Use of the hydrothermal time model to analyse interacting effects of water and temperature on germination of three grass species

2004 ◽  
Vol 14 (1) ◽  
pp. 35-50 ◽  
Author(s):  
Søren Ugilt Larsen ◽  
Christophe Bailly ◽  
Daniel Côme ◽  
Françoise Corbineau
Keyword(s):  
Water Potential ◽  
Water Content ◽  
Perennial Ryegrass ◽  
Kentucky Bluegrass ◽  
The Other ◽  
Thermal Time ◽  
Grass Species ◽  
Hydrothermal Time ◽  
Time Model ◽  
Red Fescue

The temperate grass species, red fescue (Festuca rubra ssp. litoralis), perennial ryegrass (Lolium perenne) and Kentucky bluegrass (Poa pratensis), are often sown in mixtures for turfgrass. Differences in germination response to environmental conditions often result in different establishment success. The three species were compared in a study of imbibition at reduced water potential (Ψ) and in a study of the effects of Ψ and temperature on germination. In all three species, imbibition rate and extent were reduced with decreasing Ψ, causing a prolonged lag-phase before germination, particularly in Kentucky bluegrass. In perennial ryegrass and Kentucky bluegrass, water content at radicle emergence decreased non-linearly with decreasing Ψ, with a lower asymptote expressing the critical water content for germination. Seeds were germinated in factorial combinations of two temperatures (10 and 25°C) and nine Ψ levels (–2 to 0 MPa). Kentucky bluegrass required a longer thermal time to germinate than the other species and exhibited conditional dormancy at 25°C, which affected the use of the thermal time model. The effects of Ψ were described by a hydrotime model. Kentucky bluegrass had higher base water potential (Ψb) and required a longer hydrotime for germination than the other species. However, Ψb increased with temperature in Kentucky bluegrass and red fescue, but decreased in perennial ryegrass, and the base temperatures also changed with Ψ. The interacting effects of Ψ and temperature affected the ability of the hydrothermal time model to predict germination performance across all temperature and Ψ conditions.

scholarly journals Additional Host Plants of Four Species of Billbug Found on New Jersey Turfgrasses

1990 ◽  
Vol 115 (4) ◽  
pp. 608-611 ◽  
Author(s):  
Jennifer M. Johnson-Cicalese ◽  
C.R. Funk
Keyword(s):  
New Jersey ◽  
Perennial Ryegrass ◽  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Host Plants ◽  
Cynodon Dactylon ◽  
Poa Pratensis ◽  
Kentucky Bluegrass ◽  
Grass Species ◽  
Red Fescue

Studies were conducted on the host plants of four billbug species (Coleoptera:Curculionidae: Sphenophorus parvulus Gyllenhal, S. venatus Chitt., S. inaequalis Say, and S. minimus Hart) found on New Jersey turfgrasses. A collection of 4803 adults from pure stands of various turfgrasses revealed all four billbugs on Kentucky bluegrass (Poa pratensis L.), tall fescue (Festuca arundinacea Schreb.), and perennial ryegrass (Lolium perenne L.), and S. parvulus, S. venatus, and S. minimus on Chewings fescue (F. rubra L. ssp. commutata Gaud.). Since the presence of larvae, pupae, or teneral adults more accurately indicates the host status of a grass species, immature billbugs were collected from plugs of the various grass species and reared to adults for identification. All four species were reared from immature billbugs found in Kentucky bluegrass turf; immatures of S. venatus, S. inaequalis, and S. minimus were found in tall fescue; S. venatus and S. minimus in perennial ryegrass; and S. inaequalis in strong creeping red fescue (F. rubra L. ssp. rubra). A laboratory experiment was also conducted in which billbug adults were confined in petri dishes with either Kentucky bluegrass, perennial ryegrass, tall fescue, or bermudagrass (Cynodon dactylon Pers.). Only minor differences were found between the four grasses in billbug survival, number of eggs laid, and amount of feeding. In general, bermudagrass was the least favored host and the other grasses were equally adequate hosts. The results of this study indicate a need for updating host-plant lists of these four billbug species.

scholarly journals The effect of fertilizer seed coating on the germinating capacity and initial development of some turf grass species and white clover

2012 ◽  
Vol 60 (5) ◽  
pp. 199-204
Author(s):  
Martin Sochorec ◽  
Pavel Knot
Keyword(s):  
Perennial Ryegrass ◽  
White Clover ◽  
Kentucky Bluegrass ◽  
Grass Species ◽  
Initial Development ◽  
Red Fescue ◽  
Germinating Capacity ◽  
Significant Difference ◽  
Negative Effect ◽  
Positive Effect

The effect of the iSeed method treatment on germination dynamics, total germinating capacity and the length of above-ground and root parts was studied in laboratory conditions for the Red fescue varieties Darwin and Moccasin, Kentucky bluegrass varieties Yvette and Miracle, Perennial ryegrass varieties Beatrice and Milan, and White clover varieties Pirouette and Pipolina. In the Perennial ryegrass, the iSeed treatment adversely affected the energy of germination in the first days of study. The germinating capacity gradually equalized during the experiment. Red fescue and Kentucky bluegrass did not show any response to the treatment. Similarly as the Perennial ryegrass, the two varieties of White clover exhibited higher energy of germination on the third day from the establishment. A demonstrably positive effect of the iSeed treatment was recorded on the number of germinated individuals. Particularly the variety Pirouette showed significantly higher germinating capacity until the tenth day of monitoring the treated seeds. The iSeed method had no statistically significant influence on the values of total germinating capacity in all tested species and varieties. The effect of the iSeed method treatment on the length of shoot and root parts was not statistically demonstrated. Some varieties showed a positive effect and some showed a negative effect. A significant difference was observed only in the untreated variety Moccasin whose above-ground part was by 14 mm longer as compared with the treated variant.

scholarly journals EFFECT OF DROUGHT ON THE PERFORMANCE OF THREETURF GRASS SPECIES

2018 ◽  
Vol 78 ◽  
pp. 3-22
Author(s):  
Grzegorz Żurek ◽  
Kamil Prokopiuk ◽  
Agnieszka Rachwalska
Keyword(s):  
Water Deficit ◽  
Perennial Ryegrass ◽  
Poa Pratensis ◽  
Kentucky Bluegrass ◽  
Grass Species ◽  
Drought Period ◽  
Red Fescue ◽  
Drought Avoidance ◽  
The Face ◽  
Different Response

Drought is the main environmental factor hampering world agriculture production. In the face of warmingclimate and reduced fresh water resources it become obvious that search for any factors decreasing water useis strongly recommended. Turf grasses able to withstand drought period longer could be recommended for turfareas as parks, lawns, home gardens etc. and relatively lower amounts of water should ensure satisfactory turfquality. Therefore, twelve turf varieties from three major cool-season turf grass species: perennial ryegrass(Lolium perenne L.), Kentucky bluegrass (Poa pratensis L.) and red fescue (Festuca rubra L.) were tested inglasshouse pot experiment and in the laboratory for determination of their relative ability to withstand greenlonger in the face of water deficit.The different response of the examined forms to drought was noted. Conditions that favor fast water depletionwere the most suitable for the expression of water deficit-related traits. Therefore, sandy mixture of 16%volumetric moisture content at field water capacity was mostly suitable for observation of the variation oftested forms. Turf condition of Kentucky bluegrass, as contrary to red fescue, was strongly connected with thesoil moisture. Different manifestation of drought resistance was observed in tested species. Kentucky bluegrass,as rather no resistant to drought, exposed low level of drought avoidance. Red fescue was able to survivedrought mainly due to leaf blades resistant to desiccation. In perennial ryegrass some other mechanismsevolved to survive drought. Early leaf wilting and senescence contributes to nutrient remobilization duringdrought and avoids large water loses during the transpiration. Therefore, perennial ryegrass turf was able toregenerate better after drought, as compared to the other tested grass species.Search for new turf forms should focus on searching for ability to maintain acceptable conditions longer ina presence of increasing water deficit. It will then reduce the duration of period of poor turf conditions andfurther, turf water demands.

The effect of species complexity and sodium fertilizer application on the grazing behaviour of calves

1993 ◽  
Vol 1993 ◽  
pp. 142-142
Author(s):  
M. Youssef ◽  
P.C. Chiy ◽  
C.J.C. Phillips ◽  
M. Metwally
Keyword(s):  
Perennial Ryegrass ◽  
Fertilizer Application ◽  
Grass Species ◽  
Individual Plant ◽  
Adult Cattle ◽  
High Sodium ◽  
Red Fescue ◽  
Stages Of Growth ◽  
High Sodium Diet ◽  
Grazing Behaviour

Cattle exhibit preferences not only for certain sward species but for the same species at different stages of growth, and the various parts of an individual plant and for individual plant of preferred composition. This tendency is termed selective grazing (Fontenot and Blaser, 1965). For example ruminants will select a high Sodium diet. Calves tend to be more selective than adult cattle, muzzling herbage before eating.The aim of the present experiment was to investigate the effect of sward complexity, species and sodium fertilizer on the grazing behaviour of calves.Sixteen dairy Friesian calves, aged 5 to 6 months, with no previous grazing experience, were allocated to groups of 4 similar calves, and then at random to four pasture treatments of 3480m2 each with one (Perennial Ryegrass, P), two (P and Timothy, T), three (P, T and Cocksfoot, C) and four (P, T.C and Red Fescue, R) grass species in a balanced change over design. Each species was sown in plots of 290m2 and one half of each plot received 48Kg/ha. nacl.

Carbon balance in relation to drying in four epiphytic mosses growing in different vertical ranges

1979 ◽  
Vol 57 (19) ◽  
pp. 1994-1998 ◽  
Author(s):  
Peter L. Tobiessen ◽  
Nancy G. Slack ◽  
Keith A. Mott
Keyword(s):  
Water Potential ◽  
Water Content ◽  
Carbon Balance ◽  
The Other ◽  
Moss Species ◽  
Relationship Of ◽  
The Relationship ◽  
Neckera Pennata ◽  
Lower Water Content ◽  
Photosynthesis And Respiration

The response of photosynthesis and respiration to drying was measured in four species of epiphytic mosses, Ulota crispa (Hedw.) Brid., Neckera pennata Hedw., Anomodon rugellii (C. Mull.) Keissl., and Plagiomnium cuspidatum (Hedw.) T. Kop., from habitats along a desiccation gradient. There was little difference among the mosses in these responses. The relationship of water content to water potential did differ among the mosses, with Plagiomnium, the facultative epiphyte, showing a typical response of more mesic species and the other three showing a more xeric response, i.e., water potential does not begin to fall steeply until a lower water content is reached in Ulota, Neckera, and Anomodon. Both photosynthesis and respiration in all four moss species were quite sensitive to moderate water stress.

Modeling germination and seedling elongation of common lambsquarters (Chenopodium album)

Weed Science ◽  
1999 ◽  
Vol 47 (2) ◽  
pp. 149-155 ◽  
Author(s):  
Erivelton S. Roman ◽  
A. Gordon Thomas ◽  
Stephen D. Murphy ◽  
Clarence J. Swanton
Keyword(s):  
Seed Germination ◽  
Water Potential ◽  
Mechanistic Model ◽  
Chenopodium Album ◽  
Seedling Emergence ◽  
Probit Analysis ◽  
Hydrothermal Time ◽  
Time Model ◽  
Common Lambsquarters ◽  
Radicle Elongation

The ability to predict time of weed seedling emergence relative to the crop is an important component of a mechanistic model describing weed and crop competition. In this paper, we hypothesized that the process of germination could be described by the interaction of temperature and water potential and that the rate of seedling shoot and radicle elongation vary as a function of temperature. To test these hypotheses, incubator studies were conducted using seeds and seedlings of common lambsquarters. Probit analysis was used to account for variation in cardinal temperatures and base water potentials and to develop parameters for a new mathematical model that describes seed germination and shoot and radicle elongation in terms of hydrothermal time and temperature, respectively. This hydrothermal time model describes the phenology of seed germination using a single curve, generated from the relationship of temperature and water potential.

Herbage characteristics of perennial ryegrass, cocksfoot, tall fescue and timothy pastures and their relationship with animal performance under upland conditions

1982 ◽  
Vol 99 (1) ◽  
pp. 153-161 ◽  
Author(s):  
D. A. Davies ◽  
T. E. H. Morgan
Keyword(s):  
Perennial Ryegrass ◽  
Tall Fescue ◽  
Growth Rates ◽  
Dry Matter ◽  
Live Weight ◽  
Phleum Pratense ◽  
Water Soluble ◽  
The Other ◽  
Dry Matter Intake ◽  
Grass Species

SUMMARYHerbage characteristics of perennial ryegrass (Lolium perenne L.), cocksfoot (Dactylis glomerata L.), tall fescue (Festuca arundinacea Schreb.) and timothy (Phleum pratense L.) pastures were obtained whilst rotationally grazed by ewes and their single lambs at a fixed stocking rate of 25/ha on an upland site (305 m O.D.) in mid-Wales. Drymatter production of cocksfoot averaged 32·1 kg/ha/day over the 3-year duration of the trial (1975·7) and was 13·3 kg/ha/day lower than that of the other three grass species. This resulted in a 8 kg/ha/day reduction in dry-matter intake on cocksfoot; this was significantly lower (P < 0·05) than that achieved on the other grasses, which were similar to one another around 36 kg/ha/day.In vitro digestibility of the herbage ranked in the order perennial ryegrass > timothy = cocksfoot > tall fescue. Intake of digestible organic matter (DOMI) was lower on cocksfoot than on perennial ryegrass and timothy. Differences were also detected in crude protein, water-soluble carbohydrates and sodium composition between species.Dry-matter intake was positively correlated with herbage growth rates (r = 0·95, P < 0·001) but not to digestibility of herbage on offer (r = 0·18). Both ewe and lamb live-weight gains were positively related to intake of dry matter and DOMI.Reference is made to comparative yield data between the grasses obtained under cutting trials. In the 2nd and 3rd harvest years (1967–1967) growth rates in the grazing experiment were 76, 61, 81 and 80% of the 66·2, 66·7, 67·8 and 65·0 kg D.M./ha/day obtained under a cutting regime on perennial ryegrass, cocksfoot, tall fescue and timothy swards respectively. This illustrates the danger involved in assessing the potential of grasses based on such information.The results are discussed in relation to the value of the species for use under grazing in the uplands.

Hydrothermal time analysis of tomato seed germination at suboptimal temperature and reduced water potential

1994 ◽  
Vol 4 (2) ◽  
pp. 71-80 ◽  
Author(s):  
Peetambar Dahal ◽  
Kent J. Bradford
Keyword(s):  
Seed Germination ◽  
Water Potential ◽  
Time Course ◽  
Hydrothermal Time ◽  
Tomato Seed ◽  
Time Model ◽  
Germination Time ◽  
Radicle Emergence ◽  
Time Courses ◽  
Hydrotime Model

AbstractBoth temperature (T) and water potential (ψ) have consistent and quantifiable effects on the rate and extent of seed germination (radicle emergence). Germination at suboptimal T can be characterized on the basis of thermal time, or the T in excess of a base (Tb) multiplied by the time to a given percentage germination (tg). Similarly, germination at reduced ψ can be characterized on a hydrotime basis, or the ψ in excess of a base (ψb) multiplied by tg. Within a seed population, the variation in thermal times to germination for a specific percentage (g) is based upon the normal distribution of ψb values among seeds (ψb(g)). Germination responses across a range of suboptimal T and ψ might be accounted for by a general hydrothermal time model incorporating both T and ψ components. We tested this hypothesis for tomato (Lycopersicon esculentum Mill.) seeds of two genotypes differing in germination rates and tolerance of suboptimal T and ψ. For combinations of T (10−25°C) and ψ (0 to −0.9 MPa), a general hydrothermal time model accounted for approximately 75% of the variation in times to germination within the seed populations of both genotypes, and over 96% of the variation in median germination rates. However, ψb(g) distributions were sensitive to both the T and ψ of imbibition, resulting in a poor fit of the model to specific time course data. Analysis of germination timing separately for low and high ψ ranges within a given T resulted in specific models accounting for 88−99% of the variation in individual germination times and >99% of the variation in madian germination rates. Thus, for a given T and ψ range, the hydrotime model closely matched tomato seed germination time courses. Accumulated hydrothermal time accounted well for germination rates at ψ> −0.5 MPa across suboptimal T if ψb(g) was allowed to vary with T. Germination did not show a consistent response to T at ψ < −0.5 MPa, and estimated Tb values varied over different T ranges. Generalization of the hydrothermal time model across the entire range of suboptimal T and ψ was limited by physiological adjustments of the seeds to their current environment. The hydrothermal time model detected and quantified these adjustment processes that would otherwise not be evident from inspection of germination time courses. Temperature and water potential influence the time to germination via physiological mechanisms that reciprocally interact.

scholarly journals The influence of the grass mixture composition on the quality and suitability for football pitches

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Karol Wolski ◽  
Joanna Markowska ◽  
Adam Radkowski ◽  
Marek Brennensthul ◽  
Łukasz Sobol ◽  
...  
Keyword(s):  
Perennial Ryegrass ◽  
Leaf Blade ◽  
Kentucky Bluegrass ◽  
Mixture Composition ◽  
Point Scale ◽  
Turf Grass ◽  
Red Fescue ◽  
Plant Variety ◽  
Country Club ◽  
Selection Of

AbstractThe selection of grass mixtures with appropriate visual and functional parameters for sowing football fields is a key element in shaping the sports infrastructure, ensuring the spectacularity of a match and comfort for players. The aim of the research was to investigate the properties of lawn grass mixtures and their suitability for football pitches. The experiment was conducted at the Toya Golf & Country Club (51° 20′ E, 17° 07′ N), Wrocław, Poland, between 2007 and 2009. 12 grass mixtures were selected, mainly based on red fescue, Kentucky bluegrass, and perennial ryegrass. The assessment was carried out using a nine-point scale, according to the Plant Variety Office methodology for crops and turf grass. Six features of sports turf were studied: appearance, density, colour, leaf fineness, overwintering, and susceptibility to disease and they significantly varied, depending on the grass mixture and the year of research. Our study showed that mixtures based on the dominance of meadow grass were characterized by higher values of the general visual aspect, colour and slenderness of the leaf blade and these based on the dominance of perennial ryegrass and co-dominance of perennial ryegrass and meadow grass were the most useful in terms of wintering, resistance to diseases and sodding.

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