Fescue Research Articles

Utilization of Rough Fescue and Parry Oat Grass by Two Grasshopper Species and Effect of Leaf Water Content and Stubble Height

This study was undertaken to measure destruction and feeding by two species of grasshoppers, Camnula pellucida (Scudder) and Melanoplus sanguinipes (F.), common on fescue prairie, in relation to forage preferences, stubble height, and leaf water content. C. pellucida showed no significant preferences, whereas M. sanguinipes preferred rough fescue ( Festuca scabrella Torrey ). M. sanguinipes displayed greater preference for higher leaf water content than did C. pellucida . The presence of stubble restricted feeding of both grasshopper species, but M. sanguinipes was less inhibited. The inhibition by stubble was related directly to its density (grams per cubic centimeter) and, therefore, inversely to its height. The significance of these aspects of feeding behavior in relation to grassland condition is discussed.

Comparative Demography of Three Graminoids Infected by Systemic, Clavicipitaceous Fungi

Few experimental studies have addressed the demographic consequences of plant—microbe symbiosis in natural communities. In this study the survival, growth, and reproduction of tall fescue grass (Festuca arundinacea), smut grass (Sporobolus poiretii), and green sedge (Cyperus virens) infected by the imperfect fungus Acremonium coenophialum, the ascomycetous fungus Balansia epichloe, and B. cyperi, respectively, were compared with uninfected conspecifics in field experiments conducted in natural plant communities in southern Louisiana. Equal numbers of infected and uninfected ramets of each species were propagated in the greenhouse from infected and uninfected seed lots (F. arundinacea) or from field—collected infected and uninfected plants (S. poiretii and C. virens). Ramets of the two grasses were planted into a grassland community where the two species were dominant members of the community. Ramets of the sedge were planted into a marshy area where C. virens occurred naturally. Numbers of tillers were counted for each ramet upon planting for subsequent use as a covariate, and each ramet was censused from one to three times a year for three consecutive years. All survivors were then harvested and aboveground dry biomass was determined. For F. arundinacea, infected ramets exhibited higher survival, flowering frequency, vegetative tiller production, and biomass over the 3—yr period. Relative fitness, calculated from survival and inflorescence production, was nearly twice as high for infected ramets, indicating a mutualistic relationship between F. arundinacea and its endophytic fungus. For S. poiretii, growth and survival of infected and uninfected ramets were similar, but flowering was greatly suppressed in infected ramets. Relative fitness of infected ramets was only °1/10 that of uninfected ramets, indicating a pathogenic relationship. There was evidence of substantial contagious spread of the fungus in the experimental population. Infected ramets of C. virens had significantly higher survival over 3 yr and tended to be bigger than uninfected ramets. Inflorescences were produced by both types of ramets, but the inflorescences of infected ramets were always aborted. The results indicate that, within a closely related group of fungi, both pathogenic and mutualistic relationships with host plants exist. Maternally inherited, seed—borne endophytes similar to the one in F. arundinacea are found in any grasses, suggesting that analogous mutualisms are common. The greater survival and vegetative vigor of infected C. virens call into question the traditional notion of fitness as applied to plants capable of extensive asexual reproduction. The biological mechanisms responsible for the greater survival and growth of infected plants probably include induced alterations in the host plant's hormonal balance, greater tolerance to abiotic stresses, and increased resistance to herbivores and pathogens.

Parasite Treatments for Crossbred Beef Steers Grazing High- or Low-Endophyte Tall Fescue

Summary Performance of ruminants consuming high-endophyte tall fescue ( Festuca arundinacea Schreb.) is frequently lower than when low-endophyte fescue or similar cool-season perennial grasses are ingested. This study was conducted to determine effects of different parasite treatments on daily gain by beef steers grazing high- or low-endophyte fescue (HE and LE, respectively). Ninety-six yearling Angus-Hereford steers (210 kg average initial weight) grazed HE or LE paddocks for 112 days. Steers received 1) a placebo sustained-release ruminal bolus on Day 0 (control), 2) a sustained-release ruminal bolus on Day 0 designed to deliver ivermectin at 12 mg/day for 120 days (IVM), 3) levamisole injections (subcutaneous) at 8 mg/kg body weight every 14 days (LEV) OR 4) IVM plus LEV (combination: COM). Daily gains over the entire study were .49 and .79 kg for HE and LE, respectively ( P P >.10). Trends were noted for an effect of treating for parasites ( P P P P >.10). Parasite control may affect daily gain by beef steers slightly more with HE than LE.

Registration of ‘Mesa’ Tall Fescue

Registration of ‘Mesa’ Tall Fescue

Aspergillus terreus and fescue toxicosis

The incidence ofAspergillus terreus recovered fromAcremonium coenophialum-infected and non-infected tall fescue grass and from the rumens of heifers grazing on the grasses was determined. The recovery ofA. terreus fromA. coenophialum-infected grass was similar to that from non-infected grass. The same was true of the recovery from the rumens of heifers on infected and non-infected grass. All heifers grazing onA. coenophialum-infected grass showed symptoms of the summer syndrome manifestation of fescue toxicosis while those grazing on non-infected grass did not;A. terreus is not a factor in fescue toxicosis in cattle.

Allelochemicals in tall fescue-abscisic and phenolic acids

Growth inhibitors that can be leached from excised leaves of tall fescue grass (Festuca arundinacea) were investigated as allelochemicals. Leachates of desiccated Rebel and Kentucky 31 grass cultivars contained three principal inhibitory compounds, abscisic acid (ABA), caffeic acid, andp-coumaric acid. After quantitative analysis, abscisic acid was determined to be the predominant inhibitor. A 10-fold increase in ABA levels in leachates occurred after one day of desiccation. The concentration of ABA was 40% greater in Kentucky 31 leachate than in Rebel. This difference was also found in subsequent analyses of leachates of grasses that had been allowed to dry up to 30 days; however, the ABA concentration was reduced by 60% from the 10-fold increased levels.

The delivery of cottonseed meal at three different time intervals to steers fed low-quality grass hay: effects on digestion and performance.

A ruminal fermentation trial and a steer growth trial were conducted to evaluate the effects of time interval of cottonseed meal (CSM) supplementation of predominantly meadow fescue grass hay (GH; CP = 6.6%) on nutrient digestion and growth performance of beef steers. The fermentation trial used four ruminally cannulated steers assigned to a 4 x 4 latin square design with dietary treatments of GH fed alone (C) or GH supplemented with 3 g CP/kg BW.75 daily as supplied by CSM every 12, 24 or 48 h. Nylon bags containing GH were inserted into the rumen on d 1 and 2 of each collection period and incubated for 12, 24, 48 and 96 h to measure NDF and ADF degradation. Subsequently, steers were fed Yb-labeled GH and fecal samples were collected to determine particulate passage rate (PR). Dry matter and NDF intake, mean NDF and ADF in situ disappearance and ruminal VFA concentrations were greater (P less than .05) when CSM was fed; however, the delivery of CSM at various times did not affect (P greater than .10) these variables. Supplemented diets tended (P = .08) to have faster PR compared with the C diet. In the growth trial, CSM supplemented steers consumed more digestible DM (P less than .05) and had greater (P less than .05) daily gain compared with C steers. Effects due to time of CSM supplementation were not observed for the variables measured in the present study.

A case of natural human infection by Echinostoma cinetorchis

A human case of Echinostoma cinetorchis infection was found in Seoul Paik Hospital on August 1987. Large trematode eggs, 98.9 x 62.7 micro-m in average size, were detected in stool examination. The eggs had a small-sized operculum and abopercular wrinkling. After treatment with praziquantel(single dose of 16.2 mg/kg) and purgation with magnesium citrate, an adult fluke was collected. It was 8.0 mm long, equipped with 37 collar spines around head crown, and had only one testis just behind the Mehlis' gland. It was identified as E. cinetorchis Ando et Ozaki, 1923. The patient is an 18-year old man residing in Seoul, and was hospitalized due to nephritis. He had eaten raw meat juice of fresh water fishes such as top minnows(Oryzias latipes) and loaches, or tadpoles, which are considered possible souce of this fluke infection. This is the 4th human case of E. cinetorchis infection in Korea.

Melilotus alba Medik.-a new cultivated forage plant for the Danube Delta

Melilotus alba germplasm collected from the spontaneous flora of the Danube Delta and evaluated for forage production in three experiments organized at Sfantu Gheorghe and Cisla Vadeni proved to be very successful as compared with other forage grasses ( Lolium , Festuca , Dactylis , Bromus ) and forage legumes ( Medicago , Onobrychis , Trifolium ). Dry matter production of Melilotus surpassed about 15-80 folds the production of traditional forage species used for comparison in these evaluations. Melilotus alba - largely distributed in the spontaneous flora of the Danube Delta, - seems to be best adapted to the local ecological conditions for forage biomass production. The species may have a future as a new cultivated plant in this part of Romania.

Fescue induced agalactia: Clues to the cause

Fescue induced agalactia: Clues to the cause

Impact of Tall Fescue Grass andCarduusThistle Weevils on the Growth and Development of Musk Thistle (Carduus nutans)

Field plot experiments were conducted to examine the interactions between tall fescue grass (Festuca arundinaceaSchreb.), musk thistle (Carduus nutansL. =thoermeriWeinmann # CRUNU), and two thistle weevilsTrichosirocalus horridus(Panzer) andRhinocyllus conicusFroelich. Restriction of musk thistle growth was greatest when the weevils were allowed to feed on the musk thistles competing with tall fescue. Significant reductions were found in total musk thistle seeds per plant, root weight, flower buds per plant, stem dry weight, seeds per head, root crown diameter, stem height, rosette diameter, and head diameter. Seed weight and viability were not reduced. Of the three stress factors (tall fescue and the twoCarduusthistle weevils), tall fescue had the greatest impact. When musk thistle seeds were planted in 1-yr-old tall fescue, germination was low. Seeds that germinated did not grow more than four Leaves and none of the thistles developed to the reproductive stage. A 1-year-old tall fescue stand effectively prevented musk thistle reproduction. Thus, tall fescue helped suppress musk thistle growth more quickly than the use ofCarduusthistle weevils alone without competitive vegetation. Dry weight of tall fescue grass was lower in musk thistle-infested plots than in the thistle-free plots.

In Vitro Growth of Acremonium coenophialum , an Endophyte of Toxic Tall Fescue Grass

Acremonium coenophialum, an endophytic fungus present in toxic tall fescue grass and seed, grew very slowly or not at all with conventional media and cultural practices. However, a considerable increase in growth was achieved in a relatively dilute medium consisting solely of glucose and yeast extract. The optimal levels of glucose and yeast extract were 3 to 6% and 0.35% (wt/vol), respectively. The addition of salts which lowered the pH suppressed growth. Even when the pH was controlled, the addition of KH(2)PO(4) at a level of 3.2% or more greatly inhibited growth. A. coenophialum grew better in shake culture than in stationary culture. The optimal temperature was 23 degrees C, and the optimal pH was 6.5.

Occurrence of peptide and clavine ergot alkaloids in tall fescue grass.

Evidence is presented that ergot alkaloids are ubiquitous in tall fescue pastures infected with the clavicipitaceous fungal endophyte Sphacelia typhina (or Acremonium coenophialum). Ergopeptide alkaloids, predominantly ergovaline, constituted 10 to 50 percent of the total ergot alkaloid concentration, which was as high as 14 milligrams per kilogram in sheaths and 1.5 milligrams per kilogram in blades. Ergot alkaloid concentrations were substantially increased by application of large amounts (10 millimoles per liter) of potassium nitrate or ammonium chloride to infected plants in the greenhouse. The results indicate that ergot alkaloids are probably responsible for the toxicity to cattle of this common pasture and lawn grass and that ergotism-like toxicoses may be caused by clavicipitaceous fungi other than Claviceps.

Extraction and Determination of Selected Polycyclic Aromatic Hydrocarbons in Plant Tissues

Abstract A procedure has been developed for analysis of plant material for polycyclic aromatic hydrocarbons (PAHs). Sonication is used to extract the PAHs from homogenized plant material into acetonitrile and then the PAHs are partitioned into pentane. The pentane extract is fractionated on a micro silicic acid column and is analyzed by capillary gas chromatography with flame ionization detection. Overall method recoveries for 16 PAHs spiked into hybrid grain sorghum ranged from 45 to 90%, with relative standard deviations ranging from 3 to 38% and averaging 17%. This method can be used to measure PAHs in hybrid grain sorghum, fescue grass, and similar plants at the 25 μ/kg level. The procedure was applied to a preliminary study of PAH uptake by sorghum and fescue irrigated with secondary treated municipal wastewater spiked with 5 PAHs. Accumulation of fluoranthene and pyrene by fescue and hybrid grain sorghum from the PAH-contaminated irrigation water was apparent.

Canadian grass genera: keys and descriptions in English and French from an automated data bank

An automated data bank for Canadian grass genera has been established in Ottawa under the DELTA system, capable of generating detailed taxonomic descriptions and identification keys in English and French. The descriptive information available comprises 274 characters, mainly concerned with morphology, anatomy, physiology, and geographic distribution. The present capabilities of the system are described and illustrated by automatically typeset sample keys to the 109 genera known to occur in Canada (in English) and to the taxa of the Yukon (in English) and to those of Québec (in French); by automatically typeset sample descriptions of the genus Festuca in computer-coded form (in English and in French); and by two microfiches carrying descriptions and keys for all the Canadian genera (in English and in French).

Thematic Mapper Data Used for Rangeland Management in Rough Fescue Grasslands in Western Canada

RESUMEEn 1984, le Centre canadien de teledetection, le Ministere de l'Energie et des Ressources de l'Alberta ainsi que le Centre albertain de teledetection entreprenaient conjointement un projet visant a evaluer le degre d'application des donnees du capteur Thematic Mapper (TM) pour la gestion des pâturages.Les donnees de terrain et de teledetection ont ete acquises dans une region de prairies a fetuque scabre situee en Alberta, a quatre dates differentes au cours de la saison du pâturage. Les differents parametres mesures au sol, dans les pâturages echantillonnes, comprenaient, d'une part, le pourcentage de couverture du sol par la vegetation active (verte), la vegetation senescente (brune) et par le sol nu et, d'autre part, la biomasse des graminees, des residus vegetaux et des dicotyledones herbacees. Une serie de cliches a egalement ete prise sur chaque site-temoin lors des passages de LANDSAT 5.Les donnees TM correspondant a chacune des dates ont ete corrigees pour les differences d'angle d'elevation...

LANDSAT Thematic Mapper bands for characterizing fescue grass vegetation

Abstract The relationships between reflectance in the LANDSAT Thematic Mapper (TM) bands and grass canopy characteristics were studied. Data were collected from a total of 107 tall fescue (Festuca arundinacia) plots (0·2 m2) during the 1983 growing season. Canopy height, percentage cover, total wet biomass, total dry biomass, plant water and leaf area index were correlated with spectral data obtained from a Barnes Modular Multiband Radiometer. The near-infrared wavelength region corresponding to TM band 4 appeared to be the best estimator of total wet biomass (r = 0·80) and canopy height (r =0·82). Percentage canopy cover had the highest correlation coefficients with TM band 7 (r = −0·95) and TM bands 1, 2 and 3 (r≥0·93). All canopy variables showed a curvilinear relationship with the spectral bands, except canopy cover, which showed a near linear relationship, for the biomass range in this study. Linear transformations were obtained using natural logarithms of the grass canopy variables and the spectral ...

Measurement of sunflower seed respiration rates and quotients by gas‐solid chromatography in a closed system

AbstractSunflower seed respiration rates and respiratory quotients (RQ) were measured by gas‐solid chromatography coupled to a closed system which contained the seed sample. By using a gas sampling valve fitted with a 0.5 ml sample loop, head‐space sampling is eliminated. The system is reliable, reproducible, and the data can be obtained in short time periods, as O2 and CO2 can be measured simultaneously. With this procedure, a 10°C increase in temperature produced about a two‐fold increase in respiration rates (μlCO2h−1g−1 DM) in seed samples at the same moisture level (13%); while a three‐fold increase in seed moisture (7% vs 20%) produced a 148‐fold increase in respiration rates at 42°C. High RQ values indicated that high temperatures and low seed moisture may have limited O2 uptake by sunflower seed. Under other conditions, the seed respired aerobically and used carbohydrates as an energy source (RQ=1). Germination test indicated that exposure of sunflower seed to very low O2 and high CO2 levels for 24 h did not adversely affect seed viability. This procedure was successfully applied to obtaining respiration data for soya beans and fescue grass seed.

Predicting Infiltration for Shallow Water Table Soils with Different Surface Covers

ABSTRACT TWO approximate methods were used to predict infiltration for shallow water table conditions. The method proposed by Bouwer (1969) was modified so that it would predict saturated flow through the column after the water table rose to the surface; air pressure ahead of the wetting front was not considered in this method. The second method which did consider the air impedance, was a three-stage model based on the work of Adrian and Franzini (1966). Results of these two prediction models were compared with experimental infiltration measurements on soil columns with three different surface conditions: fallow or bare, soybean, and fescue grass. Comparisons were made at different stages of the crop production cycle. Results showed that the three-stage model gave better predictions than the modified Bouwer's model for the conditions considered in this study. When original saturated hydraulic conductivity values were used, all prediction models underestimated infiltration for profiles with grass surface cover and overestimated infiltration for profiles without a surface cover. Much better predictions were obtained when hydraulic conductivities were measured after the crop had been established or, in the case of bare profiles, after the surface had been weathered or disturbed.

The distribution and ultrastructure of the endophyte of toxic tall fescue

The symptomless relationship of tall fescue grass (Festuca arundinacea Schreber) and its endophytic parasitic fungus, Sphacelia typhina (Fr.) Tul. (= Acremonium coenophialum fide Morgan-Jones et Gams), was studied with light and electron microscopy. The fungus was intercellular and was distributed throughout the plant with the exception of roots and leaf blades. The highest concentration of the fungus occurred in the base of the leaf sheath. In the seed the fungus was sequestered between the epithelial cells of the scutellum and the starchy endosperm. The seed embryo was not infected; infection was also not evident during the early stages of seed germination. At the ultrastructural level, the parasitic relationship was established in tissues where there were intercellular spaces. Micrographs indicated that the fungus did not separate the middle lamella of host cells, nor did it produce any obvious alteration in host cell morphology. Ultrastructural characteristics of the fungus depended on the age and type of fescue tissue. Hyphal cells possessed numerous vesicular and multivesicular structures, and in some sections, the hyphal walls were inordinately thickened and with or without an extracellular matrix. The fungus appeared to colonize the innermost areas of tissues in all infected organs and no signs of egress were ever detected.