The Role of Competition and Seed Production Environment on the Success of Two Perennial Grass Species in a Roadside Restoration

2015 ◽  
Vol 33 (3) ◽  
pp. 282-288 ◽  
Author(s):  
E. Espeland ◽  
L. Richardson
Keyword(s):  
Seed Production ◽  
Perennial Grass ◽  
Grass Species ◽  
Production Environment ◽  
Roadside Restoration

Silvertop in perennial grass seed production: Effects of type and timing of biotic stresses

2021 ◽  
Author(s):  
Julie Soroka ◽  
Bruce D. Gossen
Keyword(s):  
Seed Production ◽  
Poa Pratensis ◽  
Perennial Grass ◽  
Kentucky Bluegrass ◽  
Development Stage ◽  
Perennial Grasses ◽  
Grass Species ◽  
Biotic Stresses ◽  
Seed Harvest ◽  
Bromus Riparius

Seed production of perennial grasses is an important industry in Canada, but many fields exhibit high proportions of sterile heads with characteristic symptoms in a condition known as silvertop. In a 3-yr field study, biotic stress treatments were applied to caged plots of Kentucky bluegrass (<i>Poa pratensis</i>) and meadow bromegrass (<i>Bromus riparius</i>) to assess their effects on silvertop incidence. Treatments were: 1) control, 2) addition of grass-feeding insects, primarily grass plant bugs (Miridae), 3) inoculation with <i>Fusarium poae</i> spores, 4) both insects and spores, and in one year, 5) mechanical piercing of seed heads above the last node. Additionally, cores of the two grass species were potted and removed from the field in spring in each of 2 years. After 2-, 4-, and 6-wk intervals in a cold room at 4° C to stagger plant development stage, the five treatments were applied to caged plants of both grasses, which were maintained in a greenhouse until seed harvest. In both studies, the numbers of healthy seed heads, percentage of heads with silvertop, and seed weights were determined. In the field, stress treatments infrequently and inconsistently affected silvertop levels. Regression showed that the relationship between silvertop and seed yield, although significant, explained little of the variability in yield. Silvertop developed in all treatments in the greenhouse; treatments had no effect on silvertop levels, which were highest in plants treated at the R1 (boot) growth stage. This suggests that the boot stage of the two grass species is most vulnerable to silvertop occurrence.

Seed availability, landscape suitability and the regeneration of perennial grasses in moderately degraded rangelands in semiarid Australia

2015 ◽  
Vol 37 (3) ◽  
pp. 249 ◽  
Author(s):  
Judith M. Bean ◽  
Gavin J. Melville ◽  
Ronald B. Hacker ◽  
Stephen P. Clipperton
Keyword(s):  
Seed Production ◽  
Perennial Grass ◽  
Weather Conditions ◽  
Perennial Grasses ◽  
Grass Species ◽  
Natural Landscape ◽  
Seed Availability ◽  
Landscape Processes ◽  
Production Areas ◽  
Seasonal Weather

Two experimental sites were selected in the semiarid rangelands of north-west New South Wales, Australia. The sites had contrasting soil types and vegetation communities, but were similar in the existence of topographically high areas occupied by populations of perennial grasses. Adjacent slopes had very low numbers of perennial grass plants, indicating a moderate level of degradation. Shrubs, including Eremophila sturtii R.Br. (turpentine), were present but had not thickened to cause severe degradation. The topographically high areas were fenced as seed production areas. Replicates of a control and two cultural treatments: (1) piles of fine branches of turpentine placed along the topographic contour and (2) pits dug by a revolving metal drum, were established on the adjacent slopes. Maximum regeneration of perennial grasses took place, during favourable seasonal weather conditions, under the piles of branches on the site characterised by long gentle slopes of relatively impervious hard-setting red earths. Seed availability was not a limiting factor and a significant amount of seed was apparently sourced from the seed production areas. The piles of branches were very effective in promoting germination and survival of the perennial grasses, Monachather paradoxus Steud. and Aristida jerichoensis (Domin) Henrad, and species with large seed-retaining inflorescences, but not Thyridolepis mitchelliana (Nees) S.T. Blake. The piles of branches increased capture of seed, developed an improved seedbed and established a more mesic micro-environment and were, therefore, effective in enhancing natural landscape processes. At the site characterised by a medium-textured lithosol, even during favourable seasonal weather conditions, numbers of new plants were much lower. Pits were obliterated during the first heavy rains and the piles of branches had a negative impact on the survival of the second cohort of T. mitchelliana. At both sites, levels of germination and survival needed for regeneration of perennial grasses only occurred where a treatment effective in enhancing natural landscape processes had been established prior to favourable seasonal conditions. Pits were not effective in doing this at either site, nor for any of the perennial grass species.

Current state and main directions of preservation and strengthening of health of the working population of Russia

2020 ◽  
pp. 527-532 ◽  
Author(s):  
I. V. Bukhtiyarov
Keyword(s):  
Working Conditions ◽  
Russian Federation ◽  
Production Environment ◽  
Working Population ◽  
Industrial Enterprises ◽  
The Past ◽  
Production Factors ◽  
Current State ◽  
The Russian Federation

The article presents the results of the analysis of health, working conditions and prevalence of adverse production factors, the structure of the detected occupational pathology in the working population of the Russian Federation. The article presents Statistical data on the dynamics of the share of workplaces of industrial enterprises that do not meet hygienic standards, occupational morbidity in 2015-2018 for the main groups of adverse factors of the production environment and the labor process. The indicators of occupational morbidity over the past 6 years in the context of the main types of economic activity, individual subjects of the Russian Federation, classes of working conditions, levels of specialized occupational health care. The role of the research Institute of occupational pathology and occupational pathology centers in solving organizational, methodological and practical tasks for the detection, treatment, rehabilitation and prevention of occupational diseases is shown. The basic directions of activity in the field of preservation and strengthening of health of workers, and also safety at a workplace are defined.

Hymenachne acutigluma (Steud.) Gilliland in GBS 20:314 - An exceptionally important perennial grass for anatomy and indigenous practice.

2016 ◽  
Vol 5 (04) ◽  
pp. 4958
Author(s):  
Dulal De
Keyword(s):  
Perennial Grass ◽  
Secondary Growth ◽  
Grass Species ◽  
Stem Anatomy

Hymenachne acutigluma (Steud.) Gilliland, a robust rhizomatous perennial grass spreads on moist and swampy land and also floating in water. Being a grass species, they do not have any cambium for secondary growth. A peculiarity in stem anatomy especially the spongy pith of secondary tissues found in absence of the cambium. The origin and development of the parenchymatous pith tissues has been investigated in the present study. Economically this spongy pith is of very much potent for its high absorbing and filtering capacity and also used as a good fodder.

The germinable soil seedbank of Eucalyptus victrix grassy woodlands at Roy Hill station, Pilbara district, Western Australia

2004 ◽  
Vol 26 (1) ◽  
pp. 17 ◽  
Author(s):  
R. A. Graham ◽  
S. K. Florentine ◽  
J. E. D. Fox ◽  
T. M. Luong
Keyword(s):  
Species Composition ◽  
Western Australia ◽  
Perennial Grass ◽  
Summer Rainfall ◽  
Distribution Patterns ◽  
Grass Species ◽  
Surface Areas ◽  
Hill Station ◽  
Soil Seedbank ◽  
Germinable Seed

The paper reports soil seedbank species composition, of Eucalyptus victrix grassy woodlands, of the upper Fortescue River in the Pilbara District, Western Australia. In this study, our objectives were to investigate germinable soil seedbanks and species composition in response to three simulated seasons, using emergence. Variation in seed density from three depths was tested. Four field sites were sampled. Thirty samples were collected in late spring, after seed rain and before summer rainfall. From each sample spot, three soil depths (surface, 1–5, and 6–10 cm) were segregated from beneath surface areas of 100 cm2. Samples were later incubated in a glasshouse to simulate three different seasonal conditions (autumn, winter and spring). Germinating seedlings were recorded on emergence and grown until identified. Forty-one species germinated, comprising 11 grasses (7 annuals and 4 perennials), 25 annual herbs and 5 perennial herbs. Distribution patterns of germinable seed in both the important annual grass Eragrostis japonica and the perennial Eragrostis setifolia (a preferred cattle fodder species), suggest that seedbank accumulation differs among species and between sites. In part, this may be associated with the absence of grazing. Species with most total germinable seed were E. japonica (Poaceae; 603/m2), and the annual herbs Calotis multicaulis (Asteraceae; 346/m2), and Mimulus gracilis (Scrophulariaceae; 168/m2). Perennial grass seed was sparse. Spring simulation gave most germination (1059), followed by autumn (892) and winter (376) sets. Greatest species diversity was produced from the spring simulation (33 species), followed by autumn (26), and winter (22). Of the total germination, 92% came from 17 species that were represented in all three simulations. Of the 1227 grass seedlings counted, most were recruited from the surface soil (735), followed by the 5 (310) and 10 (182) cm depths. Marginally more grass seedlings germinated from the spring simulation (558) than the autumn set (523). Only 11.9% of grass germinants came from the winter simulation. All grass species recruited from the soil seedbanks had a C4 photosynthetic pathway. Except for Cenchrus ciliaris all grass species are native to Australia. Of the four sites sampled, one fenced to exclude cattle five years earlier had significantly more germination than the three unfenced sites. Seedbank sampling produced several new records for plants in the areas sampled.

scholarly journals Potential Role of Sequential Glufosinate and Foramsulfuron Applications for Management of Fescues (Festucaspp.) in Wild Blueberry

2017 ◽  
Vol 31 (1) ◽  
pp. 100-110 ◽  
Author(s):  
Scott N. White ◽  
Shanthanu Krishna Kumar
Keyword(s):  
Field Study ◽  
Seed Production ◽  
Potential Role ◽  
Seedling Recruitment ◽  
Seedling Emergence ◽  
Seed Viability ◽  
Early Spring ◽  
Seedling Mortality ◽  
Wild Blueberry

Sheep and hair fescue are perennial, tuft forming grasses that spread by seed and form dense sods in wild blueberry fields. These sods compete with the crop for resources and hinder harvest. Field and greenhouse studies were conducted in 2015 to evaluate 1) the effect of sequential glufosinate and foramsulfuron applications on suppression of fescues in the greenhouse and field, and 2) efficacy of glufosinate and foramsulfuron on fescue seedlings when applied at 2, 4, 6, and 8 wk after seedling emergence in the greenhouse. Glufosinate applications at 750 and 1,005 g ai ha−1followed by foramsulfuron application at 35 g ai ha−1reduced fescue leaf number and biomass relative to foramsulfuron application alone in the greenhouse. In the field study, fescue flowering tuft density, tuft inflorescence height, seed production, and seed viability were reduced by foramsulfuron alone, but there was a trend towards lower seed production and tuft height when fescues were treated with glufosinate at 1,005 g ha−1followed by foramsulfuron. Foramsulfuron caused low seedling mortality at all application timings evaluated, but glufosinate caused >90% mortality in seedlings when applied at 2, 4, 6, or 8 wk after seedling emergence. Our results suggest that sequential applications of these herbicides are less effective under field conditions relative to results obtained in the greenhouse, though burndown glufosinate applications may have a role in reducing fescue seedling recruitment. Additional research should be conducted to determine the effect of early spring and autumn glufosinate applications on fescue seedling recruitment and suppression of established fescue tufts with subsequent foramsulfuron applications.

scholarly journals Growth and Physiological Traits Associated with Drought Survival and Post-drought Recovery in Perennial Turfgrass Species

2010 ◽  
Vol 135 (2) ◽  
pp. 125-133 ◽  
Author(s):  
Qi Chai ◽  
Fang Jin ◽  
Emily Merewitz ◽  
Bingru Huang
Keyword(s):  
Cell Wall ◽  
Drought Stress ◽  
Osmotic Adjustment ◽  
Perennial Grass ◽  
Kentucky Bluegrass ◽  
Physiological Traits ◽  
Grass Species ◽  
Cell Wall Elasticity ◽  
Drought Recovery ◽  
Drought Survival

The objective of this study was to determine physiological traits for drought survival and post-drought recovery upon re-watering in two C3 perennial grass species, kentucky bluegrass [KBG (Poa pratensis)] and perennial ryegrass [PRG (Lolium perenne)]. Plants were maintained well watered or exposed to drought stress by withholding irrigation and were then re-watered in a growth chamber. KBG had significantly higher grass quality and leaf photochemical efficiency, and lower electrolyte leakage than PRG during 20 days of drought. After 7 days of re-watering, drought-damaged leaves were rehydrated to the control level in KBG, but could not fully recover in PRG. KBG produced a greater number of new roots, while PRG had more rapid elongation of new roots after 16 days of re-watering. Superior drought tolerance in KBG was associated with osmotic adjustment, higher cell wall elasticity, and lower relative water content at zero turgor. Osmotic adjustment, cell wall elasticity, and cell membrane stability could play important roles in leaf desiccation tolerance and drought survival in perennial grass species. In addition, post-drought recovery of leaf hydration level and physiological activity could be associated with the accumulation of carbohydrates in leaves and rhizomes during drought stress and new root production after re-watering.

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