Seed dormancy, germination, seedling emergence, and survival of some temperate perennial pasture grasses in northern New South Wales

2004 ◽  
Vol 55 (3) ◽  
pp. 345 ◽  
Author(s):  
G. M. Lodge
Keyword(s):  
Seed Production ◽  
Tall Fescue ◽  
Festuca Arundinacea ◽  
New South ◽  
Seedling Emergence ◽  
New South Wales ◽  
Perennial Grasses ◽  
South Wales ◽  
Litter Cover ◽  
Time Required

A series of seed and seedling studies was undertaken in northern New South Wales for the temperate perennial grasses phalaris (Phalaris aquatica cv. Sirosa and Australian), tall fescue (Festuca arundinacea cv. Demeter), perennial ryegrass (Lolium perenne cv. Kangaroo Valley), and 2 wallaby grasses (Austrodanthonia bipartita syn. Danthonia linkii cv. Bunderra and A. richardsonii syn. D. richardsonii cv. Taranna). Studies were conducted to determine the level of dormancy in freshly harvested seed and the time required to overcome it, effects of alternating daily temperatures on the germination of non-dormant seed, effect of time-of-sowing on seedling emergence (2 studies) and survival, levels of seed production and soil seedbanks, and the effect of litter cover and soil type on the emergence of Sirosa phalaris seedlings.Grass species, time, and their interaction all had a significant effect (P < 0.05) on both dispersal unit and caryopses germination. One month after harvest, germination of caryopses was lower (P < 0.05, 2 and 1%, respectively) for Taranna and Bunderra than for Sirosa (79.5%). In March 1993, germination of the 2 wallaby grasses was also lower (P < 0.05) than that of Sirosa. Dormancy of freshly harvested seeds of Sirosa was mainly associated with the structures surrounding the caryopses (7.7 v. 79.5% mean germination), but for Taranna and Bunderra it was related to physiological dormancy of the caryopses.Germination levels that were not significantly different to the maximum occurred for temperature ranges of 35/30–15/10�C [Sirosa (commercial)], 35/25–15/10�C (Australian phalaris), and 35/30–15/05�C (Kangaroo Valley ryegrass). In contrast, maximum germination of wallaby grasses only occurred for Taranna in the temperature range 25/20–20/10�C, and for Bunderra at 25/15 and 20/15�C.Seedling emergence in the field was episodic, occurring on only 3 occasions from 1993 to 1996. No seedlings of Sirosa phalaris, Demeter tall fescue, or Kangaroo Valley ryegrass were successfully recruited, but Taranna and Bunderra successfully recruited new plants from natural seedfalls. Whereas seed production of the perennial grasses studied was relatively high (~10 000 seed/m2 in 1992), soil seedbank levels were much lower (generally <1000 seeds/m2). These data were used to indicate the likely successful establishment of sown perennial grasses or by regeneration from natural seedfall.

Ecology of Nassella neesiana, Chilean needle grass, in pastures on the Northern Tablelands of New South Wales. II. Seedbank dynamics, seed germination, and seedling recruitment

2003 ◽  
Vol 54 (6) ◽  
pp. 621 ◽  
Author(s):  
M. R. Gardener ◽  
R. D. B. Whalley ◽  
B. M. Sindel
Keyword(s):  
Seed Production ◽  
Seedling Recruitment ◽  
Seedling Survival ◽  
New South ◽  
Seedling Emergence ◽  
New South Wales ◽  
Separate Experiment ◽  
Bare Ground ◽  
Total Percentage ◽  
South Wales

This is the second in a series of papers investigating the ecology of Nassella neesiana (Trin. & Rupr.) Barkworth (Chilean needle grass) in pastures on the Northern Tablelands of New South Wales. The reasons for its success as a pasture weed are discussed. Nassella neesiana has a large and persistent soil seedbank. After 3 years without seed input, the seedbank declined from 4676 to 1323 seeds/m2. When an exponential decay curve was fitted to the data it was predicted that the seedbank would reach 10 seeds/m2 after 12.4 years. When seed production was large in 1996, 41.6% of seeds produced were incorporated into the seedbank, whereas in 1995 and 1997 the smaller seed production was only sufficient to maintain seedbank numbers. Furthermore, it is likely that the seedbank numbers were underestimated because they did not include basal cleistogenes. In a separate experiment, basal cleistogenes were found to contribute a further 20% to the seedbank.A small proportion of the viable seeds in a natural seedbank emerged from bare ground over 2 years. Seedling survival was high, with 78% of those germinating from bare ground surviving for at least 20 months. Several experiments were designed to investigate the mechanisms of this germination and survival. It appears that the seeds of N. neesiana have an after-ripening requirement of between 3 months and 1 year for maximum germination. Lemma removal from seeds stored for 8 months increased germination from 49 to 82%. The rate of germination and the total percentage of seeds germinating also increased with time of burial in the ground. Of seeds that had been buried for 2 years, 90% germinated after laboratory incubation compared with 48% of seeds stored in the laboratory as controls. Depth of seed burial appears to affect seedling emergence and survival. A smaller number of seedlings emerged from 0–10 mm and they had lower survival than those from seed buried at 10–20 mm.

Growth of pasture species on the Northern Tablelands of New South Wales

1975 ◽  
Vol 26 (2) ◽  
pp. 269 ◽  
Author(s):  
A Lazenby ◽  
JV Lovett
Keyword(s):  
White Clover ◽  
Tall Fescue ◽  
Festuca Arundinacea ◽  
New South ◽  
New South Wales ◽  
Botanical Composition ◽  
South Wales ◽  
Available Soil Moisture ◽  
Capacitance Probe

The production of herbage by five pasture species—Phalaris tuberosa (phalaris), Festuca arundinacea (tall fescue), Lolium perenne (perennial ryegrass), Trifolium repens (white clover) and Medicago sativa (lucerne)—was measured when they were grown in the field in monoculture, and by phalaris and white clover when grown in mixture. The plots were irrigated to prevent water deficits, and five levels of nitrogen were included; the mixture was also grown under dryland conditions. All plots were defoliated at intervals during a period of 3 years. A capacitance probe was used in an attempt to determine harvest times more objectively, and to establish long-term relationships between meter readings and components of plant yield. Major differences in production were detected between the species, lucerne producing most in the first 2 years of the experiment. Nitrogen and available soil moisture affected both production and botanical composition, and significant differences were detected in species' responses to applied nitrogen and in nitrogen recovery. The performance of lucerne and tall fescue suggests that both species deserve to be more widely grown on the Northern Tablelands of New South Wales.

Establishment of small-seeded perennial grasses on black clay soils in north-western New South Wales.

1982 ◽  
Vol 30 (6) ◽  
pp. 611 ◽  
Author(s):  
LA Watt ◽  
RDB Whalley
Keyword(s):  
New South ◽  
Seedling Emergence ◽  
New South Wales ◽  
Perennial Grasses ◽  
Clay Soils ◽  
Research Centre ◽  
Establishment Success ◽  
Black Clay ◽  
South Wales ◽  
Wide Range

A range of native and exotic perennial grasses was examined for relationships between seed and seedling features and establishment success on cracking black clay soils of the north-westem slopes of New South Wales. The features examined included the effect of temperature on the speed of germination and cumulative total germination, the effect of the duration of water availability in the seedbed on seedling emergence and the rates of seedling extension. Seedbed temperatures were also monitored during the spring at the Inverell Research Centre. No single seed or seedling feature was consistently associated with establishment success. The two species with the highest rating for establishment, Dichanthium sericeum (R.Br.) A. Camus and Bothriochloa macra (Steud.) S. T. Blake, gave good seedling emergence with only 3 days of seedbed watering, had early and rapid seed germination, germinated well over a wide range of temperatures and had fast root and shoot extension rates. Chloris gayana Kunth, with the lowest establishment rating, had low ratings for all characteristics examined except that it had a moderate speed of germination. Advantageous features at one stage of the sequence from seed to established plant can compensate for weaknesses at another stage, e.g, the fast root and shoot growth rate of Panicum decompositum R. Br. compensates for slow speed of germination, to give a good establishment rating overall.

Seed production and seedling emergence of Giant Parramatta grass on the north coast of New South Wales

1996 ◽  
Vol 36 (3) ◽  
pp. 299 ◽  
Author(s):  
TS Andrews ◽  
RDB Whalley ◽  
CE Jones
Keyword(s):  
Seed Production ◽  
Seed Bank ◽  
New South ◽  
New South Wales ◽  
Seed Banks ◽  
North Coast ◽  
The North ◽  
South Wales ◽  
Seed Fall ◽  
The Impact

Inputs and losses from Giant Parramatta grass [GPG, Sporobolus indicus (L.) R. Br. var. major (Buse) Baaijens] soil seed banks were quantified on the North Coast of New South Wales. Monthly potential seed production and actual seed fall was estimated at Valla during 1991-92. Total potential production was >668 000 seeds/m2 for the season, while seed fall was >146000 seeds/m2. Seed fall >10000 seeds/m2.month was recorded from January until May, with further seed falls recorded in June and July. The impact of seed production on seed banks was assessed by estimating seed banks in the seed production quadrats before and after seed fall. Seed banks in 4 of the 6 sites decreased in year 2, although seed numbers at 1 damp site increased markedly. Defoliation from mid-December until February, April or June prevented seed production, reducing seed banks by 34% over 7 months. Seed banks in undefoliated plots increased by 3300 seeds/m2, although seed fall was estimated at >114 000 seeds/m2. Emergence of GPG seedlings from artificially established and naturally occurring, persistent seed banks was recorded for 3 years from bare and vegetated treatment plots. Sown seeds showed high levels of innate dormancy and only 4% of seeds emerged when sown immediately after collection. Longer storage of seeds after collection resulted in more seedlings emerging. Estimates of persistent seed banks ranged from 1650 to about 21260 seeds/m2. Most seedlings emerged in spring or autumn and this was correlated with rainfall but not with ambient temperatures. Rates of seed bank decline in both bare and vegetated treatment plots was estimated by fitting exponential decay curves to seed bank estimates. Assuming no further seed inputs, it was estimated that it would take about 3 and 5 years, respectively, for seed banks to decline to 150 seeds/m2 in bare and vegetated treatments.

Evaluation of pasture legumes sown into a prepared seedbed at Tamworth, New South Wales. 2. Seed production and seed reserves

1993 ◽  
Vol 33 (3) ◽  
pp. 299 ◽  
Author(s):  
GM Lodge
Keyword(s):  
Seed Production ◽  
New South ◽  
New South Wales ◽  
Pasture Legumes ◽  
South Wales ◽  
Medicago Scutellata ◽  
Seed Reserves ◽  
Annual Medics ◽  
Perennial Legumes ◽  
Seed Yields

Plots sown in 1983 were used to examine the seed production and reserves (residual hardseeds) of 15 annual legumes over 5 years at Tamworth in northern New South Wales. Seed production characteristics were measured in 1983 for these annuals, and for 6 perennial legumes. After the annuals had set seed in 1983, an area of the plots was sprayed to prevent flowering in subsequent years, and the rates of decline in seed reserves were compared with those from areas that seeded annually. Seed yields of the perennials were often significantly lower than those of the annuals except Trifolium glomeratum. Seed yields of T. subterraneum var. subterraneum cvv. Seaton Park and Woogenellup were significantly higher than those of cv. Nungarin and T. subterrarzeum var. brachycalycinum cv. Clare. Seed numbers were lowest for Medicago scutellata cv. Sava among the annual medics, and for Nungarin among subterranean clovers. There was little relationship between the mean number of seeds produced from 1983-86 and maturity grading, and between seed numbers and relative dry matter yield. Seed reserves decreased over 5 years by more than 90% in the sprayed treatments of all species. This decrease was not continuous, with the largest declines occurring from December 1983 to August 1984. In the sprayed treatments of Seaton Park, Woogenellup, and Clare, and in both treatments of Astragalus hamosus cv. Ioman, Vicia dasycarpa var. villosa cv. Namoi, and T. hirtum cv. Hykon, none of the original 1983 seed was recovered in 1987. For the annual medics and Nungarin, the number of residual hardseeds in the sprayed treatments in 1987 was about 3-5% of the seed produced in 1983. From 1983 to 1987, seed numbers in the unsprayed treatments declined by 7040% for the annual medics and by 85-95% for Seaton Park, Woogenellup, and Clare. Long-term persistence of annual medics and Nungarin depended on seed production in most years and the maintenance of a high number of residual hardseeds in the soil. In contrast, the mid- and late-maturing subterranean clovers Woogenellup and Clare had low seed reserves and were dependent on seed production in most years for their continued regeneration.

The effects of sowing time, sowing technique and grazing on tall fescue (Festuca arundinacea Schreb.) establishment

1992 ◽  
Vol 32 (5) ◽  
pp. 627 ◽  
Author(s):  
GW Charles ◽  
GJ Blair ◽  
AC Andrews
Keyword(s):  
Tall Fescue ◽  
Festuca Arundinacea ◽  
New South ◽  
Sowing Time ◽  
South Wales ◽  
Heavy Grazing ◽  
Direct Drilling ◽  
Aerial Seeding ◽  
Spring Sowing ◽  
Autumn Sowing

The effects of sowing time (autumn and spring) and technique (conventional cultivation, inverted T direct drill, triple disc direct drill and aerial seeding), on the establishment of tall fescue into a weed infested pasture on the Northern Tablelands of New South Wales were examined. A pre-sowing herbicide treatment was included in the 2 direct drilling treatments, and heavy pre-sowing grazing was used in the autumn sowing. The design used 38 plots of 0.12 ha, analysed as 2 separate, complete block experiments, with some common treatments. Tall fescue establishment, 120 days after the autumn sowing, averaged 48 seedlingslm2 on the inverted T treatment (16% establishment). Establishment was improved by 63%, to 78 seedlings/m2, with herbicide and 46%, to 70 seedlings/m2, by heavy grazing. These effects were additive, giving 105 seedlings/m2 for the combined treatments. Only 52 seedlings/m2 established on the triple disc treatment with heavy grazing and herbicide, while establishment on the cultivated seedbed was not different from the inverted T (93 seedlings/m2). There was no establishment after the aerial seeding at either sowing. Fescue establishment showed the same trends in the spring sowing, with 140 seedlings/m2 on the inverted T treatment with pre-sowing herbicide, which was higher than the establishment of 107 seedlings/m2 on the cultivated seedbed. The fescue yield, 18 months after the autumn sowing, was highest in the autumn sown, inverted T treatment with pre-sowing herbicide and heavy grazing (123 kg/ha). In the spring sowing, fescue was recorded only on the cultivated treatment (84 kg/ha) and on the inverted T treatment with pre-sowing herbicide (39 kg/ha). These results show that tall fescue can be re-established into weed dominated pastures on the Northern Tablelands with direct drilling, in either autumn or spring, and that heavy, pre-sowing grazing and herbicide increase fescue establishment.

Performance of temperate legumes and associated grasses on granitic soils of low fertility in the New England region of New South Wales

1975 ◽  
Vol 15 (77) ◽  
pp. 795 ◽  
Author(s):  
JA Thompson
Keyword(s):  
New England ◽  
Dry Matter ◽  
New South ◽  
New South Wales ◽  
Subterranean Clover ◽  
Fertilizer Application ◽  
Perennial Grasses ◽  
Low Fertility ◽  
South Wales ◽  
Applied Nitrogen

A range of temperate annual and perennial legumes, naturalized or commonly sown in the area, was examined at three field sites in low fertility soils derived from granite on the south western slopes of the New England Region, New South Wales. They were compared over a four year period in terms of their persistence, dry matter and nitrogen production and their compatibility with associated temperate perennial grasses, The response of sown grass to nitrogen fertilizer application was also examined in the absence of legume. Ten legumes were examined at one site and six of these at the other two sites. In general, nitrogen yields were ranked similarly to total dry matter yields of all treatments, including grasses in the absence of legume. However, the legumes were ranked differently in terms of productivity of the legume component and productivity of associated grass. At all sites lucerne gave the highest yields of total dry matter and of legume and the lowest yield and persistence of associated grass-comparable to grass growing in the absence of legume or applied nitrogen. Subterranean clover was ranked second or third in total dry matter yield, depending on site, but provided the highest yield of associated grasscomparable to grass receiving high levels of applied nitrogen. Under this legume soil nitrogen levels tended to be highest. Rose clover, sown at one site only, yielded more legume dry matter than subterranean clover but grass yield was comparable to that with lucerne. The results suggest that subterranean clover is the superior legume for successful mixed sowings although inclusion of white clover could be justified. Lucerne appears to be best sown as a pure sward.

Establishing surface-sown pastures in a Poa labillardieri-Themeda australis association

1986 ◽  
Vol 26 (3) ◽  
pp. 331 ◽  
Author(s):  
MH Campbell ◽  
MJ Keys ◽  
RD Murison ◽  
JJ Dellow
Keyword(s):  
Festuca Arundinacea ◽  
New South ◽  
New South Wales ◽  
Ground Cover ◽  
Cost Effective ◽  
Phalaris Aquatica ◽  
South Wales ◽  
Before And After

The effects of time and rate of application of glyphosate, 2,2-DPA and tetrapion on Poa labillardieri and Themeda australis were measured in seven experiments carried out 55 km south of Braidwood, on the southern tablelands of New South Wales between 1980 and 1982. In an eighth experiment (1981) and in a 35-ha demonstration (1983), at the same site, the effects of applying herbicides (before and after the autumn break) and surface-sowing Phalaris aquatica, Festuca arundinacea and Trifiolium repens with fertiliser on the control of P. labillardieri were ascertained. All three herbicides proved effective in reducing the ground cover of P. labillardieri from applications at any time of the year. For T. australis, tetrapion proved effective when applied at any time of the year, while glyphosate and 2,2-DPA were effective in all seasons except winter. Glyphosate at rates between 0.72 and 1.44 kg/ha a.i. was more cost effective than 2,2-DPA (11.1 kg/ha a.i.) and tetrapion (3.75 kg/ha a.i.). Best establishment and development of sown grasses and legumes was attained by applying herbicides after the autumn break but before heavy frosts, and then surface-sowing 1-3 months later. Control of P. labillardieri was best where P. aquatica and F. arundinacea established most densely.

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.

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