthus sinensis, are distributed zonally in the seaward and landward slopes, respectively, in the primary dunes in Ishikari, Japan. The seaward slope is severely disturbed by wind, while the landward slope is stabilized by the thick root system of M. sinensis. The roots and rhizosphere soils of the two grasses were collected from the slopes. The soils were sieved to destruct the fungal hyphal networks, and soil trap culture was conducted to assess tolerance of the communities to disturbance, with parallel analysis of the field communities using a molecular ecological tool. In the landward communities, large shifts in the composition and increases in diversity were observed in the trap culture compared with the field, but in the seaward communities, the impact of trap culture was minimal. The landward field community was significantly nested within the landward trap culture community, implying that most members in the field community did not disappear in the trap culture. No nestedness was observed in the seaward communities. These observations suggest that disturbance-tolerant fungi have been preferentially selected in the seaward slope due to severe disturbance in the habitat. Whereas a limited number of fungi, which are not necessarily disturbance-sensitive, dominate in the stable landward slope, but high-potential diversity has been maintained in the habitat. [ABSTRACT FROM AUTHOR]

We investigated differences between forage species with regard to micronutrients that are essential to sustain livestock health. Five grasses (timothy, perennial ryegrass, meadow fescue, tall fescue and cocksfoot), three legumes (red clover, white clover and birdsfoot trefoil) and four forbs (ribwort plantain, salad burnet, caraway and chicory) were grown on one micronutrient-poor/low p H soil and one micronutrient-rich/high p H soil (outdoor pot experiment). In addition, six grasses (timothy, perennial ryegrass, meadow fescue, tall fescue, Festulolium hybrid and cocksfoot) and one legume (red clover) were field-grown on the micronutrient-poor soil. Of the twelve pot-grown species, herbage of chicory, red clover and white clover generally had the highest micronutrient concentrations (maximum Co, Cu, Fe and Zn concentrations were 0·23, 9·8, 233 and 109 mg kg−1 DM, respectively), except for Mo, which was highest in the clovers (10·6 mg kg−1 DM), and Mn, which was highest in cocksfoot (375 mg kg−1 DM). Soil type had the strongest effect on plant Mo and Mn concentrations. We also investigated differences in micronutrients between varieties, but they were generally few and negligible. The results indicate that choice of forage species is of major importance for micronutrient concentrations in herbage and that soil type exerts a major effect through p H. Forage of chicory, red clover and white clover generally met the requirements of high-yielding dairy cows with regard to most micronutrients; therefore, diversification of seed mixtures so as to include these species could increase micronutrient concentrations in forage. [ABSTRACT FROM AUTHOR]

Highlights: [•] We assessed yield and persistence of elite grass cultivars across Mediterranean sites. [•] Cultivar adaptive responses were modelled as a function of relevant climatic variables. [•] Our results support crop recommendation and breeding, also in view of climate change. [•] Tall fescue has general interest for Mediterranean drought-prone areas. [•] Completely summer-dormant cocksfoot with improved yield can be useful in warmer sites. [ABSTRACT FROM AUTHOR]

Plains rough fescue ( F estuca hallii) is an important forage grass species in western Canada. Seed for use in pastures and ecological restoration is in high demand but supply is limited because F. hallii is an erratic seed producer. Seed producers require an understanding of the factors that influence flowering and seed set in this species. The aim of this study was to assess the effect of irrigation and nitrogen fertilization on the flowering and growth of F. hallii in a native rough fescue prairie in Alberta, Canada. Irrigation had a strong positive effect on seedhead density, whereas fertilization had limited effects on growth and reproduction of F. hallii. These results demonstrate that under field conditions, available moisture is likely to be a key factor driving flowering and seed production in F. hallii. [ABSTRACT FROM AUTHOR]

The ability to survive harsh winters is one of the primary factors limiting bermudagrass ( Cynodon spp .) distribution, especially those used for forage. Consequently, improved stress tolerance has been a goal of programmes for breeding bermudagrasses. While significant progress has been made in developing and evaluating freeze tolerance of turfgrasses, information on forage bermudagrasses is limited. Our objective was to evaluate freeze tolerance of recently released forage bermudagrasses compared with standard cultivars. Plants were established and acclimated in growth chambers and exposed to sub-freezing temperatures in a programmable freeze chamber. Plant responses to low-temperature exposures were quantified by regrowth mass. Freeze tolerance of Tifton 44 and Coastal was not significantly different from Midland, the reference cultivar. Coastcross, Tifton 85 and Tifton 68 were more susceptible to low-temperature injury than Midland, while Hardie, Goodwell, Midland 99 and Ozark were more freeze tolerant than Midland. Ozark, Midland 99, Goodwell and Hardie are less likely to sustain winterkill than Coastcross, Tifton 85 and Tifton 68 in areas that frequently experience low temperatures. Cultivars with one or more parents originating in Kenya had poor freeze tolerance, while germplasm from Yugoslavia and Afghanistan produced plants that were more freeze tolerant. [ABSTRACT FROM AUTHOR]

The total amount and the composition of varieties of all forage grass and clover seed delivered for farm use in Northern Ireland was monitored over the 25-year period of 1980–2004. Total seed use in Northern Ireland declined from the 1980s to the 1990s but then stabilized despite isolated drops in sales associated with outbreaks of animal diseases. This profile was mirrored by similar declines in the rest of the UK. The survey revealed the annual volatility of the market and its sensitivity to changes in government financial support, to changes in farm practice and farm incomes. Examination of the data on the grassland area under 5 years old showed them to be poor indicators of actual seed use. Levels of species use were very stable over the 25 years of the survey but reseeding of varieties of perennial ryegrass differing in maturity and ploidy type changed dramatically. When sufficient seed was available, selection of varieties complied with the contemporary recommended list ratings of agronomic value but in a few cases selection of varieties was determined by price. The current survey of seed sales provides a benchmark against which responses by farmers following the latest changes in the Common Agricultural Policy of the European Union can be measured. [ABSTRACT FROM AUTHOR]

How expected increases in climate variability will affect species diversity depends on the role of such variability in regulating the coexistence of competing species. Despite theory linking temporal environmental fluctuations with the maintenance of diversity, the importance of climate variability for stabilizing coexistence remains unknown because of a lack of appropriate long-term observations. Here, we analyze three decades of demographic data from a Kansas prairie to demonstrate that interannual climate variability promotes the coexistence of three common grass species. Specifically, we show that (i) the dynamics of the three species satisfy all requirements of ‘storage effect’ theory based on recruitment variability with overlapping generations, (ii) climate variables are correlated with interannual variation in species performance, and (iii) temporal variability increases low-density growth rates, buffering these species against competitive exclusion. Given that environmental fluctuations are ubiquitous in natural systems, our results suggest that coexistence based on the storage effect may be underappreciated and could provide an important alternative to recent neutral theories of diversity. Field evidence for positive effects of variability on coexistence also emphasizes the need to consider changes in both climate means and variances when forecasting the effects of global change on species diversity. [ABSTRACT FROM AUTHOR]

An experiment was conducted to determine the genetic variation among diploid perennial ryegrass ( Lolium perenne L.) varieties for sward structural characteristics considered to be important for intake by cattle. Assessments were made between June and September in 2000 and 2001. Six varieties (Abergold, Respect, Agri, Herbie, Barezane and Barnhem) were subjected to a cutting experiment where swards were cut after 3 to 4 weeks of regrowth during the growing season. The variables, measured in three 2-week periods, were herbage mass of dry matter (DM), sward surface height (SSH), bulk density, proportion of green leaf, tiller density, tiller weight, extended tiller height, length of sheath and length of leaf blade. Significant differences among varieties were found in both years for herbage mass of DM, SSH, bulk density, proportion of green leaf, tiller density, tiller weight and length of sheath. The results show that there is significant genetic variation among diploid perennial ryegrass varieties for sward characteristics important for intake during grazing. [ABSTRACT FROM AUTHOR]

Kentucky bluegrass (Poapratensis L.) is an important cool-season grass species in the turfgrass and forage industries. Understanding the genetics of Kentucky bluegrass is useful in developing improved cultivars and hybrids. However, studying the genetics of Kentucky bluegrass can often be difficult because of the high variation in ploidy level that results from its facultative apomictic reproductive nature. Flow cytometry provides an easy and accurate method for assessing this variation by quantifying DNA content. The purpose of our study was to determine the level of variation in ploidy in Kentucky bluegrass by analyzing its DNA content using flow cytometry. In addition, DNA content was compared with genetic similarity derived from DNA marker data, and was also correlated with chromosome number. Twenty-two cultivars of Kentucky bluegrass were selected for the study by considering the range of variability in morphological traits and genetic distance derived from DNA marker data. We found that the DNA content of Kentucky bluegrass genotypes from the 22 cultivars ranged from 5.39 to 17.69 pg of DNA/2C and that a majority of the genotypes had a DNA content value in the range of 7 to 13 pg. A significant correlation between DNA content and chromosome number was detected. Euploid chromosome numbers (x = 7) with a range from the pentaploid (2n = 5x = 35) to the quindecaploid (2n = 15x = 105) were found along with aneuploid numbers. The results of this research could aid both breeders and researchers in studying the genetics of the species and in improving Kentucky bluegrass cultivars via intra, and interspecific hybridizations. [ABSTRACT FROM AUTHOR]

Turf quality is a complex character of fundamental importance in turfgrass evaluation. It takes into account aesthetic and functional aspects, and depends on several individual components which may vary with time. The use of a synthetic and simple quality score is necessary when evaluating large numbers of varieties. The quality of 110 turfgrass varieties belonging to four species ( Lolium perenne, Poa pratensis, Festuca arundinacea and F. rubra) was assessed in the second and third years of growth at three Italian locations, i.e. Lodi (Po Valley, continental climate), Perugia (central Italy, sub-Mediterranean climate) and Foggia (southern Italy, Mediterranean climate), using a visual score ranging from 9 (outstanding turf) to 1 (very poor turf). A randomized block design with three replicates was used, with varieties of the same species being blocked to facilitate the comparison within species. On average, F. rubra had the lowest turf quality score in summer, whereas the other species had the lowest quality score in winter and the highest quality score in summer and autumn. Components of variance were large for genotype (i.e. variety) main effects in all species. A variety × location interaction was found in F. arundinacea and higher-order interactions were also found for P. pratensis and F. rubra. Genotype × environment effects were small relative to genotypic effects in L. perenne. Variety × year interactions were small in all cases, whereas variety × location and variety × season interactions were greater. Stability of turf quality across sites, seasons and years was measured for each variety in terms of environmental variance, i.e. the variance of score values across sites, years and seasons. Mean scores and stability values of varieties were integrated into an index of reliability that estimated the lowest score value expected in 0·80 of cases. For each species, a small subset of highly reliable varieties could be identified. Implications of the results for the testing and breeding of varieties in Italy are discussed. [ABSTRACT FROM AUTHOR]

The article provides an overview of the registration of Freedom III Kentucky bluegrass, a turf-type variety released in August 2004 by Jacklin Seed by Simplot in Post Falls, Idaho. The variety was derived from field hybrid cross 92.4230, which was created in June 1992 using Jacklin breeding line 92-0076 as the maternal parent and Midnight as the pollen source. It closely resembles the cultivar Awesome Kentucky bluegrass, differing by shorter culm length and lower turf quality ratings under the traffic stress. Details on yield and agronomic traits, breeding conditions and method, maintenance, and growth habits are presented.

The article provides an overview of the registration of Barrister Kentucky bluegrass, a turf-type variety released in July 2002 by Jacklin Seed by Simplot in Post Falls, Idaho. The variety was derived from field hybrid 89-1037, which was created in July 1989 using "Midnight" to pollinate plants of Limousine. It closely resembles the cultivar Arcadia, differing by lighter seed weight, lower spring ground coverage, and lower sod strength. Details on yield and agronomic traits, breeding conditions and method, maintenance, and growth habits are presented.

The article provides an overview of the registration of Everest Kentucky bluegrass, a turf-type variety released in August 2004 by Jacklin Seed by Simplot in Post Falls, Idaho. The variety was derived from the open-pollinated progeny of Jacklin breeding line, 87-0057. It is closely similar to Barrister, differing from it by a shorter internode length below the panicle node, shorter seed length, and lower seed weight. Details on yield and agronomic traits, breeding conditions and method, maintenance, and growth habits are presented.

The article provides an overview of the registration of EverGlade Kentucky bluegrass, a turf-type variety released in August 2004 by Jacklin Seed by Simplot in Post Falls, Idaho. The variety was derived from the offspring of hybrid cross 92-4230, which was created in the field in June 1992 using Jacklin breeding line 92-0076 as the maternal parent and Midnight as the pollen source. Details on yield and agronomic traits, breeding conditions and method, maintenance, and growth habits are presented.

The article provides an overview of the registration of Alexa Kentucky bluegrass, a turf-type variety released in August 2004 by Jacklin Seed by Simplot in Post Falls, Idaho. The variety was derived from the offspring of field cross 92-4230, which was created in June 1992 using Jacklin breeding line 92-0076 as the maternal parent and Midnight as the pollen source. It closely resembles the cultivar Liberator, differing by a wide flag leaf, more branches at the lowest node in the panicle, and later reproductive maturity. Details on yield and agronomic traits, breeding conditions and method, maintenance, and growth habits are presented.