Germination, emergence, growth, ecotypes and control of Carex appressa R. Br. (tussock sedge)

2002 ◽  
Vol 42 (1) ◽  
pp. 27 ◽  
Author(s):  
M. H. Campbell ◽  
H. I. Nicol
Keyword(s):  
New South ◽  
New South Wales ◽  
Primary Root ◽  
Germination Percentage ◽  
Pasture Production ◽  
South Wales ◽  
Heavy Grazing ◽  
Substantial Decline ◽  
Almost All ◽  
And Control

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.

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
Keyword(s):  
New South ◽  
Germination Rate ◽  
New South Wales ◽  
Germination Percentage ◽  
Grass Species ◽  
Native Grasses ◽  
Environmental Stimulus ◽  
Native Grass ◽  
South Wales ◽  
Stimulation Of

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.

Factors affecting the germination of Giant Parramatta grass

1997 ◽  
Vol 37 (4) ◽  
pp. 439 ◽  
Author(s):  
T. S. Andrews ◽  
C. E. Jones ◽  
R. D. B. Whalley
Keyword(s):  
Leaf Extract ◽  
New South ◽  
New South Wales ◽  
North Coast ◽  
Factors Affecting ◽  
The North ◽  
South Wales ◽  
Seed Fall ◽  
Allelopathic Interactions ◽  
And Control

Summary. Four experiments were conducted to determine the effects of temperature, light and leaf extract solutions on the germination of Giant Parramatta grass [GPG, Sporobolus indicus (L.) R. Br. var. major (Buse) Baaijens] collected from a population on the North Coast of New South Wales. In the first experiment, seeds were subjected to one of a range of temperature combinations immediately after collection and again after 8 and 27 weeks. Germination was restricted to a narrow range of alternating temperatures with a peak at 35°C day/15°C night when seeds were tested immediately after collection. More seeds germinated when the samples had been stored, although germination remained depressed at constant temperatures. These data indicate that freshly collected GPG seeds are subject to primary dormancy and that few would germinate in the field immediately after seed fall. In a second experiment, seeds were buried beneath leaf litter in a pasture immediately after collection. After 7 months, the seeds were exhumed and subjected to either constant (20°C) or alternating (35/15°C) temperatures in either full light, reduced red:far-red (R : FR) light or dark treatments. Over 95% of GPG seeds germinated when subjected to alternating temperatures, regardless of light treatment. At constant temperatures, 97% of seeds germinated under full light, 59% at reduced R : FR light and <1% in dark treatments. A germination response to alternating temperatures and/or light treatments has been reported in pasture weeds and may be an adaptation to detecting gaps in the pasture canopy. Consequently, the germination of GPG in a pasture may be manipulated to some extent by altering the amount of pasture cover using grazing management, mowing and fertiliser applications. In experiment 3, leaves from a range of coastal grasses were mixed with water and the solutions were used to germinate GPG seeds. Solutions extracted from setaria (Setaria sphacelata) leaves completely inhibited GPG germination while 27% of GPG seeds germinated when imbibed with kikuyu leaf extract solution. Solution extracted from carpet grass (Axonopus affinis) leaves had the least effect on GPG germination. In experiment 4, the effects of solutions that had been leached from the leaves of either setaria or carpet grass on seed germination, and root and shoot lengths of GPG seedlings were compared. Germination was less inhibited by leachate solutions compared with the extract solutions used in experiment 3. Seedlings in setaria leachates had significantly shorter roots and shoots than both those germinated in carpet grass leachates and control seedlings. This may explain, at least in part, why carpet-grass-based pastures are readily infested with GPG while setaria-based pastures are relatively resistant to infestation. The potential for allelopathic interactions between GPG and setaria to be fully utilised to reduce the abundance of GPG in coastal New South Wales pastures is discussed.

The distribution of benomyl-tolerant Sclerotinia fructicola (Wint.) Rehm. in stone fruit orchards in New South Wales and comparative studies with susceptible isolates

1979 ◽  
Vol 30 (2) ◽  
pp. 307 ◽  
Author(s):  
LJ Penrose ◽  
KC Davis ◽  
W Koffmann
Keyword(s):  
New South ◽  
New South Wales ◽  
Germination Percentage ◽  
Benzimidazole Fungicides ◽  
South Wales ◽  
Competitive Disadvantage ◽  
Fruit Orchards ◽  
Considerable Period ◽  
Block Distribution

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.

Effects of topdressed superphosphate on the sheep and pasture production of dryland lucerne in central western New South Wales

1975 ◽  
Vol 15 (75) ◽  
pp. 475 ◽  
Author(s):  
H Brownlee ◽  
BJ Scott ◽  
RD Kearins ◽  
J Bradley
Keyword(s):  
New South ◽  
Soil Phosphorus ◽  
New South Wales ◽  
Stocking Rate ◽  
Gross Margin ◽  
Pasture Production ◽  
Wool Production ◽  
South Wales ◽  
Dry Conditions ◽  
Soil Phosphorus Test

Merino ewes at 3.7, 4.9 and 6.2 ha-1 grazed dryland lucerne (Medicago sativa cv. Hunter River) topdressed annually with superphosphate at 0, 125 and 251 kg ha-1, from September 1969 until December 1972, in an experiment at Condobolin, New South Wales. Superphosphate increased ewe liveweights, total forage available and phosphorus content of the forage by a small amount but did not increase wool production per head. The Bray soil phosphorus test in the top 8 cm of the soil profile rose from 8 p.p.m. to 48 p.p.m., but most of the phosphorus was concentrated in the 0-4 cm layer, where we consider that dry conditions reduced its availability to the lucerne. As stocking rate increased, ewe liveweights and wool production per head decreased and the sheep required more handfeeding for survival. The treatment with the greatest gross margin was the lowest stocking rate with nil fertilizer.

The effect of proportion of sown grasses on pasture and animal production from fertilised pastures on the Northern Tablelands of New South Wales.

1985 ◽  
Vol 7 (2) ◽  
pp. 88
Author(s):  
GG Robinson ◽  
PM Dowling
Keyword(s):  
New South ◽  
New South Wales ◽  
Grazing Intensity ◽  
Animal Production ◽  
Pasture Production ◽  
Wool Production ◽  
South Wales ◽  
Natural Pasture

Pasture and animal production from fertilised pastures with varying proportions of sown grass (0-60%) were recorded and compared. The presence of sown grass increased pasture production when compared to natural pasture, but no difference was detected in liveweight or wool production between the var- ious pastures. It is doubtful whether sowing of introduced grasses for wool production can be justified at the levels of grazing intensity usually adopted on the Northern Tablelands.

Subplasticity in Australian soils. V. Factors involved and techniques of dispersion

Soil Research ◽  
1976 ◽  
Vol 14 (3) ◽  
pp. 273 ◽  
Author(s):  
K Norrish ◽  
KG Tiller
Keyword(s):  
New South ◽  
New South Wales ◽  
South Australia ◽  
Aggregate Stability ◽  
Clay Particles ◽  
South Wales ◽  
Montmorillonite Clays ◽  
Ionic Bonds ◽  
Almost All ◽  
Physical And Chemical

The subplastic soils studied were two from the Riverina area of New South Wales, two montmorillonite rich clays formed on basalt, from South Australia and Queensland, and a krasnozem from New South Wales. To assess the effectiveness of physical and chemical methods of dispersion, theoretical clay contents were calculated from the ratio of the CEC of the soil to that of separated clay. The composition of the clay from the soils showed little or no change with degree of dispersion. To disperse the soils without chemical pretreatment, a method of disaggregation was devised that involved vigorous shaking of a soil paste. Following this technique the Riverina soils and the krasnozem yielded almost all their clay. Lithium saturation was the only chemical treatment that aided dispersion of the montmorillonite clays, and this, together with the high tetrahedral lattice charge, suggests that aggregate stability is mainly due to a large electrostatic interaction between clay sheets. Any pretreatments involving the use of sodium hydroxide improved clay yields for the Riverina soils. The data indicated that the loss of subplasticity was accompanied by the solution of clay, suggesting that aggregate stability was due to non-ionic bonds between clay particles, possibly as the result of intergrowth of clay mineral crystals. Organic matter and/or free iron oxide was responsible for cementation of the krasnozem.

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