Impacts of seeding depth on emergence and seedling structure in eight perennial grasses

1992 ◽  
Vol 70 (1) ◽  
pp. 133-139 ◽  
Author(s):  
R. E. Redmann ◽  
M. Q. Qi
Keyword(s):  
Seedling Emergence ◽  
Warm Season ◽  
Type A ◽  
Bouteloua Gracilis ◽  
Hydraulic Conductance ◽  
Perennial Grasses ◽  
Internode Elongation ◽  
Type B ◽  
Cool Season ◽  
Agropyron Smithii

The effects of seeding depth (1.5, 3, or 6 cm) on seedling emergence, morphology, and anatomy were examined in cool-season (Agropyron dasystachyum, Agropyron desertorwn, Agropyron smithii, Elymus angustus, and Elymus junceus) and warm-season (Andropogon scoparius, Bouteloua curtipendula, and Bouteloua gracilis) perennial grasses. Caryopsis weights ranged from 0.5 mg in Bouteloua spp. to 4.7 mg in E. angustus. Prominent elongation of the subcoleoptile internode at greater seeding depths and short coleoptiles were observed in And. scoparius, B. curtipendula, and B. gracilis (type A seedlings). The remaining species had relatively long coleoptiles and no subcoleoptile internode elongation (type B seedlings). Up to 40% of the seedlings in the Agropyron species had intracoleoptile internode elongation when seeded at 3- and 6-cm depths. Relative emergence from 6 cm compared with 1.5 cm was best in Agr. dasystachyum and Agr. smithii and poorest in the type A species and in E. junceus. Diameters of xylem vessels in the subcoleoptile and intracoleoptile internodes remained relatively constant, but numbers of vesels decreased with depth of seeding, especially in the type A species. Decreases in hydraulic conductance with depth of seeding were greater in type A than in type B seedlings, mainly because of longer subcoleoptile internodes and smaller effective vessel radii in the former. Key words: grass seedling emergence, hydraulic conductance, morphology, seeding depth, seed weight, xylem dimensions.

Establishment of Warm- and Cool-Season Native Perennial Grasses on the North-West Slopes of New South Wales. Ii. Establishment and Seedling Survival in the Field

1981 ◽  
Vol 29 (2) ◽  
pp. 121 ◽  
Author(s):  
GM Lodge
Keyword(s):  
New South ◽  
New South Wales ◽  
Warm Season ◽  
Perennial Grasses ◽  
Late Winter ◽  
Cool Season ◽  
North West ◽  
The North ◽  
South Wales ◽  
Native Pastures

Emergence and survival of the seedlings of warm-season native perennial grasses Aristida ramosa R.Br., Bothriochloa macra (Steud.) S . T. Blake, Dichanthium sericeum (R.Br.) Camus, Sporobolus elongatus R.Br., Eragvostis leptostachya Steud. and Chloris truncata R.Br. and the cool-season species Stipa variabilis Hughes and Danthonia linkii Kunth were studied in both native pastures and sown monospecific plots on the north- west slopes of New South Wales. The most favourable period for the successful emergence and establishment of warm-season grasses was from mid summer to early autumn. Cool-season native perennial grasses established best from seedlings that appeared from mid autumn to late winter. Few seedlings were observed to germinate in spring, probably as a result of large variations in temperature, low minimum temperatures or intra and interspecific competition. Seedlings growing in native pasture spent long periods in the vegetative phase compared to the early flowering of seedlings in the sown plots. In the pasture studied only two seedlings flowered over 700 days after emergence, and many others after persisting for up to 2 years died without producing seed. These findings indicate that the seedlings in these native pastures were under considerable stress and that the adult populations of the species examined were relatively stable and little recruitment occurred.

Establishment of Warm- and Cool-Season Native Perennial Grasses on the North-West Slopes of New South Wales. I. Dormancy and Germination

1981 ◽  
Vol 29 (2) ◽  
pp. 111 ◽  
Author(s):  
GM Lodge ◽  
RDB Whalley
Keyword(s):  
New South ◽  
Warm Season ◽  
Perennial Grasses ◽  
Cool Season ◽  
North West ◽  
The North ◽  
South Wales ◽  
High Germination ◽  
Ecological Implications

The dormancy and germination of two groups of native perennial grasses were investigated in caryopses or dispersal units. The species were the warm-season native perennial grasses Aristida ramosa R.Br., Bothriochloa macra (Steud.) S. T . Blake. Dichanthium sericeum (R.Br.) Camus, Sporobolus elongatus R.Br., Eragrostis leptostachya Steud., Chloris truncata R.Br. and the cool-season species Stipa variabilis Hughes and Danthonia linkii Kunth. Optimum temperatures for germination were 20-35°C for A . ramosa; 15-35° for D. sericeum and C. Truncata; 20-25° for E. leptostachya; 20-30° for B. macra and S. elongatus and 15-25° for D. linkii and S . Variabilis. At 1O° and 40° D. linkii and A. ramosa respectively were the only species that had high germination percentages. Removal of the lemma and palea from freshly harvested units of A. ramosa, B. macra, D. sericeum, C. Truncata and S. variabilis significantly increased germination. In units stored at 12-27°C there was a breakdown in dormancy after 2-3 months in A. ramosa and B. macra and after 9 months in S. elongatus. In the germination of D. sericeum and D. linkii the lemma and palea appeared to have a long-term inhibitory role. Twenty-week-old whole dispersal units of B. macra, S. elongatus and E. leptostachya and 40-week-old units of S. elongatus and E. leptostachya had an obligate light requirement for germination. The ecological implications of these data in the successful germination of natural seed falls and artificial seedings are discussed.

scholarly journals Forage Yield and Nutritive Value of Cool-Season and Warm-Season Forages for Grazing Organic Dairy Cattle

Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1963
Author(s):  
Kathryn E. Ritz ◽  
Bradley J. Heins ◽  
Roger Moon ◽  
Craig Sheaffer ◽  
Sharon L. Weyers
Keyword(s):  
Nutritive Value ◽  
Warm Season ◽  
Forage Yield ◽  
Perennial Grasses ◽  
Cool Season ◽  
Organic Dairy ◽  
Annual Grasses ◽  
System 2 ◽  
System 1 ◽  
Warm Season Grasses

The objective of this study was to compare the forage nutritive value of cool-season perennial grasses and legumes with that of warm-season annual grasses grazed by organic dairy cows. Two pasture systems were analyzed across the grazing season at an organic dairy in Morris, Minnesota. Pasture system 1 included perennial ryegrass (Lolium perenne L.), orchardgrass (Dactylis glomerata L.), meadow bromegrass (Bromus riparius Rehmann), meadow fescue (Schedonorus pratensis (Huds.) P. Beauv), alfalfa (Medicago sativa L.), white clover (Trifolium repens L.), red clover (Trifolium pratense L.), and chicory (Cichorium intybus L.). Pasture system 2 was a combination of system 1 and monocultures of warm-season grasses (sorghum-sudangrass (Sorghum bicolor [L.] Moench subsp. drummondii [Steud.]) and teff (Eragrostis tef L.)). Across the grazing season, forage yield was 39% greater for system 2 than system 1 due to greater forage yield during the summer. Neutral detergent fiber (NDF) and acid detergent fiber (ADF) were similar for cool-season and warm-season grasses. Warm-season grasses had greater forage yield during the summer months compared with cool-season grasses and legumes. The total tract NDF digestibility (TTNDFD) varied by month and year across the study for both pasture systems. Overall, weather may affect the forage nutritive value for both cool-season perennial grasses and legumes and warm-season annual grasses.

scholarly journals 2020 Cool-Season Forage Variety Recommendations for Florida

EDIS ◽  
2020 ◽  
Vol 2020 (5) ◽  
pp. 6
Author(s):  
A. R. Blount ◽  
M. Wallau ◽  
E. Rios ◽  
J. M. B. Vendramini ◽  
J. C. B. Dubeux ◽  
...  
Keyword(s):  
Crude Protein ◽  
Warm Season ◽  
Perennial Grasses ◽  
Forage Production ◽  
Cool Season ◽  
Forage Crops ◽  
Previous Version ◽  
Pasture Grasses ◽  
Potential Use ◽  
Short Days

Perennial warm-season pasture grasses used in Florida become dormant in late fall and winter because of short days, cooler temperatures, and frosts. Many livestock producers may choose to establish cool-season annual pasture species to supplement their forage production. These plants are usually higher in total digestible nutrients (TDN) and crude protein (CP) than summer perennial grasses, translating into greater animal performance (Dubeux et al., 2016). Planting and growing these forage crops can involve considerable expense and is somewhat risky because rainfall is often unpredictable during the fall establishment period. The species and varieties for potential use vary in the distribution of production during the cooler months and in the type of soils where they are best adapted. This publication provides the most up-to-date information on current adapted cool-season forage varieties. The recommendation of varieties is based on multi-location, multi-year cultivar evaluation experiments that may include trials in Georgia and other states. Previous version: Wallau, Marcelo, Ann Blount, Esteban Rios, Joao Vendramini, Jose Dubeux, Md Babar, and Kevin Kenworthy. 2019. “2019 Cool-Season Forage Variety Recommendations for Florida”. EDIS2019 (August). https://journals.flvc.org/edis/article/view/115513.

Biological and Morphological Studies on Low-Leukemia-Strain Mice with Hodgkin's-Like Neoplasia Induced by Serial Cell-Free Transmission of Leukemic Organs of SJL/J Strain Mice

1968 ◽  
Vol 26 ◽  
pp. 210-211
Author(s):  
S. Fujinaga ◽  
K. Maruyama ◽  
C.W. Williams ◽  
K. Sekhri ◽  
L. Dmochowski
Keyword(s):  
Tissue Culture ◽  
Type A ◽  
Reticulum Cell ◽  
Type B ◽  
Viral Origin ◽  
Serial Transfer ◽  
Strain Mouse ◽  
Morphological Studies ◽  
Cell Neoplasm ◽  
Free Material

Yumoto and Dmochowski (Cancer Res.27, 2098 (1967)) reported the presence of mature and immature type C leukemia virus particles in leukemic organs and tissues such as lymph nodes, spleen, thymus, liver, and kidneys of SJL/J strain mice with Hodgki's-like disease or reticulum cell neoplasm (type B). In an attempt to ascertain the possibility that this neoplasia may be of viral origin, experiments with induction and transmission of this neoplasm were carried out using cell-free extracts of leukemic organs from an SJL/J strain mouse with spontaneous disease.It has been possible to induce the disease in low-leukemia BALB/c and C3HZB strain mice and serially transfer the neoplasia by cell-free extracts of leukemic organs of these mice. Histological examination revealed the neoplasia to be of either reticulum cell-type A or type B. Serial transfer is now in its fifth passage. In addition leukemic spleen from another SJL/J strain mouse with spontaneous reticulum cell neoplasm (type A) was set up in tissue culture and is now in its 141st serial passage in vitro. Preliminary results indicate that cell-free material of 39th tissue culture passage can reproduce neoplasia in BALB/c mice.

Anticoagulant Activity of β2-Glycoprotein I Is Potentiated by a Distinct Subgroup of Anticardiolipin Antibodies

1992 ◽  
Vol 68 (03) ◽  
pp. 297-300 ◽  
Author(s):  
Monica Galli ◽  
Paul Comfurius ◽  
Tiziano Barbui ◽  
Robert F A Zwaal ◽  
Edouard M Bevers
Keyword(s):  
Human Plasma ◽  
Anticoagulant Activity ◽  
Factor Xa ◽  
Type A ◽  
Lipid Vesicles ◽  
Dependent Manner ◽  
Type B ◽  
Distinct Subgroup ◽  
Glycoprotein I ◽  
Thrombin Formation

SummaryPlasmas of 16 patients positive for both IgG anticardiolipin (aCL) antibodies and lupus anticoagulant (LA) antibodies were subjected to adsorption with liposomes containing cardiolipin. In 5 of these plasmas both the anticardiolipin and the anticoagulant activities were co-sedimented with the liposomes in a dose-dependent manner, whereas in the remaining cases only the anticardiolipin activity could be removed by the liposomes, leaving the anticoagulant activity (LA) in the supernatant plasma. aCL antibodies purified from the first 5 plasmas were defined as aCL-type A, while the term aCL-type B was used for antibodies in the other 11 plasmas, from which 2 were selected for this study.Prolongation of the dRVVT was produced by affinity-purified aCL-type A antibodies in plasma of human as well as animal (bovine, rat and goat) origin. aCL-type B antibodies were found to be devoid of anticoagulant activity, while the corresponding supernatants containing LA IgG produced prolongation of the dRVVT only in human plasma.These anticoagulant activities of aCL-type A and of LA IgG's were subsequently evaluated in human plasma depleted of β2-glycoprotein I (β2-GPI), a protein which was previously shown to be essential in the binding of aCL antibodies to anionic phospholipids. Prolongation of the dRVVT by aCL-type A antibodies was abolished using β2-GPI deficient plasma, but could be restored upon addition of β2-GPI. In contrast, LA IgG caused prolongation of the dRVVT irrespective of the presence or absence of β2-GPI.Since β2-GPI binds to negatively-charged phospholipids and impedes the conversion of prothrombin by the factor Xa/Va enzyme complex (Nimpf et al., Biochim Biophys Acta 1986; 884: 142–9), comparison was made of the effect of aCL-type A and aCL-type B antibodies on the rate of thrombin formation in the presence and absence of β2-GPI. This was measured in a system containing highly purified coagulation factors Xa, Va and prothrombin and lipid vesicles composed of 20 mole% phosphatidylserine and 80 mole% phosphatidylcholine. No inhibition on the rate of thrombin formation was observed with both types of aCL antibodies when either β2-GPI or the lipid vesicles were omitted. Addition of β2-GPI to the prothrombinase assay in the presence of lipid vesicles causes a time-dependent inhibition which was not affected by the presence of aCL-type B or non-specific IgG. In contrast, the presence of aCL-type A antibodies dramatically increased the anticoagulant effect of β2-GPI. These data indicate that the anticoagulant activity of aCL-type A antibodies in plasma is mediated by β2-GPI.

Forage-Based Heifer Development Program for North Florida

EDIS ◽  
2018 ◽  
Vol 2018 (5) ◽  
Author(s):  
Jose C.B. Dubeux ◽  
Nicolas DiLorenzo ◽  
Kalyn Waters ◽  
Jane C. Griffin
Keyword(s):  
Development Program ◽  
Warm Season ◽  
Beef Cows ◽  
Good News ◽  
Cool Season ◽  
Beef Industry ◽  
Performance Targets ◽  
Grazing Systems ◽  
Heifer Development ◽  
Reducing Costs

Florida has 915,000 beef cows and 125,000 replacement heifers (USDA, 2016). Developing these heifers so that they can become productive females in the cow herd is a tremendous investment in a cow/calf operation, an investment that takes several years to make a return. The good news is that there are options to develop heifers on forage-based programs with the possibility of reducing costs while simultaneously meeting performance targets required by the beef industry. Mild winters in Florida allows utilization of cool-season forages that can significantly enhance the performance of grazing heifers. During the warm-season, integration of forage legumes into grazing systems will provide additional nutrients to meet the performance required to develop a replacement heifer to become pregnant and enter the mature cow herd. In this document, we will propose a model for replacement heifer development, based on forage research performed in trials at the NFREC Marianna.   

Genetic variation for rate of establishment in caucasian clover

1998 ◽  
pp. 213-217
Author(s):  
K.H. Widdup ◽  
T.L. Knight ◽  
C.J. Waters
Keyword(s):  
Genetic Variation ◽  
Root Growth ◽  
Seedling Growth ◽  
White Clover ◽  
Seedling Emergence ◽  
Red Clover ◽  
Dry Weight ◽  
Cool Season ◽  
Trifolium Ambiguum ◽  
Root Dry Weight

Slow establishment of caucasian clover (Trifolium ambiguum L.) is hindering the use of this legume in pasture mixtures. Improved genetic material is one strategy of correcting the problem. Newly harvested seed of hexaploid caucasian clover germplasm covering a range of origins, together with white and red clover and lucerne, were sown in 1 m rows in a Wakanui soil at Lincoln in November 1995. After 21 days, the caucasian clover material as a group had similar numbers of emerged seedlings as white clover and lucerne, but was inferior to red clover. There was wide variation among caucasian clover lines (48-70% seedling emergence), with the cool-season selection from cv. Monaro ranked the highest. Recurrent selection at low temperatures could be used to select material with improved rates of seedling emergence. Red clover and lucerne seedlings produced significantly greater shoot and root dry weight than caucasian and white clover seedlings. Initially, caucasian clover seedlings partitioned 1:1 shoot to root dry weight compared with 3:1 for white clover. After 2 months, caucasian clover seedlings had similar shoot growth but 3 times the root growth of white clover. Between 2 and 5 months, caucasian clover partitioned more to root and rhizome growth, resulting in a 0.3:1 shoot:root ratio compared with 2:1 for white clover. Both clover species had similar total dry weight after 5 months. Unhindered root/ rhizome devel-opment is very important to hasten the establishment phase of caucasian clover. The caucasian clover lines KZ3 and cool-season, both selections from Monaro, developed seedlings with greater shoot and root growth than cv. Monaro. KZ3 continued to produce greater root growth after 5 months, indicating the genetic potential for improvement in seedling growth rate. Different pasture estab-lishment techniques are proposed that take account of the seedling growth characteristics of caucasian clover. Keywords: establishment, genetic variation, growth, seedling emergence, Trifolium ambiguum

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