Smoke affects the Germination of Native Grasses of New South Wales

1999 ◽  
Vol 47 (4) ◽  
pp. 563 ◽  
Author(s):  
Tamara R. Read ◽  
Sean M. Bellairs

The germination responses to plant-derived smoke of seeds of 20 native grass species from New South Wales, Australia, were tested under laboratory conditions. The species belonged to 14 genera including Bothriochloa, Chloris, Cymbopogon, Danthonia, Dichanthium, Digitaria, Eragrostis, Eriochloa, Microlaena, Panicum, Paspalidium, Poa, Stipa and Themeda. The interaction between smoke and husk-imposed dormancy was examined by removing the floral structures surrounding the seeds, when sufficient seeds were available. Smoke was shown to be an important environmental stimulus for breaking the dormancy of native grasses; however, the response differed considerably between different genera and between species of the same genus. For almost half of the species, smoke significantly increased the germination percentage. Panicum decompositum showed the greatest response, with germination increasing from 7.7 to 63.1% when smoke was applied. Panicum effusum had no germination in the absence of smoke, but 16.7% germination when smoke was applied. Stipa scabra subsp. scabra had germination significantly reduced by smoke from 30.2 to 19.9%. Five species had their germination rate, but not the final germination percentage, affected by smoke, and a third of the species were unaffected by smoke. For five of the species, Chloris ventricosa, Dichanthium sericeum, Panicum decompositum, Poa labillardieri and Stipa scabra subsp. falcata, this is the first report of a smoke-stimulated germination response. For those species with germination promoted by smoke, retention of the covering structures did not prevent smoke stimulation of germination. Sowing smoke-treated husked seeds is likely to be preferable as it would still promote greater germination, whereas dehusking seeds can result in the seeds being more susceptible to desiccation and fungal attack in the field. It is suggested that other grassland communities that respond to pyric conditions may also contain species that respond to smoke.

2000 ◽  
Vol 40 (8) ◽  
pp. 1081 ◽  
Author(s):  
D. L. Garden ◽  
P. M. Dowling ◽  
D. A. Eddy ◽  
H. I. Nicol

Results are presented of a survey of pastoral properties on the Central, Southern and Monaro Tablelands of New South Wales carried out during 1991—92. Landholders were interviewed to obtain information on property size, enterprise types, grazing management, tree clearing, fertiliser history and carrying capacity. In addition, familiarity with native grass species, and knowledge of their value were determined. The main grazing enterprises were wool and beef. The most common form of livestock management was continuous grazing. Most properties had been extensively cleared of trees (average cleared area 80%), and there had been a significant amount of disturbance of the original pastures. This varied from 40% of total property area for the Central and Monaro Tablelands to 60% for the Southern Tablelands. The main form of disturbance was cultivation for pasture sowing or fodder cropping. Landholders had used 80% more fertiliser on disturbed areas than on undisturbed areas, with most fertiliser applied on the Southern Tablelands and least on the Monaro Tablelands. The average carrying capacities of undisturbed and disturbed pastures over the tablelands were 4.3 and 7.7 dry sheep equivalents per hectare, respectively. While most landholders were satisfied with the performance of their sown pastures, there was a lack of knowledge of the contribution of native perennial grasses to pasture production. Using survey data, it was estimated that pastures with native grasses as the major components covered a minimum of 1.38 million hectares or 40% of the surveyed area. With such a large contribution to production, there is a need to assist landholders to identify native perennial grasses so that their potential value can be more fully realised.


2017 ◽  
Vol 39 (4) ◽  
pp. 355 ◽  
Author(s):  
Sharon L. Brown ◽  
Nick Reid ◽  
Jackie Reid ◽  
Rhiannon Smith ◽  
R. D. B. (Wal) Whalley ◽  
...  

Restoring the grassy understorey to temperate woodlands in south-eastern Australia is often disregarded due to a poor understanding of the techniques involved. The natural recruitment of native grasses is uncommon in the remnants of some of these woodlands, so the restoration of the grass layer is often dependent on interventions to overcome restoration barriers. Soil enrichment from agricultural fertilisers favours the invasion of exotic broadleaf weeds and grasses, and is one of the primary barriers to the successful recruitment and establishment of native grasses, which dominated before agricultural development. This study on the Northern Tablelands of New South Wales investigated the effects of different weed control treatments – scalping, glyphosate (Roundup®) herbicide, and combinations of glyphosate with carbon (sugar and sawdust) addition and a control (nil treatment) recruitment of native grasses and weed emergence after broadcast seeding. The experimental site was a mown grass lawn consisting of fescue (Festuca arundinacea Shreb.), cocksfoot (Dactylis glomerata L.) and paspalum (Paspalum dilatatum Poir). Native grass recruitment varied significantly between treatments. The maximum number of recruits in scalped plots was 29 recruits m–2 compared with an average of <2 recruits m–2 for the glyphosate and glyphosate carbon combinations. Scalping reduced soil nitrogen from 0.6% in non-scalped plots to 0.1% and phosphorus from 191.6 ppm to 40.3 ppm. Maximum weed cover occurred in the glyphosate herbicide treatment (45%), whereas combinations of glyphosate plus either sugar or sawdust maintained weed cover at 13%. The present study suggests that scalping may be a successful intervention strategy because it has the potential to significantly improve native grass recruitment compared with other restoration methods used in this study. Scalping allows more time for native grasses to germinate and establish in the absence of competitive fast-growing exotic weeds.


1979 ◽  
Vol 30 (2) ◽  
pp. 307 ◽  
Author(s):  
LJ Penrose ◽  
KC Davis ◽  
W Koffmann

Tolerance of Sclerotinia fructicola (Wint.) Rehm, to benzimidazole fungicides was first recorded in New South Wales in 1976 and has since been confirmed on 11 orchards, all in the Orange and Bathurst districts. Crops affected include peach, nectarine, cherry and plum. The distribution of benomyl-tolerant strains was mapped in two orchards and found to be present in scattered groups of trees, rather than throughout the block. Distribution of tolerant strains was not uniform within trees, and in most cases both tolerant and susceptible strains were present in the same tree. Tolerance was found to be stable after three transfers of the fungus in fruit and after 33 transfers over 2 years in culture. The fungus persisted over the winter in mummified nectarine fruit and was still present in an orchard 18 months after the application of benzimidazole fungicides ceased. The tolerant strain was as pathogenic to peach fruit as the susceptible strain and competed successfully when peach fruits were inoculated with mixtures of spores from susceptible and tolerant strains. There were no significant differences between groups of tolerant isolates and susceptible isolates in growth, sporulation and germination percentage in vitro. It is suggested that since no competitive disadvantage was associated with tolerance, tolerant strains will exist in high numbers in orchards for a considerable period of time.


2003 ◽  
Vol 43 (8) ◽  
pp. 977 ◽  
Author(s):  
J. F. Graham ◽  
B. R. Cullen ◽  
G. M. Lodge ◽  
M. H. Andrew ◽  
B. P. Christy ◽  
...  

The effects of various grazing management systems on sown, naturalised, and native pastures were studied at 6 different locations in the temperate high rainfall zone (HRZ, >600 mm rainfall/year) of southern Australia, as part of the Sustainable Grazing Systems (SGS) Program. The treatments examined had different pasture species and fertiliser management, with grazing method ranging from set stocking (continuous grazing) to rotation with rests based on pre- and post-grazing herbage mass or season and plant phenology. Sites were located at: Albany, Western Australia; Manilla, Barraba, Nundle, New South Wales; (grazed by wethers); and Carcoar, New South Wales; Maindample, Ruffy, north-east Victoria; Vasey, western Victoria; (grazed by ewes and lambs).Grazing method significantly (P<0.001) influenced stocking rate (expressed as dry sheep equivalents (DSE)/ha), but effects were not consistent across sites. At Vasey the stocking rate of the rotation treatments ranged from 5 to 23% higher than the set stocked treatments depending upon year. For all sites, significant factors (P<0.001) affecting stocking rate were soil Olsen P, soil pH, grazing management (resting), legume percent, and an index of growing season effectiveness. Although total annual rainfall had a significant effect (P<0.002) in an initial analysis, its influence became non-significant (P>0.05), when a growing season index (P<0.001) was used. Non-significant (P>0.05) factors included solar radiation, annual average temperature, fertiliser applied in the current year, and average annual perennial and broadleaf percent composition. The implications of these data for productivity and sustainability (as assessed by perenniality and water use) were encouraging. Generally, there were positive relationships between increased stocking rate and the probability of achieving a zero mm soil water surplus in winter, and between increased productivity and the proportion of perennial grass species where extremes of treatments were compared at each site. The results indicate that stocking rate can be increased without jeopardising sustainability, that grazing management can bring about more sustainable pastures, that there is scope to increase productivity particularly through increasing soil fertility, and growing season length can be used to predict potential carrying capacity. These are positive outcomes that graziers in the HRZ of southern Australia can use to enhance productivity (thus profitability) and sustainability.


1994 ◽  
Vol 34 (4) ◽  
pp. 449 ◽  
Author(s):  
RD FitzGerald

A range of pasture legumes was either broadcast or drilled into native grass pastures on the North-west Slopes of New South Wales to identify legumes that would persist in that environment and improve the quality of winter pastures based on native grasses. There were 2 experiments conducted over 12 sites. In the first, sites were selected to permit identification of effects of altitude and 2 soil types on legume adaptation. In the second, the lower altitude range was extended and a wider range of soil types was sampled. Subterranean clover (Trifolium subterraneum L.) was the most persistent and productive species, with cultivar performance varying with altitude. At the lowest altitude (340 m) the early-maturing cv. Dalkeith was the most productive, and at 500-600 m there was little difference between the tested cultivars. Stand density, herbage yield, and seed yield all declined as altitude increased, but the decline was greater with earlier maturing cultivars than with the later maturing cv. Woogenellup White clover (T. repens cv. Haifa) established poorly in native grass swards, but plants that did establish persisted during favourable seasons at higher altitudes. Herbage yields of woolly pod vetch (Vicia dasycarpa cv. Namoi) and rose clover (T. hirtum cv. Hykon) occasionally exceeded yield of subterranean clover at some lower altitude sites, but those species failed to persist at other sites where grazing management may have been unsuitable. Barrel medic (Medicago truncatula) established satisfactorily but did not persist on the more acidic soils (pH <6.0). Both drilling and broadcasting establishment techniques produced satisfactory legume stands. Legume plant density was generally greater on heavier soils of basaltic origin than on lighter soils of rhyolitic origin.


1999 ◽  
Vol 47 (2) ◽  
pp. 221 ◽  
Author(s):  
C. H. A. Huxtable ◽  
R. D. B. Whalley

A field trial was set up to assess the emergence and survival under natural rainfall conditions of three species of native grasses when sown monthly for 8 months in seven different roadside environments. Generally, rainfall events of 40 mm or more were associated with substantial emergence events, and seed of Danthonia richardsonii cv. ‘Taranna’ and Microlaena stipoides was able to germinate after being in dry soil for up to 120 days. The highest emergence of Chloris truncata and ‘Taranna’ occurred from October and November sowings, whereas that of M. stipoides was from autumn sowings. For all species, emergence was highest in roadside environments with topsoil and poorest for a subsoil environment. Final percent survival of all species closely matched percent emergence with less than 20% seedling mortality occurring over time. A higher percentage of seeds sown in October and November germinated and survived as plants than from December and January sowings. Survival of plants from the initial seed source was generally greater than 25% for all species when sown between October and January. The highest seedling mortality occurred on an old road environment whereas the lowest was in a relatively undisturbed environment. Management implications are that on the Northern Tablelands, given adequate rainfall, these three native grasses have the best chance of successful establishment if sown in spring on a cultivated bed of topsoil. M. stipoides and D. richardsonii cv. ‘Taranna’ seed can also be sown into a dry seedbed in summer and germinate following rainfall several months later.


2002 ◽  
Vol 42 (1) ◽  
pp. 27 ◽  
Author(s):  
M. H. Campbell ◽  
H. I. Nicol

Germination of seeds of Carex appressa R.Br. (tussock sedge) collected in 1989 and 1990 from Bigga, Boorowa and Kerrs Creek, New South Wales, Australia, stored in a laboratory and germinated annually in 45-day tests, declined from an initial 75–90% in year 1 to 0.5–14% in years 10 and 11. The germination of seeds collected from Bigga and Boorowa in 1991 declined from 90–91% in year 1 to 12–61% in year 9. This decline was best described by generalised logistic curves (Bigga) and exponential curves (Boorowa). Most seeds that failed to germinate were shown to be non-viable by the tetrazolium test. Rate of germination declined with seed age, so that days for 50% of final germination percentage increased from 8 days for 1 year-old seeds to >40 days for 11-year-old seeds. Of 8–11-year-old seeds that germinated between days 45 and 140, 62–70% had deformed seedlings. Germination of seeds buried in the soil for 0.5–2.7 years was lower than that of the same seed stored in the laboratory. Germination of seeds buried at 5 mm (19%) was lower than that of the same seeds buried at 40 mm (50%). Almost all the decline in germination occurred in the first 6 months of burial. Increased depth of sowing reduced emergence (%), height of the shoot and length of the primary root and increased the time taken for emergence and length of the mesocotyl. The maximum depth C. appressa seedlings could emerge from was 44 mm. Growth of C. appressa seedlings was slower than that of pasture species and responded to nitrogen and nitrogen + phosphorus and/or sulfur but not to phosphorus and/or sulfur. Differences were recorded in the morphology of plants grown from seeds collected from various locations and grown in the 1 environment at Orange, New South Wales. Control of C. appressa was achieved by draining, slashing and removing litter, applying glyphosate, surface-sowing pasture species and topdressing with superphosphate. Five years after sowing, the foliage cover of legumes and grasses on the best treatment was 71% and that of C. appressa 2%, a substantial decline from the original 81% infestation. The best technique for control of C. appressa on infested creek flats suitable for pasture production would be to drain, plough and bury seeds below 44 mm and then sow pastures with superphosphate. Where ploughing is not possible, drainage, burning to remove foliage, spraying with glyphosate and surface-sowing pastures with superphosphate would be successful. In both situations, long-term control can be achieved by heavy grazing for short periods only when the soil is firm and removing re-infesting plants by annual spot spraying.


2001 ◽  
Vol 52 (9) ◽  
pp. 925 ◽  
Author(s):  
D. L. Garden ◽  
P. M . Dowling ◽  
D. A. Eddy ◽  
H. I. Nicol

Pastures on 126 properties on the central, southern, and Monaro tablelands were surveyed to determine their botanical composition. Data on climate, soils, pasture sowing, fertiliser history, and stock management were collected to relate current composition to environmental factors and previous management. Native grass-based pastures were found to be widespread, and in many cases, pastures were dominated by native grasses, despite many decades of pasture improvement. Seventeen genera of native perennial grasses comprising over 35 species were identified. The most common species on the central tablelands were Austrodanthonia spp., Bothriochloa macra, and Microlaena stipoides; on the southern tablelands, Austrodanthoniaspp. and M. stipoides; and on the Monaro, Poa spp., Austrodanthonia spp., Themeda australis, and Austrostipa spp. Soil type was the most important factor affecting species distribution, and other soil attributes such as texture, pH, P, and N were also important. Environmental (rainfall) and management (superphosphate application, stock type, stocking rate) factors also influenced distribution. The significant areas of native grass pastures that were found suggest a decline in sown species and a recolonisation of sown pastures with native grasses. The potential for manipulation of botanical composition of these grasslands is discussed, together with their value for production and sustainability.


1989 ◽  
Vol 37 (5) ◽  
pp. 375 ◽  
Author(s):  
JH Leigh ◽  
DH Wood ◽  
MD Holgate ◽  
A Slee ◽  
MG Stanger

The effects of rabbits and kangaroos, and rabbits alone, on the biomass and species composition of a native grassland dominated by Stipa nitida/nodosa, Danthonia caespitosa and Aristida contorta, and a grassland dominated by the exotic species Hordeum glaucum, Vulpia spp., Medicago laciniata and the native Erodium crinitum growing at Yathong Nature Reserve in central New South Wales was monitored between 1979 and 1985. Rabbits generally favoured the grassy component; kangaroos also favoured grasses but less so. Changes in non-grass species composition due to grazing was generally insignificant. Changes in species composition due to seasonal differences in rainfall was highly significant. No new species appeared on plots exclosed from grazing for 10 years, suggesting that the grazing by livestock, rabbits, and kangaroos in the past has determined the present species composition. The annual biomass consumption by rabbits averaged over 6 years was 100-200 kg ha-1, which is equivalent to reducing the carrying capacity by one sheep for every 2-4 ha rabbit-infested area. In the native grassland the spatial pattern of rabbit grazing, as indicated by faecal pellet distribution, biomass removal, and percentage of 'unpalatable' species in the pasture, shows greatest grazing pressure to be within 50 m of the warren, grazing intensity dropping off from there to 300 m the greatest distance studied. From the start of the study 'palatable' species, especially grasses, were at their lowest density within 50 m of the warren; this appeared to be a historical effect of grazing. No patterns were discernible in the pasture dominated by introduced species. Little change in species composition of these grasslands can be expected under a wide range of grazing pressure, except close to rabbit warrens.


1993 ◽  
Vol 41 (6) ◽  
pp. 627 ◽  
Author(s):  
JB Robinson ◽  
DJ Munnich ◽  
PC Simpson ◽  
PW Orchard

Pasture species form a variety of associations inn the cool temperate environment of the tablelands of New South Wales. Data from a survey of 65 paddocks on 34 farms in the Goulburn district of southern New South Wales were analysed using numerical classification methods to identify species associations. Of particular interest were the agronomic and environmental factors associated with the abundance of Danthonia spp. and Microlaena stipoides, which are persistent and useful native perennial grasses. The abundance of Danthonia spp. was negatively correlated with the abundance of exotic sown grasses (many species) and annual grass species (chiefly Vulpia spp.). M. stipoides abundance was similarly correlated with sown grass species, but had no correlation with annual grasses. It had a significant negative correlation with legume species abundance (chiefly Trifolium spp.). Sites with M. stipoides associations (n = 19 sites) had particular clearing and cultivation histories and low pH. Sites (n = 12) with a Danthonia spp. association also had particular clearing and cultivation histories, and occurred predominantly on soils derived from sedimentary parent material (11/12 sites). This association also had significantly higher annual average and total superphosphate usage. Probable mechanisms by which the concurrent environmental and agronomic factors may have determined the observed associations are discussed. It is concluded that the numerical classification system employed here revealed useful species association-site grouping units and contributed significantly to the interpretation of these data.


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